| drug effects on function in the ferret ischemic hindlimb. | in this article a new model of peripheral occlusive arterial disease is described. the lower hindlimb of an anesthetized ferret was fixed to a holder, the distal end of the achilles tendon attached to an isometric force transducer, and a passive preload of 100 g was applied to the muscle preparation. the hindlimb was stimulated to contract isometrically via supramaximal electrical stimulation of the sciatic nerve. during the initial period, when femoral blood pressure equaled aortic blood pressu ... | 1990 | 2370804 |
| helicobacter pylori-like microorganisms and chronic active gastritis in ferrets. | to determine the prevalence and histology of helicobacter pylori (hp) associated gastritis in young ferrets, we examined 36 normal 2- to 4-month old ferrets. identification of hp-like microorganisms included warthin starry stains of tissue sections, rapid urease test on fresh tissue, and culture. hp-like microorganisms were found in the stomachs of 35/36 ferrets. the highest density of microorganisms was seen in the antrum, where hp-like microorganisms were present in the pits and in deep glands ... | 1990 | 2371981 |
| relative roles of ca2(+)-dependent and ca2(+)-independent mechanisms in hypoxic contractile dysfunction. | contractile function is known to be impaired during hypoxia or metabolic inhibition, but the relative importance of activator ca2+ deficiency compared with the accumulation of depressant metabolites remains controversial. to distinguish between these possibilities, we used nuclear magnetic resonance (nmr) spectroscopy to measure the most likely mediators--intracellular [ca2+] [( ca2+]i), inorganic phosphate concentration [( pi]), and ph--before and during hypoxia in perfused ferret hearts. ca2+ ... | 1990 | 2372899 |
| functional organization in the ferret visual cortex: a double-label 2-deoxyglucose study. | the functional organization of visual cortical area 17/18 of the ferret was studied using a double-label 2-deoxyglucose (2-dg) method. animals were stimulated sequentially with moving gratings of 2 different orientations. elongated orientational patches running roughly at a right angle into the area 17/18 border were seen. the orientation maps were similar in areas 17 and 18. when animals were stimulated with 2 orthogonally oriented gratings, activation patterns were not fully complementary but ... | 1990 | 2388088 |
| mechanical restitution in isolated mammalian myocardium: species differences and underlying mechanisms. | ventricular myocardium was obtained from guinea-pig, ferret and human hearts. in each case small strips were mounted isometrically in a tissue bath and superfused with a physiological saline at 37 degrees c. the preparations were stimulated at 1 hz and ectopic stimuli of different preceding intervals were given. the relationship between the force produced by the ectopic contraction and the duration of the preceding interval was plotted to form mechanical restitution curves (mrc). in the guinea-p ... | 1990 | 2388277 |
| the effects of bathing sodium ions upon the intracellular sodium activity in calcium-free media and the calcium paradox of isolated ferret ventricular muscle. | exposure of fine trabeculae isolated from the ferret right ventricle to media depleted of ca2+, with a rapid perfusion system, causes a depolarization of the membrane and a rise in aina. this rise in aina is sigmoidally dependent upon the bathing free [ca2+], is antagonized by reduction of the [na]o, raised [mg]o and pn200-110 but augmented by removal of mg2+ or inhibition of the na-pump. on repletion of ca2+, the strength of the resulting contracture depends upon the transmembrane. na-gradient ... | 1990 | 2388280 |
| eradication of helicobacter mustelae from the ferret stomach: an animal model of helicobacter (campylobacter) pylori chemotherapy. | colonization of the ferret stomach by helicobacter mustelae has been suggested as a possible animal model for helicobacter pylori-associated gastroduodenal disease of humans. our study was designed to determine whether antimicrobial chemotherapy could eradicate h. mustelae from ferrets. triple antimicrobial therapy combining amoxicillin, metronidazole, and bismuth subsalicylate was successful in eradicating the organism from 5 of 7 (71%) adult ferrets. despite apparent in vitro susceptibility, n ... | 1990 | 2393285 |
| negative inotropy of halogenated anesthetics in ferret ventricular myocardium. | the effects of the volatile anesthetics halothane, enflurane, and isoflurane on amplitude and time variables of contraction and relaxation in isometric, isotonic, and zero-load clamped twitches of isolated right ventricular ferret papillary muscles (n = 24) were compared with those of changing extracellular ca2+ concentration [( ca2+]o). contraction and relaxation variables were compared at equal contraction amplitudes to determine whether the studied anesthetics exert specific effects on contra ... | 1990 | 2396690 |
| preliminary studies on the in vivo morphogenetic properties of dentine matrix proteins. | two fractions of isolated noncollagenous extracellular matrix proteins from dentine have been implanted into the base of exposed cavities in ferret canine teeth. after sealing the cavities, reparative dentinogenesis was assessed histologically after 14 and 28 days as compared to control cavities. reparative dentinogenesis was enhanced in the presence of these matrix proteins with evidence of tubular dentine along the walls of the exposure and on the cavity floor demonstrating the in vivo morphog ... | 1990 | 2397254 |
| topographical distribution of 5-ht3 receptor recognition sites in the ferret brain stem. | the distribution of [3h]zacopride (1.0 nm) to putative 5-ht3 receptor recognition sites in the ferret hindbrain was assessed using autoradiography. specific binding (defined by the inclusion of granisetron, 1.0 microm) was heterogeneously distributed with highest density within the dorsal vagal complex (area postrema, nucleus tractus solitarius and dorsal motor nucleus of the vagus nerve). lower densities were detected in the spinal trigeminal nerve complex whilst no other significant specific b ... | 1990 | 2402300 |
| immunohistochemical and morphologic features of chordomas in ferrets (mustela putorius furo). | | 1990 | 2402855 |
| microbiological aspects of helicobacter pylori (campylobacter pylori). | the human gastric pathogen campylobacter pylori has recently been reclassified as helicobacter pylori, and a related spiral bacterium found in the stomach of ferrets has been designated helicobacter mustelae. the general microbiological features of helicobacter pylori are delineated here, with details of phenotypic differences between helicobacter pylori and helicobacter mustelae; comparisons are made with wolinella succinogenes and campylobacter jejuni. the helicobacter organisms possess an ext ... | 1990 | 2406141 |
| prostaglandins alter methacholine-induced secretion in ferret in vitro trachea. | the ferret trachea was mounted in an organ bath containing krebs-henseleit solution with additional bovine serum albumin (bsa). tracheal secretions were collected and analyzed for albumin, and lysozyme, a specific marker of serous cell secretion. the total secretion volume and output and concentrations of albumin and lysozyme were calculated. secretion was stimulated with methacholine (20 microm) (mch), and the effects of the prostaglandins pgd2, pge1, and pgf2 alpha on methacholine-induced secr ... | 1990 | 2407140 |
| common epitopes between mycobacterial and certain host tissue antigens. | monoclonal antibodies (moab) produced against a sonicated antigen extract of mycobacterium bovis were examined for their ability to bind to 10 common tissue antigens. the binding patterns of moab mb2, mb3, mb7, mb11 and mb13 indicated that each recognized different epitopes. moab mb5 and mb17 failed to bind to any of the tissue antigens. mb3 reacted strongly with normal tissue from m. bovis infected guinea pigs and ferrets but there was no reaction with mb5 and mb17. these specificities were con ... | 1985 | 2412744 |
| relationship between force and intracellular [ca2+] in tetanized mammalian heart muscle. | to determine features of the steady state [ca2+]-tension relationship in intact heart, we measured steady force and intracellular [ca2+] ([ca2+]i) in tetanized ferret papillary muscles. [ca2+]i was estimated from the luminescence emitted by muscles that had been microinjected with aequorin, a ca2+-sensitive, bioluminescent protein. we found that by raising extracellular [ca2+] and/or by exposing muscles to the ca2+ channel agonist bay k 8644, tension development could be varied from rest to an a ... | 1986 | 2419483 |
| postnatal development of tracheal surface epithelium and submucosal glands in the ferret. | we explored the usefulness of the postnatal ferret as a model for early developmental events in the large airways, using light and scanning electron microscopy. in the first 28 postnatal days, ferret tracheal surface epithelium and glands undergo dramatic growth and development. tracheal surface area increases 8-fold. at birth, ciliated cells are sparse (9.4 +/- 1.2% of total epithelial cells). a significant increase in ciliated cells is observed at weekly intervals and by day 28 the ciliated ce ... | 1986 | 2420581 |
| morphology and histochemistry of the ferret prostate. | the gross anatomy, histology and histochemistry of the ferret prostate is described. the structure and course of the prostatic urethra and the ductus deferentes are also described. the prostate is the only accessory reproductive gland present in the ferret. the prostate consists of tubuloalveolar glands surrounded by fibromuscular connective tissue. histochemical studies showed that the glandular parenchyma contained large amounts of sialidase-labile sialomucin as well as acid phosphatase and sm ... | 1986 | 2422864 |
| camp immunocytochemistry provides evidence for functional vip receptors in trachea. | vasoactive intestinal peptide (vip), first isolated from porcine intestine (s. i. said and v. mutt, science wash. dc 169: 1217-1218, 1970), has been identified in postganglionic autonomic axons of many tissues. vip has potent regulatory effects on the function of various cell types within these tissues, ranging from relaxation of smooth muscle to ion transport. recently, vip has been implicated in the regulation of mucus secretion in the respiratory tract, a process involving release of macromol ... | 1986 | 2425626 |
| neuropeptides degranulate serous cells of ferret tracheal glands. | to determine whether serous or mucous cells in tracheal submucosal glands respond to the neuropeptides substance p (sp) and vasoactive intestinal peptide (vip), we studied the peptide-induced changes in gland cell morphology accompanying release of 35so4-labeled macromolecules from tracheal explants of ferrets. explants were labeled for 1 h in medium containing 35so4 and washed for 3.5 additional hours. base-line secretion in the absence of drugs declined between 1.5 and 3.5 h after the pulse. b ... | 1986 | 2426958 |
| biphasic contractions induced by milrinone at low temperature in ferret ventricular muscle: role of the sarcoplasmic reticulum and transmembrane calcium influx. | the effects of milrinone were studied in ferret papillary muscle stimulated at various rates and temperatures from 23 degrees to 36 degrees c. in voltage-clamp experiments, 50 micrograms/ml (0.237 mm) milrinone induced a 2.1-fold increase in calcium current at 28 degrees or 36 degrees c. at 50 micrograms/ml, milrinone transiently increased contractility in all muscles at 28 degrees c, but its steady-state effect was either increased (+50%) or decreased (-24.7%) steady-state twitch amplitude. a n ... | 1986 | 2427247 |
| sodium/calcium exchange and intracellular calcium buffering in ferret myocardium: an ion-sensitive micro-electrode study. | measurements of the intracellular activity of ca (aica), na (aina) and h (phi) ions have been made with resin-filled ion-sensitive micro-electrodes in ferret ventricular trabeculae. the mean values in quiescent muscle at 30 degrees c were: aina, 11.1 +/- 1.0 mm; aica, 58.4 +/- 6.4 nm, and phi, 7.20 +/- 0.11. the relation between aina and extracellular na activity (aona) is not linear and is sensitive to temperature: the q10 for the change in aina in normal tyrode solution is 1.3 +/- 0.5 and rise ... | 1986 | 2427694 |
| influence of the thyroid state on the calcium transient in ventricular muscle. | the purpose of this study was to determine the influence of thyroid hormone on tension development and the intracellular calcium transient in mammalian ventricular muscle. a hyperthyroid (h) state was induced in ferrets by subcutaneous injection of l-thyroxine, 0.3 mg/kg daily, for 2-3 weeks. one-half of the age matched control group (c) were injected with vehicle. aequorin was loaded into the cells of ferret papillary muscles by a chemical procedure. the muscles were stimulated at 0.33 hz and i ... | 1986 | 2428004 |
| maximal ca2+-activated force elicited by tetanization of ferret papillary muscle and whole heart: mechanism and characteristics of steady contractile activation in intact myocardium. | rapid (8-12 hz) stimulation of intact heart muscle treated with ryanodine results in steady contractile activation known as tetanus, the amplitude of which can be graded by changing extracellular ca2+ concentration ([ca2+]o). the mechanism of the sustained force generation was explored in ferret papillary muscles by measuring membrane potential and by determining the responsiveness of force and intracellular free ca2+ concentration ([ca2+]i, estimated with aequorin) to dihydropyridine ca channel ... | 1986 | 2429779 |
| mechanism of early contractile failure during hypoxia in intact ferret heart: evidence for modulation of maximal ca2+-activated force by inorganic phosphate. | we tested the hypothesis that accumulation of h+ or inorganic phosphate (pi) is responsible for the early contractile failure of hypoxia by measuring maximal ca2+-activated pressure and 31p nuclear magnetic resonance spectra in langendorff-perfused ferret hearts at 30 degrees c. maximal ca2+-activated pressure was identified by the saturation of pressure with respect to [ca2+]o observed during tetani as [ca2+]o was increased to 15 mm in hepes-buffered, 100% o2-bubbled perfusate and during hypoxi ... | 1986 | 2429780 |
| intracellular calcium transients underlying the short-term force-interval relationship in ferret ventricular myocardium. | the influence of short-term changes in stimulation pattern, both on the strength of contraction and on the amplitude of intracellular free-ca2+ transients, was investigated in ferret papillary muscles. intracellular free-ca2+ concentration ([ca2+]) was assessed from the luminescence emitted from muscles microinjected with the ca2+-sensitive photoprotein aequorin. the relationships between the strength of contraction and changes in stimulation pattern lasting 1-2 beats could be described by monoe ... | 1986 | 2432238 |
| restricted viral antibody specificity in many ferrets infected with the ferret aleutian disease parvovirus. brief report. | the majority of ferrets infected with a ferret strain of aleutian disease virus (adv) produce antibody only to a detergent-sensitive common determinant on the two closely related virion proteins. ferrets with high antibody titers and mink infected with this virus also produce antibody to one or more virion immunogenic determinants unaffected by detergent. | 1987 | 2434063 |
| enkephalinase inhibitors potentiate substance p-induced secretion of 35so4-macromolecules from ferret trachea. | to study the roles of substance p (sp) and endogenous peptidases in regulating mucus secretion from ferret trachea, we measured the sp-induced release of 35so4-labeled macromolecules after incubating segments of trachea in ussing chambers in the presence and absence of selected inhibitors of proteolytic enzymes. our strategy was based on the idea that if endogenous peptidases degrade sp, then inhibitors of these enzymes should potentiate sp-induced secretion. we found that tracheas of ferrets co ... | 1987 | 2434322 |
| sodium/calcium exchange and calcium buffering in mammalian ventricular muscle. | the na/ca exchange system was investigated in rapidly perfused small trabeculae (diameter around 250 micron) from ferret ventricle. in these preparations tension and em were recorded, aina, aik and aimg were measured using ion-selective microelectrodes. the mean aina at room temperature (22-24 degrees c) was 10.9 mmol/l +/- s.d. 4.2 mmol/l. when [na]o was reduced from 155 mmol/l to 1.5 mmol/l there was a rapid decrease in aina (half time 30 s), which was associated with a small increase in resti ... | 1986 | 2434687 |
| a method for recording isometric tension development by isolated cardiac myocytes: transducer attachment with fibrin glue. | the purpose of this study was to develop a method for attachment of single isolated cardiac myocytes to a transducer for recording isometric tension development. cardiac myocytes were isolated from the hearts of the toad, bufo marinus or ferrets by enzymatic digestion with collagenase. the method that we used provided a 60-80% yield of ca++-tolerant cells. a suspension of cells was placed into a superfusion chamber coated with bovine thrombin. two glass microtools - each attached to a micromanip ... | 1987 | 2437526 |
| characterization of substance p- and [met]enkephalin-immunoreactive neurons in the caudate nucleus of cat and ferret by a single section golgi procedure. | modifications of the single-section golgi-impregnation procedure of gabbott and somogyi are described. the modifications allow easier and more rapid preparation of the sections for golgi-impregnation and easier handling of large numbers of serial sections. the technique consists of placing a section that has been treated with osmium tetroxide and potassium dichromate on a microscope slide and "sandwiching" it with a second microscope slide. the two slides are held together at one end by tape and ... | 1987 | 2438593 |
| intracellular sodium-calcium dissociation in early contractile failure in hypoxic ferret papillary muscles. | 1. intracellular sodium activity (anai) and intracellular calcium activity (acai) were measured in isolated quiescent right-ventricular ferret muscle: anai = 9.8 +/- 2.2 mm and acai = 71 +/- 19 nm. 2. when the muscles were exposed to 10(-5) m-ouabain, anai increased to 20.4 +/- 3.1 mm while acai increased to 260 +/- 99 nm. twitch tension approximately doubled. 3. during prolonged hypoxia with glucose in the perfusate, anai and twitch tension were unchanged. 4. during prolonged hypoxia with sucro ... | 1987 | 2443694 |
| enkephalinase inhibitor potentiates substance p- and electrically induced contraction in ferret trachea. | to determine the role of endogenous enkephalinase (ec 3.4.24.11) in regulating peptide-induced contraction of airway smooth muscle, we studied the effect of the enkephalinase inhibitor, leucine-thiorphan (leu-thiorphan), on responses of isolated ferret tracheal smooth muscle segments to substance p (sp) and to electrical field stimulation (efs). leu-thiorphan shifted the dose-response curve to sp to lower concentrations. atropine or the sp antagonist [d-pro2,d-trp7,9]sp significantly inhibited s ... | 1987 | 2447055 |
| enkephalinase inhibitor potentiates mammalian tachykinin-induced contraction in ferret trachea. | to determine the roles of endogenous enkephalinase (ec.3.4.24.11) in regulating tachykinin-induced contraction of airway smooth muscle, the authors studied the effects of the enkephalinase inhibitor leucine-thiorphan on the contractile responses to substance p (sp), neurokinin a (nka) and neurokinin b (nkb) in isolated ferret tracheal smooth muscle segments. leucine-thiorphan shifted, in concentration-dependent fashions, the dose-response curves to all tachykinins to lower concentrations. leucin ... | 1987 | 2447268 |
| calcium oscillations in digitalis-induced ventricular fibrillation: pathogenetic role and metabolic consequences in isolated ferret hearts. | the pathophysiology of the ventricular fibrillation that complicates digitalis intoxication was investigated. in this and other calcium-overload states, oscillations of the intracellular free calcium concentration ([ca2+]i) have been implicated as the cause of ventricular tachyarrhythmias. we addressed two questions: 1) are [ca2+]i oscillations obligatory in the pathogenesis of ventricular fibrillation during digitalis toxicity? 2) what are the metabolic consequences of [ca2+]i oscillations? fer ... | 1988 | 2449298 |
| sexual maturation in the female ferret: circumventing the gonadostat. | the purpose of this study was to examine the role of circulating 17 beta-estradiol in the regulation of pituitary gonadotropin secretion and, hence, ovarian maturation in immature female ferrets. the hypersensitive negative feedback relationship between the ovaries and the hypothalamo-pituitary axis in developing ferrets was disrupted by infusion of a specific antiserum to 17 beta-estradiol. the effect of this treatment on gonadotropin secretion and ovarian morphology was contrasted with that ob ... | 1988 | 2450013 |
| morphology and electrophysiology of the mammalian atrioventricular node. | the av node of those mammalian species in which it has been thoroughly investigated (rabbit, ferret, and humans) consists of various cell types: transitional cells, midnodal (or typical nodal cells), lower nodal cells, and cells of the av bundle. there are at least two inputs to the av node, a posterior one via the crista terminalis and an anterior one via the interatrial septum, where atrial fibers gradually merge with transitional cells. the role of a possible third input from the left atrium ... | 1988 | 2451833 |
| auditory brainstem of the ferret: sources of projections to the inferior colliculus. | the organization of the auditory brainstem in adult, darkly pigmented ferrets was studied by using the retrograde transport of the lectin wheat germ agglutinin-horseradish peroxidase injected into one inferior colliculus. retrogradely labelled neurons were found bilaterally in every nucleus of the auditory brainstem. the greatest number of labelled neurons was found in the cochlear nuclei contralateral to the injection site, the ipsilateral medial superior olivary nucleus, both lateral superior ... | 1988 | 2453533 |
| intrinsic nerves in the mammalian colon: confirmation of a plexus at the circular muscle-submucosal interface. | slow waves in the small intestine seem to arise in plexuses of neurites with interstitial cells of cajal. in the colon, slow waves appear to arise at the circular muscle - submucosal interface. we therefore sought a plexus at this surface in the colon in the cat, dog, ferret, opossum, rabbit, rat, guinea-pig and man. segments from all levels of the colon were stained by the champy-maillet osmic acid-zinc iodide method and cut into serial 25 micron sections in the plane of the muscle layers. a de ... | 1987 | 2453550 |
| cellular substrate of the histochemically defined striosome/matrix system of the caudate nucleus: a combined golgi and immunocytochemical study in cat and ferret. | in order to learn what morphological substrate might underly the histochemical compartments of the neostriatum, sections of the caudate nucleus and the putamen of cats and ferrets were stained immunocytochemically with antisera directed against several neuropeptides and transmitter-related enzymes and were then golgi-impregnated. adjacent sections were stained to reveal acetylcholinesterase activity to identify the acetylcholinesterase-poor striosomes. the immunostaining produced by several of t ... | 1988 | 2454418 |
| non-adrenergic, non-cholinergic salivary secretion in the ferret. | secretion of parotid and submandibular saliva evoked by electrical stimulation of the parasympathetic nerves occurred in the presence of adrenergic and cholinergic blocking agents. the 'atropine-resistant' response amounted to about 30% in the submandibular gland and to about 5% in the parotid gland as compared to the response before administration of antimuscarinic agents. the 'atropine-resistant' secretion was found at relatively high frequencies, and the latency between the start of the stimu ... | 1988 | 2454500 |
| passive immunoprophylaxis with specific monoclonal antibody confers partial protection against pneumocystis carinii pneumonitis in animal models. | pneumocystis carinii is an important cause of pneumonitis in the immunosuppressed host. little is known, however, about the biology of this organism. this report demonstrates that a mab, m5e12, previously shown to be directed against a surface antigen that is present on rat-, rabbit-, ferret-, and human-derived p. carinii, is capable of hindering the development of p. carinii pneumonitis in animal models of this infection when administered throughout the period of immunosuppression. it appears t ... | 1988 | 2454947 |
| decrease in the transmembrane sodium activity gradient in ferret papillary muscle as a prerequisite to the calcium paradox. | sodium-dependent calcium exchange may be an important mediator of calcium reperfusion damage during the calcium paradox phenomenon. we measured intracellular sodium activity with ion-selective electrodes during a 15-min period of calcium reperfusion in isolated ferret papillary muscles. during the calcium-free period, alpha nai increased from 9.0 +/- 0.9 to 18.9 +/- 4.3 mm. with reinstitution of calcium there was a significant contracture. the amount of contracture after calcium reinstitution wa ... | 1988 | 2454951 |
| connections of a vagal communicating branch in the ferret. ii. central projections. | there is increasing interest in the central mechanisms involved in the regulation of gastrointestinal function. the ferret is becoming widely used for research in this area. however, knowledge of the brain stem organization of this species is inadequate. as part of an on-going study designed to provide information regarding the site of termination of abdominal afferents, the central connections of a supradiaphragmatic vagal communicating branch were determined in the ferret through the use of th ... | 1988 | 2456136 |
| the brain stem localization of vagal preganglionic neurones in the ferret, mustela putorius furo. | horseradish peroxidase-wheatgerm agglutinin was injected into the cervical vagus nerve of adult ferrets. efferent fibres coursing in the vagus nerve were shown to originate in the dorsal vagal motor nucleus (dmnx), the nucleus ambiguus (na), a region ventral to the nucleus ambiguus (vna) and the reticular formation between dmnx and na. the distribution of vagal preganglionic neurones in the ferret is compared with data already obtained in similar studies conducted in other mammals. | 1988 | 2456586 |
| tachykinin involvement in parasympathetic nerve-evoked salivation of the ferret. | 1. the tachykinin antagonist (d-arg1, d-cl2phe5, asn6, d-trp7.9, nle11)-substance p, injected intravenously, blocked salivary secretion from the ferret parotid and submandibular glands in response to subsequent i.v. injections of the tachykinins, substance p and neurokinin a. 2. the tachykinin antagonist reduced the parasympathetic nerve-evoked secretion of parotid and submandibular saliva by 15-20% and 35-40%, respectively. atropine abolished the remaining secretory response. 3. the 'atropine-r ... | 1988 | 2460178 |
| brl 34915 (cromakalim) activates atp-sensitive k+ current in cardiac muscle. | the mechanism by which the antihypertensive agent brl 34915 (cromakalim) affects action potential duration (apd) and effective refractory period (erp) in isolated cardiac muscle was investigated. brl 34915 (greater than or equal to 3 microm) shortened erp of ferret (mustela putorius furo) and guinea pig (cavia porcellus) papillary muscles in a concentration-dependent fashion. the reduction in erp resulted from a decrease in apd. erp and apd of papillary muscles were also reduced during hypoxia p ... | 1988 | 2460868 |
| neutral endopeptidase inhibitors potentiate substance p-induced contraction in gut smooth muscle. | to determine the role of endogenous neutral endopeptidase (nep), also called enkephalinase (ec 3.4.24.11), in regulating tachykinin-induced contraction of gut smooth muscle, we studied the effects of nep inhibitors on the contractile responses to substance p (sp) in isolated longitudinal strips of ileum or duodenum in rats and ferrets. leucine-thiorphan and phosphoramidon shifted the concentration-response curves of sp to lower concentrations in all tissues studied, but the sensitivity to sp was ... | 1989 | 2463769 |
| a comparison of sperm morphology and silver nitrate staining characteristics in the domestic ferret and the black-footed ferret. | ejaculated sperm from the domestic ferret (mustela putorius furo) and the black-footed ferret (mustela nigripes) were compared for differences in morphological abnormalities and argentophilic protein distribution. thawed domestic ferret sperm was also compared to fresh sperm to determine whether there were any effects on cell morphology due to cryopreservation. there were statistically significant differences between the two species of ferret in two of the categories scored. the domestic ferret ... | 1989 | 2465262 |
| shifting retinal maps in the development of the lateral geniculate nucleus. | during development, the bilateral projections from each eye to subcortical visual structures in the mammal initially overlap throughout the majority of the dorsal lateral geniculate nucleus (dlgn) and superior colliculus (sc) before retracting to their separate territories. it has been shown in the ferret that during this period the larger contralateral retinal projection to both the dlgn and sc is retinotopically organised. by making small retinal lesions, and then anterogradely labelling the r ... | 1989 | 2470530 |
| acetylcholinesterase on the dendrites of central cholinergic neurons: an electron microscopical study in the ferret. | a combination of choline acetyltransferase immunohistochemistry and acetylcholinesterase histochemistry was used to characterize the ultrastructural distribution of acetylcholinesterase in identified cholinergic and non-cholinergic neurons in the ferret brain. previous studies have shown that most of the cholinergic input to the brain arises from choline acetyltransferase-positive neurons found in the neostriatum, basal forebrain and dorsolateral pontine tegmentum. in all these cells intense sta ... | 1989 | 2474771 |
| the transport of albumin across the ferret in vitro whole trachea. | 1. the whole trachea of the ferret has been isolated in vitro in an organ bath and used to study the transport of bovine serum albumin (bsa) and two dextrans (70,000 and 9000 da) from external buffer solution to air-filled lumen, assessed by fluorescent-labelled tracers. 2. in control conditions, when mucus secretion was not stimulated by drugs, the concentration of albumin in the lumen was over half that in the buffer, and about six times greater than those of the two dextrans. 3. methacholine ... | 1989 | 2476558 |
| positive inotropic and hemodynamic properties of flosequinan, a new vasodilator, and a sulfone metabolite. | flosequinan, a new orally active vasodilator, and its sulfone metabolite were evaluated for inotropic activity in isolated ferret papillary muscles and pentobarbital anesthetized open-chest dogs. in vitro, flosequinan and its sulfone derivative increased tension development in a concentration-dependent manner (1-50 microm) in electrically stimulated papillary muscles pretreated with the beta-adrenergic blocking agent atenolol (2 microm). peak increases in tension of 75 +/- 17%, and 111 +/- 46% w ... | 1989 | 2476620 |
| terminal arbors of single on-center and off-center x and y retinal ganglion cell axons within the ferret's lateral geniculate nucleus. | the lateral geniculate nucleus of the ferret contains not only eye-specific layers, but a further subdivision of layers a and a1 into inner and outer sublaminae that contain, respectively, on-center and off-center cells (stryker and zahs, '83). to study how the arbors of single retinal ganglion cell axons correlate with these cellular divisions, we have examined the morphology of physiologically classified retinal axons in the ferret's lateral geniculate nucleus. as in cats, we could classify re ... | 1989 | 2477415 |
| lateral nasal gland secretion in the anesthetized ferret. | in anesthetized ferrets, we cannulated the duct of the lateral nasal gland for direct collection of glandular liquid. administration of methacholine and substance p into the internal carotid artery via a retrograde cannulation of the lingual artery produced a dose-dependent increase in glandular output. the dose-response curve to methacholine was significantly shifted to the right by atropine. the secretory response to substance p was only partially inhibited by atropine at the dose that complet ... | 1989 | 2481668 |
| receptors mediating the effects of substance p and neurokinin a on mucus secretion and smooth muscle tone of the ferret trachea: potentiation by an enkephalinase inhibitor. | 1. the effects of substance p (sp) and neurokinin a (nka) were examined on tracheal smooth muscle tone, mucus volume output, lysozyme output and albumin transport across the ferret in vitro whole trachea in the presence and absence of the enkephalinase inhibitor, thiorphan. 2. sp (0.001-3 microm) and nka (0.01-10 microm) contracted the tracheal smooth muscle and increased mucus volume, lysozyme and albumin outputs into the tracheal lumen. the ec50 values for sp and nka for all of the variables m ... | 1989 | 2482101 |
| effects of neurokinins on ion transport and sulfated macromolecule release in the isolated ferret trachea. | the secretory actions of substance p (sp) were studied by examining its effects on ion transport and sulfated macromolecule release in the isolated ferret trachea. responses to serosally administered sp were unmasked by thiorphan, suggesting that sp administered by this route was degraded by neutral endopeptidase. therefore, the serosal actions of neurokinins and neurokinin analogues were studied in tissues pretreated with thiorphan. in thiorphan-treated tissues, sp dose-dependently increased th ... | 1989 | 2482171 |
| secretion of protein from salivary glands in the ferret in response to vasoactive intestinal peptide. | 1. secretory responses of ferret parotid and submandibular glands were investigated in the presence of muscarinic, alpha- and beta-adrenoceptor blocking agents. 2. in pentobarbitone-anaesthetized animals i.v. doses of vasoactive intestinal peptide (vip) failed to elicit overt secretion of saliva from either gland. 3. however, an occult secretion of protein occurred in response to vip from both types of gland. this was revealed by means of a subsequent i.v. wash-out injection of substance p, whic ... | 1989 | 2484205 |
| mast cell tryptase and chymase reverse airway smooth muscle relaxation induced by vasoactive intestinal peptide in the ferret. | recent evidence suggests that nonadrenergic airway relaxation may be controlled by vasoactive intestinal peptide (vip). the magnitude and duration of smooth muscle relaxation in response to vip may be influenced by rates of peptide degradation after release from efferent peptidergic neurons. to explore the potential role of mast cell mediators in modulating neural control of airway tone, we studied the effect of the mast cell proteases tryptase and chymase on airway smooth muscle relaxation indu ... | 1989 | 2495355 |
| electromechanical effects of leukotriene d4 on ferret tracheal muscle and its muscarinic responsiveness. | we investigated the possible electrophysiological processes by which leukotriene d4 (ltd4) affects airway smooth muscle and its responsiveness to acetylcholine (ach). for study in vitro, preparations of ferret tracheal muscle (dissected free of overlying mucosal and submucosal layers) were used. these preparations were arranged so that force transducers and glass intracellular microelectrodes (having tip resistances of 35-60 megohm) could be used to measure isometric force generation and cell me ... | 1989 | 2500569 |
| cell calcium in the pathophysiology of ventricular fibrillation and in the pathogenesis of postarrhythmic contractile dysfunction. | the mechanism of ventricular fibrillation is poorly understood at the cellular level. we explored the role of intracellular free calcium in the pathophysiology and pathogenesis of ventricular fibrillation in perfused ferret hearts loaded with the ca2+ indicator 5f-bapta. nuclear magnetic resonance spectroscopy was used to measure [ca2+]i, ph, and high-energy phosphates. during ventricular fibrillation induced by burst pacing, [ca2+]i rose rapidly and dramatically, exceeding by four times the con ... | 1989 | 2502327 |
| hormonal induction of oestrus and pregnancy in anoestrous ferrets (mustela putorius furo). | three doses of fsh were tested for their ability to induce oestrus in ferrets. a dose of 0.25 mg, administered twice daily, induced oestrus and breeding in most females within 6-13 days. addition of 5 i.u. hcg during the final stages of follicular development enhanced the percentage of females with implantation sites (85%), and 23% of the ferrets so treated gave birth to kits, none of which survived for more than 3 days. this may have been due to insufficient prolactin secretion and thus inadequ ... | 1989 | 2502620 |
| sarcocystis sp. in mountain goats (oreamnos americanus) in washington: prevalence and search for the definitive host. | during october and november 1986, sarcocystis sp. was detected in 24 of 56 (43%) tongues from hunter-killed mountain goats (oreamnos americanus) in washington (usa). sarcocysts had an unusual sessile polyp-shaped branched wall. mean size of 154 sarcocysts was 71.3 x 37.8 microns (range, 20 to 248 x 10 to 120 microns), and the mean intensity was 2.3 (range, 1 to 28). in an attempt to identify the definitive host, infected tongues were fed to four coyotes (canis latrans), eight domestic dogs, four ... | 1989 | 2509738 |
| calcium and its role in myocardial cell injury during ischemia and reperfusion. | direct measurements of intracellular free ca2+ concentration ([ca2+]i) were obtained during ischemia and reperfusion in ferret hearts loaded with the ca2+ indicator, the 5,5'-difluoro derivative of 1,2-bis(o-aminophenoxy)ethane-n,n,n',n',-tetraacetic acid. during 15 minutes of ischemia at 37 degrees c, time-averaged [ca2+]i increased significantly and decreased rapidly during reperfusion. in contrast to metabolic inhibition in isolated muscle or cells, the increase in [ca2+]i during true ischemi ... | 1989 | 2513146 |
| serologic response of domestic ferrets (mustela putorius furo) to canine distemper and rabies virus vaccines. | nine unrelated 12-week-old naive domestic ferrets (mustela putorius furo) were used to evaluate the serologic responses to commercial canine distemper virus (cdv) and rabies virus (rv) vaccines. five of the ferrets (group 1) were inoculated 3 times at 2-week intervals with a multivalent modified-live virus vaccine of canine cell-line origin, containing cdv and an inactivated rv vaccine. four of the ferrets (group 2) were inoculated once with the multivalent modified-live virus vaccine containing ... | 1989 | 2537273 |
| hyperinsulinism and hypoglycemia associated with pancreatic islet cell tumor in a ferret. | pancreatic islet cell tumor causing hypoglycemia and hyperinsulinism was diagnosed in a ferret with a history of progressive neurologic dysfunction. the diagnosis was suspected by the findings of hypoglycemia when the ferret was not fed, hyperinsulinism, and an amended insulin/glucose ratio approaching infinity. a focal pancreatic mass was removed by partial pancreatectomy, resulting in euglycemia and the resolution of clinical signs. histologic diagnosis of the pancreatic mass was consistent wi ... | 1989 | 2537277 |
| auditory brain stem of the ferret: some effects of rearing with a unilateral ear plug on the cochlea, cochlear nucleus, and projections to the inferior colliculus. | to examine the influence of acoustic experience on the development of the mammalian auditory brain stem, darkly pigmented ferrets were reared with a plug inserted in the right outer ear. the plugs were first inserted on postnatal day 23-34 and produced a variable, frequency-dependent attenuation of up to 60 db. between 3-15 months after the ear plug was begun, animals were prepared for physiological recording and injection of wheat germ agglutinin-hrp (wga-hrp) in the left inferior colliculus (i ... | 1989 | 2539441 |
| cardiotonic agents. 5. fragments from the heterocycle-phenyl-imidazole pharmacophore. | to examine the role of each component in the heterocycle-phenyl-imidazole inotropic pharmacophore, several imidazolone derivatives, an arylimidazole, a substituted 3,4-dihydro-4-oxopyrimidine, and a quinolin-2(1h)-one derivative were prepared as structural fragments or representatives from this relationship. tests for cardiac inotropic activity in ferret papillary muscle strips (fpm) and for inhibition of crude camp phosphodiesterase obtained from canine cardiac tissue suggest that, while all th ... | 1989 | 2542552 |
| in vivo localization of staphylococcus aureus in nasal tissues of healthy and influenza a virus-infected ferrets. | an in vivo ferret model was used to study the association of staphylococcus aureus with specific tissues of the nasal cavity in both control and influenza a virus-infected animals. ferrets were inoculated intranasally with various doses of influenza a3/hong kong/1/68 virus. on days 2, 5, 9 and 14, four or five virus-inoculated and two uninoculated controls were challenged intranasally with a 1-ml volume of radiolabeled s. aureus (3 mg dry wt), a clinical isolate of low passage history. ferrets w ... | 1989 | 2542970 |
| effects of pimobendan, a novel inotropic agent, on intracellular calcium and tension in isolated ferret ventricular muscle. | 1. in this study we have investigated the effects of a novel inotropic agent, pimobendan (udcg 115-bs), on skinned and intact ventricular muscle from ferrets. 2. pimobendan (20 or 100 mumol/l) increased tension at a given free [ca2+] when applied to skinned ventricular muscle, i.e. it increased the ca2+ sensitivity of the myofibrils. 3. tension and intracellular free ca2+ [( ca2+]i) were measured simultaneously in intact papillary muscles using the aequorin technique. when 25 mumol/l pimobendan ... | 1989 | 2544344 |
| tissue-specific isoform regulation of na+-k+-atpase by thyroid hormone in ferrets. | we have shown previously that in the ferret heart there are two isoforms of na+-k+-atpase, alpha(+) and alpha, and that these isoforms undergo developmental changes. in the present study, we examine regulation of the isoenzymes by thyroid hormone, which is well known to increase activity of na+-k+-atpase in different tissue preparations. ferrets were injected with l-thyroxine (t4) (0.5 mg/kg, sc) for 3 wk. the t4-treated ferrets gained 58 +/- 32 g body wt compared with 366 +/- 24 g for the contr ... | 1989 | 2548405 |
| origin of the hemagglutinin on a/equine/johannesburg/86 (h3n8): the first known equine influenza outbreak in south africa. | a severe influenza outbreak occurred in horses in south africa in 1986. the causative agent was identified as an influenza virus [a/equine/johannesburg/86 (h3n8)]. antigenic analyses of the hemagglutinin (ha) with ferret antisera and monoclonal antibodies showed that the eq/johannesburg/86 virus is similar to recent equine h3 viruses. the nucleotide sequence analysis on the ha genes of eq/johannesburg/86 and other equine h3 influenza viruses, together with the epidemiological data, clearly demon ... | 1989 | 2548457 |
| parainfluenza virus infection of cultured airway epithelial cells. | studies of the cellular effects of respiratory viruses have generally used cultures of non-airway (particularly renal) epithelial cells. this requires the assumption that, despite the marked differences between renal epithelium and airway epithelium, the virus-host cell interactions in cultures of renal epithelium will be relevant to those in airway epithelium. to study viral infection of airway epithelial cells, we removed the epithelial cells from ferret tracheas using 0.1% pronase solution, a ... | 1989 | 2559102 |
| pharmacology of a potent, new antithrombotic agent, 1,3-dihydro-7,8-dimethyl-2h-imidazo[4,5-b]quinolin-2-one (bmy-20844). | the effects of 1,3-dihydro-7,8-dimethyl-2h-imidazo[4,5-b]quinolin-2-one (bmy-20844) on platelet function and experimental thrombosis were evaluated in a series of in vitro, ex vivo and in vivo experiments. the compound inhibited platelet aggregation in vitro in platelet rich plasma obtained from humans, rats and rabbits with ec50s of less than 1 microgram/ml when aggregation was induced by adp, collagen or thrombin. supra-additive interaction against adp aggregation was also observed when bmy-20 ... | 1989 | 2559492 |
| classification of beta-adrenoceptors in ferret tracheal smooth muscle by pharmacological responses. | beta-adrenoceptors in ferret tracheal smooth muscle were classified into beta 1 or beta 2 by determination of (i) the potency rank order for isoprenaline, noradrenaline and adrenaline, and (ii) apparent pa2-values for a specific beta 1-antagonist (practolol) and a specific beta 2-antagonist (ici 118.551) and (iii) concentration-inhibition curves for procaterol, a beta-agonist showing a biphasic concentration-response curve in organs with a mixed beta 1 and beta 2 adrenoceptor population. we used ... | 1989 | 2562454 |
| preponderance of beta- over alpha-adrenoceptors in mediating the positive inotropic effect of phenylephrine in the ferret ventricular myocardium. | [3h]prazosin bound to the membrane fraction derived from the ferret ventricular muscle with high affinity in a saturable manner (kd = 0.25 nmol/l and bmax = 27 fmol/mg protein in the right ventricle). [3h]cgp-12177, a beta-adrenoceptor ligand, bound to the membrane fraction with a kd value of 0.29 nmol/l and a bmax of 42 fmol/mg protein. in the isolated ferret papillary muscle driven at 1 hz at 37 degrees c, phenylephrine elicited a concentration-dependent positive inotropic effect. the maximal ... | 1989 | 2566934 |
| tracheal gland mucous cells stimulated in vitro with adrenergic and cholinergic drugs. | to determine the responsiveness of tracheal mucous cells to adrenergic and cholinergic stimulation, we analyzed changes in their structure induced by neurotransmitter-like agonists. ferret tracheal rings were exposed for 30 min in vitro to one of the following: phenylephrine, isoproterenol, or bethanechol (all at 10(-5) m), in the presence of absence of appropriate antagonists. electron microscopy and morphometric analysis revealed that the volume density of mucous cells (vvmc, i.e. the space oc ... | 1989 | 2570474 |
| somatostatin potentiates cholinergic neurotransmission in ferret trachea. | we studied the effect of somatostatin on contractile responses to electrical field stimulation (efs) in isolated ferret tracheal segments. somatostatin (up to 10(-5) m) did not change resting tension, but it potentiated the contractile response to efs dose dependently, with a maximum effect at 10(-6) m. thus, at a concentration of 10(-6) m, somatostatin significantly decreased the mean log of efs frequency producing 50% of maximum contraction from a control value of 0.52 +/- 0.07 to 0.24 +/- 0.0 ... | 1989 | 2575091 |
| beta 2-adrenoceptor stimulation inhibits ganglionic transmission in ferret trachea. | to study the effect of beta-adrenoceptor stimulation on the transmission through airway parasympathetic ganglia, we used an in vitro nerve-muscle preparation of ferret trachea. isometric muscle contractions were induced for 20 s every 2 min alternating with postganglionic activation by electrical field stimulation (efs) or with preganglionic activation by direct nerve stimulation (dns). the pulse frequency was always 12 hz. a possible modulation of ganglionic transmission was assessed by compari ... | 1989 | 2577682 |
| effects of sodium substitutes on transient inward current and tension in guinea-pig and ferret papillary muscle. | we used ouabain-treated guinea-pig and ferret papillary muscles to study transient inward current (iti), after-contractions, and tonic tension development during voltage-clamp pulses. li, sucrose and choline were used isosmotically as na substitutes to evaluate the effect of altering the na equilibrium potential. we were unable to detect outward iti at any potential up to +30 mv in normal or na-depleted solutions. however, reduction of na had a biphasic effect on iti, initially increasing it and ... | 1985 | 2580967 |
| peptide-containing nerve fibers in the respiratory tract of the ferret. | the ferret is widely used in functional and neuromorphological studies on the respiratory tract. we have examined the occurrence and distribution of peptide-containing and adrenergic nerve fibers (using dopamine-beta-hydroxylase as a marker). adrenergic nerve fibers and fibers storing vasoactive intestinal peptide have a widespread distribution along the entire respiratory tract. adrenergic nerve fibers were found in the lamina propria, as well as around blood vessels and glands and in smooth mu ... | 1989 | 2582477 |
| association of [3h]zacopride with 5-ht3 binding sites. | an assay was developed for [3h]zacopride binding to 5-ht3 specific sites in membranes from rabbit ileum muscularis. the binding was rapid, saturable, reversible, salt-insensitive, unaffected by ph between 6.5 and 9.5, and of high affinity (apparent kd = 0.65 +/- 0.15 nm). ics 205-930, a potent 5-ht3 antagonist that inhibited competitively, was utilized to define 5-ht3 specific binding. other 5-ht3 antagonists and agonists, although exhibiting marked differences in potency, were also effective in ... | 1989 | 2583241 |
| in vivo inhibition of n-nitrosodimethylamine metabolism by 4-methylpyrazole: a model for endogenous nitrosation. | the endogenous formation of n-nitrosodimethylamine (ndma) was investigated in the ferret by inhibiting metabolism and monitoring urinary ndma levels. the addition of 1.0 mg/ml of 4-methylpyrazole (4-mp) to the drinking water was sufficient to allow a 13% urinary recovery of a 4.0 nmol oral dose of ndma to be made in 24 h. without 4-mp, no ndma could be detected in urine. there was no detectable urinary ndma when dimethylamine (dma) alone was given but when as little as 5 mumol of nitrite and 0.7 ... | 1989 | 2591019 |
| pulmonary vasodilator action of ligustrazine, active principle of a traditional chinese remedy, in rats and ferrets. | the action of ligustrazine on the pulmonary circulation was tested in isolated perfused rat lung in vitro and autoperfused ferret lower left lobe preparation in vivo. ligustrazine reduced hypoxic pulmonary vasoconstriction in a dose-dependent manner. it had a lesser dilator effect on kcl-induced vasoconstriction than verapamil and a relatively small inhibitory effect on the pressor response to angiotensin ii. ligustrazine preferentially inhibited the vasoconstriction caused by hypoxia and almitr ... | 1989 | 2594738 |
| stoichiometry of net sodium and potassium fluxes mediated by the na-k-cl co-transport system in ferret red cells. | the bumetanide-sensitive na-k-cl co-transport system in ferret red cells produces net movement of 1na:1k. tracer studies have misleadingly suggested a stoichiometry of 2na:1k probably because the transporter mediates substantial na-na exchange in these cells. | 1989 | 2594943 |
| the epidemiology of echinococcus granulosus in great britain. v. the status of subspecies of echinococcus granulosus in great britain. | twenty-five years ago williams and sweatman suggested that in great britain there are two subspecies of echinococcus granulosus--e. granulosus granulosus and e. granulosus equinus. echinococcus granulosus granulosus does not mature either in foxes or in horses: e. granulosus equinus will mature in either. the prepatent period of e. granulosus granulosus in the definitive host is about 42 days while that of e. granulosus equinus is about 70 days. each subspecies has a characteristic morphology. m ... | 1989 | 2596902 |
| the antibacterial properties of four elements released from dental restorative materials. | the antibacterial activity of four elements (zinc, copper, fluoride and mercury), previously reported to be released from dental restorative materials, was investigated. this was carried out using two aerobic micro-organisms isolated from dentine beneath cavities in the ferret. these were grown in the presence of the test elements over a concentration range of 10-100 micrograms/ml for 72 hours. concentration and exposure time were found to have a highly significant effect on the growth and viabi ... | 1989 | 2599660 |
| calcium-force coupling mechanisms during vasodilator-induced relaxation of ferret aorta. | 1. the effects of three vasodilators, nifedipine, hydralazine and forskolin, were determined on isometric force and intracellular ionized calcium concentration ([ca2+]i) as indicated by aequorin in ferret aorta. three types of contraction were studied: the intrinsic tone induced by warming from 22 to 37 degrees c; the contraction to the phorbol ester 12-deoxyphorbol-13-isobutyrate-20-acetate (dpba); and the contraction to potassium depolarization. 2. on warming there was no significant steady-st ... | 1989 | 2600829 |
| cellular mechanism of the modulation of contractile function by coronary perfusion pressure in ferret hearts. | 1. isovolumic left ventricular pressure was measured at various coronary arterial pressures in langendorff-perfused ferret hearts. the concentrations of phosphorus-containing metabolites were measured using 31p nuclear magnetic resonance (nmr). intracellular free calcium concentration ([ca2+]i), was measured with 19f nmr in a group of hearts that were loaded with the calcium indicator 5f-bapta. 2. developed pressure increased when coronary arterial pressure was raised from the control value of 8 ... | 1989 | 2607438 |
| a comparison of the biomechanical properties of the periodontal ligaments of erupting and erupted teeth of non-continuous growth (ferret mandibular canines). | extrusive loads of 0.01-0.2 n were applied to the permanent mandibular canine teeth of two groups of ferrets. in one group, aged approx. 7 weeks, the tooth had only recently emerged into the mouth. in the second group, comprising adult animals, the tooth had fully erupted and had been in function for a considerable time. biphasic, viscoelastic-like responses followed both the application and removal of the load in both groups. however, there was significantly more mobility for all phases of the ... | 1989 | 2610611 |
| carnivora: the primary structure of the alpha-chains of ferret (mustela putorius furo, mustelidae) hemoglobins. | ferret erythrocytes contain two hemoglobins differing only by their alpha-chains. the primary structure of the common beta-chain has been previously described; the complete sequence of the two alpha-chains are reported in this paper. the globin chains were separated by ion-exchange chromatography; the alpha-chains (42 steps), their tryptic peptides as well as the prolyl-peptides were subjected to automatic liquid- and gas-phase edman degradation. the two alpha-chains are very similar, differing ... | 1989 | 2610931 |
| developmental changes of ferret tracheal mucin composition and biosynthesis. | we characterized the chemical composition of mucins secreted by ferret tracheal explants and the activities of key mucin glycosyltransferases in ferret tracheal epithelium during a period of rapid postnatal maturation of the mucin-secreting structures. ferret tracheal explants secrete three major groups of high molecular weight glycoconjugates: (1) those susceptible to bovine testicular hyaluronidase; (2) those resistant to hyaluronidase and exhibiting high density (p greater than or equal to 1. ... | 1989 | 2611242 |
| comparison of the effects of inotropic interventions on isometric tension and shortening in isolated ferret ventricular muscle. | in this study, we have compared the effects of a range of positive and negative inotropic interventions on isometric tension and shortening at low load in isolated ferret papillary muscles. it was found that the majority of interventions produced broadly similar effects on tension and shortening. positive inotropic interventions which behaved in this way included increasing extracellular calcium and increasing frequency at moderate stimulation rates. acidosis, the addition of cyanide, and metabo ... | 1989 | 2611813 |
| inhibition of aftercontractions and phasic calcium release by yohimbine in ferret papillary muscle. | phasic release of calcium from the sarcoplasmic reticulum occurs in all mammalian cardiac preparations when the intracellular calcium concentration is sufficiently high. the phasic calcium release is often sufficient to trigger electrophysiological responses and aftercontractions. these can be detrimental to normal cardiac function. we induced phasic calcium release in ferret papillary muscles loaded with the calcium indicator aequorin. development of phasic calcium release was associated with a ... | 1989 | 2620700 |
| [trichinelliasis in western podolia]. | situation with trichinosis in the ternopol province (ukraine) in the period from 1962 to 1987 was studied. muscle samples taken from 6695 animals of 20 species were investigated by the compressor method and by the method of digestion in artificial gastric juice. trichinosis was detected in wolves, foxes, martens, ferrets, domestic dogs, cats and gray rats. in 1954--1979 39 trichinosis cases were registered in humans with 4 lethal cases. domestic pigs proved to be the source of invasion. since 19 ... | 1989 | 2628712 |
| altered clearance of inhaled 99mtc-pentetate aerosols following exposure to cadmium chloride aerosols in ferrets. | the rate of clearance of inhaled 99mtc-pentetate aerosols has been used as an indicator of pulmonary epithelial "permeability" in human and animal studies. in order to evaluate this technique further, groups of eight male ferrets (mustela putorius furo) were given acute exposures to aerosols of cdcl2 or nacl via endotracheal tube. serial evaluations of the thoracic clearance rate of inhaled 99mtc-pentetate aerosols (mmad = 0.6 microns, sigma g = 1.6) were made before exposure and at fixed time p ... | 1989 | 2645118 |
| neoplasia in ferrets: eleven cases with a review. | records from a veterinary diagnostic laboratory in south florida, u.s.a. were reviewed for cases of neoplasia in pet ferrets. twelve ferret tumours were received over a four-year period; one case, a ferret with lymphocytic leukaemia and multi-organ involvement, had been reported previously. the other eleven tumours were: two chordomas of the tail, two sebaceous adenomas of the skin, a sebaceous epithelioma of the skin, a cutaneous mastocytoma, a malignant fibrous histiocytoma from the eyelid, a ... | 1989 | 2654203 |
| inotropic effects of endothelin in ferret ventricular myocardium. | the characteristics of the inotropic response to endothelin were studied in isolated ferret papillary muscle preparations. endothelin (0.1-10 nm) induced concentration-dependent positive inotropic effects. at 10 nm, isometric tension increased by 17%, maximum rate of tension development by 18%, maximum velocity of unloaded shortening by 23% and peak isotonic shortening by 11%. time to peak isometric tension and half isometric relaxation time were unaltered by endothelin. this pattern of change i ... | 1989 | 2656275 |
| proteolytic activities of human campylobacter pylori and ferret gastric campylobacter-like organism. | the levels of proteolytic activity in cell washes, lysates and pellets of c. pylori and gastric campylobacter-like organisms isolated from humans and ferrets, respectively, have been studied using porcine mucus glycoprotein and bovine haemoglobin substrates. the total haemoglobin degrading activity, expressed by 10(12)-10(13) cfu of either organism, was no greater than 3 micrograms chymotrypsin equivalents. the mucolytic specific activity (rate of mucus peptide bond hydrolysis by bacterial prote ... | 1989 | 2673233 |
| the effect of acidosis on excitation-contraction coupling in isolated ferret heart muscle. | the contractile response to acidosis is the final product of a number of different changes in the excitation-contraction coupling pathway: (i) cai increases and subsequently decreases during acidosis; (ii) the action potential becomes longer; (iii) the sensitivity of the contractile proteins to ca2+ decreases. the increase of cai and the lengthening of the action potential may help to maintain contractile function, although this advantage may be offset if spontaneous ca2+ release from the s.r. o ... | 1989 | 2682209 |
| replication of the bovine immunodeficiency-like virus in diploid and aneuploid cells: permanent, latent and virus-productive infections in vitro. | bovine immunodeficiency-like virus (biv) is an infectious and leukotropic retrovirus, the sole lentivirus candidate which has been isolated from cattle. although biv has recently been shown to be related to the human immunodeficiency virus, there is very limited information on the replication and the pathogenesis of biv. it is reported here that biv can permanently infect diploid and aneuploid cells from four different species: bovine, canine, ferret and ovine. with the exceptions of a bovine di ... | 1989 | 2694251 |