| retinogeniculate epsps recorded intracellularly in the ferret lateral geniculate nucleus in vitro: role of nmda receptors. | we used an in vitro preparation of the ferret lateral geniculate nucleus (lgn) to examine the role of the nmda class of excitatory amino acid (eaa) receptors in retinogeniculate transmission. intracellular recordings revealed that blockade of nmda receptors both shortened the time course and reduced the amplitude of fast and slow components of excitatory postsynaptic potentials (epsps) evoked by optic tract stimulation. the amplitude and width of the epsps mediated by nmda receptors increased as ... | 1992 | 1350209 |
| immunocytochemistry and calcium cytochemistry of the mammalian pineal organ: a comparison with retina and submammalian pineal organs. | morphologically the mammalian pineal organ is a part of the diencephalon. it represents a neural tissue histologically ("pineal nervous tissue") and is dissimilar to endocrine glands. submammalian pinealocytes resemble the photoreceptor cells of the retina, and some of their cytologic characteristics are preserved in the mammalian pinealocytes together with compounds demonstrable by cyto- and immunocytochemistry and participating in photochemical transduction. in our opinion, the main trend of t ... | 1992 | 1351408 |
| potential for hepatic and renal dysfunction during influenza b infection, convalescence, and after induction of secondary viremia. | whether infection with influenza b virus alters hepatic function was examined in the ferret. also, the possibility that viral-specific antibodies (ab) could be produced well before their detection in serum was explored. during the febrile period of influenza, reductions in the serum potassium, anion gap, ammonia, albumin and cpk and elevations of the bun, creatinine and the ggtp levels occurred. with convalescence, the electrolytes, bun and creatinine normalized, ffa, sgpt and cpk levels rose an ... | 1992 | 1352541 |
| evidence for an atypical, or beta 3-adrenoceptor in ferret tracheal epithelium. | 1. a preparation of the ferret trachea in vitro was used to examine the effects of three selective beta-adrenoceptor agonists on lysozyme secretion from submucosal gland serous cells and epithelial albumin transport into tracheal mucus following sustained, submaximal stimulation of mucus production with methacholine (20 microm). 2. prenalterol, salbutamol and brl 37344 all enhanced methacholine-induced albumin output. brl 37344 was 10,000 times more potent than salbutamol, and salbutamol was sli ... | 1992 | 1354537 |
| surgical and pharmacological dissociation of cardiovascular and emetic responses to intragastric cuso4. | under control (intact and laparotomized) conditions, arterial pressure of urethan-anesthetized ferrets rose significantly in response to intragastric copper sulfate (cuso4; 10 ml of 5 mg/ml). cuso4 was emetic 75-90% of the time, and a cardiovascular response always immediately preceded and accompanied emetic responses. the cardiovascular response was significantly reduced or abolished by hexamethonium (0.35 mg/kg) pretreatment combined with atropine methyl bromide (1 mg/kg). addition of the alph ... | 1992 | 1354943 |
| ferret red cells: na/ca exchange and na-k-cl cotransport. | the primary pathway for k influx in ferret red cells is the na-k-cl cotransporter and the primary pathway for ca influx is the na/ca exchanger. this makes ferret red cells favorable models for the study of these two transport systems. the evidence that na/ca exchange is of primary importance for steady state cell volume regulation and the na-k-cl cotransport has a minor role is presented. the approaches to, and results of, the determination of the stoichiometry, of the mechanism, and of the regu ... | 1992 | 1355025 |
| hematological and plasma chemical characteristics in beech marten (martes foina). | 1. the normal values of hematological and clinical-chemical variables in plasma of 21 males and 27 females of beech marten (martes foina) have been illustrated and compared to corresponding normal values in mink (mustela vison) and ferret (mustela putorius). 2. the number of erythrocytes, the hematocrit value, and the hemoglobin concentration were higher in male than in female beech marten. 3. divergences according to age in the investigated variables have been found. 4. the erythrocytes in beec ... | 1992 | 1355036 |
| [arrhythmogenic effects of sultopride chlorhydrate: clinical and cellular electrophysiological correlation]. | this study was designed following the first documented case of torsades de pointes induced by sultopride hydrochloride, a substituted benzamide neuroleptic drug. the patient, a 48 year-old woman with no known cardiovascular disease, had been treated for several years with this drug. she was admitted for severe bronchospasm requiring artificial ventilation. twenty-one hours after her admission, she developed several episodes of torsades de pointes, which were successfully treated with magnesium s ... | 1992 | 1363741 |
| helicobacter mustelae isolation from feces of ferrets: evidence to support fecal-oral transmission of a gastric helicobacter. | helicobacter mustelae has been isolated from stomachs of ferrets with chronic gastritis and ulcers. when h. mustelae is inoculated orally into h. mustelae-negative ferrets, the animals become colonized and develop gastritis, a significant immune response, and a transient hypochlorhydria. all of these features mimic helicobacter pylori-induced gastric disease in humans. because the epidemiology of h. pylori infection is poorly understood and its route of transmission is unknown, the feces of wean ... | 1992 | 1370432 |
| neutrophil elastase stimulates tracheal submucosal gland secretion that is inhibited by ici 200,355. | to investigate whether human neutrophil elastase (hne) stimulates airway submucosal gland secretion, we studied the effect of purified hne on secretion of 35s-labeled macromolecules from isolated tracheal tissues from ferrets, dogs, and humans. hne stimulated secretion in a concentration-dependent fashion, the secretory response being most pronounced in ferret tissues with a maximal response of 1,498 +/- 384% above baseline at 10(-5) m. in dog tissues, maximal secretory responses (509 +/- 169%) ... | 1992 | 1370750 |
| viral infection increases contractile but not secretory responses to substance p in ferret trachea. | viral infection increases the airway smooth muscle response to substance p. this effect is due to decreased activity of neutral endopeptidase (ec 3.4.24.11), an enzyme that degrades substance p. inhibition of neutral endopeptidase activity also potentiates substance p-induced 35so4-labeled macromolecule secretion. therefore we examined the in vitro effects of substance p on 35so4-macromolecule secretion from the tracheae of influenza-infected ferrets. despite a virus-induced loss of neutral endo ... | 1992 | 1373130 |
| distributions of interstitial cells of cajal in stomach and colon of cat, dog, ferret, opossum, rat, guinea pig and rabbit. | electrical slow waves vary in prominence from one location to another in stomach and colon. if interstitial cells of cajal are involved in generation of the slow waves, they might be more abundant in regions where slow waves are prominent than in regions where slow waves are small or absent. we calculated the density of distribution of interstitial cells of cajal in colon and stomach of cat, dog, ferret, guinea pig, opossum, rabbit, and rat, using the zinc iodide-osmic acid reaction for light mi ... | 1992 | 1375611 |
| cytoplasmic estrogen receptors in rat brain: immunocytochemical evidence using three antibodies with distinct epitopes. | the existence of cytoplasmic estrogen receptors (ers) has been reported in the guinea pig brain using immunocytochemical techniques. while cytoplasmic ers have been reported recently in other species, such as opossum, musk shrew, and ferrets, an exclusively cell nuclear pattern of er immunoreactivity has been reported in the rat brain. because all studies that have reported the existence of cytoplasmic ers in the brain have used the h 222 monoclonal antibody, the possibility exists that this obs ... | 1992 | 1380440 |
| cytoarchitectonic heterogeneities in the thalamic reticular nucleus of cats and ferrets. | the thalamic reticular nucleus has been classically defined as a group of cells surrounding most of the rostral and lateral surfaces of the dorsal thalamus, lateral to the fibres of the external medullary lamina and medial to those of the internal capsule. with the use of nissl staining and antibodies to gamma-aminobutyric acid (gaba), somatostatin, and parvalbumin, this study describes the cytoarchitecture of the thalamic reticular nucleus of cats and ferrets. in cats, three subdivisions of the ... | 1992 | 1381730 |
| regulation of vascular smooth muscle tone by caldesmon. | caldesmon is an actin-binding protein present in smooth muscle cells that also inhibits actin-activated myosin atpase activity. to assess the possible role of caldesmon in the regulation of smooth contraction, we investigated the effects of synthetic peptides on force directly recorded from single hyperpermeable smooth muscle cells of ferret aorta and portal vein. gs17c, a peptide that contains the residues from gly651 to ser667 of the caldesmon sequence plus an added cysteine at the c terminus, ... | 1992 | 1386078 |
| external calcium sensitivity of low sodium contractures in the control and hypertrophied right ventricle of the ferret. | the existence of possible differences of calcium (ca2+) fluxes through the sarcolemmal sodium-calcium (na+/ca2+) exchanger during hypertrophy has been tested by comparing the characteristics of the contracture--as an indicator of the intracellular ca2+ concentration--induced by partial or total withdrawal of external sodium (na+), in the absence of external potassium, in the right ventricular trabeculae of adult ferret hearts. pressure-overload was induced by pulmonary artery clipping and led to ... | 1992 | 1386173 |
| choline acetyltransferase expression studied with an oligonucleotide probe. | 1. the localization of choline acetyltransferase messenger rna has been studied using a digoxigenin-tailed complementary oligodeoxynucleotide probe for in situ hybridization. 2. putative cholinergic cells of the rat and ferret spinal cord and the ferret retina were labeled. 3. this technique affords superior resolution compared to radioactively labeled probes, with apparently equal sensitivity. | 1992 | 1394369 |
| myocardial energetics during ventricular fibrillation investigated by magnetization transfer nuclear magnetic resonance spectroscopy. | ventricular fibrillation (vf) is known to produce alterations in myocardial energetics, but the mechanism of these changes remains unclear. to investigate energy metabolism during vf, phosphorus nuclear magnetic resonance spectroscopy and magnetization transfer were applied to isolated perfused ferret hearts. vf was induced either by perfusion with digitalis (strophanthidin, 30 microm) or by high-frequency electrical stimulation. we measured the flux in two critical reactions: from inorganic pho ... | 1992 | 1394873 |
| pulmonary venous pressure increases during alveolar hypoxia in isolated lungs of newborn pigs. | the purpose of this study was to determine whether pulmonary venous pressure increases during alveolar hypoxia in lungs of newborn pigs. we isolated and perfused with blood the lungs from seven newborn pigs, 6-7 days old. we maintained blood flow constant at 50 ml.min-1.kg-1 and continuously monitored pulmonary arterial and left atrial pressures. using the micropuncture technique, we measured pressures in 10 to 60-microns-diam venules during inflation with normoxic (21% o2-69-74% n2-5-10% co2) a ... | 1992 | 1399980 |
| position of growth cones within the retinal nerve fibre layer of fetal ferrets. | optic axons are added to the retinal nerve fibre layer of fish along its vitreal border in a chronotopic manner. likewise, the optic tract of all vertebrate species acquires axons preferentially along the superficial surface of the pathway. we have examined the developing retina of fetal ferrets (mustela putorius furo) aged between embryonic day 27 (e27) and e34 to see whether a similar segregation of growth cones is apparent within the mammalian retinal nerve fibre layer. the distributions of g ... | 1992 | 1401254 |
| cellular mechanisms of paired electrical stimulation in ferret ventricular myocardium: relationship between myocardial force and stimulus interval change. | the subcellular mechanisms of twitch-force potentiation with paired electrical stimulation was studied in ferret ventricular myocardium using the bioluminescent calcium indicator aequorin. it is demonstrated for the first time that interpolation of an extrasystole in a train of conditioned twitches results in a beat-to-beat change in [ca2+]i and force. steady-state twitch force and ca2+i were increased with paired stimulation. increased [ca2+]o in the setting of paired stimulation resulted in an ... | 1992 | 1401334 |
| expression and characterization of a cdna clone encoding an immunodominant surface glycoprotein of pneumocystis carinii. | most studies of antigens of pneumocystis carinii have focused on an abundant, immunogenic 95- to 140-kda surface glycoprotein referred to as gpa. expression cloning of gpa from p. carinii obtained from ferrets resulted in isolation of colinear fragments of gpa cdna encoding approximately 87 kda of the core protein. northern hybridization detected an abundant, single species of gpa-specific mrna of 3600 nucleotides. southern hybridization revealed gpa-specific bands only in p. carinii-infected lu ... | 1992 | 1402023 |
| ultrastructural quantitation of mitochondria and myofilaments in cardiac muscle from 10 different animal species including man. | the ultrastructural quantitative composition of normal myocardial cells has been studied in 10 different species: man, dog, pig, cat, rabbit, ferret, guinea-pig, rat, mouse, and bat. volume densities of mitochondria, myofibrils, and cytoplasm were determined using morphometry. it was found that the content of mitochondria differs in various species ranging between 22.0-37.0%. it is a very specific and constant value for any particular species, the smallest having the highest content. a close cor ... | 1992 | 1404407 |
| lhrh in the ferret: pubertal decrease in the number of immunopositive arcuate neurons. | this study correlated a region-specific change in the number of luteinizing hormone-releasing hormone-immunopositive (lhrh+) neurons with pubertal development in male ferrets. there were 50% fewer lhrh+ cell bodies in the arcuate nucleus of peri- and postpubertal ferrets than in prepubertal ferrets; this significant decrease represented a 15% reduction in the overall number of lhrh+ neurons. intracerebroventricular colchicine did not reveal additional numbers of lhrh+ neurons in the arcuate nucl ... | 1992 | 1409003 |
| membrane and synaptic properties of developing lateral geniculate nucleus neurons during retinogeniculate axon segregation. | during the first postnatal month in the ferret (mustela putorius furo), the projections from the retina to the lateral geniculate nucleus (lgn) become segregated into eye-specific layers and on and off sublayers, a process that is thought to depend in part on neuronal activity. remarkably, virtually nothing is known about the physiological features of lgn neurons during this period. we have recorded intracellularly from 46 a-layer neurons in slices of the ferret lgn between the ages of postnatal ... | 1992 | 1409711 |
| sexual dimorphism in the effects of mating on the in vitro release of lhrh from the ferret mediobasal hypothalamus. | a sexually dimorphic pattern in the secretion of luteinizing hormone (lh) has previously been shown to occur in response to mating in an induced ovulating species, the ferret, with mating augmenting the secretion of lh in females but not in males. the aim of this study was to determine whether this dimorphic pattern in the postcoital secretion of lh reflects a dimorphic effect of mating on the neural release of luteinizing hormone releasing hormone (lhrh). the effect of mating on the in vitro re ... | 1992 | 1409957 |
| discovery of a peptide-based renin inhibitor with oral bioavailability and efficacy. | peptidic renin inhibitors have been poorly absorbed across the intestine or rapidly eliminated by the liver and have been reported to have oral bioavailabilities of less than 2%. a peptide-based renin inhibitor, a-72517 (molecular mass of 706 daltons), was devised that has oral bioavailabilities of 8, 24, 32, and 53% in the monkey, rat, ferret, and dog, respectively. dose-related reductions in blood pressure, plasma renin activity, and plasma angiotensin ii in parallel with increased plasma drug ... | 1992 | 1411510 |
| hepatic mixed-function oxidases of ferret. | 1. ferret liver mixed-function oxidase enzymes have been quantified using a variety of substrates and the activities have been compared with those found in rat liver. 2. ferret liver total cytochrome p-450 is only 30% of that of rat liver and exhibits higher 7-ethoxyresorufin o-deethylase (erod) activity, and lower lauric acid hydroxylase activity than rat liver; other mixed-function oxidases are at similar levels of activity in both species. 3. induction with 3-methylcholanthrene (mc), similar ... | 1992 | 1413877 |
| the attenuation phenotype conferred by the m gene of the influenza a/ann arbor/6/60 cold-adapted virus (h2n2) on the a/korea/82 (h3n2) reassortant virus results from a gene constellation effect. | a single gene reassortant (sgr) virus that derived its m gene from the attenuated influenza a/ann arbor/6/60 cold-adapted (ca) donor virus and the remaining genes from the a/korea/82 (h3n2) wild type (wt) virus (designated a/korea/82 ca m-sgr) was previously shown to be attenuated in mice, hamsters, ferrets, and humans. the attenuation (att) phenotype of this sgr virus could result directly from an altered function of the mutant m gene product of the a/ann arbor/6/60 ca virus, which differs from ... | 1992 | 1413993 |
| ca(2+)-independent isoforms of protein kinase c differentially translocate in smooth muscle. | it is generally assumed that smooth muscle contraction is dependent on changes in intracellular ca2+ concentration ([ca2+]i); however, we have previously reported that alpha-agonist-induced contraction of aorta smooth muscle cells can occur in the absence of changes in [ca2+]i [collins, e. m., m. p. walsh, and k. g. morgan. am. j. physiol. 262 (heart circ. physiol. 31): h754-h762, 1992]. the mechanism of this [ca2+]i-independent contraction is controversial. we have now identified the ca(2+)-ind ... | 1992 | 1415520 |
| intestinal uptake and lymphatic absorption of beta-carotene in ferrets: a model for human beta-carotene metabolism. | to determine the appropriateness of the ferret as a model for human beta-carotene (beta-c) metabolism, we have perfused both 15,15'-beta-[14c]c and unlabeled beta-c through the upper 30-cm portion of the small intestine of ferrets in vivo. the effluents of a mesenteric lymph duct cannulation and a common bile duct cannulation, as well as portal vein blood periodically sampled via an indwelling catheter, were collected. ten percent (9.5 +/- 0.06%) of the total administered beta-c was taken up by ... | 1992 | 1415707 |
| the l type calcium current in single hypertrophied cardiomyocytes isolated from the right ventricle of ferret heart. | the aim was to study l type calcium current alterations in relation to the action potential lengthening induced by hypertrophy in isolated cardiomyocytes from the right ventricle of ferret. | 1992 | 1423430 |
| decreased myofilament responsiveness in myocardial stunning follows transient calcium overload during ischemia and reperfusion. | the purpose of this study was to test the hypothesis that abnormal intracellular calcium handling characterizes myocardial stunning. isolated, isovolumic, buffer-perfused ferret hearts were loaded with the bioluminescent calcium indicator aequorin for simultaneous measurement of individual calcium transients and left ventricular pressure. after 15 minutes of global ischemia and 20 minutes of reperfusion, left ventricular developed pressure was significantly reduced (75 +/- 7 versus 93 +/- 6 mm h ... | 1992 | 1423931 |
| 5-ht3 receptor antagonist effects of dat-582, (r) enantiomer of as-5370. | the serotonin 5-ht3 receptor antagonist effects of dat-582, the (r) enantiomer of as-5370 ((+/-)-n-[1-methyl-4-(3-methyl-benzyl)hexahydro-1h-1,4-diazepin-6- yl]-1h- indazole-3-carboxamide dihydrochloride), and its antipode were compared with those of as-5370 and existing 5-ht3 receptor antagonists. in anesthetized rats, dat-582 antagonized 2-methyl-5-ht-induced bradycardia with an ed50 value of 0.25 microgram/kg i.v., whereas the (s) enantiomer was without effect even at 1000 micrograms/kg i.v. ... | 1992 | 1425931 |
| lucifer yellow, retrograde tracers, and fractal analysis characterise adult ferret retinal ganglion cells. | the dendritic morphology of retinal ganglion cells in the ferret was studied by the intracellular injection of lucifer yellow in fixed tissue. ganglion cells were identified by the retrograde transport of red or green fluorescent microspheres that had been injected into different target nuclei, usually the lateral geniculate nucleus or superior colliculus. this approach allows the comparison of dendritic morphologies of ganglion cells in the same retina with different central projections and als ... | 1992 | 1430318 |
| effects of sex and androgen treatment on dendritic dimensions of neurons in the sexually dimorphic preoptic/anterior hypothalamic area of male and female ferrets. | a sexually dimorphic group of cells at the dorsal border of the preoptic/anterior hypothalamic area (poa/ah) of ferrets has been previously identified in nissl-stained tissue. in this study, golgi-stained tissue was examined in order 1) to determine whether sex differences exist in dendritic dimensions of neurons from this region, and 2) to assess the effects of adult androgen treatment on dendritic morphology in ferrets of both sexes. brains from adult ferrets given daily injections of testoste ... | 1992 | 1430324 |
| ultrastructural development of the medial superior olive (mso) in the ferret. | when ferrets are born, four weeks before the onset of hearing, few synapses are evident in the medial superior olive (mso). the synapses present are immature and almost exclusively found in the neuropil. the mso somata are virtually devoid of synaptic contacts but are contacted by fine glial processes that increasingly ensheathe the somata during the first postnatal week. by p12, somatic synaptogenesis in the mso is evident. initially the terminals contain vesicles of irregular shape, size, and ... | 1992 | 1430336 |
| biocompatibility of retrograde filling materials in the ferret canine. amalgam and irm. | periapical tissue response to retrograde fillings of amalgam and irm were compared in the mandibular canine of the adult male ferret. teeth were cleaned and shaped with a standard technique and obturated with gutta-percha. the root apex was then exposed and retrofillings were placed. the animals were grouped according to observation periods of 5, 10, and 15 weeks. at the proper time the animals were killed and the lower canine tooth along with the surrounding bone was removed. the tissue blocks ... | 1992 | 1437046 |
| effect of ovariectomy on blastocyst expansion and survival in ferrets (mustela putorius furo). | the initial objective was to investigate whether progesterone alone can support full blastocyst expansion in ferrets ovariectomized on day 5 post coitum (p.c.). by day 11 p.c. blastocysts from control animals had expanded to approximately 2000 microns in diameter, whereas by days 11 or 14 p.c. blastocysts from ovariectomized animals given progesterone had diameters of < 1000 microns. thus, ovarian factors in addition to progesterone are apparently required for normal blastocyst expansion in this ... | 1992 | 1438953 |
| force production in voltage-clamped human atrial muscle. | human atrial muscle preparations obtained during open heart surgery were mounted in a sucrose gap. force and membrane currents were recorded during voltage clamp. after a 20-s rest, 10 clamps from a holding potential of -40 to 0 mv at 1.0 hz were given. this was followed by a test clamp (called 1) of a varied duration and amplitude and two more test clamps (called 2 and 3) as during the priming period. peak force of contraction 1 (f1) was independent of clamp duration from 2s to about 100 ms but ... | 1992 | 1442125 |
| an angiographic method for in vivo study of arteries of the circle of willis in small animals. | an x-ray imaging technique designed to allow sequential diameter measurements of the cerebral vessels in intact, anesthetized small animals under relatively physiological conditions is described. the ferret and the rabbit were chosen as potentially useful animal models for studying the cerebrovascular system because of the advantageous anatomic characteristics of these relatively small species. a commercially available and relatively inexpensive x-ray imaging system with a small focal spot provi ... | 1992 | 1443212 |
| the effects of intraluminal and extraluminal drug application on secretion and smooth muscle tone in the ferret liquid-filled trachea in vitro. | with the ferret liquid-filled trachea in vitro, intraluminal methacholine (mch), phenylephrine (pe) and histamine (hist) increased smooth muscle tone and salbutamol (salb) decreased tone. lysozyme output was increased by intraluminal mch and pe. albumin transport into the lumen was not altered by intraluminal hist, salb or pe. the concentration-response curves for smooth muscle contraction and for lysozyme output to extraluminal mch lay to the left of those for intraluminal mch. indomethacin shi ... | 1992 | 1446138 |
| an in vivo preparation for measurement of plasma protein and lysozyme output in the ferret tracheal lumen. | an in-vivo ferret tracheal preparation has been developed to study the appearance in the liquid-filled trachea of fluorescein-labelled plasma proteins (flp) and of lysozyme from submucosal gland serous cells. in order to investigate the influence of nervous activity on the appearance of flp and lysozyme in the tracheal lumen, the effects of intraluminal bradykinin (an inflammatory mediator and sensory nerve stimulant), intraluminal capsaicin (a stimulant of c-fibres) and electrical stimulation o ... | 1992 | 1446140 |
| development of mucociliary transport in the postnatal ferret trachea. | little is known of the developmental aspects of mucociliary transport. previous studies have documented that newborn ferret trachea has very few ciliated cells but numerous immature secretory cells in the epithelium and only rudimentary submucosal glands. rapid and complete maturation occurs in the first postnatal month. this study examines mucociliary transport during this period of rapid maturation. we made direct observations of particle movement across the epithelium of ferret tracheas. no m ... | 1992 | 1447097 |
| effect of immunisation against vasoactive intestinal polypeptide on gastric corpus tone and motility in the ferret. | the role of vasoactive intestinal polypeptide in the control of gastric corpus tone and motility was investigated using auto-antibodies to neutralise endogenous vasoactive intestinal polypeptide. six ferrets were immunised with vasoactive intestinal polypeptide thyroglobulin conjugate in freund's complete adjuvant which resulted in a significant increase in plasma vasoactive intestinal polypeptide binding activity compared with unimmunised control animals. in acute experiments the level of spont ... | 1992 | 1452070 |
| discovery of a well-absorbed, efficacious renin inhibitor, a-74273. | the development of orally active renin inhibitors has been plagued by limited bioavailability in animals and humans. a-74273 is a novel, potent nonpeptide inhibitor of human renin (ic50 = 3.1 nm). this compound was absorbed into the portal and systemic circulations of anesthetized rats, ferrets, monkeys, and dogs after intraduodenal dosing. this favorable pattern also was observed after oral dosing in conscious animals, except in monkeys. hepatic extraction of a-74273 was more efficient in rats ... | 1992 | 1452292 |
| pharmacology of the 5-hydroxytryptamine-induced depolarization of the ferret vagus nerve in vitro. | grease-gap recordings revealed that 5-hydroxytryptamine (5-ht) depolarized the ferret vagus nerve (pec50 = 4.9). this response was mimicked by 2-methyl-5-ht and 1-phenylbiguanide, but not by 5-carboxamidotryptamine. paroxetine (1 microm) or ketamine (10 microm) did not potentiate the response. ketanserin (1 microm) did not reduce the depolarization, but four 5-ht3 receptor antagonists did. it is concluded that 5-ht depolarizes the ferret vagus nerve via 5-ht3 receptors, but these receptors may d ... | 1992 | 1459188 |
| neuropharmacology of emesis in relation to clinical response. | 5-ht3 receptor antagonists such as ondansetron, granisetron, ics205-930 and zacopride are highly effective in the ferret, cat or dog to prevent emesis caused by cisplatin and other chemotherapeutic agents, and radiation treatment. the anti-emetic effects may be mediated centrally in the area postrema and associated structures of the emetic reflex such as the nucleus tractus solitarius, which have a very high density of 5-ht3 receptors. additional sites of action may be found on the 5-ht3 recepto ... | 1992 | 1467196 |
| metabolic changes during ischaemia and their role in contractile failure in isolated ferret hearts. | 1. the effects of global ischaemia on phosphorus metabolites, intracellular ph (phi) and developed pressure were measured in isolated whole ferret hearts using 31p nuclear magnetic resonance (nmr) spectroscopy. 2. brief (10 min) periods of global ischaemia reduced left ventricular developed pressure (lvdp) to undetectable levels. this fall in lvdp was accompanied by a fall in the intracellular concentration of phosphocreatine (pcr) and increases in the concentrations of inorganic phosphate (pi) ... | 1992 | 1474498 |
| age-related differences in vascular effects of pentoxifylline in isolated perfused ferret lungs. | we have determined the magnitude and sites of action of pentoxifylline (ptx), a methylxanthine derivative, in the adult and 3- to 4-week old ferret pulmonary circulation. lungs of 8 ferrets, four 3- to 4-week-old and 4 adult, were isolated and perfused with blood. during perfusion, blood flow was kept constant, as were airway and left atrial pressures (6 and 8 cm h2o respectively, zone 3 conditions). in all lungs, pulmonary artery pressure was measured continuously and the circulation was partit ... | 1992 | 1483354 |
| the quest for an animal model of high altitude pulmonary edema. | the understanding of the mechanisms underlying certain human diseases usually requires an animal model which can be manipulated in a way that will allow dissection of the pathophysiologic events which lead to the disease. high altitude pulmonary edema (hape) occurs in some healthy individuals who ascend from low to high altitude. the disease is characterized by a high protein leak into the lungs and is associated with accentuated pulmonary hypertension. attempts to find an animal model for hape ... | 1992 | 1483793 |
| concurrent mammary gland hyperplasia and adrenocortical carcinoma in a domestic ferret. | mammary gland hyperplasia associated with adrenocortical carcinoma in a domestic ferret had a histologic appearance similar to that observed in cats. it is important to consider this hyperplastic condition in the differential diagnosis of mammary gland enlargement in the ferret. | 1992 | 1483915 |
| phenylephrine-induced translocation of protein kinase c and shortening of two types of vascular cells of the ferret. | 1. the relationship between phenylephrine-induced smooth muscle contraction and the subcellular distribution of protein kinase c (pkc) was investigated. 2. cell shortening induced by phenylephrine (10(-5) m) was measured in single vascular cells freshly isolated from ferret portal vein and aorta. 3. at various time points during phenylephrine activation, single cells were fixed with paraformaldehyde and the distribution of pkc was imaged in cells labelled with the fluorescent pkc probe 12-(1,3,5 ... | 1992 | 1484363 |
| mechanisms by which cancer chemotherapeutic drugs induce emesis. | because the area postrema seems essential for chemotherapy-induced vomiting, both circulating and/or neurally mediated stimuli in this area could trigger the emetic response. in our laboratories results of cross-circulation and direct intracerebroventricular infusion experiments in dogs do not support a role for circulating substances. the large increases in serum vasopressin induced by cisplatin were not blocked by inhibitors of the angiotensin-converting enzyme. in the ferret inhibition of ser ... | 1992 | 1485177 |
| effect of chronic exposure to no2 in the developing ferret lung. | the effect of chronic exposure to low (0.5 ppm) and high (10 ppm) concentrations of no2 on the development of the ferret lung was studied in animals exposed 4 h/day, 5 days/week from age 6 weeks through 20 weeks. morphometric analysis showed significant changes in alveolar dimensions at both concentrations, compared to air-exposed controls. thickened alveolar walls, increased cellularity and collagen deposition, increased lung size and the appearance of lesions indicative of oxidant damage indic ... | 1992 | 1488775 |
| separate effects of ischemia and reperfusion on vascular permeability in ventilated ferret lungs. | in systemic organs, ischemia-reperfusion injury is thought to occur during reperfusion, when oxygen is reintroduced to hypoxic ischemic tissue. in contrast, the ventilated lung may be more susceptible to injury during ischemia, before reperfusion, because oxygen tension will be high during ischemia and decrease with reperfusion. to evaluate this possibility, we compared the effects of hyperoxic ischemia alone and hyperoxic ischemia with normoxic reperfusion on vascular permeability in isolated f ... | 1992 | 1490978 |
| bile salt stimulated lipase: comparative studies in ferret milk and lactating mammary gland. | bile salt stimulated lipase (bssl) activity is 10-20 times higher in ferret milk than in human milk. we have used the ferret to study bssl activity in lactating mammary gland and in mammary cells isolated by hyaluronidase-collagenase treatment followed by ficoll gradient centrifugation. furthermore, we have compared the characteristics of bssl in the tissue preparations (homogenate or cells) to bssl of ferret milk and to bssl purified from ferret and human milk. the characteristics of bssl in fe ... | 1992 | 1491611 |
| distemper vaccination in ferrets. | | 1992 | 1496764 |
| influenza vaccine strain selection: equivalence of two antigenically distinct haemagglutinin variants of 1989 h3n2 influenza a virus in protection of mice. | precise antigenic analysis with haemagglutinin-inhibition (hi) tests of 1989 h3n2 influenza a viruses with polyclonal ferret, rabbit and mouse antisera has shown, first, significant differences among 1989 wild-type isolates, second, antigenic differences between two high-yield vaccine candidate reassortant viruses, third, significant antigenic differences of one reassortant (x-105) from the wild-type virus (a/guangdong a/39) from which it was derived, and fourth, dependence of antigenic characte ... | 1992 | 1502837 |
| sex difference in the effect of mating on c-fos expression in luteinizing hormone-releasing hormone neurons of the ferret forebrain. | the pulsatile secretion of lh was previously found to rise in female ferrets after receipt of an intromission, whereas in males that achieved an intromission, both lh and testosterone secretion were either reduced or unchanged. we sought to determine whether this sexually dimorphic pattern of lh secretion reflects a sex difference in the effect of mating on the activity of forebrain neurons that secrete lhrh. immunocytochemical methods were used to localize the nuclear protein product of the imm ... | 1992 | 1505478 |
| pancreatic adenocarcinoma with metastasis in two ferrets. | exocrine pancreatic adenocarcinoma with carcinomatosis was diagnosed in 2 ferrets. clinical signs included abdominal distention and hind limb weakness. ultrasonography revealed moderate ascites in both ferrets, an irregular abdominal mass in 1 ferret, and multiple abdominal masses in the other ferret. the ferrets were euthanatized, and necropsy of 1 ferret revealed carcinomatosis without visceral metastasis. | 1992 | 1506255 |
| trophic influences of excitatory and inhibitory synapses on neurones in the auditory brain stem. | the effects of a reduction during development of excitatory and inhibitory synaptic input on cns neurones were studied in the lateral superior olivary nucleus (lso) of the ferret following neonatal, unilateral cochlear removal. lso neurones normally receive excitatory input from the ipsilateral ear and inhibitory input from the contralateral ear. after cochlear removal, the ipsilateral lso was smaller and contained fewer neurones than either the contralateral or the normal lso. no difference was ... | 1992 | 1515583 |
| effects of endothelin on intracellular ca2+ and contractility in single ventricular myocytes from the ferret and human. | we investigated the role of endothelin-1 on peak intracellular ca2+ ([ca2+]i) and peak shortening of ventricular myocytes (loaded with indo-1/am) from failing human hearts. 10 nm of et-1 significantly increased the cell peak shortening (84 +/- 29%, p less than 0.05) without significantly increasing the peak [ca2+]i (15 +/- 7%, p greater than 0.05). further studies on ferret cardiac myocytes indicated that in addition to producing dose-dependent (0.1-10 nm) significant increases in peak shortenin ... | 1992 | 1516644 |
| interactions of the exchange inhibitory peptide with na-ca exchange in bovine cardiac sarcolemmal vesicles and ferret red cells. | the na-ca exchange inhibitory peptide (xip), which corresponds to residues 251-270 of the na-ca exchange protein, specifically inhibits exchange activity (li, z., nicoll, d. a, collins, a., hilgemann, d. w., filoteo, a. g., penniston, j. t., weiss, j. n., tomich, j. m., and philipson, k. d. (1991) j. biol. chem. 266, 1014-1020). we have found that xip decreased na+i-dependent ca2+ uptake to 46 and 20% of control in mixed and inside-out bovine sarcolemmal (sl) vesicles, respectively, and to 22% o ... | 1992 | 1517221 |
| jaw-muscle activity in ferrets, mustela putorius furo. | electromyographical (emg) activity was recorded bilaterally from the masseter and temporalis muscles of alert ferrets (mustela putorius furo) during mastication and crushing. electromyographic activity was also recorded during biting while a bite-force transducer placed between the carnassial teeth registered forces ranging from 1.5 to 48.8 n. linear regression analysis demonstrates that temporalis and masseter emg activity are linearly related to bite force. electromyographic activity from the ... | 1992 | 1518073 |
| nicotine increases ciliary beat frequency by a direct effect on respiratory cilia. | we studied the direct effects of nicotine on the ciliary beat frequency (cbf) undisturbed by interference from mucus secretion by using epithelial strips from ferret tracheae which contain no goblet cells and, because the glands were left behind in the submucosa, no gland tissue either. strips were studied in a chamber perfused with medium m-199 at 37 degrees c at a perfusion rate of 1.6 ml min-1 using a perfusion pump (braun, melsungen). cbf was determined photometrically, the signal being subj ... | 1992 | 1521039 |
| induced periapical lesions in ferret canines: histologic and radiographic evaluation. | ferrets have been utilized in endodontic research to study periapical responses. however, various aspects of induction and healing of periapical pathosis in ferrets are unclear. this study evaluated the radiographic and histopathologic features of induced periapical lesions. periapical pathosis was consistently produced in 8 canines of 2 ferrets by extirpating the pulp, leaving the cavities open for a week, then sealing for 12 weeks. the resulting lesions were evaluated radiographically every tw ... | 1992 | 1521506 |
| pulp response to bases and cavity depths. | in cavities of ferret canines, preparation depth and bases were compared as to their effect on odontoblasts and to rate of dentin formation. these were measured by injecting 3h-proline at 0, 20 and 40 days post-preparation. odontoblast activity was determined by label density in each band; inter-band distances indicated the amount of dentin formed. correlations were by pearson's coefficient. the following were determined: 1) cavity depth (remaining dentin thickness) was the major factor in odont ... | 1992 | 1524748 |
| novel 5-ht3 antagonists. isoquinolinones and 3-aryl-2-pyridones. | synthesis and pharmacological evaluation of a series of 1,2-dihydro-1-[(5-methyl-1-imidazol-4-yl)methyl]-2-oxopyridine 5-ht3 antagonists are described. the key pharmacophoric elements were defined as a basic nitrogen, a linking group capable of hydrogen bonding interactions, and an aromatic moiety. 1,2-dihydro-2-oxopyridine moiety could be a good linking group because of its nicely planar structure. the steric limitations of the aromatic moiety were investigated by x-ray analysis and computer an ... | 1992 | 1527780 |
| 'reverse use-dependent' effects of 4-aminopyridine on the transient outward potassium current in ferret right ventricular myocytes. | | 1992 | 1529768 |
| mr lymphography with iron oxide compound ami-227: studies in ferrets with filariasis. | the purpose of this study was to assess the mr lymphographic potential of ami-227 to reduce the signal intensity of hyperplastic inflammatory lymph nodes by using ferrets with filariasis as the animal model. both interstitial and iv modes of administration were studied. | 1992 | 1529857 |
| dat-582, a novel serotonin3 receptor antagonist, is a potent and long-lasting antiemetic agent in the ferret and dog. | the antiemetic effects of a novel serotonin3 receptor antagonist, dat-582 [(6r)-(-)-n-[1-methyl-4-(3-methylbenzyl)hexahydro-1h-1,4- diazepin-6-yl]-1h-indazole-3-carboxamide dihydrochloride] were compared with those of the existing serotonin3 receptor antagonists, ondansetron and granisetron, in experimental animals. in ferrets, dat-582 (0.003-0.1 mg/kg i.v. twice) dose-relatedly prolonged the latency to the first emetic episode and decreased the number of emetic episodes induced by cisplatin (10 ... | 1992 | 1532032 |
| activation of two types of fibres in ferret, mustela putorius furo, cremaster muscle. | some contractile, histochemical, morphological and electrophysiological properties of ferret, mustela putorius furo, cremaster muscle have been estimated. histochemical fibre typing revealed the presence of two types of fibres (type i 66.2%, type ii 33.8%). morphometry performed on atpase-stained transverse sections showed that type i was composed of a large amount (40%) of small (less than 1400 microns2) cells. in mammalian ringer two groups of fibres could be recognized on the basis of the val ... | 1992 | 1534331 |
| effect of haemodynamic pressure overload of the adult ferret right ventricle on inotropic responsiveness to external calcium and rest periods. | the inotropic effects of external calcium concentration ([ca2+]o] and rest periods have been compared in papillary muscles isolated from control (n = 4) and pressure-overloaded right (n = 5) ventricles of adult ferrets. hypertrophy was induced by pulmonary artery clipping for 30-45 days. under control conditions (3 mm [ca2+]o, 0.1 hz), the isometric twitch force of hypertrophied muscles was decreased by 75%, time to peak was increased by 30% and time to half-relaxation was increased by 50% compa ... | 1992 | 1535435 |
| endogenous arachidonic acid metabolism by calcium ionophore stimulated ferret lungs. effect of age, hypoxia. | we have studied the metabolism of endogenous arachidonic acid by isolated perfused lungs of ferrets when stimulated with calcium ionophore a23187 at two ages, neonatal (2- to 3-week-old) and adult (greater than 6 months). we have also determined the effect of hypoxia on lung metabolism of arachidonic acid in the two age groups. lungs were perfused with kreb's bicarbonate buffer in a recirculating system and eicosanoid production was stimulated by addition of a23187 (5 microm). eicosanoids produc ... | 1992 | 1538590 |
| proteoglycan secretory components of surface epithelial cells in postnatal ferret trachea. | | 1992 | 1541184 |
| effects of endothelin-1 on tracheal submucosal gland secretion and epithelial function in the ferret. | | 1992 | 1541210 |
| pituitary adenylate cyclase activating peptide: a novel vasoactive intestinal peptide-like neuropeptide in the gut. | pituitary adenylate cyclase activating peptide (pacap) is a vasoactive intestinal peptide (vip)-like hypothalamic peptide occurring in two forms, pacap-27 and the c-terminally extended pacap-38. the predicted rat and human pacap sequence is identical to the isolated ovine one. in the present study, the occurrence and distribution of pacap-like peptides were examined in the gut of several species by immunocytochemistry and immunochemistry using an antibody raised against pacap-27. pacap-like immu ... | 1992 | 1542417 |
| distemper vaccination in ferrets. | | 1992 | 1546441 |
| mouse model for pneumocystis carinii pneumonia that uses natural transmission to initiate infection. | animal models for pneumocystis carinii, for the most part, have been limited to immunosuppressed rats and ferrets, while a dependable mouse model has been more difficult to develop. a p. carinii mouse model has now been established with several strains of mice, including c3heb/fej, c3hen, balb/c, dba/2n, and balb/c nu/nu (athymic). in lieu of using invasive methods for initiating p. carinii infections, mice harboring p. carinii transmitted the disease to mice without latent infection via short-t ... | 1992 | 1548065 |
| development of high-affinity 5-ht3 receptor antagonists. 2. two novel tricyclic benzamides. | two new classes of potent 5-ht3 agents have been developed and examined as inhibitors of cytotoxic drug induced emesis in the ferret and dog. the absolute configuration of the most active molecules 10 and 18 have been determined by x-ray crystallography. these two compounds are more potent than known 5-ht3 receptor antagonists both in vivo and in vitro in blocking 5-ht3 receptor activation and preventing chemotherapeutic induced emesis. compared with 5-ht3 antagonists, such as gr 38032f, zacopri ... | 1992 | 1548679 |
| [effects of magnesium on early post-depolarization and trigger activity induced by cesium on purkinje fibers in ferrets]. | the effects of magnesium (mg) on afterdepolarisations and cesium-induced activity were studied in 15 preparations of ferret purkinje fibres. when the perfusion medium was enriched with mg to concentrations of 5 mm, the duration of the action potentials stopped increasing and the diastolic membrane potential was stabilised despite persistent exposure to cesium. a suppressor effect of mg on the high and low voltage early afterdepolarisations was observed which was significant at 2.2 mm (p less tha ... | 1992 | 1550438 |
| endocardial endothelium modulates myofilament ca2+ responsiveness in aequorin-loaded ferret myocardium. | the influence of selective removal of the endocardial endothelium (by a 1-second exposure to the detergent triton x-100, 0.5%) on myofilament ca2+ responsiveness and intracellular ca2+ transients was studied in ferret papillary muscles loaded with the ca(2+)-regulated bioluminescent indicator aequorin. the removal of endocardial endothelium produced three major effects: 1) a decrease in peak developed tension and an early onset in isometric relaxation without corresponding changes in the intrace ... | 1992 | 1551201 |
| role of transsarcolemmal ca2+ entry in the negative inotropic effect of nitrous oxide in isolated ferret myocardium. | the purpose of this study was to investigate the effects of nitrous oxide (n2o) on transsarcolemmal calcium influx in isolated ferret right ventricular myocardium. using a range of loading conditions, papillary muscles were equilibrated in 50% nitrogen (n2) or 50% n2o in oxygen in the presence and absence of ryanodine, a specific inhibitor of calcium release from the sarcoplasmic reticulum. after equilibration in 50% n2o or 50% n2 in oxygen, peak developed force, peak isotonic shortening, and ma ... | 1992 | 1554125 |
| comparative vaginal cytology of the estrous cycle of black-footed ferrets (mustela nigripes), siberian polecats (m. eversmanni), and domestic ferrets (m. putorius furo). | vaginal cytology and vulva size were used to characterize the reproductive cycle of female black-footed ferrets (mustela nigripes), siberian polecats (m. eversmanni), and domestic ferrets (m. putorius furo). emphasis was on black-footed ferrets because of the need to breed these critically endangered animals and on siberian polecats because of the close taxonomic relationship to black-footed ferrets. vaginal cytology of the 3 species of ferret is similar. proestrus was characterized by an increa ... | 1992 | 1554767 |
| malignant lymphoma in ferrets: clinical and pathological findings in 19 cases. | the clinical and pathological findings in 19 ferrets (mustela putorius furo) with malignant lymphoma are reviewed. peripubescent ferrets had rapidly progressive stage iv high grade immunoblastic or small non-cleaved cell lymphoma. adult ferrets had stage ii or iv low grade diffuse small lymphocytic (dsl) lymphoma, stage iv high grade small non-cleaved cell lymphoma, or stage iv high grade immunoblastic polymorphous (ibp) lymphoma. three ferrets had concurrent ibp and dsl lymphoma involving diffe ... | 1992 | 1556256 |
| eosinophilic gastroenteritis with splendore-hoeppli material in the ferret (mustela putorius furo). | eosinophilic gastroenteritis, focal or diffuse with eosinophilic infiltrations of the stomach or intestine, has been described in human beings, cats, dogs, and horses. in this paper, we describe infiltration of the gastrointestinal tract with eosinophils accompanied by a circulating eosinophilia in six ferrets (mustela putorius furo). clinical signs included chronic weight loss, anorexia, and diarrhea. the small intestines from five ferrets had diffuse infiltrates of eosinophils. this resulted i ... | 1992 | 1557863 |
| contraction of single vascular smooth muscle cells by phenylephrine at constant [ca2+]i. | the mechanism of alpha-adrenergic agonist-mediated force generation was investigated in single hyperpermeable vascular smooth muscle cells. by use of a previously described method, force was recorded from individual ferret aortic cells made hyperpermeable by exposure to saponin. when the cells were clamped at pca 7, addition of protein kinase m (pkm), the constitutively active form of protein kinase c (pkc), caused a sustained increase in force, which was reversible upon addition of the pkc pseu ... | 1992 | 1558185 |
| effect of ketamine hcl on norepinephrine disposition in isolated ferret ventricular myocardium. | the purpose of this study was to determine if ketamine altered the release or disposition of norepinephrine at adrenergic nerve terminals in isolated ferret myocardium. in superfused right ventricular strips, the effect of ketamine on norepinephrine release and uptake was determined. dihydroxyphenylglycol, the intraneuronally derived metabolite of norepinephrine, served as an index of neuronal uptake and was also measured in superfusate. pharmacological manipulation of selective aspects of adren ... | 1992 | 1560358 |
| interactions of ibuprofen with influenza infection and hyperammonemia in an animal model of reye's syndrome. | we have previously reported that a single meal of an arginine-free diet rapidly induces hyperammonemia in young ferrets and that aspirin administration in conjunction with influenza b infection and arginine-free diet results in clinical and biochemical alterations consistent with reye's syndrome. the objective of the present study was to test whether ibuprofen administration, either alone or in combination with influenza infection and arginine-free diet, produces a similar effect. two-mo-old fer ... | 1992 | 1561011 |
| distemper vaccination in ferrets. | | 1992 | 1561749 |
| sylvatic american trypanosomiasis in argentina. trypanosoma cruzi infection in mammals from the chaco forest in santiago del estero. | trypanosoma cruzi infection in sylvatic mammals of the quebracho woods of the eastern part of santiago del estero province, argentina, was studied from october 1984 to december 1987. 301 mammals of 20 different species were caught. t. cruzi, characterized biologically and biochemically, was isolated by xenodiagnosis from 23 of 72 (32%) didelphis albiventris opposums, 2/36 (5.5%) conepatus chinga skunks, and one ferret (galictis cuja). 53 opossum refuges were located and triatomine bugs were foun ... | 1992 | 1566301 |
| a ferret model of acute multifocal gastrointestinal infarction. | based on the demonstration of mural granulomatous vasculitis in crohn's disease, it was hypothesized that this vasculitis may account for the discontinuous pattern of lesions in this condition. accordingly, the present study investigated the histological changes produced by interruption of the submucosal and mucosal microcirculation in the ferret midgut. two techniques were used. first, up to 30 adjacent vasa recta were ligated using microsurgical techniques; this produced no evidence of ischemi ... | 1992 | 1568569 |
| periapical innervation of the ferret canine one year after pulpectomy. | previous studies have shown that, following removal of the dental pulp and its replacement with a filling material, the nerves in the periapical region proliferate within an area of chronic inflammation. this study examined these responses in the ferret in more detail, both quantitatively and in three dimensions, 12 months after pulpectomy which was followed by obturation with gutta percha and zinc oxide and eugenol sealer. the results were compared with the responses after three months. the bas ... | 1992 | 1573078 |
| effects of reduced external sodium concentration and multivalent cations on caffeine contractures in young ferret atrial trabeculae. | the characteristics of caffeine (1.25-80 mm) transient contractures have been examined in small atrial trabeculae (diameters 50-250 microns) isolated from young (1-1.5 months) ferret hearts. in the control medium, the half-saturation constant and the maximum contracture strength (at infinite caffeine concentration) were 37.8 +/- 10.2 mm and 0.9 +/- 0.2 kn.kg-1 (n = 11), respectively. the contractile response to caffeine was markedly enhanced following reduction of external sodium (70-0 mm). the ... | 1992 | 1581856 |
| c-terminal modifications of nonpeptide renin inhibitors: improved oral bioavailability via modification of physicochemical properties. | we describe the development of a series of soluble, potent, and bioavailable nonpeptide renin inhibitors. these inhibitors derived from a series of novel nonpeptide renin inhibitors which were recently identified in our laboratories, by alteration of the nature of the c-terminus (p2') of the molecules. introduction of basic substituents into modified hydroxyethylene dipeptide isosteres gave inhibitors with improved solubility as well as improved potency against human plasma renin. in addition, t ... | 1992 | 1588555 |
| mechanisms of intrinsic tone in ferret vascular smooth muscle. | 1. circular strips from ferret aorta were used to investigate the mechanism of the intrinsic basal tone. 2. determinations of stiffness using small sinusoidal length changes showed an abolition of both stiffness and force with cooling, but the temperature dependence of the change in active stiffness did not parallel that of force. at temperatures below 22 degrees c there appeared to be a relatively large population of attached, non-force-generating cross-bridges, indicating that separate mechani ... | 1992 | 1593466 |
| platelet-activating factor relaxes ferret tracheal smooth muscle and reduces transepithelial potential difference in vitro. | 1. the effects of platelet activating factor (paf) were examined on the smooth muscle tone, mucus volume, lysozyme and albumin outputs and potential difference (pd) across the ferret tracheal wall. 2. paf (0.1-10 microm) had no direct effect on mucus volume, lysozyme or albumin output from the ferret trachea. paf produced concentration-dependent relaxations of the tracheal smooth muscle and reductions in pd across the tracheal wall. there was no change in the histological appearance of the trach ... | 1992 | 1596685 |
| paf-induced muscarinic cholinoceptor hyperresponsiveness of ferret tracheal smooth muscle and gland secretion in vitro. | 1. the effects of exposure of the ferret trachea in vitro to platelet activating factor (paf) were examined on methacholine-induced smooth muscle contraction, mucus volume and lysozyme outputs, and albumin transport across the tracheal epithelium. 2. methacholine (0.1-30 microm) produced concentration-dependent increases in tracheal smooth muscle tone and mucus volume, lysozyme and albumin outputs from the trachea. 3. the concentration-response curves for methacholine-induced smooth muscle contr ... | 1992 | 1596686 |
| lymphatic imaging in experimental filariasis using magnetic resonance. | to evaluate acquired lymphatic abnormalities caused by filariasis, the authors examined the peripheral lymphatic system in normal ferrets and those chronically infected with brugia malayi using magnetic resonance imaging (mri). the findings were compared with previously obtained lymphangioscintigraphic (las) images in ferrets both with and without experimental filariasis. | 1992 | 1601619 |