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the behaviour in ferrets of two closely related clones of influenza virus of differing virulence for man.clones 7a and 64d of the recombinant influenza virus a/pr/8/34-a/england/939/69(h3n2) which are of different virulence for man as judged by clinical score (7a more virulent than 64d) showed similar differences in ferrets. with intranasal inoculation the approximate 50% minimal infectious doses of both clones were similar (between 10(0) and 10(2) eid(50)) as were their titres in nasal washes 24 h after inoculation and the histologically evident damage they caused in the nasal turbinates. however, ...19761268040
effects of antibodies to oestrogens on implantation in ferrets. 19761271348
pathologic changes in ferrets exposed to pseudorabies virus.ferrets experimentally infected by various routes with pseudorabies virus were examined for gross and microscopic lesions. nonsuppurative meningoencephalomyelitis, as well as visceral lesions, occurred. the incubation period seemed related to the viral dose and to the distance between the inoculation site and the central nervous system. the distribution of the lesions in the central nervous system appeared to be closely related to the peripheral nerve pathways from the inoculation sites. other f ...19761275345
production of highly cross-reactive hemagglutination-inhibiting influenza antibodies in ferrets.ferrets were sequentially infected at time intervals of 3 weeks with different influenza virus a strains. it was found that secondary infection can result in the appearance of antibodies highly cross-reacting with a virus strain closely related to the strain of first infection. such highly cross-reacting antibodies were designated as hcr antibodies. evidence is presented that hcr antibodies were not antineuraminidase antibodies and, in addition, were not specifically oriented to the strain with ...19761278996
haemagglutination profiles of helicobacter species that cause gastritis in man and animals.thirty-five helicobacter pylori isolates, 21 h. mustelae isolates and four strains of h. felis were compared for their ability to agglutinate red blood cells (rbcs). isolates were examined in a slide haemagglutination assay with rbcs from 11 animal species, including rodents, carnivores and primates, as well as man. rbcs were agglutinated by 65-90% of h. mustelae isolates and 16-57% of h. pylori isolates. treatment of h. mustelae with pronase and heat inhibited haemagglutination (ha) whereas hea ...19921279175
origin and fate of fetuin-containing neurons in the developing neocortex of the fetal sheep.the development of the neocortex has previously been extensively studied in carnivores (cat and ferret), rodents (rat and mouse) and primates (monkey and human). in these species, it has been shown that the initial population of cells migrating from the ventricular zone forms the primordial plexiform layer. this is subsequently split into marginal zone and subplate zone by the insertion of later-migrating cells into the primordial plexiform layer, to form the cortical plate proper. many of the c ...19921280010
nitric oxide synthase in ferret brain: localization and characterization.1. in the present study, we have investigated the distribution of nitric oxide synthase in the ferret brain. nitric oxide synthase was determined biochemically and immunochemically. 2. in the rat brain, the highest nitric oxide synthase activity has been detected in the cerebellum. however, in the ferret brain, the highest activity was found in the striatum and the lowest in the cerebellum and cerebral cortex. the enzymatic activity was localized predominantly in the cytosolic fractions, it was ...19921282076
cyclic gmp inhibits the inotropic response to alpha 1-adrenoceptors in the papillary muscle of the ferret.the physiological role of cyclic gmp in the heart remains controversial. in the present study we investigated the interaction between a number of agents known to increase the level of cyclic gmp in the myocardium and alpha 1-adrenergic stimulation in isolated preparations of cardiac papillary muscle in the ferret. inotropic responses to the cumulative addition of phenylephrine were measured in papillary muscles of the ferret in the absence and presence of 1 microm sodium nitroprusside, 1 microm ...19921282377
ventricular function and calcium handling during ischemia.ischemia-induced ventricular dysfunction has been shown to be associated with increased diastolic and systolic intracellular concentrations of free, ionized calcium ([ca2+]i). the present study was designed to determine the effects of the calcium antagonist nisoldipine on the relationship between [ca2+]i and left ventricular contraction and relaxation during ischemia and reperfusion on a beat-to-beat basis. nine isovolumic coronary-perfused ferret hearts were made globally ischemic for 3 min and ...19921282612
photoperiod modulates pubertal shifts in behavioral responsiveness to testosterone.this study examined the effect of photoperiod on pubertal maturation of steroid-dependent reproductive behaviors in male european ferrets (mustela putorius furo). in the first experiment, levels of neck gripping, mounting, and pelvic thrusting in gonadally intact prepubertal (pre) ferrets were compared with those of adults that had undergone puberty either while housed in short days (8 hr light/16 hr darkness per day; sd), or after transfer from sd to long days (18 hr light/6 hr darkness per day ...19921286204
multiple motor pathways to single smooth muscle cells in the ferret trachea.1. we investigated the distribution and characteristics of motor pathways to individual smooth muscle cells activated by electrical stimulation of either, single nerves which enter the tracheal plexus (inlet nerves), or a longitudinal nerve trunk (lnt) located near the entrance of an inlet nerve into the plexus. excitatory junction potentials (ejps) were recorded using intracellular microelectrodes as an index of smooth muscle cell activation. in all experiments ejps were completely blocked by t ...19921293288
two components of the pineal organ in the mink (mustela vison): their structural similarity to submammalian pineal complexes and calcification.the pineal complex in the mink (mustela vison) consists of a larger ventral and a smaller dorsal pineal. both organs contain pinealocytes, neurons, glial cells, nerve fibers and synapses in an organization characteristic of nervous tissue. the cellular elements are arranged circularly around strait lumina. these lumina correspond to the photoreceptor spaces of submammalian pineals. a 9 + 0-type cilium marks the receptory pole of the pinealocytes which may form an inner-segment-like dendrite term ...19921295547
[the fever reaction of the polecat mustela putorius x mustela putorius furo to a bacterial pyrogen: the hypo- and hyperthermic phases].it has been demonstrated that the ferret (mustela putorius x mustela putorius furo) responds to intramuscular injection of salmonella typhi lipopolysaccharide (30 ng/kg-100 micrograms/kg) by biphasic change in the body temperature (tb): the initial decrease in the latter is followed by hyperthermia. maximum rise in tb (1.6 +/- 0.1 degrees c) was observed after the injection of lipopolysaccharide in the highest dose. rabbit leucocytic pyrogen/interleukin-1 (1 ml from 3.5 x 10(7) peritoneal phagoc ...19921302417
development of high-affinity 5-ht3 receptor antagonists. 1. initial structure-activity relationship of novel benzamides.this report describes the development of novel benzamides which are orally active, highly potent, specific antagonists of 5-ht3 receptors. described in this first report are the structure-activity relationships that led to novel structures with improved potency and selectivity. from this series of compounds, (s)-28 was identified and selected for further evaluation as a 5-ht3 receptor antagonist. compared with 5-ht3 antagonists such as gr 38032f, brl 43694, and metoclopramide, (s)-28 was most ac ...19921312602
characterization of a new avian-like influenza a virus from horses in china.in march 1989 a severe outbreak of respiratory disease occurred in horses in the jilin and heilongjiang provinces of northeast china that caused up to 20% mortality in some herds. an influenza virus of the h3n8 subtype was isolated from the infected animals and was antigenically and molecularly distinguishable from the equine 2 (h3n8) viruses currently circulating in the world. the reference strain a/equine/jilin/1/89 (h3n8) was most closely related to avian h3n8 influenza viruses. sequence comp ...19921314452
cellular mechanisms that control pulmonary vascular tone during hypoxia and normoxia. possible role of ca2+atpases.we investigated cellular mechanisms that may be involved in controlling cytosol calcium and pulmonary artery pressure during hypoxia and normoxia in isolated blood-perfused ferret lungs. alveolar hypoxia in ferret lungs causes an active increase in pulmonary vascular resistance. hypoxic pulmonary vasoconstriction directly correlates with extracellular calcium ([ca2+]o), and the absence of [ca2+]o in the perfusate markedly attenuates the hypoxemia-induced pulmonary vasoconstriction. alveolar hypo ...19921317692
are all 5-ht3 receptor antagonists the same?a number of 5-ht3 receptor antagonists are currently in clinical development as antiemetics. in this paper we focus on two of these antagonists, granisetron and ondansetron, and compare their antimetic activity against cisplatin (10 mg/kg i.v.)- or whole body x-irradiation (200 rads)-induced emesis in the conscious ferret. the results presented here have been discussed in the light of the recently published literature. our data suggest that in comparison to ondansetron, granisetron is a more pot ...19921320915
contractile agonists activate voltage-dependent calcium channels in airway smooth muscle cells.to determine whether agents that cause contraction of airway smooth muscle affect sarcolemmal calcium channel activity, unitary calcium channel currents (using ba2+ as the charge carrier) were recorded in on-cell configuration from acutely dissociated (dog, pig, and ferret) and cultured (human) airway smooth muscle cells. addition of the contractile agonists methacholine or bradykinin increased the open-state probability of the large-conductance calcium channel 37.2- and 45-fold, respectively. t ...19921322035
endothelin reverses the effects of acidosis on the intracellular ca2+ transient and contractility in ferret myocardium.endothelin may play an important role in modulating myocardial contractility under certain pathophysiological conditions. to determine whether endothelin beneficially modulates myocardial contractility in the common clinical condition of acidosis, we compared the effects of endothelin-1 on intracellular ca2+ transients and isometric contractions under normal (extracellular ph [ph(o)] 7.4) and acidotic (ph(o) 6.4) conditions in ferret papillary muscles (n = 33) loaded with the ca(2+)-regulated bi ...19921323435
morphine 6-glucuronide: a metabolite of morphine with greater emetic potency than morphine in the ferret.1. the emetic potencies of morphine and its metabolite morphine 6-glucuronide have been determined in the ferret by constructing dose-response curves for mean total retches and vomits for subcutaneous doses of 0.05 mg kg-1 to 5 mg kg-1. morphine 6-glucuronide induced retching and vomiting at lower doses than morphine and at a maximal dose induced more retching and vomiting than morphine. 2. the emesis induced by both morphine and morphine 6-glucuronide was abolished by the preadministration of n ...19921324067
differential inotropic effects of flosequinan in ventricular muscle from normal ferrets versus patients with end-stage heart failure.1. in right ventricular papillary muscles from control ferrets, flosequinan (10(-7)-10(-4) m) produced a concentration-dependent positive inotropic effect (10(-5) m = 153 +/- 24, 10(-4) m = 198 +/- 44% increase in isometric tension; control tension = 100%; n = 11) associated with a corresponding increase in amplitude of the intracellular ca2+ ([ca2+]i) transient recorded with aequorin (10(-5) m = 133 +/- 11, 10(-4) m = 187 +/- 36% increase in [ca2+]i transient; n = 11). 2. the positive inotropic ...19921324072
the neuropharmacology of loperamide-induced emesis in the ferret: the role of the area postrema, vagus, opiate and 5-ht3 receptors.loperamide, an opiate receptor agonist, commonly used in the treatment of diarrhoea, reliably induced emesis in the ferret, when given subcutaneously. the response latency was short (less than 10 min) and the emesis lasted for approx 70 min. the dose-response curve for the emetic response was "bell-shaped" and all animals responded at 0.5 mg/kg but none at 5 mg/kg (s.c.). the response was unaffected by dopamine d2 receptor antagonism (domperidone 1.0 mg/kg, s.c.) or 5-ht3 receptor antagonism (gr ...19921326727
expression of na(+)-k(+)-atpase alpha 1- and alpha 3-isoforms in adult and neonatal ferret hearts.we have demonstrated previously that in adult ferret heart two alpha-subunit isoforms of the na(+)-k(+)-atpase, alpha(+) and alpha, are expressed. the alpha(+)-isoform may comprise either alpha 2-, or alpha 3-, or both isoforms. the present studies further characterize the alpha(+)-isoform. the alpha(+)-isoform of ferret heart did not react with an alpha 2-specific monoclonal antibody, but rather with two different alpha 3-specific polyclonal antibodies. electrophoretic mobility of the alpha(+)- ...19921332511
relationship between vomiting and taste aversion learning in the ferret: studies with ionizing radiation, lithium chloride, and amphetamine.the relationship between emesis and taste aversion learning was studied in ferrets (mustela putorius furo) following exposure to ionizing radiation (50-200 cgy) or injection of lithium chloride (1.5-3.0 meq/kg, ip). when 10% sucrose or 0.1% saccharin was used as the conditioned stimulus, neither unconditioned stimulus produced a taste aversion, even when vomiting was produced by the stimulus (experiments 1 and 2). when a canned cat food was used as the conditioned stimulus, lithium chloride, but ...19921333765
antibodies, implantation and embryo survival.the diverse strategies adopted among species for the maintenance of luteal function converge to meet the indispensable requirement for this hormone particularly at the time of onset of implantation. what has emerged from immunization studies is the difference that exists between various species in the effects of progesterone depletion. the findings affirm the uterus as a primary site of progesterone action in the preimplantation period of gestation in the mouse, whereas in the hamster the positi ...19921338606
inhibition of cisplatin-induced emesis in ferrets by the non-nmda receptor antagonists nbqx and cnqx.the excitatory amino acid (eaa) receptor antagonists, 2,3-dihydroxy-6-nitro-7-sulphamoylbenzo(f)quinoxaline (nbqx) and 6-cyano-7-nitroquinoxaline-2,3-dione (cnqx), which preferentially block non-n-methyl-d-aspartate (non-nmda) subtypes of eaa receptors, effectively inhibit cisplatin-induced emesis in ferrets. a high dose of cisplatin (10 mg/kg i.v.) was used which induced emesis in all saline-treated control ferrets. at 10 mg/kg i.v., nbqx totally prevented cisplatin-induced emesis in 5 of 6 fer ...19921350077
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 ...19921350209
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 ...19921351408
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 ...19921352541
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 ...19921354537
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 ...19921354943
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 ...19921355025
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 ...19921355036
nicotine-induced airway smooth muscle contraction: neural mechanisms involving the airway epithelium. functional and histologic studies in vitro.to assess the mechanism of and the role of the epithelium in nicotine-induced bronchoconstriction in vitro, we performed a combined functional and histologic study. functional study: we suspended tracheal strips or rings from 16 ferrets (1124 +/- 561 g, mean +/- sd) in organ baths. alternate tracheal strips had their epithelium removed. dose-response curves to acetylcholine (ach) and nicotine were established for pairs of tissues with and without epithelium, each pair receiving only one dose of ...20171355677
[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 ...19921363741
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 ...19921370432
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%) ...19921370750
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 ...19921373130
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 ...19921375611
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 ...19921380440
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 ...19921381730
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, ...19921386078
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 ...19921386173
pharmacology and preclinical antiemetic properties of ondansetron.ondansetron (gr 38032) has potent and highly selective antagonist properties at the 5-hydroxytryptamine (5-ht, serotonin) 5-ht3 receptor. the selectivity ratio for ondansetron on 5-ht3 receptors compared with actions on other neurotransmitter receptor types is greater than 1,000. the antiemetic properties of ondansetron have been determined in ferrets against the nausea and vomiting induced by cisplatin, cyclophosphamide, and whole-body radiation. ondansetron (intravenous 0.01 to 0.1 mg/kg or su ...19921387245
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.19921394369
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 ...19921394873
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 ...19921399980
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 ...19921401254
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 ...19921401334
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 ...19921402023
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 ...19921404407
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 ...19921409003
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 ...19921409711
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 ...19921409957
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 ...19921411510
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 ...19921413877
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 ...19921413993
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 ...19921415520
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 ...19921415707
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.19921423430
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 ...19921423931
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. ...19921425931
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 ...19921430318
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 ...19921430324
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 ...19921430336
a nuclear magnetic resonance investigation of the upper airways in ferrets. i. effects of histamine and methacholine.alterations induced in the upper airways of ferrets by intranasal provocation with methacholine (mc) and histamine (hs) were monitored using proton magnetic resonance imaging (mri) and spin-spin relaxation rate (r2) measurements. both mc and hs cause a significant increase in the mri signal intensity and a decrease in r2 in the nasal turbinates. a dose-dependent response is observed for 20 to 315 nmol of hs, with a maximum increase in intensity of ca. 50% occurring above 80 nmol. a single unilat ...19921435207
a nuclear magnetic resonance investigation of the upper airways in ferrets. ii. contrast-enhanced imaging to distinguish vascular from other nasal fluids.proton magnetic resonance imaging (mri), used in conjunction with the intravascular contrast agent albumin-(gd-dtpa), provides a means to distinguish vascular fluids from other nasal fluids in the upper airways. ferrets were given an intravenous dose of albumin-(gd-dtpa) followed by an intranasal challenge with either histamine (hs) or methacholine (mc). an observed increase in image intensity indicates that hs and mc both cause an accumulation of fluids in the nasal turbinate region. the mri da ...19921435208
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 ...19921437046
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 ...19921438953
aleutian disease in ferrets. 19921441131
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 ...19921442125
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 ...19921443212
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 ...19921446138
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 ...19921446140
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 ...19921447097
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 ...19921452070
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 ...19921452292
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 ...19921459188
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 ...19921467196
transfusions in exotic species.there has been a considerable increase in the popularity of exotic species as pets, particularly, birds and domestic ferrets. blood transfusions in birds and ferrets are discussed. there is a brief review of hematology, blood collection techniques, the selection and maintenance of donor animals, and the mechanics of transfusion. because of the marked differences between birds and mammals, attention is given to avian anatomy and physiology as it applies clinically to blood transfusions.19921472773
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) ...19921474498
responses of sagittally aligned purkinje cells during perturbed locomotion: relation of climbing fiber activation to simple spike modulation.1. the purpose of these experiments is to test the hypothesis that the synchronous activation of sagittally aligned purkinje cells by a physiologically relevant stimulus is associated with an increase in the simple spike responses of the same neurons. 2. this hypothesis was tested using a perturbed locomotion paradigm in decerebrate locomoting ferrets. the responses of 3-5 sagittally aligned purkinje cells were recorded simultaneously in response to the intermittent perturbation of the forelimb ...19921479447
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 ...19921483354
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 ...19921483793
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.19921483915
translaminar deficits in the retinae of albinos.the central retina in albino mammals is poorly developed. there is a general reduction in ganglion cell density compared with the normal animal, and there are irregularities in the center to periphery gradient in ganglion cell density. it is not known whether, and if so to what extent, this abnormality is associated with deficits in other retinal layers. in this study the distribution of cells in the ganglion cell layer has been determined in horizontally sectioned eyes from pigmented and albino ...19921484126
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 ...19921484363
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 ...19921485177
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 ...19921488775
role of pulmonary blood flow in postpneumonectomy lung growth.to study the influence of blood flow on postpneumonectomy lung growth, we banded the left caudal lobe pulmonary artery of eight ferrets in such a way that blood flow to the caudal lobe did not increase when the right lung was excised 1 wk later. the fraction of the cardiac output received by the right lung before pneumonectomy was therefore directed entirely to the left cranial lobe. three weeks after pneumonectomy the weight, volume, and protein and dna contents of the two lobes of the left lun ...19921490957
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 ...19921490978
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 ...19921491611
distemper vaccination in ferrets. 19921496764
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 ...19921502837
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 ...19921505478
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.19921506255
emesis in ferrets following exposure to different types of radiation: a dose-response study.ferrets were exposed to gamma rays (60co), fission neutrons, high-energy electrons (18.5 mev) or iron particles (56fe, 600 mev/amu) in order to establish the dose-response relationships for emesis following exposure to different types of radiation. the results showed that the mean effective doses (ed50s) for iron particles (35 cgy) and neutrons (40 cgy) were similar. high-energy electrons were the least effective radiation, with an ed50 of 138 cgy. gamma rays, with an ed50 of 95 cgy, showed an i ...19921510644
beta-carotene, retinol and retinyl ester concentrations in serum and selected tissues of ferrets fed beta-carotene.the concentrations of beta-carotene, retinol and retinyl esters in serum and selected tissues of ferrets fed diets supplemented with beta-carotene (80 micrograms/g wet diet) for 3 wk were determined. the initial concentration of serum beta-carotene was 0.011 +/- 0.006 mumol/l (mean +/- sem); at the end of the experimental period it was 5.75 +/- 1.60 mumol/l. no significant differences in serum retinol and total retinyl esters were observed between beta-carotene-fed and control ferrets that had b ...19921512640
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 ...19921515583
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 ...19921516644
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