SEARCH · Search PubMed

Results for “Ferrets”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources

PubMedDate not supplied

Genetic diversity and fitness in black-footed ferrets before and during a bottleneck.

The black-footed ferret (Mustela nigripes) is an endangered North American carnivore that underwent a well-documented population bottleneck in the mid-1980s. To better understand the effects of a bottleneck on a free-ranging carnivore population, we used 24 microsatellite loci to compare genetic diversity before versus during the bottleneck, and compare the last wild population to two historical populations. We also compared genetic diversity in black-footed ferrets to that of two sibling species, the steppe polecat (Mustela eversmanni) and the European polecat (Mustela putorius). Black-footed ferrets during the bottleneck had less genetic diversity than steppe polecats. The three black-footed ferret populations were well differentiated (F(ST) = 0.57 +/- 0.15; mean +/- SE). We attributed the decrease in genetic diversity in black-footed ferrets to localized extinction of these genetically distinct subpopulations and to the bottleneck in the surviving subpopulation. Although genetic diversity decreased, female fecundity and juvenile survival were not affected by the population bottleneck.

Animals↗

PubMed1983

Arginine requirement and ammonia toxicity in ferrets.

Hyperammonemia of varying magnitude was produced in young, male ferrets by either feeding them a purified diet containing low amounts of arginine or by intraperitoneal injections of jackbean urease. The responses were different depending on the method used to produce hyperammonemia. When hyperammonemia was produced by feeding a synthetic diet containing less than 0.2% arginine, ferrets developed encephalopathy soon after eating the diet and recovered after 4 hours. Although intraperitoneal injection of jackbean urease (100 IU/kg) caused severe hyperammonemia, ferrets did not become sick. Ferrets injected with 450 IU/kg of jackbean urease developed hyperammonemia but developed encephalopathy only after 15 hours. Ferrets showed remarkable capacity to tolerate elevated blood ammonia levels.

Ammonia↗

PubMed1989

Dietary beta-carotene absorption and metabolism in ferrets and rats.

The ability of the ferret (Mustela putorius furo) to absorb dietary beta-carotene was studied to determine its appropriateness as a laboratory animal model for studies on beta-carotene metabolism. At baseline, the mean serum beta-carotene level in ferrets was 0.6 micrograms/dl and no beta-carotene was present in liver or adipose tissue. After the ferrets were fed 4 or 20 mg of beta-carotene/kg body wt daily for 2 wk, serum levels were 15.3 and 41.5 micrograms/dl, liver values were 0.9 and 4.1 micrograms/g and adipose tissue values were 0.1 and 0.2 microgram/g of beta-carotene, respectively. Thus, like humans, ferrets are able to absorb dietary beta-carotene intact. Further, these animals can store quantifiable amounts of dietary beta-carotene in their liver and, to a lesser extent, in adipose tissue. In contrast, serum beta-carotene levels in rats fed the two levels of beta-carotene were very low (0.5 to 0.6 microgram/dl) and no beta-carotene was found in liver or adipose tissue. Thus, the ferret is a more appropriate animal model for studying the intestinal absorption of beta-carotene and its storage and metabolism in body tissues.

Adipose Tissue↗

PubMed2000

Tissue distribution of lycopene in ferrets and rats after lycopene supplementation.

To determine lycopene uptake and tissue distribution in ferrets (Mustela putorius furo) and F344 rats, we supplemented orally 4.6 mg/(kg body wt.d) lycopene in a tomato oleoresin-corn oil mixture (experimental groups). After 9 wk of supplementation, the animals were killed and blood and organs were collected. Plasma and tissue carotenoids were extracted and measured using HPLC. Mean concentrations of lycopene (nmol/kg wet tissue) in saponified tissues of ferrets were as follows: liver 933, intestine 73, prostate 12.7 and stomach 9.3. Levels of lycopene (nmol/kg wet tissue) in saponified tissue of rats were as follows: liver 14213, intestine 3125, stomach 78.6, prostate 24 and testis 3.9. When these organs were extracted without saponification, the lycopene levels were lower, except for rat testis. All-trans-lycopene was the predominant isomer found in tomato oleoresin and in the majority of rat tissues, whereas cis-lycopenes were predominant in rat prostate and plasma. This pattern was reversed in ferrets. The results show the following: 1) lycopene from tomato oleoresin is absorbed and stored primarily in the liver of both animals; 2) saponification generally improves the extraction of lycopene from most tissues of both animals; 3) cis-lycopene and all-trans-lycopene are the predominant isomers in ferret and rat tissues, respectively; and 4) rats absorb lycopene more effectively than ferrets.

Administration, Oral↗

PubMed2004

Alpha-tocopherol and ascorbic acid decrease the production of beta-apo-carotenals and increase the formation of retinoids from beta-carotene in the lung tissues of cigarette smoke-exposed ferrets in vitro.

Previously, we found that exposing ferrets to cigarette smoke enhanced oxidative excentric cleavage of beta-carotene. In the present study, we examined whether alpha-tocopherol, ascorbic acid, or the two combined can prevent smoke-altered beta-carotene metabolism. In vitro incubation of beta-carotene (10 micro mol/L) with lung postnuclear fractions from ferrets exposed to cigarette smoke was carried out in the absence or presence of alpha-tocopherol (50 micro mol/L), ascorbic acid (10 or 50 micro mol/L), or both vitamins to evaluate their effects on the production of beta-apo-carotenals and retinoids from beta-carotene. The oxidative cleavage metabolites of beta-carotene, beta-apo-carotenals (beta-apo-14', beta-apo-12', beta-apo-10', and beta-apo-8'), retinoic acid (RA), and retinal were analyzed by HPLC. We found that the smoke-enhanced production of individual beta-apo-carotenals was significantly decreased by 36-77% when alpha-tocopherol (50 micro mol/L) and ascorbic acid (50 micro mol/L) were added together to the incubation mixture. alpha-Tocopherol alone had a modest effect. Ascorbic acid in the presence of alpha-tocopherol inhibited the production of beta-apo-carotenals in a dose-dependent manner, although ascorbic acid alone had no effect. In contrast, the production of RA and retinal among smoke-exposed ferrets was substantially increased ( approximately 3-fold, P < 0.05) when both alpha-tocopherol and ascorbic acid were added to the incubation mixtures. However, when ascorbic acid or alpha-tocopherol alone was added, the production of RA among smoke-exposed ferrets increased only modestly (80%, P < 0.05) and did not differ from the RA levels in control ferrets. In conclusion, these data indicate that alpha-tocopherol and ascorbic acid may act synergistically in preventing the enhanced oxidative excentric cleavage of beta-carotene induced by smoking exposure, thereby facilitating the conversion of beta-carotene into RA and retinal.

Analysis of Variance↗

PubMed2003

Developmental capacity of ferret embryos by nuclear transfer using G0/G1-phase fetal fibroblasts.

With the ultimate goal of establishing experimental protocols necessary for cloning ferrets, the present study has established parameters for the reconstruction of ferret embryos by nuclear transfer (NT) using G0/G1-phase donor fetal fibroblasts. Cumulus-oocyte complexes were harvested from superovulated ferrets and cultured in maturation medium for 24 h. Matured oocytes were then enucleated and injected with the fibroblast nuclei derived from 14-16-h serum-starved cells. Reconstructed embryos were then activated by a combination of electric pulses and chemical stimulations. Subsequently, the reconstructed and activated embryos were either cultured in vitro or transferred to pseudopregnant ferrets to evaluate their developmental capacity in vitro and in vivo. Our results demonstrated that 56.3% of reconstructed embryos (n = 187) cleaved, while 26.0% and 17.6% developed to morula and blastocyst phases in vitro, respectively. The blastocysts derived from NT embryos demonstrated normal morphology by differentially staining as compared to normal blastocysts developed in vivo following fertilization. In vivo developmental studies at 21 days posttransplantation demonstrated 8.8% of reconstructed embryos (n = 91) implanted into the uterine lining of recipients, while 3.3% formed fetuses. However, reconstructed embryos (n = 387) failed to develop to term (42 days). These results demonstrate donor nuclei of G0/G1-phase fetal fibroblast cells can be reprogrammed to support the development of reconstructed ferret embryos in vitro and in vivo; however, a significant third-trimester block occurs preventing full-term development.

Animals↗

PubMed1982

Is estrogen required for implantation in the ferret?

A series of experiments was designed to further test the hypothesis that ferret corpora lutea synthesize and secrete estrogen between Days 6 and 8 of pregnancy, and that this estrogen is required to initiate implantation of blastocysts on Day 12. Corpora lutea, removed on Day 8 of pregnancy contained significant quantities of testosterone. Incubation of aliquots of the same luteal tissue for 4 h significantly elevated estrogen levels above those of nonincubated controls. Peripheral plasma estrogen levels exhibited a slight increase on Day 8 over those observed on Day 6 of pregnancy (7.9 +/- 3.4 vs. 4.1 +/- 1.1 pg/ml). However, continuous release of estradiol from Days 6-8 from two different sizes of Silastic capsules failed to induce implantation in ovariectomized-progesterone treated ferrets, whereas this same treatment was compatible with nidation in intact ferrets. Administration of the aromatase inhibitor, androsta-1,4,6-triene-3,17-dione (ATD) on Days 5-8 of pregnancy prevented implantation of blastocysts on Day 13. Simultaneous administration of estradiol and ATD failed to reverse the inhibitory effect of ATD. Results of this study confirm that luteal tissue of ferrets possesses at least one aromatizable androgen which is converted to estrogen under physiological conditions. However the data do not support the hypothesis that estrogen is required for implantation in the ferret.

Androstatrienes↗

PubMed1984

Hormonal correlates of photoperiod-induced puberty in a reflex ovulator, the female ferret (Mustela furo).

In an attempt to develop an animal model wherein the pubertal process could be initiated or accelerated by a readily controlled, noninvasive, external signal, this study examined sexual development of the female ferret, a photoperiodic, reflex ovulator. These animals exhibit signs of precocious sexual maturation within 6 wk of exposure to a stimulatory, long-day photoperiod at 15 wk of age. In the first study, females matured under a long-day stimulus were allowed to mate with a fertile male ferret. All six females ovulated after mating, and three of six became pregnant and successfully delivered and reared litters, demonstrating that vulvar edema induced by long days reflected the onset of true precocious sexual maturation. The second study attempted to determine the endocrine basis of this photoperiod-induced puberty. Immature ferrets were either left intact or were ovariectomized at 13 wk of age. These females either remained untreated or immediately received an estradiol implant. Controls in each group remained in short days, and others were transferred to stimulatory long days at 16 wk of age. Results indicated that immature ferrets exhibited a rise in plasma luteinizing hormone (LH) upon ovariectomy, and that the extradiol implant was an effective negative feedback signal for the duration of the study in animals in short days. In contrast, females in long days exhibited an "escape" from LH inhibition by the steroid implant at the same age at which the intact females in long days were beginning to mature. These data suggest the young ferret exhibits a high sensitivity to estradiol negative feedback which is decreased in response to a stimulatory photoperiod, and which decrease is coincident with sexual maturation in intact animals under the same conditions.

Animals↗

PubMed1997

Sexually dimorphic activation of midbrain tyrosine hydroxylase neurons after mating or exposure to chemosensory cues in the ferret.

Mating with intromission induces a prolonged preovulatory LH surge in the estrous female ferret but inhibits LH secretion in the male. We used the dual immunocytochemical localization of Fos (as a marker of neural activation) and tyrosine hydroxylase (TH) to determine whether neurons containing norepinephrine or other catecholamines are activated after mating. Breeding male ferrets were allowed to intromit with estrous females; both animals were perfused 90 min after the onset of intromission. Other male and female ferrets were perfused 90 min after being placed in a cage in which an opposite-sex ferret in breeding condition had previously been housed for 48 h. Control ferrets of each sex were perfused 90 min after being placed alone in a clean testing cage. Mating with intromission significantly augmented the percentage of TH-immunoreactive (TH-IR) neurons colabeled with nuclear Fos-like immunoreactivity (Fos-IR) in both the A6 and the rostral A2 midbrain catecholamine cell groups in females, but not males. Exposure to chemosensory cues alone also increased the percentage of Fos-IR TH neurons in the rostral A2, but not the A6, cell group in females. Chemosensory cues alone did not affect the percentage of double-labeled neurons in either cell group in males. These activated midbrain TH-IR neurons are most likely noradrenergic, and their activation in estrous females may facilitate the mediobasal hypothalamic release of LHRH required for the preovulatory LH surge. In both sexes, mating with intromission, but not chemosensory cues alone, augmented the percentage of periglomerular TH-IR neurons in the main olfactory bulb (MOB) that were colabeled with Fos-IR. These activated TH-IR neurons in the MOB are most likely dopaminergic. Their role in the neural response to mating is currently unknown.

Animals↗

PubMed1998

Sex difference and testosterone modulation of pheromone-induced NeuronalFos in the Ferret's main olfactory bulb and hypothalamus.

A carnivore, the ferret possesses a vomeronasal organ--accessory olfactory bulb (VNO-AOB) projection to the hypothalamus; however, little is known about its function. Pheromones in soiled bedding from estrous female ferrets or an artificial peppermint odor significantly augmented nuclear Fos protein immunoreactivity (Fos-IR), a marker of neural activation, in several main olfactory bulb (MOB) sites but not in the AOB of gonadectomized male and females. Testosterone propionate (TP) significantly augmented the MOB's neuronal Fos responses to estrous females' pheromones, but not to peppermint. Estrous odors, but not peppermint, also augmented neuronal Fos-IR in the medial preoptic area (mPOA) of female, but not male, subjects. Pheromones in soiled bedding from breeding male ferrets significantly augmented neuronal Fos-IR in the MOB and in the medial amygdala of gonadectomized, TP-treated male and female subjects. Again, male pheromones failed to influence neuronal Fos-IR in the AOB of either sex, and only females showed significant increases in neuronal Fos-IR in the lateral aspect of the ventromedial nucleus and mPOA. These results point to an essential role among higher mammals of the main olfactory epithelium-MOB projection to the hypothalamus in detecting and processing pheromones. Gonadectomized ferrets showed significant increases in sniffing behavior when placed on either female or male bedding. This occurred regardless of whether they had received TP or oil vehicle, suggesting that testosterone's facilitation of neuronal Fos responses to estrous females' odors in the MOB of both sexes cannot be attributed to increased scent gathering. Androgen receptor-IR was present in the MOB granule cell layer of male and female ferrets, raising the possibility that testosterone acts directly on these cells to augment their responsiveness to pheromones.

Animals↗

PubMed1994

Myocardial salvage efficacy of the thromboxane receptor antagonist ifetroban in ferrets and dogs.

The effects of the thromboxane A2 (TXA2)/prostaglandin endoperoxide (TP) receptor antagonist ifetroban (BMS-180291) on infarct size (IS) resulting from coronary occlusion/reperfusion was determined in anesthetized dogs and ferrets. In dogs, ifetroban (1 + 1 mg/kg/h, intravenously, i.v.) or vehicle administration was initiated 10 min before left circumflex coronary artery (LCX) occlusion. In ferrets, the left anterior descending coronary artery (LAD) was occluded; after 75 min, a continuous infusion of ifetroban (0.3 + 0.3 mg/kg/h i.v.) or vehicle was started. After 90-min ischemia in both species, the LCX or LAD occlusion was released; reperfusion was continued for 5 h, at which time IS was determined. Regional myocardial blood flow (RMBF) before and during occlusion and during reperfusion were measured with radioactive microspheres. Ifetroban significantly decreased the extent of infarction to 39 +/- 5% of the area at risk (AAR) from 64 +/- 5% in dogs and to 15 +/- 2% of the left ventricle as compared with a control of 22 +/- 2% in ferrets. The protective effect of ifetroban in both species occurred with no increase in collateral BF or treatment-related alterations in peripheral hemodynamic status. Ifetroban, at the doses that reduced IS in ferrets, inhibited 99% of platelet TP receptors throughout the experiment, as measured by inhibition of the ex vivo platelet shape change response to U-46,619, a TP receptor agonist. Thus, doses of ifetroban causing profound TP receptor blockade also salvaged jeopardized myocardium in dogs and ferrets without changing collateral BF or peripheral hemodynamics.

Animals↗

PubMed1983

The similar interaction of ferret alveolar macrophages with influenza virus strains of differing virulence at normal and pyrexial temperatures.

The possibility that ferret lung macrophages may be one factor operating in vivo to prevent infection of susceptible alveolar cells (as demonstrated by organ cultures) by both virulent and attenuated strains of influenza virus has been investigated. Phagocytosis of four strains of influenza virus [A/PR/8/34 (H1N1) and clone 64d (attenuated for ferrets) and clones 64c and 7a (virulent for ferrets) of the recombinant virus A/PR/8/34-A/England/939/69 (H3N2)] by ferret alveolar macrophages in vitro showed that all strains, whether virulent or attenuated, attached equally well (72 to 93%). Recoveries of virus were similar (17 to 44%) whether phagocytosis occurred at the normal temperature of the ferret (39 degrees C) or at pyrexial temperatures induced during infection (40 degrees C for A/PR/8/34 and clone 64d; 41 degrees C for clones 7a and 64c). Thus, alveolar macrophages probably contribute to the lack of alveolar infection observed in vivo.

Animals↗

PubMed1981

Immunization of ferrets against Dirofilaria immitis by means of chemically abbreviated infections.

Ferrets were exposed to two successive inoculations with 30 third-stage larvae of the canine heartworm Dirofilaria immitis, the inoculations being approximately 5 months apart. Each infection was terminated by ivermectin therapy approximately 2 months after inoculation. The ferrets were challenged with 30 larvae 3 weeks after the termination of the second infection, and were necropsied approximately 6 months after challenge. Of the four ferrets that survived this protracted experimentation, two were entirely free of heartworm while the other two had only a single female worm each. In contrast, 14 control ferrets that had not been immunized (four of which had been given ivermectin doses) were all infected at necropsy, yielding a mean of 6.6 worms per ferret.

Animals↗

PubMed1991

Intranasal infection of ferrets (Mustela putorius furo) with canine parainfluenza virus.

Immunocompetent and cyclophosphamide-immunosuppressed ferrets were intranasally infected with canine parainfluenza virus (CPIV) and observed for clinical signs, histopathologic lesions, the immunocytochemical demonstration of CPIV antigen in the respiratory tract and scanning electron microscopic alterations of the tracheal epithelium until 36 days post infection (p.i.). In both groups, clinical signs were minimal, restricted to the upper respiratory tract and consisted of cough elicited by tracheal compression between 3 and 7 days p.i. Microscopically, inflammatory and degenerative lesions were observed in the trachea and less frequently in the nasal cavity; bronchiolitis or interstitial pneumonia was not demonstrated. By immunocytochemistry, CPIV antigen was demonstrated in tracheal epithelial cells, whereas nasal cavity, bronchi, bronchioles and lung were devoid of viral antigen. Ferrets given CPIV alone developed a minimal lymphocytic tracheitis with minimal loss of cilia and CPIV antigen was observed only 4 days p.i. 17 days p.i., normal epithelial organization and ciliary reappearance was reestablished. Ferrets treated with cyclophosphamide and infected with CPIV exhibited mild to moderate histological lesions as above with similar scanning electron microscopic changes until 36 p.i. Tracheal lesions consisted of intraepithelial and submucosal infiltration of lymphocytes and macrophages, focal epithelial hyperplasia and multifocal loss of cilia. In addition, mild and transient neutrophilic infiltration was observed. In immunosuppressed ferrets, viral antigen expression was prominent and demonstrated 4 and 8 days p.i. These data suggest that ferrets are susceptible to aerosol CPIV infection.

Animals↗

PubMed2004

Susceptibility of ferrets (Mustela putorius furo) to experimentally induced rabies with European Bat Lyssaviruses (EBLV).

Twenty ferrets (Mustela putorius furo) were inoculated by intramuscular (i.m.) injection with European Bat Lyssaviruses (EBLV) type-1 and 2 using 10(4.0) foci-forming units (FFU) EBLV-2 (n = 6), 10(4.0) FFU EBLV-1 (n = 7) and 10(6.0) FFU EBLV-1 (n = 7). Furthermore, 15 mice received 10(2.5) FFU EBLV-2 (n = 5), 10(2.5) FFU EBLV-1 (n = 5) and 10(4.5) FFU EBLV-1 (n = 5) by i.m. inoculation. All ferrets and mice receiving the higher dose of EBLV-1 succumbed to infection. In contrast, only three of seven ferrets and two of five mice inoculated experimentally with the lower EBLV-1 dose died. By comparison, all of the EBLV-2 infected ferrets and four of five mice survived infection. All 20 infected ferrets seroconverted. Using sensitive molecular tools, the virus was detected in different tissues, but it could not be found in any saliva samples taken during the 84-day observation period.

Animals↗

PubMed1993

The development of retinal ganglion cell decussation patterns in postnatal pigmented and albino ferrets.

The decussation patterns of retinal ganglion cells in postnatal pigmented and albino ferrets were examined by using retrograde axonal tracers. Following unilateral injections into the optic pathway of newborn pigmented ferrets, approximately 13,000 cells were labelled in the ipsilateral retina. The majority (11,500) of these were located in temporal retina. Postnatally, the numbers of cells projecting ipsilaterally from temporal retina fell by 49%. High rates of loss were observed in both the smaller uncrossed projection from nasal retina (92%) and also in the crossed projection from temporal retina (84%). After injections on the day of birth, a decussation line was not obvious in the crossed projection: > or = 14,000 labelled cells were found in temporal retina. Double tracer studies showed that very few of these cells had axons which projected bilaterally. The numbers of ipsilaterally projecting cells labelled in neonatal albino ferrets was dramatically reduced. Only approximately 2500 were labelled in temporal retina following injections at birth. As in pigmented ferrets, about half of these cells subsequently died. The reduced uncrossed projection in albino neonates was associated with an increase in the crossed projection from temporal retina, in which approximately 21,000 cells were labelled following injections at birth. These results suggest that differential postnatal ganglion cell death establishes the adult decussation pattern in the contralateral retinal projection but merely refines the pattern already established in the uncrossed projection. Postnatal ganglion cell death plays no significant role in generating the abnormal projections found in albino ferrets.

Albinism↗

PubMed2004

Differential activation of glomeruli in the ferret's main olfactory bulb by anal scent gland odours from males and females: an early step in mate identification.

Peripheral anosmia was previously found to disrupt sex discrimination and partner preference in male and female ferrets. Here we show directly that volatile anal scent gland odourants from male and female ferrets activated overlapping but distinguishable clusters of glomeruli located in the ventral-caudal portion of the main olfactory bulb (MOB) of breeding ferrets of both sexes. No glomerular activation was seen in the accessory olfactory bulb (AOB). The profile of MOB glomerular activation induced in oestrous females by male anal scents was very similar to that induced by direct contact with a male during mating, and oestrogen treatment failed to alter the profile of glomerular activation induced in ovo-hysterectomized females by male anal scents. In rodents, 'atypical' MOB glomeruli, which have dense acetylcholinesterase (AChE) activity in the neuropil, may be activated by body odours from conspecifics. No such AChE-staining 'atypical' glomeruli were found in the ferret's MOB, suggesting that in this carnivore they do not constitute a subset of MOB glomeruli that respond to body odourants. In ferrets of both sexes, volatile body odourants that are detected by the main as opposed to the vomeronasal-AOB accessory olfactory system may play a critical role in mate identification.

Anal Sacs↗

PubMed2005

The anterior ectosylvian visual area of the ferret: a homologue for an enigmatic visual cortical area of the cat?

The present paper describes the results of electrophysiological mapping experiments focused on the anterior limb of the ectosylvian gyrus of the ferret (Mustela putorius). The aim was to determine if the ferret possessed a homologous cortical area to the anterior ectosylvian visual area (AEV) of the domestic cat, but not clearly delineated in any other mammal studied to date. We were able to gather data on the visuotopic organization of a region that we consider to be a homologue of cat AEV. The visual map in this area showed a distinct visuotopic organization and covered a large extent of the visual field. Within the ferret AEV there were clusters of bimodal recording sites (somato-visual and audio-visual) that were located adjacent to surrounding unimodal cortical areas (such as the second somatosensory area and primary and secondary auditory areas). The ferret AEV, like that of the cat, was topographically isolated from other visual cortical areas by intervening auditory and somatosensory areas. Taken together these features suggest that the region described here as AEV in the ferret is indeed a direct homologue of the previously described cat AEV.

Animals↗