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At least 19 recordsLinked to original sources

PubMed2004

A non-invasive method for assessing adrenal activity in the chinchilla (Chinchilla lanigera).

The Chinchilla is a rodent that was once abundant in the central Andes of South America. Excessive hunting for fur greatly reduced its distribution at the beginning of the twentieth century, and today Chinchilla species are nearly extinct in the wild. Although protected, wild populations of chinchilla are still declining. In general, this species has received little research attention and its biology is poorly understood. Improvements in captive breeding, husbandry, and genetic management are needed to ensure the conservation of the species. In this study, a noninvasive corticosteroid hormone monitoring technique was validated for use in Chinchilla lanigera. Two male domestic chinchillas were administered 3H-corticosterone (i.m.) to determine the time course and relative proportion of urinary and fecal steroid metabolites. Most radioactivity was detected in urine and feces 5-10 and approximately 30 h post-isotope administration, respectively. Corticosteroid immunoreactivity was assessed by corticosterone radioimmunoassay (RIA) and cortisol enzyme immunoassay (EIA). High-pressure liquid chromatography (HPLC) separation of corticosteroid metabolites in unprocessed urine revealed the presence of highly polar corticosteroid metabolites, but after enzymatic hydrolysis and diethyl ether extraction, most immunoreactivity co-eluted with unconjugated cortisol. A 'cause-and-effect' relationship between the administration of exogenous adrenocorticotrophic hormone (ACTH), and the appearance of increased urinary corticosteroid metabolites demonstrated the physiological relevance of these measures for evaluating adrenal status in male chinchillas. From a conservation perspective, these methods can aid in situ and ex situ initiatives designed to evaluate how environmental conditions and management strategies affect overall animal health, well-being and reproduction.

Adrenocorticotropic Hormone↗

PubMed1976

Cell mediated immunity in the chinchilla (Chinchilla laniger): in vitro lymphocyte transformation.

The cell mediated immune system of the chinchilla (Chinchilla laniger) was examined using both in vivo and in vitro methods. An in vitro lymphocyte transformation microassay was developed utilizing tritiated thymidine incorporation into spleen cells stimulated by the nonspecific mitogen, phytohemagglutinin-M. Peak stimulation of blastogenesis occurred between 48 and 72 hours of incubation with 5 X 10(6) cells/ml in 12.5 mul phytohemagglutinin-M/ml. In spleen cell cultures from chinchillas sensitized 2 weeks previously with Freund's complete adjuvant plus additional Mycobacterium tuberculosis, incubation of 2.5 X 10(6) or 5 X 10(6) cells/ml with 50 mug/ml of the specific antigen, purified protein derivative, produced marked blastogenesis after 96 hours. The blastogenic response of the chinchilla to this specific antigen was extraordinarily high when compared with transformation responses of canine, bovine and avian peripheral blood lymphocytes utilizing a similar microassay system. The macroscopic in vivo delayed cutaneous hypersensitivity response to an intradermal injection of 10 mug purified protein derivative into chinchillas previously sensitized with Freund's complete adjuvant plus Mycobacterium tuberculosis appeared to be deficient. Grossly, erythema and induration were very slight or absent; however, histologically a slight cutaneous inflammatory response of mixed but predominantly mononuclear leukocytes was observed. The chinchilla's unique ability to display an extraordinary in vitro lymphocyte transformation response and its apparent inability to mount a consistent observable delayed cutaneous hypersensitivity response makes it an excellent model for the further study of the relationship of these phenomena to the total concept of cell mediated immunity.

Animals↗

PubMed1990

Cytoarchitectonic atlas of the cochlear nucleus of the chinchilla, Chinchilla laniger.

A detailed cytoarchitectonic atlas of the chinchilla cochlear nucleus complex was prepared in the transverse plane with the Nissl method. Subdivisions of the cochlear nucleus were defined on the basis of cell size, cell packing density, and, in some cases, on cytological features of cell types. In general, the chinchilla cochlear nucleus has an organizational plan similar to that described for other mammalian species. As in other rodents, the chinchilla has a large and well-developed dorsal cochlear nucleus consisting of three distinct layers. The ventral cochlear nucleus consists of two distinct nuclear masses, a posterior nuclear group and an anterior nuclear group, each composed of several subdivisions, which are qualitatively similar to those described for other mammals. Thus it is now possible to compare detailed observations, such as tonotopic maps, in the chinchilla with findings from the analogous cell populations in other mammals, such as the cat, with considerable precision. In the chinchilla, three cell groups, previously undescribed in mammals, have been defined and their counterparts in the cat identified.

Animals↗

PubMed2006

Geometry of the semicircular canals of the chinchilla (Chinchilla laniger).

The orientations of the semicircular canals determines the response of the canals to head rotations and, in turn, the brain's ability to interpret those motions. The geometry of chinchillas' semicircular canals has never been reported. Volumetric representations of three chinchilla skulls were generated using a microCT scanner. The centroids of each semicircular canal lumen were identified as they passed through the image slices and were regressed to a plane. Unit vectors normal to the plane representing canal orientations were used to calculate angles between canal pairs. Pitch and roll maneuvers required to bring any canal into the horizontal plane for physiologic investigation were calculated. The semicircular canals of the chinchilla were found to be relatively planar. The horizontal canal was found to be oriented 55.0 degrees anteriorly upward. Pairs of ipsilateral chinchilla canals were not orthogonal and contralateral synergistic pairs were not parallel. Despite this arrangement, the canal plane unit normal vectors were organized to respond with approximately equal overall sensitivity to rotations in any direction. The non-orthogonal chinchilla labyrinth may provide an opportunity to determine whether the frame of reference used by the central vestibular and oculomotor system is based on directions of afferent maximum sensitivity or prime directions.

Afferent Pathways↗

PubMed2003

Specific distribution pattern of nerve fibers containing catecholamine-synthesizing enzymes, neuropeptide Y (NPY) and C-terminal flanking peptide of NPY (CPON) in the pineal gland of the chinchilla (Chinchilla laniger)--an immunohistochemical study.

The sympathetic nerve fibers originating from the superior cervical ganglia and supplying the pineal gland play the most important role in the control of the pineal activity in mammals. NPY and CPON are also present in the majority of the pinealopetal sympathetic neurons. In this study, immunohistochemical techniques were used to demonstrate the existence and coexistence of tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH) as well as NPY and CPON in the nerve fibers supplying the chinchilla pineal gland. Ten two-year-old female chinchillas housed in natural light conditions were used in the study. The pineals were fixed by perfusion. ABC immunohistochemical technique and immunofluorescence labelling method were employed. TH-immunoreactive (TH-IR) varicose nerve fibers were observed in the pineal gland as well as in the posterior commissural area. Within the chinchilla pineal gland, TH-IR nerve fibers were located in the capsule and connective tissue septa. Numerous varicose TH-IR branches penetrated into the parenchyma and formed a network showing the highest density in the proximal region of the gland. In the central and distal parts of the pineal parenchyma, a subtle network, composed of thin varicose nerve branches, was observed. Double immunostaining revealed that the majority of TH-IR nerve fibers was positive for DbetaH or NPY. TH- and DbetaH-positive neuron-like cells were observed in the proximal region of the gland. The pattern of pineal innervation immunoreactive to CPON was similar to the innervation containing NPY, TH and DbetaH. The chinchilla intrapineal innervation containing TH, DbetaH, NPY and CPON is characterized by the higher density in the proximal part of the gland than in the middle and distal ones. The specific feature of the chinchilla pineal is also the presence of single TH/DbetaH-immunoreactive neuron-like cells in the proximal part of the gland.

Animals↗

PubMed2005

Electroejaculation in the Chinchilla (Chinchilla lanigera): effects of anesthesia on seminal characteristics.

Repetitive electroejaculation is probably extremely stressful in conscious animals and could adversely affect fertility. The present study was designed to (a) evaluate the effects of anesthesia (40 mg ketamine/kg body weight, i.m.) on a method of electroejaculation used previously in conscious chinchillas (Chinchilla lanigera), and (b) determine the quality of the electroejaculated semen obtained under anesthesia. In Experiment 1 (8 animals), a 4 x 4 Latin square design was used to study the effects of anesthesia and ejaculatory voltage on semen collection, ejaculate volume, sperm concentration, motility, viability, response to the hypoosmotic swelling test (HOST), and acrosomal status. In Experiment 2 (12 animals), the effects of differing voltages and the number of stimuli on ejaculation by conscious or anesthetized males was determined. In both experiments, all the conscious animals ejaculated, but only 60% ejaculated under anesthesia and they required more stimuli and higher voltages to achieve ejaculation. Ejaculate volume was significantly lower in anesthetized (<5 microl) than in conscious animals (>40 microl), but sperm concentration was unaffected. None of the indices of sperm quality were affected by anesthesia. The techniques we have developed in anesthetized domestic chinchillas should be applicable to endangered chinchillas in the wild, and though the number of sperm available is reduced, there are still sufficient for assisted reproduction.

Anesthetics↗

PubMed1997

Age-related decline of auditory function in the chinchilla (Chinchilla laniger).

The aim of this study was to examine the functional consequences of aging in the chinchilla, a rodent with a relatively long life span and a range of hearing similar to that of humans. Subjects were 21 chinchillas aged 10-15 years, and 23 young controls. Thresholds were determined from auditory evoked potentials (EVPs), and outer hair cell (OHC) functioning was assessed by measuring 2f1-f2 distortion product otoacoustic emissions (DPOAEs). Six cochleas from 11-12-year-old animals were examined for hair cell loss and gross strial pathology. The results show that the chinchilla exhibits a small but significant decline of auditory sensitivity and OHC functioning between 3 and 15 years of age, with high-frequency losses exceeding and growing more rapidly than low-frequency losses. Compared to rodents with shorter life spans, the chinchilla has a rate of loss that is more similar to that of humans, which could make it a valuable model for understanding the etiology of human presbycusis.

Acoustic Stimulation↗

PubMed1994

Fine structure of the vomeronasal organ in the chinchilla (Chinchilla laniger).

Fine structure of the vomeronasal organ (VNO) was examined in the chinchilla (Chinchilla laniger) from a viewpoint of comparative anatomy. The VNO of chinchilla was a pair of tubular structure, about 6mm in length, and situated bilaterally along the base of the nasal septum. The VNO was encircled rostrally by the vomeronasal cartilage, but caudally by a bony capsule. The VNO communicated with the nasal cavity via a small pore at its rostral end, while it ended blindly at its caudal end. Its lumen was crescent to elliptical in a transverse plane, and lined medially with the vomeronasal sensory epithelium (VSE), but laterally with the vomeronasal respiratory epithelium (VRE). Jacobson's glands were tubulo-alveolar in type and distributed from the dorsolateral to the ventrolateral region of the VNO and opened with the duct to the lumen in the transitional region from the VSE to the VRE. Their secretions were periodic acid-Schiff (PAS)-positive but alcian blue (AB)-negative. The VSE consisted of sensory, supporting and basal cells. Supporting cells were characteristic of a large number of huge dense bodies in the perinuclear cytoplasm. The other ultrastructural features in sensory, supporting and basal cells of the VSE were similar to those in the previous reports. The VRE consisted of ciliated, non-ciliated and basal cells. Acinar cells of Jacobson's gland possessed two types of secretory granules. Secretory granules of one type were homogeneous and electronlucent, about 1,700nm in diameter, while granules of the other type were about 2,200nm in diameter, and various in electron density. The present findings suggest that the VNO is functionally active in the chinchilla.

Animals↗

PubMed1980

Ultrastructural observation of paracrystalline aggregates of microtubules in anterior pituitary cells of the chinchilla (Chinchilla laniger).

Unusual paracrystalline aggregates of microtubules which have not been described in any other mammalian species were observed in cultured anterior pituitary cells of normal chinchillas as well as in situ in the pituitary glands of these animals. These aggregates appeared as regularly arranged tubular structures in the longitudinal plane, and as a checkerboard pattern of closely and regularly packed microtubules when examined in transverse section. Supplementation with vinblastine, colcemide or colchicine in the culture medium did not change these structures morphologically. Each unit of tubules consisted of an outer wall or parallelogram profile and an inner wall composed of a single hexagonal doublet or in a figure "8"form. The outer wall of the parallelogram was 35 X 28 nm in length for both sides, while the diagonal of the inner wall was 18 X 28 nm. These paracrystalline aggregates of microtubules in the chinchilla pituitary cells are morphologically distinct from the paracrystalline assembly of cytoplasmic microtubules induced by vinblastine or other alkaloids. The function and significance of these paracrystalline aggregates in anterior pituitary cells of the chinchilla are uncertain.

Animals↗

PubMed1998

Use of computed tomography to investigate cheek tooth abnormalities in chinchillas (Chinchilla laniger)

Computerised tomographic scanning was used to investigate tooth structure in chinchillas (Chinchilla laniger), both cheek tooth crown and root abnormalities being common in this species. This paper describes a common form of dental disease affecting species with continuously growing teeth, with particular reference to the chinchilla, and confirms the potential role of computed tomography (CT) in its early diagnosis. CT imaging is compared with previously available methods of investigation which frequently fail to detect early pathological changes.

Animals↗

PubMed2002

Diagnosis of sexual cycle by means of vaginal smear method in the chinchilla (Chinchilla lanigera).

An investigation was made as to whether the sexual cycle and pregnancy can be determined by means of vaginal smear in chinchillas. This study represents the first attempt to record changes which occur in the pattern of exfoliated cells in chinchilla's vaginal smear during anoestrus, proestrus, oestrus, metoestrus and pregnancy. Fifteen female chinchillas aged from 8 months to 3 years and bred through harem breeding method were used. The major change during proestrus was an increase in the proportion of superficial cells, with a corresponding decrease in other cells. Goblet cells were observed in the smears prepared by strong aspiration during this cycle. Neutrophils, small and large intermediates and parabasal cells were not found in the smear during oestrus and the smear consisted of superficial cells only. In the proportion of neutrophils, small and large intermediates and parabasal cells increased during metoestrus. In addition, metoestrum and foam cells were found in this cycle. In anoestrus; superficial and parabasal cells were present in small numbers. Also small and large intermediate cells as well as neutrophils were present. Traces of foam and metoestrum cells were found. During pregnancy, neutrophils generally of medium density were present, parabasal; small and large intermediate cells were present at low or medium density, and superficial cells were only present in trace amounts.

Animals↗

PubMed2002

Spontaneous human herpes virus type 1 infection in a chinchilla (Chinchilla lanigera f. dom.).

A 1-year-old male chinchilla with a 2-week history of conjunctivitis suffered subsequently from neurological signs comprising seizures, disorientation, recumbency and apathy. After 3 weeks of progressive central nervous disease the animal was killed in view of the poor prognosis. A non-suppurative meningitis and polioencephalitis with neuronal necrosis and intranuclear inclusion bodies were observed at necropsy and by light microscopy. The brain stem and cerebral cortices were most severely affected. Both eyes displayed ulcerative keratitis, uveitis, retinitis and retinal degeneration, and optical neuritis. Additionally, a purulent rhinitis with focal erosions, epithelial degeneration and intranuclear inclusion bodies was present. Ultrastructurally, herpes virus particles were detected in neurons of the brain. Immunohistochemistry with antisera specific for human herpes virus types 1 and 2 resulted in viral antigen labeling in neurons, glial cells and in neuronal processes. Viral antigen was found in the rhinencephalon, cerebral cortices, hippocampus, numerous nuclei of the brain stem, single foci in the cerebellum, and in a solitary erosive lesion of the right nasal vestibulum. Viral antigen was not detected in the eyes. The virus was isolated from the CNS, and nucleic acid sequence analysis of the glycoprotein B and the DNA polymerase revealed a sequence homology with human herpes virus type 1 of 99% and 100%, respectively. The clinical signs, the distribution of the lesions and the viral antigen suggest a primary ocular infection with subsequent spread to the CNS. Chinchillas are susceptible to human herpes virus 1 and may play a role as a temporary reservoir for human infections.

Animals↗

PubMed1985

Seasonal fluctuations in plasma protein fraction levels of chinchillas (Chinchilla laniger, M.).

Seasonal changes in blood plasma protein fractions in chinchilla females and males were found. Plasma albumin levels in both sexes vary according to season, generally low in winter and spring and high in summer and autumn. The levels of alpha 1-globulin and gamma-globulin increase markedly in spring (1.5 times higher than in winter and autumn). In chinchilla females, the levels of alpha 2-globulin and beta 2-globulin varied biphasically, being higher in winter and summer. In males, clear seasonal trends in the levels of both fractions were not observed. The beta 1-globulin fraction levels vary throughout the year. In females as well as males, globulin decreases during winter to minimal values in late spring, and then increases again during the summer to remain at the same level till autumn.

Alpha-Globulins↗

PubMed1987

Twenty-four hour changes in lysozyme levels, total plasma protein concentration, gamma-globulin concentration, white blood cell count and numbers of lymphocytes and granulocytes in the peripheral blood of chinchillas Chinchilla laniger M. and rabbits Oryctolagus cuniculus L.

Twenty-four hour changes in lysozyme level, total plasma protein concentration, gamma-globulin concentration, leucocyte number and different forms of leucocyte in the peripheral blood of male chinchillas and rabbits were investigated. All investigated parameters in both species showed statistically significant 24-hr changes, but only total plasma protein concentration in rabbits and gamma-globulin concentration and leucocyte number in chinchillas have a circadian rhythm character. The cosine curve characteristics for these rhythms are as follows; acrophases 0.45 + 2.18 hr, 10.02 + 4.29 hr, 2.14 + 3.20 hr; amplitudes 0.48 + 0.32 g%, 0.34 + 0.41 g%, 1.12 + 0.88 X 10(3)/min3; mesors 6.10 + 0.22 g%, 2.23 + 0.21 g%, 8.78 + 0.65 X 10(3)/mm3, respectively.

Animals↗

PubMed2006

Noninvasive monitoring of ovarian endocrine activity in the chinchilla (Chinchilla lanigera).

Reproductive endocrinology information is limited for Chinchilla lanigera, a South American species characterized by extremely long gestation and estrus cycle compared with others rodents. This study was designed to validate a non-invasive technique for monitoring ovarian endocrine activity. Animals were exposed indoors to natural photoperiod (31 degrees S-64 degrees W, Argentina); temperature range: 17-26 degrees C, with food and water ad libitum. Radiolabelled infusion (n=4): (3)H-estradiol ((3)H-E(2)) and (14)C-progesterone ((14)C-P(4)) were injected (i.p). Biochemical validation: HPLC-UV detector was employed to determine natural steroids in urine and fecal extracts and to determine immunoreactive metabolites. Physiological validation: (1) pregnancy (n=5): body weight and urinary and fecal steroidal metabolites were measured until birth; (2) Seasonality (n=9): urine and feces were collected in May, August, November, and February. Total (3)H-E(2) and (14)C-P(4) radioactivity recovered was 60.5+/-15.5 and 74.5+/-19.4%, respectively. After (3)H-E(2) injection, urinary radioactivity peaked at 7.0+/-0.6 hr; in contrast, urinary (14)C-P(4) excretion peaked at 44.0+/-4.0 hr (p=0.000). Peak radioactivity in feces occurred between 24-48 hr for both hormones. Several correlations were detected during pregnancy between body weight vs. urinary progestagens/day (r=0.44, p<0.03); vs. urinary progestagens/creatinine (r=0.73, p=2.9 x 10(-5)); vs. urinary estrogens/day (r=0.74; p<0.2); and vs. urinary estrogens/creatinine (r=0.74; p<2.0 x 10(-5)). On the other hand, urinary and fecal progestagen excretion exhibited significant seasonal fluctuations and urinary estrogen concentrations showed a similar pattern (p=0.062 for winter-spring vs. summer-autumn). This methodology proved to be useful for monitoring ovary endocrine activity in urine of chinchilla female.

Animals↗

PubMed2004

Identification and characterization of a mucosal antimicrobial peptide expressed by the chinchilla (Chinchilla lanigera) airway.

Cationic antimicrobial peptides (APs) are produced at mucosal surfaces and play a key role as a first line of defense against infection. To understand how APs might impact disease progression in otitis media (OM), our goal was to identify and characterize APs expressed by the epithelium lining the uppermost airway of the chinchilla, the established rodent host for the study of the bacterial-viral pathogenesis in OM. Using a molecular approach, we cloned a cDNA encoding a homolog of human beta-defensin 3, designated chinchilla beta-defensin-1 (cBD-1), and found by Northern analysis expression of the corresponding mRNA in nasopharyngeal and tongue mucosae as well as skin. By reverse transcription-PCR, cBD-1 mRNA was also detected in RNA isolated from trachea, lung, and Eustachian tube tissues. The predicted mature form of cBD-1, expressed as a recombinant peptide in Escherichia coli, demonstrated bactericidal activity against the three primary opportunistic pathogens of OM as well as Candida albicans. Continued study of this and other APs will allow us to determine their role in bacterial colonization of the upper airway as well as how viruses might contribute to the pathogenesis of OM by modulating AP expression.

Amino Acid Sequence↗

PubMed2004

Anaesthesia with midazolam/medetomidine/fentanyl in chinchillas (Chinchilla lanigera) compared to anaesthesia with xylazine/ketamine and medetomidine/ketamine.

We studied four different drug regimes for anaesthetic management in chinchillas and evaluated and compared their cardiovascular and respiratory effects. In this randomized, cross-over experimental study, seven adult chinchillas, five females, two males [515 +/- 70 (SD) g] were randomly assigned to one of the following groups: group 1 [midazolam, medetomidine and fentanyl (MMF), flumazenil, atipamezole and naloxone (FAN); MMF-FAN] received 1.0 mg/kg midazolam, 0.05 mg/kg medetomidine and 0.02 mg/kg fentanyl i.m., and for reversal 0.1 mg/kg flumazenil, 0.5 mg/kg atipamezole and 0.05 mg/kg naloxone s.c. after 45 min; group 2 (MMF) 1.0 mg/kg midazolam, 0.05 mg/kg medetomidine and 0.02 mg/kg fentanyl i.m.; group 3 [xylazine/ketamine (X/K)] 2.0 mg/kg xylazine and 40.0 mg/kg ketamine i.m.; and group 4 [medetomidine/ketamine (M/K)] 0.06 mg/kg medetomidine and 5.0 mg/kg ketamine i.m. Reflexes were judged to determine anaesthetic stages and planes. Anaesthesia with X/K and M/K was associated with a prolonged surgical tolerance and recovery period. By reversing MMF, recovery period was significantly shortened (5 +/- 1.3 min versus 40 +/- 10.3 min in MMF without FAN, 73 +/- 15.0 min in X/K, and 31 +/- 8.5 min in M/K). Without reversal, MMF produced anaesthesia lasting 109 +/- 16.3 min. All combinations decreased respiratory and heart rate but compared with X/K and M/K, respiratory and cardiovascular complications were less in the MMF groups. Focussing on the clinical relevance of the tested combinations, completely reversible anaesthesia showed two major advantages: anaesthesia can be antagonized in case of emergency and routinely shortens recovery. In small animals particularly these advantages lead to less complications and discomfort and thus often can be lifesaving. As all analgesic components (medetomidine and fentanyl) are reversed, postoperative analgesia should be provided before reversal of anaesthesia.

Anesthesia↗

PubMed1975

Naturally occurring histoplasmosis in the chinchilla (Chinchilla laniger).

Histoplasmosis was diagnosed histopathologically in a female chinchilla. This animal had originated from a commercial chinchilla ranch in central Missouri. Seventeen of 130 animals in the colony had died within a month's period with a respiratory illness. This animal had a history of fur chewing, but this was not true of all the other animals that had died. Histoplasma capsulatum was cultured from timothy hay used for food.

Animal Feed↗