Clinical blood chemistry values in normal Wistar-Imamichi rats using the RaBA-System (author's transl)]

In order to establish the normal baseline of blood values in rats using the RaBA-System, the following eight parameters were analyzed in 8-22-week-old Wistar-Imamichi rats of both sexes: hemoglobin, total protein, glucose, BUN, total cholesterol, GOT, GPT, and alkaline phosphatase. With the exception of glucose, all these parameters were significantly different depending upon ages. Significant sex differences were observed in the values of hemoglobin, total cholesterol, GOT, and alkaline phosphatase.     

Impaired triacylglycerol catabolism in hypertriglyceridemia of the diabetic, cholesterol-fed rabbit: a possible mechanism for protection from atherosclerosis

The etiology of the hypertriglyceridemia in alloxan-diabetic rabbits was studied by two independent methods. Production and removal rates of VLDL triacylglycerol were measured in diabetic rabbits by injection of [3H]palmitate-labelled VLDL. Similarly, triacylglycerol total removal rates were determined in non-diabetic rabbits which were infused with Intralipid to mimic the plasma triacylglycerol concentrations of diabetic rabbits. Compared to nondiabetic rabbits, triacylglycerol removal rats were decreased in diabetic rabbits, particularly at higher levels of plasma triacylglycerol. During cholesterol and triacylglycerol supplementation of the diet, post-heparin plasma lipoprotein lipase activity of diabetic rabbits with severe hypertriglyceridemia averaged 36% of that of nondiabetics, suggesting an impaired triacylglycerol removal capacity. Furthermore, plasma triacylglycerol was inversely related to post-heparin plasma lipoprotein lipase activity among diabetic rabbits. VLDL triacylglycerol production increased with increasing plasma triacylglycerol concentration among diabetic cholesterol-fed rabbits with moderately severe hypertriglyceridemia, but reached an apparent plateau among rabbits with plasma triacylglycerol concentrations from approx. 2000-9000 mg/dl. Thus, severe hypertriglyceridemia in this model of insulin deficiency can be attributed only partially to VLDL hypersecretion, whereas a removal defect, resulting in saturation of the triacylglycerol removal mechanism, appears to be largely responsible. The impaired removal of plasma triacylglycerol is also related to the presence of cholesterol predominantly in lipoproteins of increased size. The data support the hypothesis that protection against atherosclerosis in cholesterol-fed diabetic rabbits results from exclusion of very large cholesterol-containing lipoproteins from the arterial wall.     

Monitoring of Venus transgenic cell migration during pregnancy in non-transgenic rabbits

Cell transfer between mother and fetus were demonstrated previously in several species which possess haemochorial placenta (e.g. in humans, mice, rats, etc.). Here we report the assessment of fetal and maternal microchimerism in non-transgenic (non-TG) New Zealand white rabbits which were pregnant with transgenic (TG) fetuses and in non-TG newborns of TG does. The TG construct, including the Venus fluorophore cDNA driven by a ubiquitous cytomegalovirus enhancer, chicken ß-actin promoter (CAGGS), was previously integrated into the rabbit genome by Sleeping Beauty transposon system. Three different methods [fluorescence microscopy, flow cytometry and quantitative polymerase chain reaction (QPCR)] were employed to search for TG cells and gene products in blood and other tissues of non-TG rabbits. Venus positive peripheral blood mononuclear cells (PBMCs) were not detected in the blood of non-TG littermates or non-TG does by flow cytometry. Tissue samples (liver, kidney, skeletal and heart muscle) also proved to be Venus negative examined with fluorescence microscopy, while histology sections and PBMCs of TG rabbits showed robust Venus protein expression. In case of genomic DNA (gDNA) sourced from tissue samples of non-TG rabbits, CAGGS promoter-specific fragments could not be amplified by QPCR. Our data showed the lack of detectable cell transfer between TG and non-TG rabbits during gestation.     

Impacts of antemortem ingestion of alcoholic beverages on insect successional patterns

This paper studies the impacts of antemortem ingestion of alcoholic beverages by the domestic rabbit, Oryctolagus cuniculus L., on postmortem successional patterns of insects during winter and summer 2018 in Riyadh, Saudi Arabia. Insect samples were collected from the carcasses of rabbits fed alcoholic beverages as well as untreated rabbits for 15 days postmortem during two successional studies in each season. The results showed that, during both seasons, the decomposition process for the carcasses of rabbits fed alcoholic beverages antemortem was one to two days longer. The results also showed, however, that alcoholic beverages did not affect insect succession patterns in either season. In fact, the number of insects appeared to be influenced by the ambient temperature during the two seasons, with 4415 insects in the winter compared to 1033 insects in the summer. In total, 30 insect taxa were collected during the winter study from the carcasses of rabbits fed alcoholic beverages antemortem; while 26 of these same taxa were collected from the carcasses of the untreated rabbits. Among the treated rabbits, those fed 25 ml alcoholic beverages treated attracted the highest number of insect taxa (24 taxa). In the summer study, 21 insect taxa were collected in total, 19 from the carcasses of the alcohol-treated rabbits and 13 from untreated rabbits. Among the treated rabbits, those fed 50 ml alcoholic beverages attracted the highest number of insect taxa (14 taxa). These results contribute to the understanding of the factors affecting the use of insects in medical investigations, given that alcoholic beverages are a common addictive agent.     

A comparative radioautographic study of chondrocytic proliferation in nasal septal cartilage of the 5-day-old rat, rabbit, guinea pig and beagle.

Growth sites within the cartilaginous nasal septa of four different species of animals (5-day-old rats, rabbits, guinea pigs and beagles) were identified by monitoring cellular proliferation radioautographically. A statistical analysis (MANOVA) was employed. It showed that, of the six combinations compared (rat-beagle, rat-guinea pig, rat-rabbit, beagle-guinea pig, beagle-rabbit, and guinea pig-rabbit), in only one (beagle-guinea pig) was there any similarity in growth pattern. The other five combinations all were significantly different. Since no particular areas emerged, with any consistency, as common growth sites within any of the four kinds of septa, it was concluded that the nasal septum might well play a passive role in midfacial growth, rather than an active role as previously thought.     

大鼠与家兔生后各年龄阶段跖肌纤维的比较

应用建立在肌球蛋白重链异构体基础上的标准肌动球蛋白ATP酶和琥珀酸脱氢酶组织化学方法,分析大鼠和家兔出生后发育各年龄阶段跖肌纤维型分布。在生后2周至24周龄的大鼠和家兔Ⅰ、ⅡX型肌纤维百分比例减少,而ⅡA、ⅡB型纤维则增加。进行大量单肌纤维的组织化学特征的比较和相关性探讨。结果显示动物平均体重与跖肌的平均湿重随生后发育逐渐增加,Ⅰ、ⅡX、ⅡA及ⅡB型纤维均在生后各年龄组的全部肌肉内被发现,但出生后2日龄组是个例外。在生后发育期间,雄性大鼠和家兔ⅡB型纤维的平均肌纤维型构成要大于雌性大鼠和家兔,而雄性大鼠和家兔Ⅰ、ⅡX、ⅡA型三种氧化组织化学分类的肌纤维型构成均小于雌性大鼠和家兔。大鼠Ⅰ、ⅡX、ⅡA和ⅡB型纤维的平均横切面积显然要比家兔的同类型肌纤维要小。在大鼠和家兔可见明显的性别差异。大鼠和家兔的ⅡX型纤维横切面积是最小的,Ⅰ、ⅡA型纤维呈中等大小,ⅡB型纤维最大。该重要的测试有助于我们深入研究啮齿类动物快肌纤维生理特征的适应。     

Pentatrichomonas hominis from beagle dogs--detection method, characteristics and route of infection

Pentatrichomonas sp. from the feces of beagles was cultured axenically, and identified as P. hominis. The culture medium used was slightly modified Diamond's medium supplemented with chicken liver extract and rifampicin. Based upon good proliferation after inoculating only a few organisms in this medium, a fecal examination method employing cultivation was developed. Resistance of the trichomonad against disinfectants and metronidazole was tested, and it was found that the protozoan was rather susceptible. After oral administration of the organism to mice and rats, all the treated animals were infected. Since two types of the trichomonad, moving and non-moving, were detected, the presence of any type resistant to standing or drying was ruled out. A possible route of trichomonad infection to beagles is discussed.     

Herpesvirus sylvilagus in cottontail rabbits: evidence of shedding but not transplacental transmission.

Herpesvirus sylvilagus was inoculated into five cottontail rabbits (Sylvilagus floridanus) at various stages of pregnancy; they subsequently had litters in the laboratory. Three other cottontails chronically infected with the virus were bred and bore young in large outdoor pens. Thirty-four living neonates and dead fetuses were weighed, measured and aseptically necropsied. A total of 31 liver, spleen and kidney samples, 16 lymph node, 28 heart and 10 brain samples were collected and processed for inoculation into rabbit kidney cell cultures to attempt virus isolation. Virus was not detected in the 147 tissue samples tested. Pre-conception viremias ranged from 10-21 plaque-forming units per 0.5 ml. Virus isolation was attempted from 26 oral and lacrymal, 23 genital, nine urine and fecal, and four milk and male ejaculate samples from eight infected rabbits. Virus was recovered from two salivary samples from the same rabbit. Triamcinolone acetonide administered daily for four days to five rabbits did not stimulate excretion of virus.     

A study on the possible utilization of immunodiffusion and immunofluorescence techniques as the diagnostic methods for American foulbrood of honeybees (Apis mellifera)

Four types of antisera were obtained from rabbits hyperimmunized with either spores or vegetative rods from two strains of the American foulbrood pathogen, Bacillus larvae. The specificity and sensitivity of these antisera were tested with immunofluorescence and immunodiffusion methods. No cross-reactions were observed between the antisera and other different species of Bacillus or different genera of bacteria. The specificity was not found between the antisera and two strains of B. larvae although stronger fluorescent intensity was observed between the antiserum and its corresponding strain of antigen in the immunofluorescence tests. Eight samples of 1- to 2-day-old larvae, 3- to 4-day-old larvae, decayed tissue, and dry remain, collected from eight infected colonies, were tested against antisera by the immunofluorescence and the immunodiffusion methods. The results indicated that both methods are sensitive and specific for making diagnosis of field samples of American foulbrood of honey bees.     

Alterations in canine coronary arteries produced by chronic cigarette smoking

Segments of left circumflex coronary artery were obtained from beagles that had been exposed to cigarette smoke for 2 years and from nonsmoking controls. A ring sample from each was used to determine passive (0-Ca2+ and 2 mM EGTA) and active (75 mM K+) force-length relations. Other contiguous samples were used to determine collagen and elastin content, water content and distribution, and total electrolyte content. No significant differences were found in passive mechanical properties or the collagen and elastin content of arteries from the two groups of animals. Maximum values of active force development were found to be increased in arteries from smoking dogs as were values on the ascending part of the active force-length curve. Total water content and the distribution space of an extracellular marker (60Co-EDTA) were not significantly different among arteries from the two groups. This along with the similarity of total electrolyte contents suggests that values of cell volume were not different between the two groups and that the above differences in active force development represent alterations in smooth muscle cells at the subcellular level. These results suggest that the contribution of chronic smoking as one of a group of cardiac risk factors may be due to an effect of augmenting coronary artery smooth muscle contractility.     

Developmental Toxicity of the HMG‐CoA Reductase Inhibitor (PPD10558) in Rats and Rabbits

PPD10558 is an orally active, lipid‐lowering 3–hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) reductase inhibitor (statin) being developed as a treatment for hypercholesterolemia in patients who have not been able to tolerate statins because of statin‐associated myalgia. We have studied the potential developmental toxicity effects of PPD10558 in pregnant rats and rabbits given daily oral doses during the period of organogenesis. Rats were dosed with 0, 20, 80, or 320 mg/kg/day from Gestation Day (GD) 6 to 17 and rabbits received dose levels of 0, 12.5, 25, or 50 mg/kg/day from GD 6 to 18. Additional groups in both studies served as toxicokinetic animals and received the PPD10558 in the same manner as the main study groups at the same dose levels. Blood samples were collected from toxicokinetic animals at designated time points on GD 6 and 17 in rats and GD 6 and 18 in rabbits. Fetal exposure in rats was assessed on GD 20. Maternal and developmental parameters were evaluated in rats and rabbits on GD 20 and GD 29, respectively. No maternal and developmental toxicity was observed at any of the dose levels used in the rat study. Evidence of fetal exposure was determined in fetal plasma with mean fetal concentrations of PPD10558 and the metabolite (PPD11901) found to be between 1 and 6% of the mean maternal concentrations. In rabbits, marked maternal toxicity including mortality (eight deaths; 1 dose at 25 and 7 at 50 mg/kg/day), abortions (2 at 25 mg/kg/day and 6 at 50 mg/kg/day) and reduction in gestation body weight, gestation body weight changes and decreased food consumption were observed. In addition, fetal body weights of the combined sexes were significantly reduced at 50 mg/kg/day in comparison with the controls. Mean peak exposure (Cmax) and total exposure (AUC(0–24)) of PPD11901 in both rats and rabbits were higher than that of PPD10558 on GD 6 and GD 17 at each of the three dose levels.. Based on the results of these studies, the no observed adverse effect level (NOAEL) for maternal and developmental toxicity in rats was considered to be ≥320 mg/kg/day, the highest dose level used in the study. The NOAEL for maternal and developmental toxicity in rabbits was 12.5 mg/kg/day and 25 mg/kg/day, respectively.     

Comparison of temperature rise interpretations in the rabbit pyrogen test among Chinese, Japanese, European, and United States pharmacopeias and 2-2-2 theoretical models proposed by S. Hoffmann

Although the rabbit pyrogen test is one of the crucial methods included in each pharmacopeia to evaluate the safety of parenteral medicine, the experimental procedures and pyrogen result judgment algorithms (PRJAs) are still greatly different from one another. In the first stage of testing, original data of 879 batches from a total of 2637 rabbits in our laboratory were judged by PRJAs in the Chinese Pharmacopoeia 2005 III, the Japanese Pharmacopoeia XIV, the Japanese Pharmacopoeia XV, the European Pharmacopeia 6.0, the United States Pharmacopoeia 32 NF27 and two theoretical models proposed by S. Hoffmann, respectively. The results were analyzed to evaluate the effects of various PRJAs. It was shown that: (i) the significant differences in the results judged by various pharmacopeias and Hoffmann's theoretical models were mainly due to the PRJAs and the great differences in PRJAs should be harmonized throughout the world based on balance of reducing animal use and guaranteeing the safety of medicines; (ii) it is better to use PRJAs that depend on the threshold of the sum of temperature rise of all tested rabbits than those that depend on the number of rabbits that are over the threshold of temperature rise of individual rabbit according to clinical proof and the experimental data; and (iii) the PRJA of the Japanese Pharmacopoeia XV has obvious advantages when the total suspicious rate of samples was less than 10%. Additionally, a new PRJA designed for reducing the additional experiment stages and animal consumption is promoted for evaluation.     

Karyotypes of Pneumocystis carinii derived from several mammals

Pneumocystis carinii is the most important opportunistic pathogen of humans in the world. Pneumocystis carinii is experimentally detected in the lungs of rats, mice, rabbits, and monkeys, however, the organisms from different mammals are identical in microscopic morphology. The present study tried to find out more mammalian hosts of P. carinii and also to differentiate the organisms from different mammals by karyotyping. Rats, mice, hamsters, rabbits, cats, and dogs were successfully infected by P. carinii, but guinea pigs and pigs were not. Karyotype of P. carinii from rabbits showed similar size range of chromosomes with that of the prototype, but in different pattern. The patterns from cats and dogs were also different from that of rats. The present study confirms that cats and dogs are infected by P. carinii and at least total three karyotype strains of P. carinii are proven in Korea.     

Study on systemic reaction of delayed type hypersensitivity

Effectiveness of two different samples of PPD tuberculins was studied quantitatively. No differences were found in the effect on skin test in rabbits, extent of skin reaction in guinea pigs, edema of foot-pad in rats and inhibition of spleen cell migration in guinea pigs. Differences were observed in the systemic febrile reaction in rabbits and in examinations of the thickness of infiltrated skin in guinea pig tests. The results may serve as a basis for standardization of systemic reaction in rabbits.     

The effect of euthanasia technique on vascular arachidonic acid metabolism and vascular and intestinal smooth muscle contractility

This study was designed to determine the effects that specific euthanasia methods have on vascular arachidonic acid metabolism and vascular and intestinal smooth muscle contractility. Rats were euthanatized by decapitation (DC), pentobarbital overdose (PB), or anesthesia with CO2, methoxyflurane or ether followed by DC (CO2-DC, Met-DC, Ether-DC, respectively). Rabbits were killed by a similar protocol, but CO2 overexposure replaced Ether-DC. The rat and rabbit aortas produced mainly 6-keto PGF1 alpha, the prostacyclin metabolite, and lesser amounts of PGE2. No qualitative differences were seen in arachidonate metabolites. However, aortic tissue from rabbits and rats killed by Met-DC produced more prostacyclin. In contrast, aorta from rabbits euthanatized by CO2-DC produced less prostacyclin than controls, whereas aorta from rats killed in the same way yielded greater amounts of prostacyclin. Aortic tissue from rabbits killed by Met-DC and CO2-OD was less responsive to acetylcholine (ACH). Intestinal contractility to ACH was increased in rabbits when Met-DC was used as the method of euthanasia, while colon from rats sacrificed by Met-DC showed decreased responsiveness to ACH. Colon from rats killed by intraperitoneal PB exhibited altered contractility to ACH and norepinephrine. The results of this study show that methoxyflurane, carbon dioxide (rabbit) and pentobarbital (rat) alter the vascular synthesis of prostacyclin and smooth muscle contractility. We conclude that the method of euthanasia affects certain physiologic parameters and careful consideration should be given to the selection of a particular euthanasia technique.     

Profile of hematological values in hybrid hairless dogs

The purpose of this paper is to describe some fundamental physiological data in F 1 hybrids bred from a Mexican hairless dog and beagle cross. These F 1 hybrids numbered 5 hairless dogs and 12 haired dogs. The hematological profile of these offspring was assessed via an automated cell counter and compared with those of healthy beagles. In hairless dogs, red blood cell count, hemoglobin concentration and packed cell volume tended to be higher than in beagles. White cell distribution curves in hairless dogs and beagles yielded a single peak, while in haired dogs one or two peaks were present. Red blood cell and platelet distribution curves revealed few differences among the 3 kinds of dogs.     

Chemiluminescence (CL) in blood samples reflects leukocyte activation (LA) during anaphylactoid reactions in dogs

Inflammation is accompanied by leukocyte activation (LA). We decribe a simple ex vivo technique for studying LA that might help to find new LA inhibitors for the treatment of pathologic events related to LA. Arterial and venous blood samples obtained from six permanently catheterized beagle dogs ?60, 0, +15 min and +23 h after i.v. challenge with C 48/80, and also blood samples from six normal beagles, were minimally diluted 1:2.5 with buffer. Total leukocyte counts (LC), and luminol amplified CL, induced by opsonized zymosan (C₃-Z), were estimated. Blood samples from dogs elicited CL responses of almost 1/10 the magnitude of erythrocyte-free human leukocytes, whereas blood samples from rats reacted three orders of magnitude less. Obviously quenching of CL by accompanying erythrocytes in blood samples from dogs is not important, for CL correlated almost linearly with the CL in differently diluted samples. In arterial, but not in venous samples from catheterized dogs, absolute CL and LC, both were significantly depressed (p < 0.05) 15 min after C 48/80 challenge. CL/10⁶ leukocytes was augmented twofold. All leukocyte deviations returned to pre-values 23 h post-challenge.     

Identification of nonspecific reactions in laboratory rodent specimens tested by Rotazyme rotavirus ELISA

Fecal specimens from several laboratory animal species were tested for rotavirus antigen by Rotazyme II, a commercially available enzyme-linked immunosorbent assay (ELISA) that is widely used in human diagnostic studies. Fecal samples from rabbits, hamsters, guinea pigs, dogs, and cats tested negative; whereas those from rats and mice yielded a high proportion of positive results. Rats had the highest rate with 82% of the samples being positive. However, the presence of rotavirus in positive rodent samples could not be confirmed by virus isolation, electron microscopy or blocking ELISA using anti-EDIM mouse rotavirus serum. Several lines of evidence indicated that these positive reactions were false positives, apparently due to a non-specifically reacting substance in the diet of rats and mice. All the positive fecal samples were from rats and mice that had been fed nonautoclaved diet. Samples from rodents fed autoclaved diet were consistently negative in the Rotazyme test. When rats fed autoclaved diet were subsequently fed nonautoclaved diet, their stool converted from negative to positive within 6 hours. Conversely, rats with positive stool samples converted to negative within 15 hours when fed autoclaved diet. Similar results were found with mice. Positive fecal specimens and nonautoclaved rodent diet both contained a substance that apparently attached nonspecifically to the antibody coated beads used in the ELISA and reacted directly with the substrate in the absence of the conjugate. This substance was heat labile and trypsin sensitive, suggesting that it was a protein.     

Fission fragment RBE for bone sarcoma induction

Thirty beagles and 277 mice were injected with 249Cf, and 30 beagles and 274 mice were injected with 252Cf. The skeletal dose (in Gy) from 252Cf was about half from fission fragments and half from alpha particles, whereas 249Cf emits alpha particles in 100% of its transformations. Bone sarcomas (mostly osteosarcomas) were the main radiation-induced cancer. The relative biological effectiveness (RBE) of fission fragment dose relative to alpha-particle dose for bone sarcoma induction was calculated from the ratio of 249Cf/252Cf doses at equal times to bone sarcoma in (a) beagles and (b) mice, and (c) from the ratio 252Cf/249Cf risk coefficients in mice. The average RBE +/- standard deviation of the three evaluations was 0.1 +/- 0.1. The very low RBE for bone sarcomas is supported by the data of A. L. Batchelor, T. J. Jenner, and L. M. Cobb [Phys. Med. Biol. 28, 475-483 (1983)] for lung cancer induction in rats and by that of A. L. Brooks, J. A. Mewhinney, and R. O. McClellan [Health Phys. 22, 701-706 (1972)] for producing chromosome aberrations in the liver cells of Chinese hamsters. The low effectiveness of fission fragments relative to alpha particles, per gray of absorbed dose, is ascribed primarily to the much larger number of cells traversed by the alpha particles. Consideration might be given to decreasing the quality factor of fission fragments by an order of magnitude below that for alpha particles.     

Qualitative and quantitative differences in normal vaginal flora of conventionally reared mice, rats, hamsters, rabbits, and dogs

We examined quantitatively the vaginal flora of conventionally reared mice, rats, hamsters, rabbits and dogs, species that are widely used as laboratory animals. Vaginal specimens were examined according to the method of analyzing intestinal flora (Mitsuoka's procedure). The total number of bacteria (aerobes and anaerobes) and the prevalence of specific bacteria were determined. The total number of bacteria was highest during estrus and lowest during diestrus or anestrus in mice, rats, hamsters, and dogs. The most predominant bacteria during estrus were streptococci in mice; gram-negative rods (GNR), streptococci, and members of the family Bacteroidaceae in rats; GNR, Bacteroidaceae and gram-positive anaerobic cocci in hamsters, and Bacteroidaceae in dogs. The increase in the total number of bacteria during estrus was caused by an increase of predominant bacteria in the vagina. Aerobes were more predominant than anaerobes in mice, and number of aerobes was comparable to that of anaerobes in rats and dogs. On the other hand, in hamsters, anaerobes were more predominant than aerobes and the total number of bacteria was highest among the laboratory animals (mice, rats, hamsters, rabbits, and dogs). However, in rabbits, bacteria were not isolated from about 90% of the vaginal specimens. Rabbits do not have cyclic reproductive stages and are usually in precoital status in the laboratory. In precoital rabbits, vaginal epithelium manifests few signs of secretion. Therefore, we suspect that the vaginal environment in precoital rabbits is comparable to that during diestrus or anestrus in mice, rats, hamsters, and dogs. These results suggest that the vaginal flora of laboratory animals is influenced by the estrous cycle, and probably by mucous secretion. Our data imply that vaginal flora differ among laboratory animals species, and researchers need to take into consideration the estrous cycle of laboratory animals when studying their vaginal flora.