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PubMed1996

Differential immune responses to fetal intracameral spinal cord and cortex cerebri grafts.

While the central nervous system (CNS) has been characterized as an immunologically privileged site, there are also several reports describing immunological reactions within the CNS. A certain degree of immunological privilege has also been ascribed to the anterior chamber of the eye. We have used the intraocular transplantation model to study immunological reactions in transplants of embryonic neural tissue. Outbred Sprague-Dawley rats and inbred Fisher rats were used. Pieces of rat parietal cortex or the cervical spinal cord were prepared from embryonic day 14 and implanted into the eye chambers of adult rats of the same strain. Following intraocular maturation, grafts were analysed using antibodies against: major histocompatibility complex (MHC) class I, MHC class II; rat antigens CD4, CD8, CD11b; T-cell receptor; rat antigen ED1; and glial fibrillary acidic protein. Using this set of markers for immunological reactions, transplants were scored on a blind basis. We found no significant differences in immunological scores between transplants obtained from different litters of fetuses of the outbred animals. Grafting in the outbred strain led to increased numbers of immunologically reactive cells in the grafts. This was not seen in grafts in the inbred strain. Spinal cord transplants led to a significantly higher degree of cytotoxic immunity-related cells expressing MHC class II as well as CD4-positive cells. There was a positive correlation between ED1 negativity and well-developed ramified microglia. From these results we conclude also that well-developed intraocular CNS tissue grafts do contain cellular evidence of immunological events and that different areas of the CNS may provoke different degrees of response. Reactive microglial proliferation appears to be one of the most sensitive ways to monitor the immunological condition of grafted CNS tissue.

Animals↗
PubMed1975

The major histocompatibility complex of the guinea pig. I. Serologic and genetic studies.

Serologic and genetic studies of the antigens which comprise the guinea pig MHC have demonstrated three distinct but linked genetic regions. Antisera to the B region were raised by cross-immunization of random-bred animals; this region controls antigens B.1, B.2, B.3, and B.4 which behave as alleles at a single locus and which resemble the products of the murine D or K region genes in their tissue distribution and molecular characteristics. Cross-immunization of inbred strain 2 and strain 13 animals, both of which bear the B.1 antigen, leads to sera which identify antigens which resemble the products of the I region of the murine MHC. Specific absorption experiments have demonstrated four distinct I region antigens. In addition to the B and I regions, inbred strain 2, strain 13, and some outbred animals bear an antigen (S.1) which is the product of a third genetic region and which also resembles the murine D or K region gene products in molecular size. The results of these studies should facilitate the use of the guinea pig as an experimental model for studies of genetic control of the immune response and the function of the histocompatibility-linked Ir genes.

Animals↗
PubMed1991

[Genetic fingerprinting of inbred lines, outbred lines, transgenic individuals and 3T3 cells of Mus musculus with the probe B.E.S.T. MZ 1.3].

DNA samples from different inbred strains and F1-hybrids, from two outbred strains and from transgenic animals of the species Mus musculus were tested according to the "DNA fingerprint" technique (Jeffreys et al., 1985) using the B.E.S.T.-probe MZ 1.3 (Fa. Biotest, Frankfurt) and the restriction endonuclease Hinf I. In addition, the same method was applied to two cell types i.e. BALB/3T3 clone A 31 and 3T3 B-SV40. The DNA fingerprinting technique with probe MZ 1.3 proved to be a reliable method for genetic monitoring of different strains of mice. All inbred strains tested as well as their substrains could be identified and distinguished from each other without any doubt. Congenic and transgenic individuals, however, were identical with their background strains. After several in vitro passages, cells from cultures showed the similar DNA configuration as the donor strains. Within outbred strains, it was possible to quantify heterozygosity by the configuration of the DNA-patterns. These results suggest that it might be appropriate to replace the mathematically estimated inbreeding coefficient by so-called identity-coefficient (IK), which would depend on the probe and the restriction endonuclease used (e.g. IKMZ 1.3/Hinf I). Using the MZ 1.3 probe, the DNA fingerprint technique allows a unique genetic identification of different strains of mice and offers, furthermore, the possibility to use a colour kit rather than the usual P-32 marker.

Animals↗
PubMed1996

Development in vitro of preimplantation embryos from 55 mouse strains.

Mouse pronuclear embryos were obtained by in vitro fertilization with oocytes of 55 strains of immature females by gonadotrophin-induced ovulation and epididymal sperm of Slc:ICR strain. The number of oocytes ovulated with hormones (5.3-49.4 oocytes per head; average, 22.6), rates of in vitro fertilization (12.2-95.3%; average, 70.7%) and subsequent preimplantation development in Whitten's medium (WM) varied greatly among strains. F1 hybrids developed significantly better than other strains of mice and outbred animals did not develop as well as inbred animals. Within inbred mice, coat colour had no significant effect. In addition, the observation of preimplantation development in WM supplemented with ethylenediamine tetraacetic acid (EDTA) showed that the beneficial effect of the chelator was not universal to mouse embryos; EDTA had a good effect on ICR and PW/aSlc embryos but not on AKR or ddY embryos. The results indicate that strain differences should be considered when interpreting reproductive experiments using mouse embryos.

Analysis of Variance↗
PubMed1979

Bone formation in cartilage produced by transplanted epiphyseal chondrocytes.

Chondrocytes were isolated from rat epiphyseal cartilage, cultured in vitro, and exposed to exogenous tracers which accumulated in their lysosomes. The cells were then injected into the posterior tibial muscle of animals from the same outbred strain, where they reconstructed calcifying hyaline cartilage. The mineralization of the tissue was followed by ingrowth of blood capillaries from the host bed. Macrophage-like cells surrounding the vessels phagocytized degenerated chondrocytes and unmineralized matrix, whereas multinucleated chondroclasts removed some of the mineralized cartilage matrix. Mesenchyme-like cells accompanying the invading vessels attached to the remaining septa of calcified cartilage matrix and developed into osteoblasts depositing bone matrix on the surface of these septa. The apparent lack of inherent tracer labeling of the lysosomes in the different bone cells indicate that they were derived from the host. No signs of transformation of chondrocytes into bone cells were observed. When isolated rat epiphyseal chondrocytes were injected into the wall of the hamster cheek pouch, calcifying cartilage was reconstructed without signs of subsequent ossification. Transplantation of cartilage reconstructed in the hamster into the dorsal muscles of rats was, however, followed by formation of bone by a sequence analogous to that described above. Such an osteogenetic response was also obtained when the cartilage had been devitalized before transplantation. These experiments show that calcified cartilage, developing in or grafted into an intramuscular site, is able to induce and serve as a substrate for endochondral bone formation, similar to that occurring during normal development. They further indicate that bone induction by calcified cartilage does not require the presence of living chondrocytes.

Animals↗
PubMed1987

Halothane hepatotoxicity in guinea pigs.

A recently reported animal model of halothane-associated hepatotoxicity in males of a colored strain of guinea pig was further characterized as to possible sex and strain specificity in outbred albino Amana, inbred albino Hartley, inbred colored strain 2, and inbred colored strain 13 guinea pigs. Exposure to 1% halothane for 4 hr in 21% O2 proved to be hepatotoxic in both sexes. Forty-eight hours after halothane exposure fatty vacuolization of hepatocytes was present in all animals. Histologically identifiable hepatic necrosis occurred in 60% of the guinea pigs exposed, along with concomitant increases in SGPT. Approximately one half of these responding animals had extensive centrilobular necrosis, which was still present 96 hr after halothane exposure. Females of the inbred strain 2 and males and females of strain 13 were the most susceptible to halothane-induced hepatic necrosis whereas the inbred Hartley strain was almost totally refractory to necrosis. Outbred Amana and male inbred strain 2 animals exhibited an intermediate hepatotoxic response. Comparison of the halothane-associated hepatic lesion with that induced by anoxic/ischemic mechanisms, (exposure to low (8%) oxygen during 1.7% enflurane anesthesia) showed obvious differences in the morphology of the hepatic necrosis and the apparent time course of lesion development. This guinea pig model of halothane-associated hepatotoxicity appears to be superior to previous animal models in that no pretreatment of the guinea pigs is required, both sexes are affected, and the resulting hepatic lesion is more persistent.

Animals↗
PubMed2001

Mitigation of hookworm disease by immunization with soluble extracts of Ancylostoma ceylanicum.

Hookworms are a leading cause of anemia in developing countries, and a strategy aimed at reducing pathology caused by blood-feeding adult parasites would be a valuable addition to global control efforts. This article describes experiments designed to induce resistance to the major clinical sequelae (weight loss and anemia) of Ancylostoma ceylanicum hookworm infection in Syrian golden hamsters of the outbred LVG strain. Previously infected animals acquired long-lived resistance to weight loss and anemia caused by a secondary hookworm infection. Furthermore, transfer of pooled serum from twice-infected hamsters to animals undergoing a primary infection was associated with partial resistance to growth delay and anemia. Active vaccination of hamsters with soluble adult hookworm antigens emulsified in alum led to partial protection from hookworm-associated pathology in the absence of reductions in adult worm burden. This intriguing result may have important implications for human vaccine development.

Ancylostoma↗
PubMed2003

The role of glutathione in metabolism of selected dimethylnaphthalenes in rat.

OBJECTIVES: Methylnaphthalenes have been used extensively as chemical intermediates in organic synthesis, as solvents for pesticides, sulphur and various aromatic compounds. A wide use of methylnaphthalenes has contributed to their emission into the environment. The aim of the study was to explain the role of glutathione in metabolism of selected dimethylnaphthalenes in rat. MATERIALS AND METHODS: The experiments were conducted on male rats of the strain outbred IMP:WIST The animals were administered a single intraperitoneal dose (600 mg/kg body weight) of dimethylnaphthalenes (1,2-DMN; 1,3-DMN; 1,4-DMN) or dimethylnaphthalenes-[ring-U-3H]: (1,2-DMN-[3H]; 1,3-DMN-[3H]; 1,4-DMN-[3H]). The analysis was performed after 4, 8, 24, 48 h. The biochemical parameters were indicated: hepatic and pulmonary GSH, a-GST, SDH, GPX in blood, and adduct levels in the liver and lung. RESULTS: The investigations demonstrated that a single intraperitoneal administration of dimethylnaphthalenes to rats at a dose of 600 mg/kg body weight caused a substantial depletion of reduced glutathione (GSH) level both in the liver and lung. The activity of a-glutathione S-transferases in serum of experimental animals exposed to dimethylnaphthalenes increased only after 1,2-DMN administration, the compound for which in earlier investigations the largest number of sulphur-containing metabolites was found in urine. To evidence that deep GSH depletion in analyzed organs has no oxidative nature, glutathione peroxidase activity in blood was determined. CONCLUSIONS: Lack of changes in glutathione peroxidase and sorbitol dehydrogenase activity for all the investigated compounds suggests that significantly deep GSH depletion in liver was not of oxidative nature and did not lead to necrotic changes in produced metabolites binding with GSH.

Analysis of Variance↗
PubMed2004

Age disproportionately increases sepsis-induced apoptosis in the spleen and gut epithelium.

Both aging and sepsis independently increase splenic and gut epithelial apoptosis. Sepsis-induced apoptosis in either cell type is also associated with increased mortality in young mice. We sought to determine whether age alters sepsis-induced splenic and gut epithelial cell death. Young (2 months) and aged (22 months) male ND4 mice were subjected to either single-puncture cecal ligation and puncture (CLP) with a 23-gauge needle or sham laparotomy. Apoptosis was assessed 24 hours later in the spleen and gut epithelium by active caspase 3 and hematoxylin and eosin staining. Aged septic mice had increased splenic apoptosis compared with either young septic animals or aged sham animals (15 vs. 7 vs. 5 apoptotic cells/high-powered field, P < 0.05). Similarly, aged septic animals had an elevation in gut epithelial cell death compared with either young septic or aged sham mice (33 vs. 16 vs. 6 apoptotic cells/100 contiguous crypts, P < 0.05). Elevated intestinal cell death was not associated with changes in either gut proliferation or cell division. To verify that the increase in splenic apoptosis seen in septic aged animals was not strain specific, double-puncture CLP with a 25-gauge needle or sham laparotomy was performed on young (4 months) or aged (24 months) C57BL/6 male mice. Similar to results seen in outbred animals, aged septic animals in this inbred strain had increased splenic apoptosis compared with either young septic animals or aged sham animals (23 vs. 7 vs. 4 apoptotic cells/ high powered field, P < 0.05). These results indicate that although infection and aging each independently cause an increase in splenic and gut epithelial apoptosis, their combination leads to a disproportionate increase in cell death in these rapidly dividing cell populations,and potentially plays a role in the marked increase in mortality seen with aging in sepsis.

Aging↗
PubMed1983

[Effect of islet isograft on diabetes in pancreatectomized rat--long term comparative studies between outbred and inbred animals].

A reproducible model of a diabetic state was produced after resecting more than 90% of pancreatic tissue in Wistar strain male rat (outbred and inbred group). Of a total of 10 animals of outbred group, 6 animals illustrated a blood glucose level over 250 mg/dl in an earlier stage after an injection of 1500 islets into the portal vein. However, in 4 of them blood glucose levels were maintained within normal limit until 4 months. On the other hand, 5 inbred rats in which 500-600 islets were injected demonstrated reversal of diabetes within 1 week after the injection and the effect of the transplantation lasted until about 6 months. A morphometric analysis using 1190 serial histological sections of the control rat pancreas showed that the islet distribution accorded satisfactorily with Weibull or Gamma distribution. The estimated values of size and number of the islet were 0.0155 mm and 131.2/mm3, respectively, while volume ratio of splenic and gastric segments or parabiliary and duodenal segments was estimated to be 1.45 or 0.98%, respectively. The mean size of the isolated islets under dissecting microscope reached 0.080 mm and 500 of them were equivalent to about 10% volume fraction in a whole control pancreas. In the inbred group a transplanted animal contained about 17% of islet volume as compared with control animal.

Animals↗
PubMed2005

No relationship between sequence variation in protein coding regions of the Tas1r3 gene and saccharin preference in rats.

Nearly all mammalian species like sweet-tasting foods and drinks, but there are differences in the degree of 'sweet tooth' both between species and among individuals of the same species. Some individual differences can be explained by genetic variability. Polymorphisms in a sweet taste receptor (Tas1r3) account for a large fraction of the differences in consumption of sweet solutions among inbred mouse strains. We wondered whether mice and rats share the same Tas1r3 alleles, and whether this gene might explain the large difference in saccharin preference among rats. We conducted three experiments to test this. We examined DNA sequence differences in the Tas1r3 gene among rats that differed in their consumption of saccharin in two-bottle choice tests. The animals tested were from an outbred strain (Sprague-Dawley; experiment 1), selectively bred to be high- or low-saccharin consumers (HiS and LoS; experiment 2), or from inbred strains with established differences in saccharin preference (FH/Wjd and ACI; experiment 3). Although there was considerable variation in saccharin preference among the rats there was no variation in the protein-coding regions of the Tas1r3 gene. DNA variants in intronic regions were detected in 1 (of 12) outbred rat with lower-than-average saccharin preference and in the ACI inbred strain, which also has a lower saccharin preference than the FH/Wjd inbred partner strain. Possible effects of these intronic nucleotide variants on Tas1r3 gene expression or the presence of T1R3 protein in taste papillae were evaluated in the ACI and FH/Wjd strains. Based upon the results of these studies, we conclude that polymorphisms in the protein-coding regions of the sweet receptor gene Tas1r3 are uncommon and do not account for individual differences in saccharin preference for these strains of rats. DNA variants in intron 4 and 5 are more common but appear to be innocuous.

Animals↗
PubMed1998

Development and use of genetically uniform strains of common carp in experimental animal research.

Fish are widely used in numerous fields of basic and applied research. Currently, they are the third laboratory animal group in numbers, and will become increasingly important. Common carp is a major species in both aquaculture and research. Inbred strains of carp by gynogenetic (only female inheritance) and androgenetic (only male inheritance) reproduction techniques were developed at our university. With these methods, homozygous animals are produced in one generation and we present the production of homozygous inbred and F1 hybrid strains of common carp. As in mammalian research, using genetically well defined fish is a methodological necessity since in outbred stocks: (1) repeatability between experiments is low, (2) high levels of inbreeding may have accumulated and (3) high intrastrain variability might obscure treatment effects. Within inbred strains, the variation is reduced and as a result, less animals (compared to outbreds) are necessary to obtain statistically significant results. We illustrate this with experimental data from an F1 hybrid and partly outbred strain of common carp, both subjected to an antibiotic treatment resulting in reduced gonadal growth. Results obtained from a single inbred strain should be generalized with the use of a panel of inbred strains. We show that optimal allocation of animals between and within inbred strains depends on the ratio (variation between strains): (variation within strains). When selecting a panel of inbred strains, attention has to be paid to genetic relations between strains to avoid testing within a limited genetic range. It should be considered that in inbred strains, (genic) dominance and interaction effects are absent, due to the absence of heterozygous genotypes. In general, variation within inbred strains will be reduced for traits with a high degree of genetic determination. However, in inbred strains of carp produced by gynogenesis or androgenesis, the chromosome manipulation treatment induces considerable (environmental) variation. By using F1 hybrids of carp, derived from crossing homozygous clonal siblings this source of variation can be avoided. Still, variation in F1 hybrids of carp is relatively large and varies greatly between strains when compared to inbred strains of laboratory rodents. It is assumed that their poikilothermic nature makes them more susceptible to environmental variation. Using inbred fish lines will increase experimental quality and leads to a more efficient use of experimental animals.

Animals↗
PubMedDate not supplied

Male reproductive effects of octylphenol and estradiol in Fischer and Wistar rats.

4-tert-Octylphenol is a non-ionic surfactant used as a detergent, emulsifier and wetting agent. It is generally accepted that it acts as a weak estrogenic substance when evaluated in in vitro and in vivo short-term screening assays. The sensitivity of animal species (mouse versus rat), strain (inbred versus outbred) has been a matter of concern when selecting assay type for testing of estrogenicity of chemicals. The present study was designed to investigate whether the choice of different animal strain, could affect the outcomes of studies. Fischer and Wistar adult male rats were exposed to vehicle or 400 mg/kg bw of 4-tert-octylphenol administrated orally by gavage. Estradiol benzoate, at a dose of 40 microg/kg bw, was used as positive control agent. Treatment with estradiol benzoate decreased serum levels of testosterone, LH, FSH, inhibin and increased prolactin. Additionally, estradiol benzoate decreased the weight of all investigated reproductive organs, decreased sperm production and increased seminiferous tubular degeneration in both strains. More progressive effects on testis weight and histopathology were observed in the Fischer rats. Oral administration of octylphenol at 400 mg/kg bw to both rat strains increased prolactin levels but had no effect on LH, FSH, testosterone or inhibin. In the octylphenol-treated Fischer rats the weights of the seminal vesicles and the levator ani/bulbocavernosus muscle were significantly decreased, whereas only the levator ani/bulbocavernosus muscle was affected in Wistar rats. The weights of all other reproductive organs and sperm count were unaffected. It is concluded that there might be an organ specific difference in sensitivity between the two strains with the Fischer rat being the most sensitive rat model as demonstrated mainly by the more progressive effects on testis weight and histopathology in estradiol benzoate-treated Fischer rats but also by the decrease in seminal vesicle weight in octylphenol-treated rats.

Administration, Oral↗
PubMed1994

Genetic characterization of the mouse strains of the Institute for Animal Breeding of the Veterinary Faculty of the University of Munich, Germany.

A total of 15 strains of mice (11 inbred lines, 4 outbred stocks) of the institute for animal breeding of the veterinary faculty of the university of Munich (FRG) were scored for 23 biochemical loci each. The allelic distribution and frequencies were recorded as a basis for a so far not established genetic monitoring system. The inbred strains revealed the expected homozygosity with one exception (strain UMDH/+; locus Es1). The outbred stocks showed a remarkable degree of variable loci (17.4-36.3%) with a mean heterozygosity between 0.05 and 0.12. The markers in use allow differentiation between all strains (except for one pair of sublines) and stocks. 14 of the loci show allelic differences among the strains and thus can be used for a genetic monitoring system.

Alleles↗
PubMed1988

Individual odors of rats are discriminable independently of changes in gonadal hormone levels.

Male Long-Evans hooded rats were tested for their ability to discriminate between the urine odors from individual outbred Long-Evans rats using the habituation-dishabituation method. There were discriminable differences between the urine odors of two individual intact males, castrated males, estrous/proestrous females, diestrous/metestrous females and ovariectomized females. Thus, individual outbred rats of both sexes can be discriminated on the basis of their urine odors using this technique and discrimination between individuals occurs despite changes in gonadal hormone levels. This suggests that individual recognition is independent of reproductive state and social status although these may influence the production of body odors used for individual discrimination in rats. Individual odors most likely reflect genetic differences between individuals within the outbred strain.

Animals↗
PubMedDate not supplied

Outcome of xenografted fetal porcine pancreatic tissue is superior in inbred scid (C.B-17/Icr-scid/scid) compared to outbred nude (CD-1-nu/nu) mice.

Nude mice are used as recipients of foreign tissue because of their inability to reject these grafts. Our experience has been that there is variable rejection of fetal porcine insulin-producing tissue transplanted into CD-1 (athymic) outbred nude mice. To examine the suitability of this line of nude mouse as a recipient of the tissue, fetal porcine pancreas was grafted either into these outbred animals or into an inbred mutant strain of mice, the more immunocompromised severe combined immunodeficient (scid) mouse. Eight weeks after transplantation grafts were recovered from recipients and assayed for insulin content. Mean insulin levels were not significantly different between the two groups of mice, but a wider range of values was obtained from grafts recovered from nude (CD-1-nu/nu) mice. Reversal of diabetes in hyperglycemic recipients was achieved in 4 of 8 nude mice and 8 of 8 scid (C.B-17/lcr-scid/scid) mice. The time taken to achieve this was longer in the nudes than the scid mice, 121 +/- 12 vs. 44 +/- 2 days, the grafts increasing in size at a slower rate in the nude mice. Time taken for the weight of the grafts to double in size was 94 +/- 17 vs. 32 +/- 1 days, respectively. Histologically the grafts in the scid mice contained mostly epithelial cell clusters, a majority of which were insulin containing. In the nude mice that achieved normoglycemia, a similar pattern was observed and, as well, there was a localized lymphoid infiltrate. In those nude mice that remained diabetic fibrous tissue predominated together with a lymphoid infiltrate. In summary, fetal porcine pancreatic tissue grows and develops more efficiently when xenografted into scid rather than outbred nude mice.

Animals↗
PubMed1994

Genetic control of the antibody repertoire against excretory/secretory products and acetylcholinesterases of Dictyocaulus viviparus.

Outbred Dunkin-Hartley and inbred strain 2 and strain 13 guinea pigs were immunized with Dictyocaulus viviparus adult ES products prior to challenge with third stage larvae. Antibody responses of the three strains to adult ES products and the acetylcholinesterase (AChE) isoforms which they contain were examined. Using immunoprecipitation and ELISA, it was observed that responses in the three strains to adult ES products were distinct: considerable heterogeneity in the antibody repertoire was observed between outbred Dunkin-Hartley animals, with only slight variation occurring amongst the inbred individuals. Responses to the AChE isoforms were heterogeneous amongst individual outbred guinea pigs but were more consistent in inbred strain 2 and 13 animals in which strain-specific patterns of recognition were observed. Previous studies with nematode infections have indicated a role for the major histocompatibility complex in determining the nature and level of the immune response. As the inbred strains bear different alleles at the Class II region but are identical at the Class I region, the differences observed are likely to be due to genes mapping to the Class II locus. This is therefore the first report of genetic restriction of the antibody repertoire to secreted AChEs of a parasitic nematode.

Acetylcholinesterase↗