Experimental Animals
Online ISSN : 1881-7122
Print ISSN : 1341-1357
ISSN-L : 0007-5124
55 巻 , 5 号
選択された号の論文の14件中1~14を表示しています
Original
  • Shin TANAKA, Sachi KUWAHARA, Kazutoshi NISHIJIMA, Tamio OHNO, Masahiro ...
    2006 年 55 巻 5 号 p. 415-418
    発行日: 2006年
    公開日: 2006/11/08
    ジャーナル フリー
    The characteristics of the mandible bone were compared through DXA methods between two major substrains of F344 rats, F344/DuCrlCrlj and F344/NSlc at around 60 days of age. Since these two substrains are clearly different in survival and mandible morphology, some genetic differences are supposed to exist. In contrast to a previous microsatellite analysis, clear and significant differences were detected in the body and mandible weights, the mandible bone mineral contents (BMC), bone area (AREA), bone mineral density (BMD) and bone mineral ratio (BMR), between F344/DuCrlCrlj and F344/NSlc, with the mandible molar teeth intact in the bone. Thus, care is needed in the experimental use of these substrains, as results may differ between them. The newly proposed parameter, BMR, may especially contribute to the comparison of bone characteristics among species.
  • Masanobu HAYASHI, Sayaka FUSE, Daiji ENDOH, Noboru HORIGUCHI, Kenji NA ...
    2006 年 55 巻 5 号 p. 419-426
    発行日: 2006年
    公開日: 2006/11/08
    ジャーナル フリー
    Copper accumulation and induction of DNA strand breaks were investigated in the brain of Long-Evans Cinnamon (LEC) rats, an animal model for human Wilson disease that is a heritable disease of copper accumulation and copper toxicity in the liver, kidney and brain. Copper contents in the brain of LEC rats increased from 20 weeks of age and were approximately 3.5 to 6 folds higher than those in the brain of WKAH rats at 24 weeks of age. Hepatic copper contents in LEC rats increased from 4 to 12 weeks of age in an age-dependent manner, and then decreased from 16 to 20 weeks of age. Thus, we consider that copper accumulated in the liver was released from severely damaged hepatocytes and deposited in the brain, although copper contents in the brain were 1/20-fold lower than those in the liver. We also evaluated the amounts of DNA single-strand breaks (SSBs) in the brain by comet analysis. The proportions of nuclei in the cerebrum and cerebellum without DNA damage decreased, and nuclei with severe DNA damage appeared in LEC rats at 24 weeks of age. The comet scores of cerebrum and cerebellum cells significantly increased in LEC rats and were significantly higher than those in WKAH rats at 24 weeks of age. The results show that SSBs in LEC rat brain cells are induced at a lower concentration of copper than are SSBs in hepatic cells.
  • Jong-Hwan PARK, Seung-Hyeok SEOK, Min-Won BAEK, Hui-Young LEE, Dong-Ja ...
    2006 年 55 巻 5 号 p. 427-432
    発行日: 2006年
    公開日: 2006/11/08
    ジャーナル フリー
    In this study, microbiological monitoring of guinea pigs reared conventionally in two facilities was performed twice in 2004, with a three-month-interval between surveys. This study was based on the recommendations of the FELASA Working Group, with some modifications. In serological tests in the first survey, some animals from facility A showed positive results for Encephalitozoon cuniculi, Sendai virus, pneumonia virus of mice (PVM), and Reovirus-3 (Reo-3); facility B showed a positive result only for E. cuniculi. The results of the second survey were similar to the first, except for the presence of Sendai virus; all animals from the two facilities were Sendai virus-negative in the second experiment. No pathogenic bacteria were cultured in the organs of any of the animals in the first survey. However, in the second survey, Bordetella bronchiseptica was cultured from the lung tissue of two 10-week-old animals from facility A. Chlamydial infection was examined by the Macchiavello method, but no animal showed positive results. Tests using fecal flotation or the KOH wet mount method showed no infection of endoparasites, protozoa, ectoparasites, or dermatophytes in any animal in both surveys. However, in the histopathological examination, an infection of protozoa-like organisms was observed in the cecum of some animals from facility A. The present study revealed that microbiological contamination was present in guinea pigs reared conventionally in two facilities in Korea, suggesting that there is a need to improve environmental conditions in order to eradicate microbial contamination.
  • Shin TANAKA, Sachi KUWAHARA, Kazutoshi NISHIJIMA, Yasunori NAKAMURA, Y ...
    2006 年 55 巻 5 号 p. 433-438
    発行日: 2006年
    公開日: 2006/11/08
    ジャーナル フリー
    The shape of the mandible was compared by morphometric methods to ascertain the genetic differences between two substrains of F344 rats, F344/DuCrlCrlj and F344/NSlc. Since these two substrains are clearly different in survival and the incidence of age associated disorders; thus, some genetic differences are suggested to be present between them. Although previous microsatellite analysis did not detect any differences between the two F344 substrains, the present study clearly detected interesting differences in the mandible morphology. At 2 months of age, the F344/Du mandible was characterized by a larger size, especially in length, than the F344/N mandible. The shape of the mandible seemed to be more variable in F344/N. This clear substrain difference suggests the importance of the substrain recognition in F344 rats, especially in experimental usage.
  • Cheng HE, Qi YANG, Ming LEI, Wanyong PANG, Jianmin YANG, Hong ZHU, Qin ...
    2006 年 55 巻 5 号 p. 439-447
    発行日: 2006年
    公開日: 2006/11/08
    ジャーナル フリー
    The objective of this study was to investigate the pathogenicity and associated lesions of a new reovirus (ReoV) isolated from patients with Severe Acute Respiratory Syndrome (SARS) in China. Twenty-five four-week-old BALB/c female mice inoculated intranasally with either ReoV (strain BYD1) alone, or ReoV combined with SARS-CoV (strain BJF) displayed ejecting fur and loss of body weight compared with control animals. ReoV and SARS-CoV were isolated from most postmortem tissues. The histopathological features of ReoV infected animals consisted of diffuse alveolar damage, with scattered hemorrhage, hyaline membrane formation and interstitial pneumonia. A typical type II pneumocyte hyperplasia and fibrogranulomatous tissue formation in the alveolar septae were observed both in the animals inoculated simultaneously with these two viruses and in the animals inoculated firstly with SARS-CoV, followed by ReoV. The animals inoculated firstly with ReoV, followed with SARS-CoV displayed scattered hemorrhage in the alveolar septa. Furthermore, other lesions in above two combination groups included depletion of lymphocytes in the germinal center of lymph nodes in the lung hilus and the spleen, hemorrhagic necrosis in white pulp of spleen, hydroid degeneration, and fatty degeneration in the liver and kidney. Mice induced with SARS-CoV alone did not display clinical signs, characteristically hyaline membrane formation, hemorrhage and early pulmonary fibrosis in lung tissue. This study demonstrated that the newly isolated ReoV might be a virulent pathogen for BALB/c mice. Mice infected firstly with SARS-CoV, followed with ReoV developed a typical diffuse alveolar lesion.
  • Ilknur OZDEMIR, Zeliha SELAMOGLU TALAS, Mehmet GUL, Burhan ATES, Yetki ...
    2006 年 55 巻 5 号 p. 449-455
    発行日: 2006年
    公開日: 2006/11/08
    ジャーナル フリー
    The balance between prooxidants and antioxidants is crucial to the survival and functioning of aerobic organisms. Partially reduced derivatives of oxygen, which are produced in aerobic organisms as part of normal physiological and metabolic processes, are toxic species, oxidizing numerous biomolecules, which initiate tissue injury and cell death. DMBA (7,12-dimethylbenz[a]anthracene) is a polycyclic aromatic hydrocarbon (PAH) known to cause tumors in rats. DMBA is known to generate DNA-reactive species, which may enhance oxidative stress in cells, during its metabolism. Besides the formation of DNA adducts, oxidative products derived from mutagen metabolism, such as DMBA, might impair vital cellular functions by damaging proteins and lipid membranes. Synthetic organoselenium compounds inhibit the initiation phase of carcinogenesis by inhibiting DMBA-DNA adduct formation in the target organ in vivo. Because of the health problems induced by many environmental pollutants, many efforts have been undertaken to evaluate the relative antioxidant potential of selenium and synthetic organoselenium compounds. We undertook the present study to evaluate the chemopreventive potential of the novel synthetic organoselenium compounds (1-isopropyl-3-methylbenzimidazole-2-selenone (SeI) and 1,3-di-p-methoxybenzylpyrimidine-2-selenone (SeII)) in the well-established DMBA-treated rat model by monitoring the extent of lipid peroxidation and mammary duct damage. In this study, adult female Wistar rats were treated with DMBA and the novel organoselenium compounds (SeI and SeII) in determined doses. In DMBA-treated rats, the effects of the organoselenium compounds on malondialdehyde (MDA) levels and histological changes in the rat mammary lactiferous duct were studied. The ability of the organoselenium compounds to prevent oxidative damage induced by DMBA in rat mammary ducts was demonstrated. Protection against lipid peroxidation measured as MDA in the SeI and SeII treated groups was provided by the novel synthesized organoselenium compounds. SeI and SeII both provided chemoprevention against DMBA-induced oxidative stress in the rat mammary duct.
  • Jun IWAMOTO, Tsuyoshi TAKEDA, Yoshihiro SATO, Chwan-Li SHEN, James K. ...
    2006 年 55 巻 5 号 p. 457-466
    発行日: 2006年
    公開日: 2006/11/08
    ジャーナル フリー
    The purposes of the present study were to differentiate the effects of pre-surgery treatment with risedronate and post-surgery treatment with a reduced dosing frequency of risedronate on trabecular bone loss in ovariectomized rats and to determine whether post-surgery treatment with a reduced dosing frequency of risedronate would have a beneficial effect on trabecular bone loss after pre-surgery treatment with risedronate by means of bone histomorphometric analysis. The short-term experiment (6 weeks) was performed on fifty, 4-month-old, female Sprague-Dawley rats randomized into five groups (n=10 in each group). Forty rats were treated with vehicle or risedronate for 4 weeks before ovariectomy (OVX), and then treated with either vehicle or risedronate for 2 weeks following OVX (the Vehicle-OVX-Vehicle [OVX control], Vehicle-OVX-Risedronate [post-OVX treatment with risedronate], Risedronate-OVX-Vehicle [pre-OVX treatment with risedronate], and Risedronate-OVX-Risedronate [continuous treatment with risedronate] groups). The remaining 10 rats were treated with vehicle for 6 weeks, with a sham operation performed 4 weeks after the start of the experiment (the Vehicle-Sham-Vehicle [Sham control] group). During the 4 weeks prior to surgery, risedronate was administered five times a week subcutaneously at a dose of 2.5 μg /kg body weight, and during the 2 weeks after surgery, the dosing frequency was reduced to twice a week. The long-term experiment (10 weeks) had the same design as the short-term one, except that the post-OVX treatment was 6 weeks. In the short-term experiment, both pre- and post-OVX treatments with risedronate prevented trabecular bone loss of the proximal tibial metaphysis 2 weeks after OVX. In long-term experiment, however, pre- and post-OVX treatments with risedronate attenuated trabecular bone loss until 6 weeks after OVX, with pre-OVX treatment having a less pronounced effect than post-OVX treatment. In the short- and long-term experiments, pre-and post-OVX treatments had an additive effect on trabecular bone mass. The present study has shown the efficacy of pre-OVX treatment with risedronate or post-OVX treatment with a low dosing frequency of risedronate for preventing trabecular bone loss early after OVX. Post-OVX treatment with a low dosing frequency of risedronate was beneficial for attenuating trabecular bone loss late after OVX. Treatment with risedronate before OVX had an additive effect on trabecular bone mass with the treatment after OVX, suggesting that treatment with a low dosing frequency of risedronate might be acceptable for reducing OVX-induced trabecular bone loss after treatment with risedronate prior to OVX.
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