Experimental Animals
Online ISSN : 1881-7122
Print ISSN : 1341-1357
ISSN-L : 0007-5124
Volume 44, Issue 3
Displaying 1-14 of 14 articles from this issue
Original
  • Sumio MINEMATSU, Masahiro HIRUTA, Masayuki WATANABE, Sakae AMAGAYA
    Article type: Original
    1995 Volume 44 Issue 3 Pages 173-179
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    Spectral analyses by maximum entropy method were performed on the time-seriesdata of body weight, food and water consumption and spontaneous motor activity in Sprague-Dawley rats. These parameters were recorded by a monitoring system collected every 30 min for 10 days. All the parameters had circadian (24 ± 4 hr) and ultradian (less than 20 hr) rhythms. From the logarithmic transformation of spectral frequencies and their power spectral densities, the characteristics of the spectrum of body weight showed 1/f fluctuation and those of food and water consumption were white noises. The spectrum of the spontaneous motor activity showed complex characters. The range of frequencies lower than 0.1 Hz showed white noise while the range of those higher than 0.1 Hz were 1/f or 1/f 2 fluctuations, especially in the range between 0.5 and 1.0 Hz (1-2 hours cycle). The auto-correlation coefficients of body weight did not declined suggesting that 24 hours cycle is only periodic phenomenon in body weight changes. Though the auto-correlation coefficients of food and water consumption also did not declined, they had not enough auto-correlations. This was consistent with the appearence of white noise in spectral analyses. The auto-correlation coefficients of spontaneous motor activity declined remarkably, and this suggests that there are various periodic changes in spontaneous motor activity including one to two hours cycles. These results suggest that the possibility of further extension of research is expected by using rhythmicity. It is also indicated that the time of measurement of body weight must be taken into consideration in experiments because of the presence of the circadian rhythmic changes.
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  • Tsutomu KOIZUMI
    Article type: Original
    1995 Volume 44 Issue 3 Pages 181-185
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    The distribution of deoxyribonuclease I (DNase I) in mouse tissue and body fluids, the effects of sex on the enzyme activity, and the postnatal developmental regulation of the enzyme were examined in C3H/He mice. DNase I activity was high in the salivary gland and urine; and moderate in the liver, kidney, spleen, preputial gland and seminal vesicle. Weak activity was detected in the pancreas, heart, lung, brain, small intestine, thymus, coagulating gland and serum. Sexual dimorphism, of which males had significantly higher activity than females, was observed in the kidney, urine and liver. This sexual dimorphism in renal DNase I activity was eliminated by gonadectomy to males and testosterone treatment to females. These results reveal sex hormonal control of DNase I production in the kidney. DNase I activity in the liver of infant mice was almost equivalent to that of adult mice while the enzyme activity in the salivary gland, kidney and spleen remained at a low level; less than 5% at one week old and less than 20% at four weeks old. These results suggest tissue specific control of DNase I activity levels during postnatal development.
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  • Keiko ODAGIRI, Yasuo MATSUZAWA, Yasuhiro YOSHIKAWA
    Article type: Original
    1995 Volume 44 Issue 3 Pages 187-192
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    In this study, a matured ram was paired with an estrus ewe and sexual behavior was investigated. All the behavior was recorded by a time-lapse video tape recorder from the start of pairing. The series of unit movements comprising the sexual behavior, the mounting series (MS), was extracted from the record and analyzed quantitatively (n=774). The MS starts from ram's approaching or following a ewe and ends by ram’s mounting on a ewe. The sexual behavior was consisted of the following eight unit movements, following or approaching (F/A), chin resting (CR), flehmen (Fl), mounting (Mo), nosing (No), nudging (Nu), pushing (Pu) and twisting (Tw). Analysis of a frequency of any combinations of two unit movements consisted of preceding and succeeding ones, observed in the MS was conducted by cell-by-cell test using the transitional matrix to make a flow-diagram of the ram's sexual behavior. As a result, the pattern of unit movements, F/A-Tw-Nu-CR-Mo, formed a main route of the MS, whereas the repertoire of a sequential pattern increased by diverging. Though Fl and No didn’t lead to mounting directly, these movements associated with olfactory perception also belonged to sexual behavior and may have independent function from other six unit movements that constitute the MS.
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  • Osamu UCHIUMI, Shoei SUGITA, Katsuhiro FUKUTA
    Article type: Original
    1995 Volume 44 Issue 3 Pages 193-203
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    Retinal projections in the Japanese field vole (Microtus montebelli) were determined by anterograde transport of horseradish peroxidase (HRP). Injection of HRP into the unilateral vitreous body demonstrated that the terminal labeling of the optic projections was seen bilaterally in the suprachiasmatic nucleus (SCH), the ventral (GLv) and dorsal (GLd) lateral geniculate nuclei, the intergeniculate leaflet (IGL), the medial pretectal nucleus (NTOM) of the pretectum (PT) and the superficial layer of the superior colliculus (CS), with contralateral predominance, and only contralaterally labeled terminals were found in the lateroposterior thalamic nucleus (LP), the lateral pretectal nucleus (NTOL) of the PT, the dorsal (DTN) and medial (MTN) terminal nuclei of the accessory optic system (AOS). The distribution area of the retinofugal terminals was divided into a three laminar arrangement in the GLd, i.e., layers 1 and 3 and layer 2, received the retinal input from contralateral and ipsilateral eye, respectively, as in arboreal squirrels. The contralateral CS received retinal fibers in the superficial layer, while ipsilateral optic fibers projected sparsely to the stratum opticum of the colliculi. Retinal connections to the DTN and MTN of the AOS were clearly discerned but no lateral terminal nucleus with retinal afferents was found. In addition, the AOS had no inferior fasciculus. These findings indicate that the vole has a contradictory features of a well- and a less-developed sense of vision. Namely, the image forming visual system such as the retino-GLd was as well-developed as in a squirrel, on the other hand, the non-image forming visual system such as the retino-AOS was less-developed as in an insectivore's brain.
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  • Otoya UEDA, Kouichi JISHAGE, Nobuo KAMADA, Satomi UCHIDA, Hiroshi SUZU ...
    Article type: Original
    1995 Volume 44 Issue 3 Pages 205-210
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    Mice entirely derived from ES cells were obtained from aggregates of TT2 ES cells and cytochalasin B induced tetraploid embryos. Tetraploid embryos were cocultured with ES cells in a well on the Multiplate-Terasaki. After embryo transfer of the aggregates, the male newborns were recovered normally after Cesarean section and reached adulthood. The male mice exhibited complete pigmentation of the eye and coat, suggesting ES cell contributions alone. Alkaline phosphatase-1 analysis yielded no evidence of tetraploid cells in the kidney or liver. The TT2-derived males were fertile, produced normal offspring, and exclusively transmitted the TT2 genotype to their progeny. This result clearly shows that ES cells are able to support complete fetal development.
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  • Katsuaki DAN, Yoshiko SETO, Tomonobu FUJITA, Yoshiaki ASABA, Izumi TAK ...
    Article type: Original
    1995 Volume 44 Issue 3 Pages 211-218
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    A murine diabetes mellitus induced with a new diabetogenic variant (DK-27) which we isolated from the M variant of the encephalomyocarditis (EMC) virus was characterized. Male DBA/2 mice (9.5 weeks old) were infected with various infectious doses of DK-27 intraperitoneally. Blood glucose and insulin levels were examined in association with the viral replication. Pancreatic pathology and hormone contents and stable hemoglobin A1c (St-A1c) levels were also examined on the final day of observation (35 days of post-infection). In infected mice, blood glucose levels rapidly elevated at 72 hr, slightly decreased between 7 and 10 days and finally became sustained hyperglycemia. On the other hand, blood insulin levels elevated at 48 hr, promptly decreased, and subsequently became sustained hypoinsulinemia. Viral replication in pancreases reached the highest titers at 48 hr and rapidly disappeared with all infectious doses used. Pancreatic insulin contents in infected mice were not detectable, and glucagon contents were not affected. In pathological examination, atrophy of islets and marked diminution of B-cells were observed, and A-cells occupied the major part of an infected islet. St-A1c levels reflected lasting hyperglycemia. These findings show that DK-27 causes insulin-dependent diabetes mellitus by the specific and direct destruction of pancreatic B-cells in susceptible mice. Such a diabetic model mouse will be useful for therapeutic studies.
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  • Kazuhiro HIRAYAMA, Kazuhiro MIYAJI, Seiji KAWAMURA, Kikuji ITOH, Eiji ...
    Article type: Original
    1995 Volume 44 Issue 3 Pages 219-222
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    Development of intestinal flora in newborn human-flora-associated (HFA) mice was compared with that in newborn conventional (CV) mice. Facultative anaerobes were detected from the first day after birth in both CV and HFA mice but anaerobes were not detected in the first week. Anaerobes rapidly increased from the 2nd week after birth and became predominant in newborn intestine. Most of the intestinal bacteria in adult CV and HFA mice were colonized in the intestine of CV and HFA mice, respectively, within 3 weeks after birth. The human intestinal flora established in the intestine of HFA mice finally reproduced without any remarkable change in composition in the intestine of newborn HFA mice. The development of intestinal flora in HFA mice was similar to that in CV mice but not that in human infants. These results indicated that human flora associated in HFA mice could be transferred from mothers to their offspring although HFA mice could not simulate the development of intestinal flora of the human infant.
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  • Sumio MINEMATSU, Masahiko WATANABE, Naoko TSUCHIYA, Masayuki WATANABE, ...
    Article type: Original
    1995 Volume 44 Issue 3 Pages 223-232
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    Diurnal variations in 23 blood chemical items were investigated in Sprague- Dawley rats of both sexes at 6 weeks of age. Blood samples were obtained every two hours. One to three periodic components detected by the maximum entropy method from the observed time-series and the optimum fitting parameters were calculated by the least squares method. The fitting curves were compared with the observed data for the evaluation of systematic and fluctuating parts of the time domain as circadian variations. The periodic components were detected from all the blood chemical items examined. This suggests that all items have systematic parts as basic rhythmic changes. The optimum fitting curves corresponded to the observed time-series in the following items: glucose, total protein, A/G ratio, alkaline phosphatase, Na, K, Cl and BUN of both sexes and total cholesterol, triglyceride, cholinesterase, CPK, inorganic phosphorus, direct and total bilirubin, creatinine and uric acid in males. Others showed insufficient correspondence to many fluctuating parts. This randomness was more frequently seen in females than in males.
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  • Toru URANO, Kazuhiro NOGUCHI, Guangcheng JIANG, Kiyoshi TSUKUMI
    Article type: Original
    1995 Volume 44 Issue 3 Pages 233-239
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    Several serotypes of Pseudomonas (P.) aeruginosa were isolated from the oral cavities of researchers, but no positive cases were found among the animals they had contacted or in the environment. These results indicated that researchers are not a source of P. aeruginosa infection for animals. However, P. aeruginosa was detected on the hands of researchers and animal caretakers after they finished their work. The same serotype of P. aeruginosa was found in the animals and the environment. These findings demonstrated that the researchers and the animal caretakers were contaminated with P. aeruginosa by the animals, and then became infective vehicles.
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Note
  • Kazuyoshi HASHIZUME, Hirotada TSUJII, Makoto ROKUTANDA
    Article type: Note
    1995 Volume 44 Issue 3 Pages 241-244
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    Folliculogenesis in female hypogonadal (hpg) mice was examined after treatment with exogenous gonadotropins. The female mutant mice were characterized by a deficiency of hypothalamic gonadotropin-releasing hormone (GnRH), leading to the absence of estrus and ovulation. Gonadotropin administration induced resumption of gonadal development and vaginal opening. The follicles that developed with gonadotropin treatment were very similar to those in normal littermates. The oocytes from hpg mice showed the capacity for fertilization and development to produce viable young after in vitro fertilization and embryo transplantation. Thus, the combination of the exogenous gonadotropin administration, in vitro fertilization and embryo transfer method appear to be helpful to breed mutant hpg mice efficiently.
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  • Masayuki KEMI, Hiroyoshi MATSUMOTO, Yasuo NOMURA, Reiji TAKAHASHI
    Article type: Note
    1995 Volume 44 Issue 3 Pages 245-249
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    Isoproterenol-induced early myocardial lesions were compared histomorphologically to commonly observed postmortem artifacts in the rat hearts which were collected up with 40 min after death. Isoproterenol-induced early lesions were characterized by multifocal myocardial eosinophilia restricted to the inner one third of the left ventricle and septum. These very early lesions were similar to the artifacts which were also characterized by myocardial eosinophilia and increased with time after death. The dilation of intercellular spaces which was also an artifact occurred at 40 min. Contraction bands, fragmentation of fibers and inflammatory cellular infiltration noted only in the isoproterenol-induced lesions were the differentiating criteria from artifacts. The postmortem artifacts were not observed in the hearts fixed immediately after death.
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  • Atsushi KOGUCHI, Koichi NOMURA, Toshihisa FUJIWARA, Yoshiaki KAWAI, Az ...
    Article type: Note
    1995 Volume 44 Issue 3 Pages 251-253
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    Three thumb-sized segmental swellings were found in both uterine horns of a 15 month-old, non-pregnant and non-pseudopregnant female beagle dog. Histopathological examination of the uterus revealed a marked proliferation of the endometrium that was characterized by two distinct parts, an inner tightly-folded banded layer and an outer dilated spongy layer, quite similar to the maternal placenta except for the fetus and chorion in the lumen. Because the plasma level of progesterone was unusually high at autopsy, this hormonal disorder might be related to the pathogenesis of the endometrial hyperplasia in the present case.
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  • Tien Mei PAN1, Kouji SHIMODA, Yi CAI, Yoshihiro KIUCHI, Kazumasa NAKAM ...
    Article type: Note
    1995 Volume 44 Issue 3 Pages 255-259
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    Deodorizing effect of ozone was investigated comparing two types of compact ozonizing apparatus made on an experimental basis. The concentrations of ammonia and trimethylamine were examined as an indicator for deodorizing effect of ozone in animal rooms of rats and guinea pigs at laboratory animal facilities of three different universities. Both of the ozonizing apparatus were able to remove ammonia and trimethylamine in animal rooms, with no significant difference in the performance of the two apparatus.
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  • Takashi YAMADA, Hiroshi OHNO, Tadahiro INOUE
    Article type: Note
    1995 Volume 44 Issue 3 Pages 261-265
    Published: 1995
    Released on J-STAGE: December 23, 2003
    JOURNAL FREE ACCESS
    It has been reported that the metrial glands, which form yellowish-white masses on the mesometrial triangle after pregnancy, coincide with the number of implants in the rat. In this study, the migration of the metrial gland cells (MGC) from the metrial glands to the endometrium after placental desquamation was investigated by the smear method. In smeared specimens, MGC appeared as large round cells with an unstained nucleus (a large binucleate cell was frequently seen), surrounded by a pinkish rim of cytoplasm, with PAS-staining; or appeared as a large reddish violet nucleus surrounded by dark violet cytoplasm with Giemsa staining. Numerous MGC were observed on the endometrium on the mesometrial side after artificial desquamation of the placenta on day 20 of pregnancy and day 0 of delivery. Further, MGC were observed on the endometrium on the antimesometrial side or in the cervix (including the internal and external orifice of the uterus) on day 0 of delivery, but no MGC could be detected in the cervix or on the antimesometrial side either during the period of placental signs (days 11-13) or on day 20 of pregnancy. Although MGC disappeared rapidly after delivery, slight traces of MGC remained on the mesometrial side until day 3 after delivery. In the case of abortion, MGC were observed in the cervix on the day of vaginal bleeding. In view of these results, it is considered that confirmation of MGC on the endometrium or the cervix provides evidence of abortion or delivery.
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