official journal of Congeital Anomalies Research Association of Japan
Online ISSN : 2433-1503
Print ISSN : 0037-2285
Volume 41 , Issue 4
Congenital Anomalies
Showing 1-7 articles out of 7 articles from the selected issue
  • 2001 Volume 41 Issue 4 Pages 307-311
    Published: 2001
    Released: August 04, 2021
    JOURNAL OPEN ACCESS
    ABSTRACT Optic nerves of the Otsuka Long-Evans Tokushima Fatty (OLETF) rat, an animal model of non-insulin dependent diabetes mellitus, were examined using quantitative stereological procedures. At 67 weeks of age, OLETF rats showed a mild hyperglycemia: their blood glucose level was 196 ± 93 mg/dl, significantly higher than that of non-diabetic control Long-Evans Tokushima Otsuka (LETO) rats (110 ± 24 mg/dl). However, there were no differences in the cross sectional area of optic nerves (the mean minimum diameter), the total number and mean diameter of both myelinated and non-myelinated fibers, or the thickness of the myelin sheath between OLETF and LETO rats. The results suggested that a mild hyperglycemia in OLETF rats could not cause any morphological changes in the optic nerve.
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  • 2001 Volume 41 Issue 4 Pages 312-320
    Published: 2001
    Released: August 04, 2021
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    ABSTRACT Sprague-Dawley rats were treated intraperitoneally with 5-bromo-2′-deoxyuridine (BrdU) at 0,12.5 or 50 mg/kg/day on days 9 through 15 of gestation to evaluate the effects on development of the brain of offspring. Prenatal exposure to BrdU induced abnormal development of the brain; dilatation of the lateral ventricles in male offspring in the postnatal period. The ratio of the length of the longitudinal fissure to that of the cerebral cortex decreased in a dose-dependent manner in the embryonic period and thereafter. In 14-week-old male offspring exposed prenatally to BrdU at 50 mg/kg, the cortex layer of the cerebrum was thinner than that of the controls. Masculine sexual behavior was markedly impaired and the volume of the sexually dimorphic nucleus of the preoptic area (SDN-POA) was decreased in the 50 mg/kg group as compared with the controls. These results demonstrate that prenatal exposure to BrdU affected the development of the brain hi the prenatal and postnatal stages and reduced the volume of SDN-POA after puberty, resulting in a disruption of reproductive ability in male rats.
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  • 2001 Volume 41 Issue 4 Pages 321-328
    Published: 2001
    Released: August 04, 2021
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    ABSTRACT The studies were conducted in rats and rabbits to elucidate the potential developmental toxicity of p, p'-DDT in general accordance with the improved Japanese MAFF guidelines (12-Nousan-No. 8147,2–1–18, 2000). p, p'-DDT suspended in 1% aqueous solution of CMC was administered orally to pregnant Jcl:SD rats on gestational days (GD) 6–19 at a dose of 0,5, 25, or 100 mg/kg/day and to pregnant KbI: JW rabbits on GD 6–27 at a dose of 0,5,20, or 80 mg/kg/day. Maternal animals were killed on the day after the last day of administration for morphological examination of their fetuses with special attention to the reproductive organs. Adverse effects on maternal animals were found only at the highest dose in both species; i.e., clonic convulsion (2/24 in rats, 5/22 in rabbits), mortality (1/24 in rats), abortion or premature delivery (4/22 in rabbits), and reduced body weight gains and food consumption. However, the control and treated groups showed comparable values for the numbers of corpora lutea and implants, percent preimplantation losses, number of live fetuses, percent resorptions and fetal deaths, sex ratio, fetal body weights, and placental weights in both species, and anogenital distance and testicular histology in rats. Although fetal examination revealed slightly increased incidence of 27 presacral vertebrae in the highest dose group in rats, there was no treatment-related increase in the incidence of malformations in any of the species. Based on these results, it is concluded that p, p'-DDT causes no malformations, including male reproductive organ abnormalities, in either rats or rabbits, although it results in an increased incidence of skeletal variations in rats at a maternally toxic dose.
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  • 2001 Volume 41 Issue 4 Pages 329-337
    Published: 2001
    Released: August 04, 2021
    JOURNAL OPEN ACCESS
    ABSTRACT The studies were conducted in rats and rabbits to elucidate the potential developmental toxicity of methoxychlor in general accordance with the improved Japanese MAFF guidelines (12-Nousan-No. 8147, 2–1–18, 2000). Methoxychlor dissolved in corn oil was administered orally to pregnant Jcl:SD rats on gestational days (GD) 6–19 at a dose of 0,1,50, or 150 mg/kg/day and to pregnant Kbl:JW rabbits on GD 6–27 at a dose of 0,1, 15, or 45 mg/kg/day. Maternal animals were killed on the day after the last day of administration for morphological examination of their fetuses with special attention to the reproductive organs. Adverse effects on maternal animals were found at 2 higher doses in both species; i.e. vaginal red discharge (rat only), abortion or premature delivery (rabbit only), and significantly decreased body weight gains and food consumption. While the numbers of corpora lutea and implants were comparable between the control and treated groups in both species, slight increase in the percent resorptions and fetal deaths in rats and a reduction of fetal weights in both species were observed at the highest dose. Anogenital distance and testicular histology were not affected in rats. Although fetal examination revealed significant increase in the incidences of 27 presacral vertebrae at 2 higher doses in rabbits, there was no treatment-related increase in the incidence of malformations in rats and rabbits. Based on these results, it is concluded that methoxychlor causes no malformations, including male reproductive organ abnormalities, in either rats or rabbits, although it results in decreased fetal weights and an increased incidence of fetal resorptions or skeletal variations at maternally toxic doses.
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  • 2001 Volume 41 Issue 4 Pages 338-339
    Published: 2001
    Released: August 04, 2021
    JOURNAL OPEN ACCESS
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  • 2001 Volume 41 Issue 4 Pages 414-415
    Published: 2001
    Released: August 04, 2021
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  • 2001 Volume 41 Issue 4 Pages 416-424
    Published: 2001
    Released: August 04, 2021
    JOURNAL OPEN ACCESS
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