Biomedical subjects

J Yanai

Publications and source records attributed to J Yanai.

129 records · Page 8Linked to original sources

PubMedDate not supplied

Transplacental effects of methylmercury chloride in mice with specific emphasis on the audiogenic seizure response.

Sabra mice were exposed to a single injection of 8 mg/kg body weight of methylmercury chloride on day 12 of their gestation. The mice were then sacrificed on day 19 and their fetuses were removed for examination. The fetal malformation rate was 8.6% with the most common anomaly being cleft palate. In another group, offspring who were exposed in utero to a single dose of 8 mg/kg methylmercury chloride were tested for their susceptibility to the audiogenic seizure response on days 28-31 after birth. There was a significant (p less than 0.05) increase (almost twofold) in the susceptibility of treated versus controls to this response, suggesting possible neurological damage.

Abnormalities, Drug-Induced↗

PubMedDate not supplied

Implications of changes in apomorphine-induced hypothermia after prenatal exposure to phenobarbital.

Pregnant mice were exposed to phenobarbital (PhB) on gestation days 9 to 18 (3 gm/kg milled food). Their offspring, who were exposed to the drug transplacentally (B offspring), were tested at an age of 50 days for apomorphine- (0.5, 1.0 and 2.0 mg/kg) induced hypothermia. At doses of 1.0 and 2.0 mg/kg, B offspring had less hypothermic response to apomorphine than controls (p less than 0.01); the effect was similar in both sexes. In order to acquire further understanding of the alterations in apomorphine hypothermia, mainly in relation to dopamine (DA) receptors, adult intact mice were exposed to haloperidol for 4 weeks (25 mg/kg milled food) in order to increase their DA receptor number, and their hypothermic response to apomorphine was tested 4 days post withdrawal. The treated animals had an increased DA receptor number, as was attested by a 23% increase in 3H-spiroperidol binding (P less than 0.01) and a 77% increase in apomorphine-induced climbing. However, their apomorphine-induced hypothermia did not differ from control. Therefore, there is no evidence as yet that alterations in apomorphine-induced hypothermia after prenatal exposure to PhB indicates changes in DA receptors, and the implications of this phenomenon still remain an open question.

Animals↗

PubMedDate not supplied

Lessened sensitivity to apomorphine induced climbing behavior in mice following neonatal exposure to phenobarbital.

Heterogeneous HS/Ibg mice were injected daily with 50 mg/kg phenobarbital (PhB) from age 2 to 21 days (B group), while control litter mates received vehicle injections. Control and a B mice were then tested for striatal climbing behavior induced by 2 or 5 mg/kg apomorphine, at ages 22, 28, 35 or 44 days. At age 22 days B mice had reductions of climbing from control levels of 44% and 41% for 2 and 5 mg apomorphine respectively (p less than 0.01), regardless of sex differences. On day 28 the respective reductions were 16% and 32% (p less than 0.05). The differences on days 35 and 44 were small and did not reach statistical significance. Since climbing has been found to be induced primarily by postsynaptic striatal dopaminergic receptors, it is suggested that neonatal exposure may reduce the behaviors mediated by striatal postsynaptic dopamine receptors. The present findings support other studies implicating postsynaptic striatal dopamine receptors in the behavioral alterations induced by early PhB exposure.

Animals↗