The Effect of Myleran on Developing Rat Fetuses

Abstract

Sprague•Dawley strain rats were administered orally once with the d,,"e of Myleran 20mg/kg, body weight on the 6th , 7th 10th , 11th , 12th day of gestation and with the dose of Myleran 30mg/kg, body weight on the 9th , 10th , 11th , 13th day of gestation and with the dose of myleran 40mg/kg body weigh on the 9th , 11th, 12th, 13th day of gestation. Gross anomalies in the fetuses, weigh, length and breadth of the brain of the live fetuses, survival rate of fetuses, changes of fetal body weight, and numbers of corpus Iuteum of maternal ovaries, and crown rump length and transumbilical distance were studied after hysterectomy on the 21st day of gestation and the following results were obtained. 1. The gross anomalies were appeared only in the groups administered with the dose of myleran 40mg/kg body weight and those were short tail, growth retardation microcephalus, hydrocephalus, micromelia, growth retardation of the limb, abnormal number of digits, syndactyli, anophthalmia and edema. The abnormal tails were observed in the highest incidence throughout the anomalies appeared in the fetuses of experimental groups. Combined anomalies of micromelia, syndactylia and edema were charactaristic. The 9th day of gestation seemed to be the most susceptible to the effect of the administration of Myleran. 2. Significant change of fetal body weight came out in the result of the all groups treated with the administration of the Myleran, and in the later administration g' roups, the more obvious decrease of body the fetal weight were obscr 、' e d . 3. Weight of the brain occured little changes in the group which was administered with the dose of 20mg/kg body weight, but gradual decrease of the weight appeared in the other groups. And notable decrease resulted in the group which was aclminist• ered with the dose of 40mg/kg body weight 4. Ohvious reduction of the fetal brain took place in all groups. And the results 、，v c r c in proportion to the doses 5. Gradual reduction of the breadth of the brain was observed in proportion to the do~es and aceor• ding to the days of gestation treated \vith Mylcran. 6. Trans--umhilical distances were observed only in the group which administered with the dose of 40mg/kg body weight, and the reduction of the distance was gradual in acιordance with the date of administration 7. Crown-rump length \\o'as measured only in the groups of 40mg/kg body weight. No significant change of CRL was observed at the group which received administration of Myleran on the 9th day of gesta tion , but gradual reductions 、，y e r e occurred in the other groups. 8. Most obvious decrease of the survival rate was observed in the group of 40mg/kg body weight. Gradual decrease of the survival rate was in inverse accordance with days of gestation. 9. Numbers of the corpus luteum were not effected by the administration of the Myleran