Fetotoxicity and reproductive effects of monocrotaline in pregnant rats.

Four groups of 12 pregnant Wistar rats each were fed with rations containing 0, 0.01, 0.015 and 0.02% of monocrotaline (MCT) from day 6 to 21 of gestation. Liver weights of the dams from the three experimental groups were significantly lower than those from the control group. Serum levels of aspartate aminotransferase; alkaline phosphatase; lactate dehydrogenase; gamma glutamyltransferase, urea and creatinine were significantly higher in dams from MCT 0.02% group. The weights of the placenta, fetuses and fetal lungs of the 0.02% MCT group were significantly lower than those of the control group. A mild to moderate interstitial pneumonia and liver lesions were observed in dams ingesting 0.02% of MCT. These results showed the toxicity of MCT to the females that ingested 0.02% and their fetuses. Because there was no differences on the weight gains and food and water consumption of the dams it is suggested that this toxic effects in the fetuses was caused by the diffusion of MCT through the placenta. No significant differences were observed in the frequency of skeletal and visceral malformation or anomalies between the control and treated groups suggesting that MCT had no teratogenic effect.