The activities of drug-metabolizing enzymes in goats treated orally with the latex of Calotropis procera and the influence of dieldrin pretreatment

The effects of oral administration of different doses of the latex of Calotropis procera on the activities of drug-metabolizing enzymes in the liver, kidneys and duodenal mucosa of Nubian goats were investigated. Lesions and changes in total plasma protein concentration and in the activities of plasma sorbitol dehydrogenase (SD), glutamate dehydrogenase (GD) and aspartate aminotransferase (AST) were studied. The daily oral administration of the latex at dose rates of 0·4 and 0·8 ml per kg for 7 days resulted in a significant inhibition of the activity of aniline 4-hydroxylase. No significant effects on the activities of aminopyrine N-demethylase and UDP-glucuronyltransferase were observed. A single oral dose of 1·2 or 1·6 ml per kg killed goats within 7 h and resulted in increased activities of aminopyrine N-demethylase and aniline 4-hydroxylase. UDP-glucuronyltransferase was found to be insensitive to tissue injury induced by the latex of C. procera. There were no pathological changes in goats given 10 mg per kg of dieldrin alone or in those pretreated with dieldrin and given the latex at a dose rate of 1·2 ml per kg 14 days later. Dieldrin pretreatment resulted in the induction of the activities of drug-metabolizing enzymes in the liver, kidneys and duodenal mucosa and it may have protected goats from the lethal effects of the latex.