Ascorbic acid deficiency and induction of hepatic microsomal hydroxylative enzymes by organochlorine pesticides

Abstract

Hepatic microsomal hydroxylative enzyme systems, O-demethylation of p-nitroanisole and hydroxylation of aniline, were induced by dietary dieldrin and to a lesser extent by DDT and lindane in guinea pigs. However, liver weights were not consistently increased nor were microsomal protein concentrations elevated. Ascorbic acid deficiency impaired the induction by dieldrin as early as 2 days on deficient diet. As scurvy developed through stages of normal weight gains, depressed gains and finally hemorrhagic lesions, the impairment became consistently lower during the period of depressed weight gains due to the accompanying decline in basal enzyme activity. Sex had no effect on either induction by dieldrin or its impairment in ascorbic acid deficiency. Maintenance of induction was related to dietary levels rather than hepatic concentrations of the vitamin and required higher dietary levels of ascorbic acid than scurvy prevention.