Perinatal toxicology of mirex administered in the diet: II. Relationship of hepatic mirex levels to induction of microsomal benzphetamine N-demethylase activity

Abstract

Hepatic levels of mirex and their relationship to microsomal metabolism were studied in rat pups exposed either prenatally, postnatally or perinatally. The exposure was dietary (25 ppm) from day 4 of gestation through day 46 postpartum. Liver mirex levels indicated both placental and lactational transfer. No remarkable quantitative or qualitative differences were noted between postnatal and perinatal exposure. Fractionation of livers indicated the highest percentage of mirex was found in the crude nuclear and microsomal fractions. Perinatal and postnatal exposure resulted in a 667 and 691% induction of N-demethylase activity at 9 days postpartum, respectively. No linear relationship could be established between the level of mirex in the microsomal subfraction and induction of benzphetamine N-demethylase activity (r = 0.56).