Mathews_1993_Vet.Hum.Toxicol_35_6

The effects of prenatal exposure to 13.78 mg, 27.56 mg or 82.6 mg malathion/100 g body weight po from 6-13 d of gestation, to 1 microgram estradiol-17-beta/d/100g body weight or 4 mg progesterone/d/100 g body weight sc from 3-20 d of gestation, or to their various combinations on brain acetylcholinesterase activity and ascorbic acid metabolism were investigated in rat dams and pups. Brain acetylcholinesterase activity was taken as an index of toxicity. Significant inhibition of acetylcholinesterase from malathion exposure was further exaggerated by estradiol-17-beta, but was reversed by progesterone. Significant increases of ascorbic acid levels and L-gulonolactone oxidase was observed with malathion toxicity. Estradiol-17-beta decreased ascorbic acid levels and stimulated dehydroascorbatase, while progesterone had no significant effect on ascorbic acid levels or on enzyme activities.