Toxaphene: accumulation in the adrenal cortex and effect on ACTH-stimulated corticosteroid synthesis in the rat.

Uptake and distribution of [14C]toxaphene was studied in the adrenals of rats using whole-body autoradiography. An accumulation of radioactivity was seen in the adrenal cortex (zona fasciculata) 1-24 h after a single gavage of [14C]toxaphene (16 mg/kg b.w.). In in vitro studies toxaphene was found to inhibit ACTH-stimulated corticosterone synthesis in the cultured rat adrenocortical cells (IC50 2.8 X 10(-5) M). Moderate but significant inhibition (P less than 0.001) of ACTH-stimulated corticosterone synthesis was also observed in the adrenocortical cells isolated from rats after a prolonged exposure (5 weeks) to low levels (1.2 ppm) of toxaphene in feed. The results indicate a direct adrenotoxic effect of toxaphene.