Effect of chronic administration of nicotine or cocaine on steroidogenesis in rat adrenocortical cells

Abstract

Rats were implanted subcutaneously with osmotic mini-pumps containing either 0.9% NaCl, nicotine (1.5 or 4.5 mg kg-1 day-1), or cocaine (30 mg kg-1 day-1), for 14 days. Neither nicotine nor cocaine treatment significantly altered the maximal rate of steroidogenesis in adrenocortical cell preparations from the animals. However, pretreatment with cocaine increased the sensitivity of the preparation to stimulation by ACTH, the ED50 was 5 pM compared with 10 pM from control animals. Addition of nicotine or cocaine at concentrations up to 100 microM to adrenal cell suspensions from naive rats did not stimulate steroidogenesis or increase the sensitivity of cells to ACTH stimulation. These results suggest that the primary chronic effect of nicotine on steroidogenesis is exerted at the level of the hypothalamus and/or pituitary and not directly on adrenocortical cells. On the contrary, pretreatment with cocaine causes persistent changes in adrenocortical cells.