Effects of chloramphenicol on the long term trophic action of ACTH on rat adrenocortical cells: a combined stereological and enzymological study.

Chronic chloramphenicol administration was found to block the ACTH-induced increase in both the surface area of mitochondrial cristae and the activity of 11 beta-hydroxylase in zona fasciculata cells of the rat adrenal cortex. The surface area of agranular endoplasmic reticulum membranes and the activity of 3 beta-hydroxysteroid dehydrogenase were not affected by treatment with chloramphenicol. These findings suggest that the mechanism of the ACTH-induced enhancement of the growth and steroidogenic capacity of rat adrenocortical cells involves stimulation of mitochondrial DNA-dependent protein synthesis.