The influence of prolonged ACTH treatment on rat adrenal steroidogenesis.

A series of in vitro experiments using pregnenolone-14C-4 and progesterone-14C-4 as precursors were performed to determine the effects of prolonged ACTH administration on adrenal steroid biogenesis in the rat. Under ACTH administration there was a tendency for the isolated steroids to have larger quantities and specific activities from both precursors than under control conditions. In contrast to the rabbit, the rat did not produce any detectable amounts of 17 alpha-hydroxylated steroids under either control or prolonged ACTH treatment using the very sensitive double isotope derivative assay for quantitation.