Influence of ions and dinitrophenol on adrenocortical steroidogenesis

¹ Naval Medical Research Unit No. 1, University of California, Berkeley, California; and Naval Medical Research Institute, Bethesda, Maryland

The Na, K, Ca, Mg or PO₄ content of an artificial medium, shown to support steroidogenesis as well as homologous blood, was altered individually, and the influence of each ionic change on the biosynthetic function of the perfused calf adrenal investigated under three conditions: a) without ACTH, b) with ACTH and c) with steroid substrates. The effect of dinitrophenol (DNP) was explored under similar conditions. Both ACTH-stimulated and unstimulated glands perfused without Ca exhibited an appreciable decrement in corticoid output without any depletion in metabolic activity. Omission of Mg, K or PO₄ ions, and reduction of the Na content from 149 to 125 mEq/l. exerted no significant effect. None of the ionic alterations modified the specific, enzymatic hydroxylation or 3ß-dehydrogenase activities of adrenals perfused with various steroid substrates. Adrenals perfused with a markedly elevated K level (25.0 rather than 3.4 mEq/l.) were not inhibited but instead autonomously responded to it by secreting increased amounts of corticoids. Addition of 10^–4 M DNP, with and without ACTH, resulted in a striking suppression of corticoid production without a commensurate metabolic depression, and induced depletions of from 80 to 100% in the ability of exposed glands to perform 11ß-, 17- and 21-hydroxylation without affecting their transformation of the ⁵-3ß-OH group to ⁴-3-ketone.