Possibility of adrenal-testicular interaction as indicated by plasma androgens in response to HCG in men with normal, suppressed and impaired adrenal function.

In order to assess possible adrenal-testicular interactions in vivo, adrenal and testicular plasma androgens (testosterone, delta4-androstenedione, dehydroepiandrosterone and dehydroepiandrosterone sulfate) were measured by specific radioimmunoassays before and after stimulation with HCG in men with normal, dexamethasone suppressed and impaired adrenal function. It was found that men with Addison's disease, in whom circulating dehydroepiandrosterone sulfate levels amounted to 1/10 of normal values, had a decreased response of testosterone to HCG. Simultaneously, the Addison patients and the men under dexamethasone had only an increase of delta4-androstenedione but not of dehydroepiandrosterone, while normal men showed an almost equal increase in both precursors under HCG. The results are interpreted as demonstrating that the delta5-pathway in the testis becomes less important under adrenal suppression and in Addison's disease due to a lack of substrate (possibly dehydroepiandrosterone sulfate) from the adrenals.