Evidence for existence of cortical androgen-stimulating hormone.

Abstract

An animal model using dexamethasone-suppressed, castrated dogs was developed to test the hypothesis that a pituitary hormone other than ACTH modulates adrenal androgen (AA) secretion. Plasma samples were obtained every 15 min during infusions of saline, synthetic .alpha.1-24 ACTH, porcine 1-39ACTH, or bovine pituitary gland extract (PE) in a wide range of doses. Androstenedione (A), dehydroepiandrosterone (DHA) and cortisol (F) were quantified by radioimmunoassay. When the ratio of AA levels was related to those of F, to correct for ACTH content in the PE, the slopes of the dose-response curves for ACTH and PE were different at the 0.01 level. For A the dose-response slope for the PE was 0.18 .+-. 0.5 SE, whereas that of ACTH was 0.02 .+-. 0.01. For the DHA response the slopes were 0.17 .+-. 0.04 for the PE and 0.04 .+-. 0.03 for ACTH. Related studies showed no increase in AA levels in response to luteinizing hormone-releasing hormone, bovine growth hormone (GH), bovine prolactin, ovine thyroid-stimulating hormone (TSH), or synthetic aqueous Arg vasopressin (AVP). A pituitary factor other than ACTH, prolactin, GH, luteinizing hormone, follicle-stimulating hormone, TSH, or AVP may be responsible for the observed increase in AA concentrations.