Further studies on the effects of prolonged prolactin administration on the zona glomerulosa of the rat andrenal cortex

Abstract
Summary The effects of a prolonged treatment with prolactin on the morphology and hormone secretion of adrenal zona glomerulosa of gonadectomized testosterone-replaced rats were investigated by coupled morphometric and radioimmunologic techniques. The dexamethasone/captoprilinduced atrophy of zona glomerulosa cells (−42%) and fall in the blood level of aldosterone (−37%) were partially counteracted by chronic prolactin administration: the values had increased by about 15% and 17%, respectively, but remained lower than in the control animals. The prolonged treatment with prolactin of dexamethasone/captopril-administered ACTH/angiotensin II-replaced rats provoked a striking increase in the zona glomerulosa cell volume (24%) and in the blood level of aldosterone (33%) above the control values. The possibility is discussed whether prolactin may be directly involved in the stimulation of the growth and steroidogenic capacity of rat zona glomerulosa, without interacting with the gonads and interfering with the hypothalamo-hypophyseal axis and the renin-angiotensin system.