Role of Adrenomedullin and Related Peptides in the Regulation of the Hypothalamo–Pituitary–Adrenal Axis

摘要: NUSSDORFER, G. G., P. ROSSI AND MAZZOCCHI. Role of adrenomedullin and related peptides in the regulation hypothalamo–pituitary–adrenal axis. PEPTIDES 18(7) 1079–1089, 1997.—Adrenomedullin (ADM) is a hypotensive peptide, originally isolated from human pheochromocytomas, then found to be widely distributed various body systems. ADM derives preproadrenomedullin, 185-amino acid residue prohormone, containing at its N-terminal 20-amino sequence, named proadrenomedullin 20 peptide (PAMP). PAMP immunoreactivities have been detected (HPA) axis humans, rats, pigs. Adrenal glands possess binding sites for both PAMP, former being mainly subtype 1 calcitonin gene-related (CGRP) receptors. exerts direct inhibitory action on angiotensin II- or potassium-stimulated aldosterone secretion zona glomerulosa cells. This effect mediated by CGRP1 receptor mechanism probably involves blockade Ca2+ influx. In contrast, enhances production situ perfused rat adrenals adrenal slices (containing medullary chromaffin cells), again through activation secretagogue blocked β-adrenoceptor antagonist l-alprenolol, thereby suggesting that it indirectly release catecholamines The effects glucocorticoid are doubtful increase blood flow rate inhibition ACTH pituitary corticotropes. concentrations reached rule out possibility they act HPA as circulating hormones. Conversely, their content hypothalamo–pituitary complex consistent with paracrine action, which may play potentially important role fluid electrolyte homeostasis.