The heart as an endocrine gland.
The evidence presented here indicates that atrial cardiocytes, apart from their contractile function, are bona fide endocrine cells which synthesize a peptide of known composition (152AA) through identified pathways [6,7]. Part of the peptide is released into the circulation where it can be measured by radio-immunoassay. A synthetic fragment (8-33AA) of the peptide is endowed with potent and variegated effects on several target tissues: massive diuresis and natriuresis of rapid onset and short duration, inhibition of the secretion of aldosterone from beef and rat zona glomerulosa and, to a lesser extent, of cortisol from beef zona fasciculata, vasodilatation and inhibition of the arterial contraction induced by catecholamines or angiotensin II. This peptide is a potent antihypertensive agent. The presence of receptors in the anterior and posterior pituitary, as well as the significant decrease of adenylate cyclase activity observed in both portions of the gland, indicate that the hormone may act at these levels as well. Thus, the heart is raised from the status of a pump to that of a putative endocrine integrator of cardiovascular homeostasis.
D000067956:Adenylyl Cyclase Inhibitors; D000311:Adrenal Glands / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001158:Arteries / Q000187:drug effects; D009320:Atrial Natriuretic Factor / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology; D001810:Blood Volume / Q000187:drug effects; D002417:Cattle; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000502:physiology; D004702:Endocrine Glands / Q000378:metabolism*; D006321:Heart / Q000502:physiology*; D006973:Hypertension / Q000503:physiopathology; D009126:Muscle Relaxation / Q000187:drug effects; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D010902:Pituitary Gland / Q000187:drug effects / Q000201:enzymology; D011863:Radioimmunoassay; D051381:Rats
D000067956:Adenylyl Cyclase Inhibitors; D009320:Atrial Natriuretic Factor; D006152:Cyclic GMP