AJP - Regulatory, Integrative and Comparative Physiology, Vol 271, Issue 4 1047-R1053, Copyright © 1996 by American Physiological Society
Atrial natriuretic peptide in multiple system atrophy
M. Bevilacqua, G. Norbiato, V. Righini, L. Castelli, A. Rogolino, R. Furlan, S. Piazza, E. Chebat and T. Vago
Servizio di Endocrinologia, Ospedale L. Sacco (Vialba), Milan, Italy.
Central nervous system feedback loops centered on hypothalamic neurons
control atrial natriuretic peptide (ANP). We evaluated the ANP response to
arterial hypotension, isotonic blood volume expansion, and increase in
plasma osmolality in 14 patients with multiple system atrophy (MSA). Seven
of the patients were characterized by a lack of vasopressin response to
hypotension (MSA type B), suggesting chronic sinoaortic denervation, and
seven by a preserved response (MSA type A). Orthostatic hypotension
decreased ANP in controls and type A patients, whereas ANP in type B was
not affected. Isotonic saline infusion increased ANP and diuresis in
controls and type A patients, whereas it did not affect ANP in type B.
Osmotic load increased plasma osmolality and vasopressin in controls and
MSA patients and ANP in controls and type A but not in type B patients. In
MSA patients with altered afferent control of vasopressin, ANP secretion is
not stimulated by blood volume expansion, osmotic load, or blood pressure,
suggesting that afferent excitatory control plays a role in the release of
ANP.
