Does plasma ANP participate in natriuresis induced by alpha-MSH?
alpha-Melanocyte-stimulating hormone (alpha-MSH; 0.6 and 3 nmol) micro-injected into the anteroventral region of the third ventricle (AV3V) induced a significant increase in diuresis without modifying natriuresis or kaliuresis. Intraperitoneal (ip) injection of alpha-MSH (3 and 9.6 nmol) induced a significant increase in urinary sodium, potassium and water excretion. Intraperitoneal (3 and 4.8 nmol) or iv (3 and 9.6 nmol) administration of alpha-MSH did not induce any significant changes in plasma atrial natriuretic peptide (ANP), suggesting that the natriuresis, kaliuresis and diuresis induced by the systemic action of alpha-MSH can be dissociated from the increase in plasma ANP. These preliminary results suggest that alpha-MSH may be involved in a gamma-MSH-independent mechanism of regulation of hydromineral metabolism.
Picanço-Diniz
D L
DL
Departamento de Fisiologia, Centro de Ciências Biológicas Universidade Federal do Pará, Belém, PA, Brasil.
Ribeiro-Oliveira
G
G
Favaretto
A L
AL
Gutkowska
J
J
McCann
S M
SM
Antunes-Rodrigues
J
J
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000502:physiology*; D002552:Cerebral Ventricles / Q000502:physiology*; D004231:Diuresis / Q000502:physiology*; D008297:Male; D009318:Natriuresis / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D000521:alpha-MSH / Q000502:physiology*
D000521:alpha-MSH; D009320:Atrial Natriuretic Factor