The aim of the present study was to determine if atrial natriuretic peptide (ANP-induced natriuresis is dependent on increases in glomerular filtration rate (GFR). Intrarenal blood flow distribution an urinary excretion of prostaglandins were also determined during the infusion of a dose of ANP that does not induce changes in GFR and mean arterial pressure (MAP). It was found that the intrarenal infusion of ANP (8-33) at a dose of 0.05 μg·kg-1·min-1 in seven anesthetized dogs did not produce any change in GFR or MAP, but its natriuretic effect was similar to that obtained by a larger dose (0.3 μg·kg-1·min-1, n = 5) that produces significant changes in both MAP and GFR. The natriuresis induced by the lower dose of ANP was associated with a redistribution (P < 0.05) of renal blood flow (RBF) from the superficial to the juxtamedullary cortex and with an increase (P < 0.05) in urinary excretion of prostaglandin E2 (PGE2)(0.8 ± 0.2 to 2.4 ± 1.0 ng/min) and 6-keto-F(1α) (6-keto-PGF(1α)) (2.8 ± 0.6 to 5.5 ± 1.7 ng/min). Renin secretion rate decreased from 610 ± 165 to 279 ± 61 ng angiotensin I/min. These results show that the natriuresis induced by ANP is not necessarily produced by an increase in GFR and is associated with a redistribution of RBF to the deep cortex and an increase in urinary excretion of PGE2 and 6-keto-PGF1α.
|Original language||English (US)|
|Journal||American Journal of Physiology - Renal Fluid and Electrolyte Physiology|
|State||Published - Dec 1 1986|
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