Physiologic role and diuretic efficacy of atrial natriuretic peptide in health and chronic renal disease.
In recent years, different clinical studies have provided new information on the pathophysiological role and diuretic effectiveness of atrial natriuretic peptide (ANP) in subjects with normal renal function and patients with chronic renal disease. Plasma ANP (pANP) was increased by infusion at the lowest doses ever tested in humans who were on low salt diet to the levels that the same subjects gained when on a normal salt diet; ANP accounted for at least 40% of the increase of natriuresis. Similarly, ANP appeared to be mainly involved in the physiological down-regulation of salt excretion (that is, during the shift from a normal to low-sodium diet). Interestingly, data have been also attained on the efficacy of ANP as diuretic agent when administered at a low nonhypotensive dosage in normals as well as CRF patients. Indeed, low-dose ANP promoted a marked increase of sodium excretion in CRF patients to the same levels observed in normals, likely because the renal patients exhibited a more marked pANP increment secondary to the lower renal catabolism of the infused hormone. Moreover, aldosterone suppression was greater in CRF patients with respect to normals. Furthermore, the fractional urinary excretion of cGMP increased more in CRF patients than in normals. Finally, ANP infusion augmented the urinary losses of the main solutes retained in CRF (urea, potassium, phosphorous) with a significant decrease in the plasma levels. Hence, ANP per se not only plays a significant role in the up- and down-regulation of sodium excretion in healthy state and chronic renal disease, but it may also be considered to be a powerful and unique diuretic agent in CRF at nonhypotensive dosages.
Conte
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G
Chair of Nephrology, Med School, I and II University of Naples, University of Reggio Calabria, Italy.
Bellizzi
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V
Cianciaruso
B
B
Minutolo
R
R
Fuiano
G
G
De Nicola
L
L
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology / Q000502:physiology*; D004232:Diuretics / Q000494:pharmacology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000188:drug therapy*; D012964:Sodium / Q000378:metabolism
D004232:Diuretics; D009320:Atrial Natriuretic Factor; D012964:Sodium