Natriuretic peptides and acute renal failure.

Atrial natriuretic peptides (ANPs) are a family of peptide hormones, e.g., ANP, long-acting natriuretic peptide, vessel dilator, and kaliuretic peptide synthesized by the ANP gene. Brain natriuretic peptide (BNP) and C-type natriuretic peptide are also members of this family but are synthesized by separate genes. Within the kidney, the ANP prohormone's posttranslational processing is different from that of other tissues, resulting in an additional four amino acids added to the NH2 terminus of ANP (e.g., urodilatin). Each of these natriuretic and diuretic peptides increases within the circulation with acute renal failure (ARF). Renal transplantation but not hemodialysis returns their circulating concentrations to those of healthy individuals. BNP and adrenomedullin, a 52-amino acid natriuretic peptide, have beneficial effects on glomerular hypertrophy and glomerular injury but do not improve tubular injury (i.e., acute tubular necrosis). Vessel dilator ameliorates acute tubular necrosis with regeneration of the brush borders of proximal tubules. Vessel dilator decreases mortality in ARF from 88 to 14% at day 6 of ARF, even when given 2 days after renal failure has been established.