Is the renal natriuretic peptide urodilatin involved in the regulation of natriuresis?

Abstract

Recent evidence has shown that the kidneys produce and secrete a member of the atrial natriuretic peptide family, named urodilatin. This 32-amino acid peptide does not circulate in blood, but is secreted into urine. Urodilatin excretion closely parallels renal sodium excretion under various conditions that influence body fluid regulation, such as circadian rhythm, salt ingestion, acute intravenous sodium loading, water immersion, atrial distension, and cerebral hypernatremia. In contrast, the plasma concentration of the atrial member of the natriuretic peptide family often is only weakly and occasionally even negatively associated with natriuresis under these conditions. We conclude from these observations that urodilatin rather than atrial natriuretic peptide might be the member of the natriuretic peptide family that is involved in the regulation of natriuresis in normal physiology.