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 intra- venous 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 urodilatinrather than atrial natriuretic pepteide might be the member of the natriuretic peptide family that is involved in the regulation of natriuresis in normal physiology.