Urodilatin is a natriuretic peptide hormone involved in sodium regulation, fluid balance, kidney signaling, and regulation of renal blood flow. The hormone functions locally within the kidneys to promote sodium excretion and contribute to maintenance of extracellular fluid homeostasis and blood pressure balance.
Urodilatin influences renal tubular sodium transport, glomerular filtration dynamics, vascular relaxation, and communication between renal epithelial cells and circulatory signaling systems. Through these actions, it helps coordinate kidney adaptation to changes in sodium load and fluid volume.
Urodilatin is produced mainly by distal tubular epithelial cells within the kidneys. It is derived from the same precursor molecule as atrial natriuretic peptide but undergoes tissue-specific processing within renal structures to generate the locally active peptide hormone.
Unlike circulating natriuretic peptides produced by the heart, urodilatin acts primarily in paracrine fashion within renal tissues. Local production allows highly targeted regulation of sodium transport and tubular signaling pathways inside the kidney.
Urodilatin production is regulated by sodium intake, renal tubular flow, extracellular fluid volume, blood pressure-related signaling, and local renal mechanical forces. Increased sodium delivery to distal nephron regions can stimulate secretion.
The hormone acts through natriuretic peptide receptors linked to cyclic GMP signaling pathways within renal epithelial and vascular tissues. Activation promotes natriuresis, vasodilation, and modulation of tubular sodium transport systems. Interactions with renin-angiotensin signaling and additional natriuretic pathways help coordinate renal fluid and electrolyte regulation. Through these integrated renal-endocrine systems, urodilatin contributes to sodium balance, kidney signaling, and extracellular fluid homeostasis.
Renal natriuretic peptide that raises cGMP via NPR-A to increase sodium/water excretion and support vascular relaxation.
