[Biosynthesis of hormones in renal tubular and interstitial cells].
Renal tubular and interstitial cells produce various hormones. Renin is synthesized in juxtaglomerular cells which are derived from the media of the afferent arteriole. Endothelin-1 is formed in mesangial cells of glomeruli and inner medullary collecting duct. In contrast, endothelin-3 synthesis is observed in glomeruli and all the tubule segments. 1 alpha-hydroxylase is present in proximal tubule and catalyzes production of 1,25(OH)2D. PGE2 is synthesized in glomeruli, all the tubule segments, and interstitial cells. The major production sites of PGF2 alpha and 6-keto-PGF1 alpha are glomeruli and medullary collecting duct. Kallikreins are mainly produced in connecting tubule. The cells responsible for erythropoietin synthesis are thought to be interstitial cells which are localized around the proximal tubule.