Ontogenesis of Fibrinolytic Activity in the Human Kidney

Abstract

The fibrinolytic activity of 63 embryonal and foetal kidneys was studied histochemically. Fibrinolytic activity originating from the arcuate and intralobular vessels was demonstrated from the time of the development of the metanephros. No significant age-related differences in activity were found in the foetus. No activity was confined to the site of the glomeruli, tubuli or large collecting tubuli. The epithelium of the renal pelvis was inactive. The fibrinolytic activity demonstrated histochemically is believed to be due to the presence of tissue plasminogen activator and not to the presence of urokinase.