Decreased fibrinolytic activity in vessels and ureters of rejecting human kidneys.

Plasminogen activator (PA) activity was determined with a histochemical fibrin slide technique in renal arteries, veins and ureters in 62 transplanted kidneys and again at transplantectomy in 12 transplants who later underwent irreversible rejection. At transplantation PA activity was the same whether the grafts later rejected or not. There was a significantly decreased PA activity in the vessels and ureters in rejected transplants. The role of the fibrinolytic system as a pathogenetic factor in rejected kidneys is discussed.