FIBRINOLYTIC ACTIVITY IN HUMAN ISOLATED GLOMERULI
1979 Volume 70 Issue 2 Pages 144-158
Details
1979 Volume 70 Issue 2 Pages 144-158
In order to investigate the actual site of urokinase production in the kidney, fibrinolytic activity in isolated glomeruli has been determined quantitatively or immunologically using a histochemical fibrinolysis autography and tissue culture.
The results obtained are as follows.
1. The glomerular fibrinolytic activity estimated by the fibrinolysis autography was significantly decreased after methanol fixation of the glomeruli. It was suggested that fresh isolated glomeruli had the ability of plasminogen activator production during incubation periods adopted for the fibrinolysis autography.
2. Using fibrin films incorporating antiurokinase serum in different concentrations, no inhibition of fibrinolytic activity in isolated glomeruli fixed by methanol was observed. In contrast, a significant inhibition of fibrinolytic activity was obtained in case of fresh isolated glomeruli. This showed that plasminogen activator activity released from isolated glomeruli into the fibrin films was identified immunologically as urokinase type.
3. The outgrowth of epithelial cells from in vitro cultivated glomerular tufts was observed in 6 to 8 days after explantation.
4. There was a considerable accumulation of plasminogen activator in supernatants of glomerular cultures from 6 kidneys, and their values ranged from 0.77 to 18.5 CTA units/ml.
5. Using fibrin plates incorporating antiurokinase serum in a final concentration of 1:1000, plasminogen activator activity seen in the supernatants was markedly inhibited. Percentage neutralization of the activator activity in the 6 cultures ranged from 88.7 to 100 percent. The majority of plasminogen activator released from in vitro cultivated glomerular tufts were referred to urokinase type.
6. Epithelial cells derived from in vitro cultivated glomerular tufts showed a marked plasminogen activator activity on the fibrinolysis autography.
These findings indicated that the fibrinolysis autography and tissue culture used were virtually useful for intimate studies of fibrinolysis in the kidney and the glomerulus would be a potent source of urokinase production.
