A lowering of urinary fibrinolytic activity would result in an increase in the amount of mucosub-stances in the urine, which is seen in patients with renal calculi, and is a prelude to the formation of the matrix of calculi. Fifty-two patients with urinary calculi were subjected to the determination of urinary total nondialyzable solids (TNDS), fibrinolytic activity and urokinase inhibitory activity in urine and blood. Eighteen presumed normal individuals served as control. In a preliminary experiment, degradation products of urinary mucosubstances by fibrinolysin and urokinase (Green Cross Co., Osaka) were estimated in 2 cases of urolithiasis.
The results obtained were as follows:
1. A significant increase of TNDS was noted in the urolithiasis group when compared with the control group (p<0.05).
2. There was no significant difference in the urinary fibrinolytic activities per 12-hour urine output between the two groups, but in terms of the activity per one ml of the 12-hour specimen the considerable decrease was observed in the urolithiasis group (0.05<p<0.1).
3. Fibrinolytic activity in blood on euglobulin lysis time was reduced in 18 patients of the urolithiasis group, and plasma urokinase inhibitory activity was significantly increased in the urolithiasis group (p<0.01).
4. Urinary TNDS underwent rapid degradation with fibrinolysin, but was little affected with the urokinase in vitro.
