van Aswegen C H, Neitz A W, Becker P J, du Plessis D J
Department of Urology, H.F. Verwoerd Hospital, University of Pretoria, Republic of South Africa.
Urol Res. 1988;16(3):143-8. doi: 10.1007/BF00256008.
The formation of renal calculi is one of the most widely studied urinary ailments. Spectrophotometric analysis of urinary inhibition on the urokinase/plasmin system revealed a significant difference between subjects with and without renal calculi (P less than 0.001). The percentage urokinase/plasmin inhibition in the two groups was 77.1% for those with, and 47.1% for those without renal calculi. Because of the significant (P less than 0.015) positive correlation (r = 0.762) between the percentage inhibition of urokinase/plasmin and urinary urate concentration, the inhibition of urate on urokinase/plasmin and on plasmin and urokinase was investigated. The urokinase/plasmin system was inhibited up to 94.4% with 0.5 mM urate. Inhibition occurred with both low and high molecular weight urokinases. In order to determine which enzyme of the complex was inhibited, each was investigated independently and a 50% inhibition of urokinase activity was obtained with 4 mM urate. It was found that the urine of stone formers contained a higher concentration of urate than the urine of healthy subjects and that at the same time there was a decrease in urinary urokinase activity in these patients.
肾结石的形成是研究最为广泛的泌尿系统疾病之一。对尿液对尿激酶/纤溶酶系统的抑制作用进行分光光度分析发现，有肾结石和无肾结石的受试者之间存在显著差异（P小于0.001）。两组中尿激酶/纤溶酶的抑制百分比，有肾结石者为77.1%，无肾结石者为47.1%。由于尿激酶/纤溶酶抑制百分比与尿尿酸浓度之间存在显著的（P小于0.015）正相关（r = 0.762），因此研究了尿酸对尿激酶/纤溶酶以及纤溶酶和尿激酶的抑制作用。用0.5 mM尿酸可使尿激酶/纤溶酶系统的抑制率高达94.4%。低分子量和高分子量尿激酶均受到抑制。为了确定复合物中的哪种酶受到抑制，对每种酶进行了单独研究，用4 mM尿酸可使尿激酶活性受到50%的抑制。结果发现，结石形成者尿液中的尿酸浓度高于健康受试者的尿液，同时这些患者的尿激酶活性降低。
