【摘要】 <正> 尿中β-葡萄糖醛酸酶(简称GRS)活力升高与膀胱肿瘤的形成及恶性病变程度有关。目前认为经过肝脏解毒失活的致癌物的结合物——葡萄糖醛酸甙,可受尿中的GRS还原而裂解,致使致癌活性部分重新释放,引发膀胱肿瘤。抑制尿中GRS的活力,可以控制肿瘤复发。总之尿中GRS更多还原

【Abstract】 Phenolphthalein glucuronic acid was used as the substrate for the assay of urine β-glucuronidase （GRS） and the kinetics of its hydrolyis was studied. The enzyme reachessaturation with 0.003M substrate, the Michaelis constant （Km） is 4.4 × 10^-4, the optimumpH for reaction is 4.7 and its activity is stable at pH 6.0. Experiment with dilution ofsamples by heat--inactivated urine proved that inhibitors and activators for the enzymeactivity were not significantly influenced. The assay of urine GRS in 14 preoperative casesof bladder cancer revealed that the activity in 9 cases exceeded the normal upper limit （95percentile）. The assay is simple to carry out; the product of enzymatic hydrolysis of thesubstrate phenolphthalein develops a stable color in strong alkali. Urinary of GRS activitymay be used as a parameter in studies on the etiology of bladder cancer as well as in theearly detection and prevention of its recurrence.更多还原