CLINICAL APPLICATION OF URINARY NAG INDEX AND SDS-PAGE ANALYSIS OF URINARY PROTEIN IN FELINE AND CANINE URINARY DISORDER

本研究旨在确定尿NAG指数测定和尿蛋白SDS-PAGE分析作为动物泌尿系统疾病标志物的临床实用性。结果表明：（1）重铬酸钾或磺胺类药物诱发的牛、猫肾病模型，早期尿NAG指数升高，肾毒性药物给药后尿NAG同工酶B升高。(2)慢性和急性肾功能衰竭患者尿NAG指数均高于健康动物。而猫下尿路疾病或下尿路感染患者的NAG指数在正常范围内。下尿路感染伴肾盂肾炎犬NAG指数升高。NAG指数升高提示感染和炎症向盆腔的扩展。因此，尿NAG指数的测定似乎是有用的肾盂肾炎的标志物。对于糖尿病、子宫积脓等继发性肾功能衰竭患者，尿NAG指数的测定也可作为肾损伤的一个指标。(3)采用SDS-PAGE法检测慢性肾衰竭患者尿液中的视黄醇结合蛋白等低分子蛋白质。在SDS-PAGE分析中，观察了下尿路感染患者尿液中的血清蛋白谱。尿蛋白SDS-PAGE分析有助于区分肾脏和下尿路的实质病变。SDS-PAGE法测定尿蛋白与尿NAG指数联合测定更为有效。总之，本研究结果证实了尿NAG测定和尿蛋白SDS-PAGE测定作为动物肾脏疾病标志物的临床实用性。

This study was undertaken to determine the clinical usefulness of measurement of urinary NAG index and SDS-PAGE analysis of urinary protein as a marker for urinary disorder in animals. The results were as follows :(1) Urinary NAG index elevated from the early stage of nephrosis model experimentally-induced by potassium dichromate or sulfonamide in cattle and cat. Isoenzyme B of urinary NAG was increased after the administration of renal toxic drugs. (2) Urinary NAG index of the cases with chronic or acute renal failure was higher than that of healthy animals. On the other hand, NAG index of the cases with feline lower urinary tract disease or lower urinary tract infection was in the normal range. The dogs with lower urinary tract infection accompanied by pyelonephritis showed elevated values of NAG index. The elevation of NAG index indicated the extension of infection and inflammation to the pelvis. Therefore, measurement of urinary NAG index seemed to be useful as a marker of pyelonephritis. In secondary renal failure such as diabetes mellitus and pyometra, observation of urinary NAG index was also useful as a marker of renal injury. (3) In urine of chronic renal failure, low molecular proteins such as retinol-binding protein were detected by SDS-PAGE assay. In the assay of SDS-PAGE, serum protein pattern was observed in urine of lower urinary tract infection. SDS-PAGE assay of urinary protein was useful to distinguish the parenchymal lesions between kidneys and lower urinary tract. SDS-PAGE assay of urinary protein was more effective when it was done with the measurement of urinary NAG index. In conclusion, the clinical usefulness of measurement of urinary NAG and SDS-PAGE assay of urinary protein as the markers for renal diseases in animals were attested from the results obtained in this study.