URINARY NAG ISOENZYMES IN COWS WITH EXPERIMENTALLY -INDUCED NEPHROSIS AND BOVINE CLINICAL CASES.

本研究旨在探讨尿NAG作为动物肾脏疾病标志物的临床应用价值。结果表明：(1)3种底物(4MU、MCP和PNP)测定的牛尿NAG指数个体间存在显著相关性。不同性别间尿NAG指数均值无显著差异，不同年龄组奶牛尿NAG指数均值也无显著差异。肾实质病变奶牛尿液NAG指数高于健康奶牛尿液。(2)尿NAG同工酶可用DEAE-SepharoseCL6B微型柱层析法或电泳法分离。用微柱法和电泳法测得健康牛和猫尿中NAG-A和NAG-B的比例分别为8：2和6.5：3.5，本研究得到的NAG-A比例与健康Parsons和大鼠相似。在肾实质损害的动物中，NAG-B升高。(3)重铬酸钾致小牛肾病后，尿NAG指数升高，尿NAG-B升高。肾组织匀浆NAG-B含量也明显升高。总之，本研究结果证实了尿NAG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 as a marker for renal diseases in animals. The results were as follows: (1) The individual values of urinary NAG index measured by using of 3 substrates ( 4MU, MCP and PNP) were correlated significantly with each other in cattle. There was no significant differences in mean values of urinary NAG index between bovine sexes, and neither amoung cows of various age groups. NAG index in urine samples obtained from cows with renal parenchymal lesions was higher than that obtained from healthy cows. (2) Urinary NAG isoenzymes were separated either by the mini column of DEAE-Sepharose CL6B or electrophoresis. The proportions of NAG-A and NAG-B in the urine of healthy cows and cats measured by mini column method or electrophoresis were 8 : 2 and 6.5 : 3.5, respectively, The proportion of NAG-A obtained in this study is similar to those in healthy parsons and rats. An increase of NAG-B was observed in the animals with renal parenchymal lesions. (3) Urinary NAG index in calves with nephrosis experimentally-induced with potassium dichromate was high and the increase of urinary NAG-B was observed. NAG-B of renal homogenate was also increased. In conclusion, the clinical usefulness of measurement of urinary NAG as a marker for renal diseases in animals was attested from the results obtained in this study.