Fushimi H, Tarui S
Clin Chim Acta. 1976 Aug 16;71(1):1-8. doi: 10.1016/0009-8981(76)90267-9.
In previous studies, beta-N-acetyglucosaminidase activities were found to be markedly decreased in streptozotocin diabetic rat kidney, while that of the liver, spleen and intestine remained unchanged. The decrease in total kidney enzyme activity was in parallel with a decrease in the enzyme activity of the main isozyme of beta-N-acetylglucosaminidase, of which little or none was contained in the other three tissues. The present paper reports that the retina, also sensitive to diabetic microangiopathy, showed a similar isozyme pattern to that of kidney, composed of mainly type II isoenzyme of beta-N-acetylglucosaminidase. Type II isoenzyme was not detectable in any of the other materials tested including human and rat erythrocytes, lymphocytes and platelets, and human buccal epithelia and saliva, except human tear. The physiologic significance of the human tear beta-N-acetylglucosaminidase is unknown, but this enzyme was found to contain a considerable amount of Type II isoenzyme, and the enzyme activities were decreased in poorly controlled diabetic patients. Patients with retinopathy also showed markedly lowered tear enzyme activity. The diabetic patients were followed up for several months with occasional ophthalmoscopic examination and determination of serum beta-N-acetylglucosaminidase activity. As a result, changes in the latter were found to be useful as an indicator of the development of microangiopathy.
在以往的研究中，发现链脲佐菌素诱导的糖尿病大鼠肾脏中的β-N-乙酰氨基葡萄糖苷酶活性显著降低，而肝脏、脾脏和肠道中的该酶活性保持不变。肾脏中总酶活性的降低与β-N-乙酰氨基葡萄糖苷酶主要同工酶的活性降低平行，而其他三种组织中几乎不含或不含该同工酶。本文报道，同样对糖尿病微血管病变敏感的视网膜，其同工酶模式与肾脏相似，主要由β-N-乙酰氨基葡萄糖苷酶II型同工酶组成。除人泪液外，在包括人及大鼠红细胞、淋巴细胞和血小板，以及人颊黏膜上皮和唾液在内的任何其他测试材料中均未检测到II型同工酶。人泪液β-N-乙酰氨基葡萄糖苷酶的生理意义尚不清楚，但发现该酶含有相当数量的II型同工酶，且在血糖控制不佳的糖尿病患者中酶活性降低。患有视网膜病变的患者泪液酶活性也明显降低。对糖尿病患者进行了数月的随访，偶尔进行眼底检查并测定血清β-N-乙酰氨基葡萄糖苷酶活性。结果发现，后者的变化可用作微血管病变发展的指标。
