期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1973
卷号：70
期号：8
页码：2211-2214
DOI：10.1073/pnas.70.8.2211
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The enzymes of the {gamma}-glutamyl cycle have been found in rabbit ciliary body and, except for 5-oxoprolinase, also in the ocular lens. Histochemical studies show that {gamma}-glutamyl transpeptidase is localized mainly in the basal portions of the epithelial cells of the ciliary body; the findings are similar to those observed in the chloroid plexuses. The histochemical staining reaction in the ciliary epithelium is more intense than in the chloroid plexus, intestine, and kidney. {gamma}-Glutamyl transpeptidase staining activity in the epithelium of the intestinal and renal proximal convoluted tubules is confined to the microvillus border. Moderate transpeptidase activity was found in the cytoplasm of nonpigmented epithelial cells of the iris at the posterior pupillary margin. The histochemical and enzyme activity studies are consistent with the thesis that the {gamma}-glutamyl cycle functions in transport of amino acids across the blood-aqueous humor barrier.
