期刊名称:Journal of Clinical Biochemistry and Nutrition
印刷版ISSN:0912-0009
电子版ISSN:1880-5086
出版年度:1992
卷号:12
期号:2
页码:93-107
DOI:10.3164/jcbn.12.93
出版社:The Society for Free Radical Research Japan
摘要:Glutathione S-transferase (GST) isozymes purified from rat ovary and testis cytosols were grouped immunochemically into two classes, alpha and mu. The class-alpha isozymes of both tissue cytosols exhibited catalytic activities of Δ5-3-ketosteroid isomerase and glutathione (GSH)-peroxidase. The class-mu isozymes were characterized by showing potent GSH-conjugation activity toward a wide variety of electrophilic compounds. The most conspicuous difference in the isozymes between these gonadal tissue cytosols was shown to reside in the isozymes having Δ5-3-ketosteroid isomerase activity. Only GST 1-2 among the testicular GST isozymes showed the steroid isomerase activity, whereas two distinct ovarian class-alpha isozymes, GSTs 1-2 and 1′-1′, revealed the activity. Immunohistochemical analysis showed that the class-alpha isozymes were localized in the cells related to steroid hormone production such as testicular interstitial Leydig cells and the ovarian cells of theca folliculi and interstices, and the corpus lutheum. The class-mu isozymes were shown to be distributed throughout both gonadal tissues, but in the testis a remarkable localization of the isozymes was observed within Sertoli cells. These results suggest that each class of GST isozymes may be distributed in appropriate locations of the gonadal tissues to serve roles in generation of steroid hormones or in protection of ovum and sperm from various xenobiotics.