In situ demonstration of both TUNEL-labeled germ cell and Sertoli cell in the cimetidine-treated rats

Abstract

Cimetidine has caused dysfunction in the male reproductive system. In the rat testis, intratubu l a r alterations and loss of peritubular tissue due to p e r i t u bular myoid cell death by apoptosis have been recently shown. Thus, the aim of this study is to evaluate which cells of the seminiferous epithelium have been affected and/or died by apoptosis after the treatment with cimetidine. For this purpose, an experimental group containing five male albino Wistar rats received intraperitoneal injections of cimetidine (50 mg/kg body weight) during 52 days. The testes were f i xed with 4% bu ff e r e d f o r m a l d e hyde and were embedded in paraffin. Fo r detection of DNA breaks (apoptosis) in the cells of the seminiferous epithelium, the testicular sections were treated by the TUNEL method (Apop-Tag Plus Peroxidase Kit). In the tubules affected by cimetidine, altered p e r i t u bular tissue, including the presence of TUNEL labeling in the myoid peritubular cells, were usually found. In these tubules, the seminiferous epithelium exhibited low density of germ cells and TUNEL-positive labeling in the germ cells of the basal compartment. The concomitant staining in both germ cells of the basal compartment and late spermatids suggest a sensitivity of these cells in the damaged tubules. Besides germ cells, T U N E L - p o s i t ive Sertoli cells were also found in the injured seminiferous tubules. Thus, a relationship between dying germ cells and Sertoli cell damage and/or death must be considered in tubules where peritubu l a r tissue has been affected by toxicants.