The study on apoptosis and immunohistochemical localization of annexin 5 in rat cryptorchid testis

Aim: To investigate the expression of annexin 5, the distribution of annexin 5 and 3b-HSD and apoptosis of germ cells in cryptorchid testis. Methods: After cryptorchid surgery, abdominal and scrotal testes were removed at 96h, 1 w, 2 w and 4 w respectively. Immunohistochemistry, Western-blot and TUNEL were used. Results : Results showed that the annexin 5 was increased significantly in abdominal testis at 1 w (p < 0. 05) and at 4 w.(p < 0. 01). Annexin 5 was appeared mainly in intra seminiferous tubules at I week and was aggregated with stronger intensity at 2 week in cryptorchid testis. The sperm was disappeared and the number of spermatocyte was reduced from 1 w of surgery. Annexin 5 in all scrotal testis was localized mainly in interstitial tissue and Setoli cells. 3b-HSD in abdominal testis was diminished at 1 d and disappeared at 1. w of cryptorchidism. Apoptosis in abdominal testes was found at 1 d and increased at 1w. In scrotal testis, no apoptotic cell was found. Conclusions: As a conclusion, the variation of expression and distribution of annexin 5 in cryptorchid testis, as well as the decrease of 3b-HSD and apoptosis in abdominal testis implied on that annexin 5 may play a certain physiologic role in abdominal testis after experimental cryptorchid surgery.