RESUMEN
AIM: To investigate the apoptosis and Bcl-2/Bax expression in the early follicles of women at reproductive age. METHODS: 12 ovarian specimens were collected from reproductive women (aged 23-38 years) undergoing gynaecological operation. Histopathological examination of these specimens was performed to confirm its' morphological normalities. Using TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) assay and immunohistochemistry method, cell apoptosis and Bcl-2/Bax expression were examined in the early follicles including mainly primordial, intermediary and primary follicles. RESULTS: 18.75% of the oocytes were found TUNEL positive in the early follicles, but no granulosa cells in these follicles were found TUNEL positive. Bax expression was detected in 76.07% of the oocytes in the early follicles, but Bcl-2 expression was negative in these oocytes. In addition, Bcl-2/Bax expression were not present in the granulosa cells in early follicles. CONCLUSION: The oocyte apoptosis occurs in the early follicles of reproductive woman, and pro-apoptotic protein Bax may play a role in regulating this process. It suggests that Bax mediated oocyte apoptosis may be the molecular mechanism of the early follicle atresia in the ovaries of reproductive woman. [
RESUMEN
AIM: The cytoplasm Ca 2+, expression of Bcl-2 and Bax and germ cell apoptosis of testes in adult male rats with varicocele were observed to investigate the relationship between apoptosis and infertility. METHODS: Thirty-five healthy male Wistar rats were divided into two groups randomly: varicocele group (VG, n=20) and sham operation group (SOG, n=15). Bilateral testes were removed after ten weeks. One part of it was homogenized, the other part was performed for tissue sectioning. The atomic absorption method was used to detect the cytoplasm Ca 2+. The germ cell apoptosis was detected by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) technique. The expression of Bcl-2/Bax was detected by immunohistochemical method. RESULTS: The cytoplasm Ca 2+ in testes of rats with varicocele was decreased obviously. The apoptosis indexes of germ cells and Bax expression in VG were significantly increased as compared with those in the SOG, while Bcl-2 expression was obviously decreased. CONCLUSION: The results showed that apoptosis was increased in testes of VG rats, suggesting that male infertility with varicocele may be caused by some apoptosis agents such as high temperature, testes toxin and oxygen free radical. The cytoplasm Ca 2+ and change of expression of Bcl-2/Bax may contribute to germ cell apoptosis and cause male infertility.