Assessment of germ cell apoptosis in cryptorchid rats

Aim: To investigate the relationship between germ cell degeneration and apoptosis in cryptorchid rats. Methods: Thirteen 21-day-old Wistar rats were made unilaterally cryptorchid by closing the left inguinal canal. At day 30 (Group 1, n=6) and day 60 (Group 2, n=7) after operation, the testes were removed for histopathological examination. The controls (n=8) were sham operated and were sacrificed at day 60. Germ cell apoptosis was assessed by means of the TUNEL method. Results: Spermatogenesis was arrested and the testicular and seminiferous tubular diameters were significantly reduced In the unilateral undescended testes (UUTs) compared with the contralateral descended testes (CDTs) and the control rats. However, atrophic changes, pathological calcification, necrosis of seminiferous tubule, and absence or sloughing of germ cells were not found in all the animals. The spermatocytes were the main type of germ cells undergoing apoptosis in all the groups. In the UUTs, there was a significant and time-dependent increase in the mean apoptotic index. By 60 days after surgery, increased apoptosis in germ cells was also observed in the CDTs. Conclusion: Apoptosis is the predominant mechanism of germ cell death rather than atrophy and necrosis in cryptorchidism.

Effects of estrogen replacement therapy on apoptosis and vascular endothelial growth factor expression in ocular surface epithelial cells:An experimental study

AIM:To investigate the effects of estrogen replacement therapy (ERT) on apoptosis and vascular endothelial growth factor (VEGF) expression in ocular surface in an experimental rat model.· METHODS:Forty female,Wistar rats were randomized in 4 groups in the study.Subcutaneous ERT (17β-estradiol,10g/kg/day) was administered to the first group without ovariectomy and to the second group with ovariectomy for three months.Third group had only ovariectomy and fourth group had sham operation.All rats were sacrificed in estrous cycles determined by vaginal smear test and their right eyes were enucleated at the end of the third month.Enucleated eyes were analyzed by immunohistochemical method for expressions of caspase-3,bcl-2,VEGF and TUNEL assay.· RESULTS:Caspase-3 expression of conjunctival epithelium was significantly higher in group 3 than group 1 (P =0.005),and group 2 (P =0.007).TUNEL score of conjunctival epithelium was significantly higher in group 3 than group 1 (P =0.006).TUNEL score of corneal epithelium was significantly higher in group 3 than group 2 (P =0.012),and group 4 (P =0.002).There was no significant difference between groups in that bcl-2 and VEGF expressions.· CONCLUSION:We determined increased apoptosis in ocular surface epithelial cells in ovariectomized rats.ERT and endogen estrogen decreased the apoptosis,and did not result in difference in VEGF expression between the groups.Estrogen may be beneficial for the treatment of apoptosis-mediated ocular surface disorders such as dry eye.Further studies are needed on this subject for a better understanding of the role of estrogen and to provide a new insight for treatment and prevention of apoptosis-mediated ocular surface disorders.