Survival rate of preantral follicles derived from vitrified neonate mouse ovarian tissue by Cryotop and conventional methods.

The aim of this study was to investigate the growth and survival rate of preantral follicles isolated from vitrified ovarian tissue by Cryotop and conventional methods. The ovaries of 14-day-old mice were separated and divided into four groups as following: Cryotop group, vitrified by Cryotop; CV (Conventional; CV) group, vitrified by conventional straw; toxicity test group and control group. After warming the vitrified ovaries, isolated preantral follicles from four groups were cultured for 4 days to compare survival rate and follicular growth between above-mentioned groups. Survival rate (97.3%) in toxicity test group alike the control group (98.7%) were significantly higher (P<0.05) than the Cryotop (92.7%) and CV (47.7%) groups. Increase in follicle diameters after 4 days in Cryotop and CV groups was significantly lower (P<0.05) than the control and toxicity test groups, but growth and survival rate of follicles in Cryotop group was significantly higher (P<0.05) than the CV group. These results demonstrated that ovarian tissue vitrification by Cryotop highly preserves the viability rate of preantral follicles.

Stereological study of the effects of vitamin E on testis structure in rats treated with para-nonylphenol.

This study was organized to see whether vitamin E, as a strong antioxidant, could affect the abnormalities of testis structure caused by para-nonylphenol (p-NP) during its development. A total of 32 female Wistar rats after mating were divided into four groups (n = 8): control, vitamin E (100 mg kg(-1) per day), p-NP (250 mg kg(-1) per day) and p-NP + vitamin E. The rats were treated from the seventh day of pregnancy till the twenty-first day. After weaning, the male pups were divided into the same groups and were treated orally for 90 days. Finally, the right testis was fixed, processed, stained and studied using stereological methods. The weight and volume of testis, volume of seminiferous tubules and its diameter, thickness of the basement membrane, height of the germinal epithelium, total number of types A and B spermatogonia, spermatocyte, spermatid and Sertoli cells were significantly reduced in p-NP group when compared with other groups. Co-administration of vitamin E and p-NP compensated for the adverse effects of p-NP on the above parameters. In addition, treatment with only vitamin E caused a significant increase in diameter, basement membrane thickness and height of germinal epithelium, number of spermatogonia and spermatocytes. Co-administration of vitamin E with p-NP could prevent the adverse effects of p-NP on the testis structure during its development.