Effects of cryopreservation on sperm DNA integrity in normospermic and four categories of infertile males.

This study examined the effects of cryopreservation on DNA integrity of spermatozoa from 34 fertile subjects and 166 infertile subjects comprised of 80 teratospermic, 32 normospermic, 30 astheno-teratospermic, and 24 oligo-astheno-teratospermic individuals. Semen samples were prepared by swim-up and the Percoll density gradient centrifugation method (Pdgc) prior to freezing in liquid nitrogen. Neat and prepared samples were supplemented with cryoprotectant (SpermFreez) in cryoampoules and were frozen using the static phase vapor cooling procedure. Sperm DNA integrity of all thawed samples was determined using the alkaline comet assay. It was noticed that the sperm DNA integrity of frozen samples of fertile subjects was considerably higher than that of infertile subjects with greater catch-up integrity similar to the fresh samples. Freezing caused less chromatin damage to sperm of Pdgc samples from both fertile and infertile subjects as was compared to the neat and swim-up samples. It is concluded that the increase in comet frequency of frozen-thawed samples from infertile subjects was more prominent (8.25-22.78%; P<0.01) than in the fresh samples. Frozen-thawed samples from Ts (Teratospermic individuals) and ATs (Astheno-teratozoosspermic) showed higher level of OTM (Olive tail moment) indicating a higher level of chromatin fragmentation than fertile, Ns (Normospermics), and OATs (Oligo-astheno-teratozoospermics).

Adverse effects of arsenic exposure on uterine function and structure in female rat.

The present investigation examined the adverse effects of arsenic exposure on uterine function and structure of female rat at 56 days of age, exposed to different doses (50, 100, and 200ppm) of sodium arsenite in drinking water at immature age (28 days) for 28 days. Dose-dependent decrease (P<0.001) was observed in mean uterine weight and length in all treated groups compared to control. Higher arsenic deposition was found in uterine tissue against increased doses of arsenite. Arsenite treatment altered the histomormphology of the uterus. Uterine epithelium in 50ppm group was lined by cuboidal cells instead of columnar cells observed in control epithelium. In 100 and 200ppm groups, no demarcation was observed between epithelial cells and endometrial stroma. No basement membrane was seen in these groups; even in 50ppm, basement membrane was disturbed. The endometrial stroma in 100 and 200ppm groups was very dense in appearance and contained irregular-shaped cells. In myometrium, loosening of cells was observed in 100 and 200ppm groups. Dose-dependent decrease (P<0.001) was observed in mean uterine diameter, epithelial height, thickness of endometrium, myometrium, and in plasma levels of estradiol, progesterone, FSH and LH in all the treatment groups compared to control. In summary, arsenic is a major threat to female reproductive health acting as a reproductive toxicant and as an endocrine disruptor, restricted the function and structure of uterus, by altering the gonadotrophins and steroid levels, not only at high dose concentration but also at low (50ppm) levels, when they become mature.

Genotoxicity of sodium arsenite and DNA fragmentation in ovarian cells of rat.

Present study examined the genotoxic effects of arsenite in ovarian tissue of rat at 56 days of age. Immature (28 days old) female rats were exposed to different doses (50, 100, and 200 ppm) of sodium arsenite in drinking water for 28 days. DNA damage in ovarian tissue was measured by comet assay. All doses induced significant decrease in ovarian weight in a dose-dependent manner compared to control, more prominently at (P<0.001) 100 and 200 ppm. All the comet assay parameters showed significant difference with arsenite treatment compared to control group. In treatment groups, mean number of cells with intact DNA decreased while, mean comet number increased (P<0.001) in a dose-dependent manner compared to control. Significant decrease (P<0.05) was observed in mean comet length, height, comet head diameter and %DNA in comet head of high dose groups compared to control group. Dose dependent increase was found in mean comet tail length, %DNA in tail, tail moment and olive tail moment in high dose groups compared to control group. The study indicates that arsenic caused DNA damage to ovarian cells particularly at high doses and ensure comet assay as an effective method to detect DNA damage in tissue caused by metals.