آسيب هاي زمينه DNA در اسپرم هاي افراد سالم و نابارور با استفاده از روش سنجش ستاره دنباله دار

Study of baseline DNA damage in the sperms offertile and infertile men using comet assay

Introduction: Male infertility constitutes the primary cause of infertility for up to 30% of couples amongst many other reasons. Genetic disorders are too important because DNA integrity in sperm is necessary for having healthy next generation. The aim of this study was to evaluate the baseline DNA damage in sperm samples obtained from normal and infertile individuals. Methods: Baseline DNA damage in spermatozoa from, fertile (n-30) and infertile (n=90) individuals was compared using a modified alkaline single cell gel electrophoresis (comet assay). This technique was used to assess DNA integrity in the cells by measuring damages reflected as strand break under alkaline conditions. The cells were embedded in agarose on glass slides followed by lysis of the cell membranes after which, damaged DNA strands migrate under electrophoresis from nucleus towards the anode and deposited to one side giving the appearance of a tail. DNA damage in each group was calculated following visual observation and grading of comets under a fluorescence microscope. The significance of inter-group differences was statistically evaluated using analysis of variance (ANOVA) and Post hoc tests. Results: Results indicate that the average DNA damage in normal sample is less than any other groups. Samples from oligospermic, oligoasthenospermic and asthenospermic patients showed various degrees of DNA damage significantly different from normal (p<0.05). The highest degree of DNA damage was seen in asthenospermic samples. Conclusion: DNA damage in infertile individuals is, found to be higher than normal. The reason for this observation may be due to a deficiency in antioxidants which is essential present during spermatogenesis. The presence of antioxidants prevents DNA damages in sperms due to oxidative agents.