GSTM1 genetic polymorphism andglutathione S-transferase activity in Iranianinfertile men
Introduction: Mu-GST class of glutathione Stransferaseis present on human sperm surface andplays an important role against oxidative stress.Therefore, any defects in the enzyme activity maybe associated with male infertility by GSTM1 nullgenotype without enzyme activity. Thus, GSTM1polymorphism in association with enzyme activityand spermiogram parameters were studied.Materials and Methods: This case-control studyinvolved 95 men with oligoastenoteratozoospermiaand 26 controls with normozoospermia. Semenanalyses were carried out according to WHOguidelines. DNA was extracted from blood bysalting out procedures. Polymorphisms at GSTM1gene determined by multiplex PCR. Glutathione Stransferaseenzyme activity was measured byspectrophotometric method at 340 nm.Results: Sperm concentration, morphology andmotility were significantly lower in theoligoastenoteratospermic men compared withindividuals on the control group (p<0.001).Frequencies of GSTM1 null genotype in case andcontrol groups were 52.1% and 53.8%,respectively. There were no statistically significantdifferences in spermiogram parameters andenzyme activity in GSTM1 null and positivegenotypes in the two groups. There were nostatistically significant differences at mean ± SDGST activity in oligoastenoteratospermia andnormospermic groups, 7.43 ± 2.84 and 7.07 ± 1.68nmol/min/1×106 sperms, respectively.Conclusion: Total GST activity and spermiogram parameters are not affected by deficient GSTactivity in GSTM1 null genotype. Compensationof activities of other sperm surface GST isozymes,like GSTP1, may justify the cause.