RESUMO
Microscopically abnormal (n = 26) semen showed significantly higher levels of malondialdehyde (MDA), protein carbonyl (PC) and protein-bound sialic acid (SA) in seminal plasma as compared with normal semen (n = 24). The percentage of nonmotile spermatozoa showed significant (P < 0.01) positive correlation with MDA (r = 0.5) and PC (r = 0.49). Sperm counts showed a significant negative correlation with MDA (r = -0.63, P < 0.001) level of seminal plasma. SA correlated (r = 0.56, P < 0.01) with MDA. The receiver operating characteristic (ROC) curve of MDA and SA showed that MDA of 3.15 micromol l(-1) and SA of 3.85 micromol l(-1) were optimum cut-off limits to discriminate abnormal semen from normal. In conclusion, high SA might be a protective response against prevailed oxidative stress in abnormal semen. Seminal plasma MDA and SA may act as potential markers of abnormal semen.
