engleski

Effect of zinc on superoxide anion production and superoxide dismutase activity in human spermatozoa

Apart from its role as a co-factor of the Cu,Zn-SOD, zinc per se was reported to have antioxidant properties. In this study we investigated the in vitro effect of zinc (Zn) on superoxide anion generation (O2-) and SOD-like activity in human spermatozoa. Cytochrome c reduction in the presence of myristate acetate phorbol ester was used to determine O2- production and SOD-like activity was measured using the xanthine/xanthine oxidase assay. Washed spermatozoa preincubated with Zn (1 and 3 mmol/l; 30 min, 37C, N=16)released less (p<0.001 and p<0.0005, respectively) superoxide anions than untreated spermatozoa. S imilar results were obtained using activated PMNs (1x10 6 cells/ml)in the presence of 1 and 3 mmol/l Zn (p<0.001 and p< 0.0002, respectively; N=9). The incubation of sperm suspension (37 C,30 min, N=18) with increasing Zn concnetration (0.1, 0.5, 1.0, 1.5 and 3 mmol/l) resulted in a concnetration-dependent decrease in the SOD-like activity (0.4, 6.6, 44.1, 54.8 and 81.8 % from initial values, respectively). Zinc at physiological levels in vitro suppresses the O2- production of spermatozoa, and unexpectedly inhibits the SOD-like activity. These results indicate a peculiar mechanism by which zinc might be related to oxidative changes in spermartozoa.

zinc; superoxide anion; superoxide dismutase; spermatozoa; human

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