The effect of smoking and varicocele on human sperm acrosin activity and acrosome reaction

Smoking and varicocele are frequent findings in the medical history and physical examination of patients attending andrological outpatient departments. However, data about their influence on human semen parameters, such as sperm concentration and motility, are contradictory. Therefore, the purpose of this study was to examine sperm function (acrosin activity and induction of the acrosome reaction) in smokers (n = 30) and varicocele patients (n = 30) compared with normal fertile donors (n = 20). The acrosome reaction was detected by triple staining after 3 h of incubation at 37 degrees C, followed by treatment with 0.1% dimethylsulphoxide (spontaneous acrosome reaction) and 10 microM calcium ionophore A23187 (induced acrosome reaction) for 1 h at 37 degrees C. Acrosin activity was measured by gelatinolysis. The diameters around the sperm heads after gelatinolysis and the percentages of spermatozoa showing halo formations were evaluated. The inducibility of the acrosome reaction was significantly lower in semen samples from smokers than in those from the fertile group (7.1 +/- 3.2 versus 11.2 +/- 4.0%, P < 0.01), whereas no statistically significant difference was demonstrated in spermatozoa from patients with varicocele (9.3 +/- 4.3%). Both the percentages of spermatozoa with halo formation (53.3 +/- 20.0 versus 76.6 +/- 13.6%, P < 0.05) and the halo diameters (16.1 +/- 6.6 versus 31.0 +/- 14.5 microns, P < 0.001) were significantly lower in the varicocele group than in the samples from fertile men. These data suggest that smoking and varicocele affect sperm function, and that the standard semen parameters alone are insufficient to evaluate the influence of both factors on human male fertility.