Chronic cigarette smoking induces an oxidantantioxidant imbalance in the testis.

OBJECTIVES

We have previously demonstrated the harmful effect of chronic inhalation of cigarette smoke on the testis in Sprague-Dawley rats. The aim of the present study was to investigate the role of free oxygen radicals and reactive oxygen species in inducing testicular damage in Sprague-Dawley rats following exposure to cigarette smoke.

MATERIALS AND METHODS

Sprague-Dawley rats, 25 days old, were exposed daily to cigarette smoke by the Walton smoking machine for a period of 15, 30, and 45 days. Age-matched Sprague-Dawley rats were exposed to room air with the smoking machine and served as controls. Rats were sacrificed from each group at 15, 30, and 45 days and the testes were removed. The testicular tissue levels of glutathione and lipid peroxidation product malonaldehyde (MDA) were measured colorimetrically using the Bioxytech GSH-400 and LPO-586 kits, respectively. The activity of glutathione peroxidase was assessed colorimetrically using the Bioxytech GPx-340 kit. Statistical analysis was performed using ANOVA followed by the t test.

RESULTS

There was a 47.8% increase in the MDA in the treated rat testis compared with the control rat after 45 days of exposure to cigarette smoke or air, respectively (p < 0.05). This was associated with a parallel significant decrease in the level of glutathione and glutathione peroxidase activity in the treated rat testis, 38.2% and 29.1%, respectively, after 45 days of cigarette smoke exposure (p < 0.05). No significant difference was noted in the levels of glutathione, glutathione peroxidase, and lipid peroxidation end products after 15 and 30 days of treatment.

CONCLUSIONS

Chronic cigarette smoke inhalation is associated with an increase in the level of oxidants and a simultaneous decrease in the level of antioxidants in the rat testis. This abnormality of the oxidant-antioxidant balance may be one of the mechanisms leading to testicular tissue damage and abnormal spermatogenesis in the rat testis following chronic inhalation of cigarette smoke.