Calcium antagonists modulate oxidative stress and acrosomal reaction in rat spermatozoa

INTRODUCTION: Calcium ions are vital in many biological processes and qualify as an almost ubiquitous intracellular second messenger. This indicates the multiplicity of the effects associated with drug actions aimed at interfering with calcium ions. To examine the cellular process involved in the induction of infertility in males by calcium antagonist (CA) even in the presence of normal semen parameters, we studied the effects of different CA namely; nifedipine, verapamil and diltiazem on oxidative balance and acrosome reaction in the sperm. MATERIAL AND METHODS: For this purpose, lipid peroxidation, antioxidants such as superoxide dismutase, catalase and reduced glutathione, and acrosomal reaction were determined in sperm samples of rats. RESULTS: Calcium antagonist causes significant oxidative stress in the epididymal sperm with increased malondialdehyde level and a concomitant decrease in antioxidant activities of catalase and superoxide dismutase. The percentage value of acrosomal-reacted sperm in the nifedipine, verapamil and diltiazem-treated rats were 41 ±2.45, 39 ±2.92 and 42 ±1.22 respectively, compared with the control group value of 86 ±2.92. CONCLUSIONS: It appears CA oxidatively modify the sperm resulting in functional inhibition of acrosomal reaction. Suppression of the sperm acrosomal reaction is known to have serious adverse implications for fertilization.