Cytosolic calcium levels in spermatozoa are modulated differently in healthy subjects and patients with varicocele

OBJECTIVE: To study parameters connected to fertility in the semen of patients with varicocele. DESIGN: We examine the ability of spermatozoa obtained from patients with varicocele to respond with an increase of cytosolic Ca2+ ([Ca2+]i) to some stimuli that are connected with spermatozoa activation. SETTING: An academic research environment. PATIENT(S): Ten healthy volunteer donors and 10 patients affected by II or III grade left varicocele. INTERVENTION(S): Spermatozoa and prostasomes (vesicles of prostatic origin obtained from semen) were prepared according to standard procedures. Spermatozoa were stimulated with 1 microM P. The [Ca2+]i was evaluated with the FURA II method. MAIN OUTCOME MEASURE(S): The level of [Ca2+]i. RESULT(S): In resting cells, the level of [Ca2+]i was 120 +/-15 nmol/L (10 determinations). This value increases by > or =100 nmol/L upon stimulation with P. No difference was observed between spermatozoa obtained from healthy donors or from patients with varicocele. S-nitrosocysteine, a nitric oxide donor, and the fusion between spermatozoa and prostasomes increased the effect of P on [Ca2+]i in control spermatozoa but not in spermatozoa obtained from patients with varicocele. CONCLUSION(S): Different responsiveness of varicocele patients' spermatozoa to S-nitrosocysteine and/or to fusion with prostasomes may be among the possible causes of reduced fertility.