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.