THE ROLE OF SEMINALCALCIUM IN MALE INFERTILITY

It has long been known that extracellular calcium is required for successful fertilization. In all systems examined, an influx of Ca+2, is required to initiate the acrosomal reaction, with its attendant release of enzymes and membrane alterations necessary for sperm-egg interaction.

There is also evidence that this ion may be involved in sperm motility . In the present study, the mean seminal calcium value in fertile men was found to be higher than those of both infertile groups. The lowest value detected in the normozoospermic infertile groups was significant when compared to the fertile men . These findings may suggest that significantly decreased seminal calcium may be related to infertility seen in normozoospermic subjects. In a study performed by Umeyama et al., seminal calcium concentrations were almost the same between fertile and infertile men, and the highest level was determined in the normozoospermic infertile subjects. Our findings do not confirm these results, but are similar with those of Abou-Shakra , who determined the lowest concentration in the normozoospermic infertile group, being nonsignificant in relation to infertility classification.

A study by Prien et al. examined the relationship between sperm motility and seminal Ca++. They determined that seminal fluid of men with hypomotility exhibited a significantly lower Ca++ concentration when compared with that of men with normal motility. Although we have assessed total calcium level, our results do not support this finding, since we have found weak and negative, but nonsignificant correlations
between seminal calcium and sperm motility both in the fertile and infertile groups .

However, another study indicating that a high concentration of calcium suppresses sperm motility, confirms our findings . Of the 33 infertile subjects included in our study, 27 were asthenozoospermic; in order to draw a more definite conclusion about seminal calcium and sperm motility, we plan to determine ionized calcium (Ca++) level in the seminal fluid in a group including only asthenozoospermic infertile men, and make comparison with samples exhibiting normal sperm motility. When our results are evaluated with those of other reports, it may be concluded that seminal calcium may be involved in sperm motility, and this effect can be stimulatory or inhibitory, depending on its concentration.

As reported by Fraser , an optimal seminal calcium concentration is required to promote sperm motility, and all steps leading to successful fertilization. The most important result of our study reveal that seminal calcium concentration has to be determined in normozoospermic infertile men, who also have the asthenozoospermia problem. Further study is necessary for an understanding of the male infertility and seminal calcium relationships.

REFERENCES
Umeyama T, H Ishikawa, H Takeshima, et al : A comparative study of seminal trace elements in fertile and infertile men.Fertil Steril 46:494-499, 1986.

Prien SD, CD Lox, RH Messer, et al: Seminal concentrations of total and ionized calcium from men with normal and decreased motility. Fertil Steril 54:171-172, 1990.

Abou-Shakra FR, NI Ward and DM Everard : The role of trace elements in male infertility. Fertil Steril 52:307-310, 1989.

Zanaveld LJD, CJ Dejonge, RA Anderson et al : Human sperm capacitation and acrosome reaction. Human Reprod 6:1265-1274, 1989.

Fraser LR : Motility patterns in mouse spermatozoa before and after capacitation. J Exp Zool 202:439-444, 1977.

Yanagimachi R and N Usui : Calcium dependence of the acrosome reaction and activation of guinea pig spermatozoa. Exp Cell Res 89:161-174, 1974.

Arver S : Studies on zinc and calcium in human seminal plasma. Acta Physiol Scand 507(suppl):1, 1982.

Fraser LR : Minimum and maximum extracellular Ca+2 requirements during mouse sperm capacitation and fertilization invitro. J Reprod Fert 81:77-89, 1987.