[Spermatogenesis and maturation of spermatozoa in rats exposed to lead]

The performed investigations have covered the effect of lead on the course of spermatogenesis, and on maturing and stored spermatozoa in epididymis. Moreover, the effect of this element, exerted on spermatozoa under in vitro conditions, has been evaluated. For intravital investigations the rats were given lead acetate during the period of 1 and 3 spermatogenesis, and throughout 1 seminiferous epithelium cycle. It has been disclosed that there was a delayed spermiation as well as release of immature spermatogenic cells in the tubules of testis. A transient weakening of 3 beta-HSD activity was seen to occur in the interstitial gland, whereas decreased concentration of testosterone was recorded in the blood. Changes observed in epididymis were decidedly more pronounced. A drop in the number of spermatozoa in the duct lumen as well as intensified phagocytosis of abnormal reproductive cells, and also reduced activity of SDH, particularly LDH, were revealed. The lead was found to handicap also the conduction in the autonomous nervous system of epididymis, which was evidenced by the absence of the duct wall tension and by the relaxed AChE and MAO activities. The spectrophotometric examinations have shown that the lead was accumulating to a considerable degree in epididymis, and in insignificant amount in the testis. The described changes within reproductive system kept increasing with the prolongation of the experiment. The detected minor changes in testis and markedly stronger in epididymis are likely to result from the direct, toxic action of the lead upon the epididymis. The in vitro examinations have demonstrated that spermatozoa live shorter in the presence of lead acetate, which supports the view that it exerts cytotoxic effect on the cells in question.