Oxidative and Biosynthetic Utilization by Human Spermatozoa of a Metabolite of the Female Reproductive Tract

Abstract

In vitro investigations of the metabolism of mammalian spermatozoa have amply demonstrated their ability to utilize a variety of glycolysable and oxidizable substrates¹. No information is, however, available on the metabolism of spermatozoa within the female reproductive tract. If, as is probable, the epithelial cells use up not only the glucose supplied by the circulatory system, but also oxidizable intermediates such as pyruvate and lactate, the spermatozoa in contact with those cells would have to oxidize their endogenous reserves of lipid material, provided that the oxygen tension in the various regions of tho tract is adequate to support the aerobic metabolism of the spermatozoa. In the absence of external substrates the conditions in the female genital tract would not be favourable for the survival of spermatozoa for prolonged periods of time. Whereas this may not affect fertility in animal species in which mating occurs at the time of oestrus, with rapid ascent of an adequate number of spermatozoa, a limited survival capacity due to the lack of substrates may affect the prospects of fertilization in man.