In vitro release and uptake of zinc and magnesium by human spermatozoa.

Abstract

Changes in the zinc and magnesium content of human spermatozoa with time have been followed over the first 24 hours after ejaculation. Magnesium did not change but marked alternations were noted for the zinc concentration. During the first hour there was a significant decrease followed by a "steady state" for 2 hours. Then a significant increase during the following 4 hours was recorded. Between 7 and 24 hours after ejaculation there was no further increase in the zinc concentration, nor did addition of 100 ug zinc per ml seminal plasma after 24 hours alter the sperm content of this ion. The importance of the seminal plasma for sperm uptake of zinc could be demonstrated. One subject presented semen specimens in which the uptake of zinc by the spermatozoa was very rapid and higher than that in the others. The seminal plasma from this man had biochemical signs of a markedly decreased prostate function. Incubation of normal spermatozoa in this seminal plasma for 4 hours increased their zinc content 3 times over the control values. The observation that the secretory function of the accessory genital glands can influence functional properties of the spermatozoa seems of principal interest from many points of view. Further studies along the same line may give leads to new male contraceptives.