Removal of zinc from subcellular regions of human spermatozoa by EDTA treatment studied by X-ray microanalysis.

The distribution of zinc in the head, neck and mid-piece of human ejaculated spermatozoa was investigated with energy-dispersive X-ray microanalysis. EDTA treatment within 1 h after ejaculation caused removal of 80-90% of the zinc in these regions. Storage for 24 h in own seminal plasma did not alter sperm zinc content. However, these aged spermatozoa only lost 35% of their zinc content on EDTA treatment. The stronger binding of zinc, occurring upon storage in seminal plasma, developed in all 3 parts of the cell investigated. These results are discussed in the light of the role of zinc in nuclear chromatin decondensation ability and sperm head-tail connection.