The human sperm nucleus takes up zinc at ejaculation

Ejaculated and vasal sperm were obtained from men referred for vasectomy, and sperm nuclear elements were determined by X-ray microanalysis. Sperm head zinc concentrations, expressed as the ratio Zinc to Sulphur, were significantly higher in ejaculated than in vasal sperm. A physiological sperm nuclear zinc uptake is discussed in relation to sperm chromatin decondensation.