Heavy metals and spermatozoa. 1. Inhibition of the motility and metabolism of spermatozoa by metals related to copper.

The toxicity to human spermatozoa of seven metals (nickel, palladium, platinum, silver, gold, zinc, and cadmium) and one alloy (brass: 80% copper, 20% zinc) related to copper was assessed in vitro. Only brass and cadmium significantly reduced the percentage of motile unwashed spermatozoa; however, washing the spermatozoa increased the spermicidal effectiveness of both brass and cadmium and also resulted in a significant reduction in motility caused by zinc and silver. Oxygen consumption by once-washed spermatozoa was apparently increased by zinc and brass, but the high rate of oxidation of these metals confounds interpretation of their effect. Silver caused a decline in the oxygen uptake of spermatozoa. Silver, zinc, brass, and, to a lesser extent, cadmium decreased the quantity of glucose utilized by spermatozoa and also decreased the glucose oxidized. Accumulation of lactate by washed spermatozoa was impaired severely by zinc and less severely by brass and cadmium.