Sperm cell motility as a new experimental model for toxicological studies

The effects of environmental and toxicological factors were tested in a new and 'simple' biological system; the collective motility exhibited by ram spermatozoa. Motility of highly concentrated semen (> 1 x 10⁹ cells/ml) was evaluated objectively with a multichannel reflectospermiograph (RSG) connected to a minicomputer for an on-line analysis. The effect was tested on one of the energy-producing systems in the sperm cells, while the other was inhibited by 2-deoxy-D-glucose or antimycin-A so that the energy source for motility was known. The effects of the addition of ethanol to the semen in various concentrations, as well as various levels of oxygen in the environment were tested. When motility of the sperm cells was driven by mitochondrial respiration, the intensity and duration of motility was inhibited significantly above a threshold level. At the same level of ethanol, the motility was not significantly affected when the energy source was the fructolysis pathway. The effects of oxygen level were tested below and above the normal oxygen level (21% O₂). When fructolysis was inhibited, the motility was fully dependent on oxygen supply, namely, that lower levels of oxygen inhibited motility. It was also found that under higher levels of O₂ (hyperbaric hyperoxia conditions) the motility was inhibited due to the known oxygen toxicity effects.