Effects of hyperbaric oxygenation on spermatozoan motility driven by mitochondrial respiration

The effects of hyperbaric oxygen (HPO) on ram sperm motility driven by mitochondrial respiration are described. Sperm motility was assessed by a multichannel optical objective technique (Reflectospermiography). Motility was simultaneously measured from four semen samples at various pH levels in room air atmosphere and compared with four other samples exposed to various high oxygen (100%) levels 1, 3, 5, and 7 atmospheres absolute (ATA). Two main effects were observed under HPO oxygen: 1) shortening of motility durations, and 2) abolishment of motility regulation by pH. These effects were found to be attributed to the hyperoxic conditions. Above 3 ATA the effects of HPO with regard to the above-described parameters were considered toxic. Below this pressure level the effect of HPO was found to be moderate. The exposure of sperm cells to HPO (7 ATA) did not cause morphological alterations. Also, exposure of seminal plasma to HPO (7ATA) 150 min did not cause any toxic effects when added to washed spermatozoa. The ram semen preparation seems to provide a useful model for studying the mechanisms underlying HPO effects.