Assessment of recovery from hyperbaric-induced subfertility in male mice

This study was designed to investigate whether subfertility in male mice produced by exposure to high pressures of heliox showed any recovery. Male mice were exposed to 50 ATA heliox (controls exposed to 1 ATA air) during one spermatogenic cycle; subsequently each male was housed with 10 untreated females. After 14 days males were removed and housed with 10 more females. This was repeated four times. Male libido, pregnancy rate, pre- or early implantation loss, and fetal survival were determined for each mating. Results showed that all variables were significantly reduced in the pressure group during the first mating, but there were differing rates of recovery. Male libido was consistently reduced (12%) and showed no recovery trend. Pregnancy rate showed continuing improvement throughout all matings but did not reach control levels after 8 wk. Pre/early implantation loss and fetal survival had returned to control values by the fourth mating. These data suggest that pressure-induced subfertility is largely reversible, and at least two separate events contribute to it.