The effects of oxygen toxicity on the pregnant rat using an apparatus designed to measure oxygen consumption method

To evaluate the effects of oxygen toxicity in the pregnant rat at high and low concentrations of oxygen, an oxygen-consumption apparatus was devised to measure the consumption of oxygen continuously over long periods. Oxygen consumption, partial oxygen pressure on the skin (tcPo2), and lipid peroxide levels in the serum were measured. There was a close correlation between oxygen consumption and body weight of rats that weighed between 150 g and 450 g. Oxygen consumption during the later stages of pregnancy increased by 1.8 ml/day, an increase of 8%. Oxygen consumption by rats during parturition increased markedly for up to 1 h and then reached and remained at a plateau value until the end of delivery. Exposure of pregnant rats to low concentrations of oxygen resulted in a marked depression in oxygen consumption and tcPo2 during the exposure time. A significant increase in the lipid peroxide level in serum was observed in the mother rat after birth and in the newborn offspring of pregnant rats exposed to 16% oxygen for 3 h.