Effects of Normoxic Prenatal Low Pressure on Gestation and Development in Mesocricetus Auratus

Abstract

The effects of a normoxic low pressure environment on gestation and postnatal development in Mesocricetus auratus were examined to test the widely held assumption that the deleterious effects of exposure to high altitude during pregnancy are due to hypoxia alone. Animals exposed to low pressure alone during days 8-12 of gestation gained significantly less weight than control animals, but most of the weight difference was eliminated by the second day after treatment. No differences were found in litter size, sex ratio, postnatal weights, eye opening, vagina opening, or regularity of estrous cycle of the prenatally treated pups as compared to controls, suggesting that postimplantation fetuses may be protected from a low pressure maternal environment. It was concluded that weight losses observed at high altitude in previous studies were probably due to the combined effects of hypoxia and low pressure exposure, but that the low pressure component alone does have physiological significance.