Effects of Hypoxic Exposure on Embryonic Implantation in Mice

Abstract

SummaryInseminated mice were exposed to different degrees of hypoxia ranging from 8-14% during the first 6 days of gestation. The frequency of animals with embryonic implantation sites was reduced by 42% after exposure to either 12 or 10% oxygen and by 93% at 8% oxygen. When implantation occurred, the number of nida-tory sites per uterus did not differ significantly, which suggests an all or none response for blastocyst implantation. The failure of embryos to implant was associated with histologic evidence of luteal regression. An increased incidence of fetal resorption was apparent following implantation in mice exposed to 14, 12, or 10% oxygen. The reproductive dysfunction noted during hy-poxic exposure is attributed to a substantial loss in body weight and to altered tropic and endocrine support of pregnancy.The authors are deeply indebted to Ms. Marcia M. Pargament and Mr. Milton G. Parker for their assistance in this study.