Oxidative stress and the endometrium

Abstract

The endometrium plays a key role in successful implantation and pregnancy. A delicate balance exists between the antioxidant mechanisms and the reactive oxygen species in the endometrium. When pregnancy occurs, successful implantation results in the production of Human Chorionic Gonadotropin (HCG) which maintains progesterone levels. Progesterone increases the activity of superoxide dismutase in the endometrium which in turn suppresses the production of reactive oxygen species and prostaglandin F2α. (PGF2α). On the other hand, in the absence of pregnancy, progesterone levels drop and superoxide dismutase activity declines. As a result, cyclooxygenase enzyme 2 (COX2) and PGF2α increase, resulting in menstruation. HCG might improve the uterine environment prior to implantation by suppressing the apoptotic response to oxidative stress in the maternal decidua.