Medicine and Health Sciences Commons^™

Estrogens Regulate Placental Angiogenesis In Horses, Shingo Haneda, Pouya Dini, Alejandro Esteller-Vico, Kirsten E. Scoggin, Edward L. Squires, Mats H. T. Troedsson, Peter Daels, Yasuo Nambo, Barry A. Ball

Maxwell H. Gluck Equine Research Center Faculty Publications

A sufficient vascular network within the feto-maternal interface is necessary for placental function. Several pregnancy abnormalities have been associated with abnormal vascular formations in the placenta. We hypothesized that growth and expansion of the placental vascular network in the equine (Equus caballus) placenta is regulated by estrogens (estrogen family hormones), a hormone with a high circulating concentration during equine gestation. Administration of letrozole, a potent and specific inhibitor of aromatase, during the first trimester (D30 to D118), decreased circulatory estrone sulfate concentrations, increased circulatory testosterone and androstenedione concentrations, and tended to reduce the weight of the fetus ( …