COMT and preeclampsia: Placental and vascular oxidative stress are also detected in animal models of preeclampsia including catechol-O-methyltransferase deficient (COMT−/−) mice, endothelial nitric oxide synthase deficient (eNOS−/−) mice, RUPP rats, rodents/sheep experiencing gestational hypoxia, and rodents infused with preeclampsia-related bioactive factors [264,265,293,294,295,296,297,298,299,300,301,302,303].