Intrauterine Growth-Restricted Pregnant Rats, from Hypertensive Placental Ischemic Dams Display Preeclamptic-like Symptoms: A New Rodent Model of Preeclampsia

Abstract

ABSTRACTPreeclampsia (PE) is characterized by de novo hypertension (HTN) and is one of the primary causes of intrauterine growth restriction (IUGR). PE is associated with placental ischemia, decreased nitric oxide (NO) bioavailability, oxidative stress (OS), and organ damage in the kidneys and brain. This study aims to characterize a new model of PE using IUGR rats from hypertensive placental ischemic dams. It is hypothesized that pregnant IUGR rats from hypertensive placental ischemic dams will have elevated blood pressure (BP), OS, and organ damage.MethodsPregnant Sprague Dawley rats are divided into 2 groups: normal pregnant (NP) and reduced uterine perfusion pressure (RUPP) hypertensive placental ischemic dams. Offspring from NP and RUPP dams were mated at 10 weeks of age to generate pregnant IUGR (IUGR Preg; n=3-8) and pregnant CON (CON Preg; n=3-6) rats. BP and other markers of PE were evaluated during late gestation.ResultsPregnant IUGR rats had elevated BP and systemic OS, as demonstrated by higher trending 8-isoprostanes and lower circulating antioxidant capacity. Maternal body weight of pregnant IUGR rats and their pups’ weights were decreased, while the brains were enlarged. Brain OS was elevated, with a rise in hydrogen peroxide (H2O2) and heat shock protein 1 (HSP- 1), along with lower Manganese Superoxide Dismutase (MnSOD) and antioxidant capacity.ConclusionPregnant IUGR rats, born from hypertensive placental ischemic dams, have HTN and increased systemic and brain OS, with larger brain sizes and smaller pups. Pregnant IUGR rats exhibit an preeclamptic-like phenotype, which suggests a new epigenetic model of PE.