Abstract 049: Preeclampsia in the Dahl Salt Sensitive Rat is Associated with Increased Uterine Artery Resistance and Reduced Placental Microvascular Density
We showed that the Dahl salt sensitive (Dahl S) rat is a spontaneous model of preeclampsia superimposed on chronic kidney disease and hypertension. This model exhibits intrauterine growth restriction, decreased pup weight, increased fetal death, and placental hypoxia; however, the underlying mechanisms are unknown. We hypothesized that a pathological remodeling and rarefaction in the maternal placental bed drives the development of preeclampsia in this model. Pregnant Dahl S and Sprague-Dawley (SD) rats were used in this study. Uterine artery resistance index (UARI) was calculated via Doppler ultrasound (Vevo 770) on day 18 of pregnancy (UARI=(peak systolic flow velocity - end diastolic flow velocity)/ peak systolic flow velocity). On day 20 of pregnancy, placentas were perfused through the uterine circulation with a silicon-polymer contrast (Microfil MV122). Individual placentas were then excised, scanned using a micro-CT scanner (SkyScan 1076), and 3D reconstructed for analysis and quantification of the placental vasculature on the maternal side. Microvascular density was calculated for vessels of diameters in the 0-500 μm ranges. UARI was higher in the Dahl S compared to the SD (0.71±0.02 vs 0.51±0.02, n=4-12, p<0.05). Density of placental microvessels in the 200-500 μm range was significantly decreased in placentas from Dahl S rats, and we observed a strong trend towards a decrease in density of microvessels in the 0-200 μm range (n=3-5, Figure). These results suggest that the impaired fetal growth and placental hypoxia in the Dahl S rat may be mediated by insufficient placental vascularization and reduced blood flow to the feto-placental unit.
Author Disclosures: E.E. Gillis: None. A.R. Chade: None. F.T. Spradley: None. M.R. Garrett: None. J.M. Sasser: None.
This research has received full or partial funding support from the American Heart Association, Greater Southeast Affiliate (Alabama, Florida, Georgia, Louisiana, Mississippi, Puerto Rico & Tennessee).
- © 2015 by American Heart Association, Inc.