Abstract MP20: Prepartum 1,3-butanediol Treatment Improves Placental Perfusion In The Preeclamptic Dahl Salt-sensitive Rat

Abstract

Chronic hypertension increases the risk of developing superimposed preeclampsia (PE). Previous reports showed that 1,3-Butanediol (BD) lowers blood pressure (BP) in male Dahl salt-sensitive (S) rats and female congenic S.SHR(11) rats which exhibit increased kidney injury over Dahl S rats. The goal of this study was to test if attenuating hypertension before pregnancy through the placentation period via BD prevents the onset of PE. Female Dahl S rats (a spontaneous model of superimposed PE, 11-16 weeks old) were divided into two groups: BD treated (20% via drinking water) and control (ad libitum water). Animals received BD for 7 weeks, baseline BP measurements (telemetry) were taken, and both groups were then mated. On gestation day (GD) 12, treatment was stopped because pilot studies showed that treatment reduced water intake during late pregnancy. Both groups were maintained on low-salt rodent chow (Teklad 7034, 0.3% NaCl; n=8/group). At GD18 (late pregnancy), uterine artery resistance index (UARI) was measured via Doppler ultrasound, 24h urine was collected on GD19, and tissues were harvested on GD20. Mean arterial pressure was lower in the treated group at baseline (141.9 ± 4.1 vs. 165.7 ± 4.5 mmHg, p= 0.008), early (135.9 ± 3.4 vs. 168.9 ± 4.6 mmHg, p= 0.0003), mid (142.0 ± 5.2 vs. 170.8 ± 4.61, p= 0.0048) but not late pregnancy (144.9 ± 5.9 vs. 161.9 ± 4.5 mmHg, p= 0.165). Late pregnancy maternal body weight was similar between groups (299.3 ± 5.6 vs. 311.3 ±7.0 g, p=0.201). Treated dams had a lower UARI (0.71 ± 0.02 vs. 0.81 ± 0.02, p=0.008) and less fetal resorptions (1.12 ± 0.29 vs. 2.25 ± 0.41, p= 0.043). No harm to the fetus was noted as no differences in pup weight (2.20 ±0.05 vs. 2.20 ± 0.09, p= 0.994) and pup length (30.19 ±0.24 vs. 29.45 ± 0.28 cm, p=0.072) were observed. Placentas from treated dams had decreased VEGF levels via ELISA (276.2 ± 33.4 vs. 498.9 ± 16.8 pg/mL, p= 0.001), suggesting reduced placental ischemia. In this study, we observed slightly improved placental perfusion and lower fetal demise following prepartum BD treatment; however, the antihypertensive effects of BD were not sustained through late pregnancy when supplementation was stopped at mid-pregnancy.