104-POS

Abstract

Objectives Blood pressure (BP) elevation after experimental reduction in uteroplacental blood flow in primates is associated with proteinuria and has been a surrogate for studying placental dysfunction manifesting as preeclampsia in humans. Controlling BP is the mainstay of treatment but the effect of antihypertensive treatment on the acute BP response is poorly understood in this animal model. We examined the effect of three oral antihypertensive agents in the treatment of BP in an experimental setting to determine the BP response. Methods Papio hamadryas (baboon) BP was recorded continuously via intra-arterial telemetry in late pregnancy after induction of placental ischaemia by surgical ligation of a uterine branch artery. Proteinuria, haematology, biochemistry and fetal growth were assessed. Antihypertensives hydralazine 15 mg bid, methyldopa 10 mg/kg bid and labetalol 40 mg bid were administered orally for four days followed by a three-day washout phase. The average BP change for each drug from day 1 and 2 of treatment compared to day 3 and day 4 of treatment was evaluated. Results The antihypertensives resulted in a reduction in BP (average 1.4 mmHg, n = 2). Hydralazine and methyldopa showed a 0.4 mmHg and 2.4 mmHg reduction in systolic BP respectively, whereas labetalol showed no decrease; hydralazine and methyldopa showed a 0.5 mmHg and 1.8 mmHg reduction in diastolic BP respectively, and labetalol showed a 0.6 mmHg decrease in diastolic BP. Conclusions Preliminary data shows that hydralazine and methyldopa cause an acute decrease in systolic BP and diastolic BP in an experimental model of preeclampsia in non-human primates. The lack of BP reduction with labetalol may reflect altered drug efficacy or metabolism in this species or inadequate dosing. Disclosures S.J. Pears: None. A. Hennessy: None. S. Lim: None. K. Chau: None. K. Yeung: None. S. Heffernan: None. A. Makris: None.