AGTR1 and Hypertension: Treatment with Losartan (10 mg/day for 5 days), an AT1 receptor antagonist, significantly reduced the hypertension in response to placental ischemia (113 ± 2 mmHg, n = 9, P < 0.05) while having no effect on normotensive, normal pregnant rats (94 ± 2 mmHg, n = 9) (Fig.2).