Experimental Pregnancy-Associated Hypertension in Pregnant Rats

Abstract

An attempt was made to develop a model for pregnancy-associated hypertension (P-AH), by constriction of abdominal aorta in pregnant rats. The abdominal aorta was constricted by an extraperitoneal technique with silver clips (a) 0.426 mm or (b) 0.356 mm in diameter, between 5 and 15 days of gestation in rats. Systolic blood pressure (BP) in the tail, carotid artery mean blood pressure, litter size, pups weight, gain in body weight and histology of various organs were investigated. In contrast to the elevation in blood pressure associated with human P-AH, tail systolic blood pressure decreased significantly in all the rats with aortic constriction. No change was observed in carotid artery BP following constriction of the abdominal aorta. Gain in body weight, litter size, pups weight and histology of various organs were comparable between the aorta constricted rats and sham operated controls. The results do not support the theory that decreased blood flow in the abdominal aorta leads to utero-placental ischaemia and P-AH.