Experimental Pregnancy-Associated Hypertension in the Pregnant Rabbit

Abstract

The role of utero-placental ischaemia in the development of pregnancy associated hypertension was investigated in rabbits. The abdominal aorta was constricted to 1.0 or 0.8 mm in diameter at two weeks of gestation in pregnant rabbits. Intraarterial mean blood pressure and plasma renin activity were measured before mating the rabbits and throughout the gestation period. Litter size, kitten weights and organ histology were studied after delivery. Five out of the nine pregnant rabbits developed hind limb paralysis after constriction of the aorta to 0.8 mm. No differences were observed in the blood pressure in aorta constricted rabbits, before and after aortic constriction, or between sham operated and aorta constricted rabbits. Litter size, kitten weights and organ histology were not different between groups. Plasma renin activity followed the same course in control rabbits and in rabbits with aortic constriction. The results obtained in this study do not support the theory that utero-placental ischaemia is the primary factor in pregnancy-associated hypertension.