Abstract: To duplicate a model for pregnancy - induced hypertension in rats,normal saline solution and L - NAME (L - nitro - arginine methyl easter, an inhibitor of nitric oxide synthase) in different doses were infused subcutaneously to pregnant Wistar rats from the 15th day to the end of gestation. The effects of L - NAME on the pregnant rats and their fetus - placenta units were observed. The results showed that subcutaneous infusion of L -NAME resulted in significant increase in maternal blood pressure and urine protein accompanied by relevant functional injuries and histophathologic changes of the liver and kidney. This treatment also caused a substantial decrease in the weights of the pups and the sizes of the placentas. These signs are similar to those of pregnancy - induced hypertension in women,and indicate that a decrease in nitric oxide synthesis may be one of the important factors in the pathogenesis of this disorder.

Key words: Rat, L-nitro-arginine methyl easter, Nitric oxide, Pregnancy-induced hypertension