Abstract: AIM: To observe the effect of L-arginine on blood pressure(BP)in stress rats.METHODS: Thirty rats were divided into three groups.L-ARG +stress group:L-arginine was added in drinking-water and electric stimulus were given intermittently in rat foot-plate for 15 days;stress group:electric stimulus was given as above;control group:no stress.The Bplevels of tail artery were measured per two days,and the concentrations of nitric oxide(NO)of plasma were detected on 15^th day.RESULTS: There were significantly differences on Bpbetween control groupand stress groupin the 9th,11th,13th,15th day(p<0.05 or p<0.01).After the stimulus in the stress group,the level of Bpincreased,the concentration of NO decreased(p<0.05).However,the Bpdid not show obvious difference between control groupand L-ARG +stress group.On the 15 th day,the Bplevel decreased in L-ARG +stress group(p<0.05),and the concentration of NO was higher than that of control group(p<0.01).CONCLUSION: L-ARG can resist the increase of Bpin stress rats.

Key words: L-arginine, stress, BP