Objective:This paper was to study the effects of propofol on systemic and pulmonary circulation in rats. Methods:Using electronic
physiological apparatus, we examined the changes of
mean aortic pressure (MAP)、
mean pulmonary arterial pressure(MPAP)and heart rate(HR) in anesthetized rats. Results:MAP,HR,and MPAP in basal condition bolus decreased after intravenous injection of 4.0 mg/kg propofol. The effect of propofol on decreasing MAP and HR in basal condition was most evident after three minutes of injection. The effect on decreasing MPAP was the strongest in 5 min. The effect of decreasing MAP and HR was apparently stronger than that of decreasing MPAP. Propofol significantly decreased MAP,HR,and MPAP which had been increased by 1.0 mg/kg norepinephrine and 100 mg/kg 5 hydroxytryptamine. Its effect on MPAP and HR were remarkable. Conclusions:Propofol exerted inhibitive effect on circulatory system,mainly on systemic circulation. The mechanism might be related to the decreasing of reactivity to vasoexcitor material and to the relaxation of vascular smooth muscle.