Double effects of propofol on cardiac function of rats with metabolic acidosis

Objective To study the effect of propofol on cardiac function of rats with metabolic acidosis. Methods A metabolic acidosis model of in vitro rat heart was established with modified Langendoff apparatus.Twenty-four SD rats were randomly divided into control group,25mmol/L propofol group（PL group） and 50mmol/L propofol group（PH group）,8 in each group.Metabolic acidosis was induced by perfusion with K-H solution（pH=7.4） for 40min,then with acidic K-H solution（pH=6.5） for 20 min and K-H solution（pH =7.4） for 30min.Propofol was added into the K-H solution 25min after stable perfusion.Heart rate（HR）,left ventricular develop pressure（LVDP）,left ventricular pressure ±dP/dtmax,perfusion circuit pressure and myocardial water content（MWC） were recorded before acidosis and 1,5,10,20 and 30min after reperfusion. Results The HR,LVDP and left ventricular pressure ±dP/dtmax were lower in PL and PH groups than in control group and significantly lower in PH group than in control group during the 10min reperfusion（P＜0.05）.The pH value was higher in PL group than in control group and lower in PH group than in control group during the 20min reperfusion（P＜0.05）.No significant difference was observed in perfusion circuit pressure and MWC among the 3 groups.However,the perfusion circuit pressure and MWC were significantly lower in PL and PH groups than in control group（P＜0.05）. Conclusion Appropriate propofol concentration can protect the heart of rats against metabolic acidosis.The effect of 25mmol/L propofol is better than 50mmol/L propofol on recovery of cardiac function and improvement of cardiac muscle reperfusion and edema.