丙泊酚对代谢性酸中毒心脏功能的双重影响

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

目的探讨丙泊酚对代谢性酸中毒心脏功能的影响。方法应用改良Langendorff装置,制备离体心脏代谢性酸中毒模型。将24只SD大鼠随机分为对照组(C组)、丙泊酚25μmol/L组(PL组)和丙泊酚50μmol/L组(PH组),每组8只。C组用pH=7.4的K-H液平衡灌注40min,然后用pH=6.5的K-H液酸化20min造成心脏整体的代谢性酸中毒,用pH=7.4的K-H液恢复灌注30min;PL组和PH组的灌注方式与C组相同,在平衡灌注25min后向K-H液中加入相应浓度的丙泊酚。记录酸化前,pH恢复后1、5、10、20和30min时的心率(HR)、左室发展压(LVDP),左室压力变化速率(±dP/dtmax),灌注环路内压力,心肌含水量(MWC)。结果在pH恢复初期(10min之内),PH组和PL组的HR、LVDP和±dP/dtmax的恢复率与C组比较均有所降低,但PH组降低有统计学意义(P<0.05)。在pH值恢复后期(20min后),PL组心功能的各项指标的恢复率均有所上升,部分指标略超过C组,但无统计学意义;而PH组的各项指标与C组比较仍略低,但无统计学意义。PL组和PH组环路内压力,心肌含水量与C组比较均有所降低,PL组降低显著(P<0.05)。结论适当浓度的丙泊酚对酸中毒心脏有一定的保护作用,在本研究实验条件下25μmol/L丙泊酚在心功能恢复、心肌灌注的改善以及降低心肌水肿等方面均优于50μmol/L丙泊酚。

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（P0.05）.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（P0.05）.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（P0.05）.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.