异丙酚和硫喷妥钠对离体缺血后心脏左室功能的影响

Effect of propofol and thiopental on postischemic left ventricular function myocardium in isolated rabbit heart

目的 在离体灌注兔心比较了异丙酚和硫喷妥钠对缺血后心脏左室收缩、舒张功能作用的差异。方法 分别在非缺血心脏和缺血 2 0分再灌注 15分心脏给予异丙酚 ( 2 0 μmol/ L、5 0 μm ol/L )或硫喷妥钠 ( 2 0 0μmol/ L、5 0 0μmol/ L ) ,观察左室收缩功能 ( L V+dp/ dtmax、L VDP)、舒张功能 ( L V- dp/ dt max、L VDEP)及灌出液内 L DH、CPK活性的变化。结果 2 0μmol/ L异丙酚对缺血后心肌L V+dp/ dtmax和 - dp/ dtmax的抑制幅度比正常心肌分别增强 12 .7%和 13 .3 % ( P<0 .0 1) ,但5 0 μmol/ L 时其负性肌力作用与正常组相似 ( P>0 .0 5 ) ;两种浓度硫喷妥钠对缺血后 L V+dp/ dtmax及 - dp/ dtm ax的抑制分别较正常心肌增强 ( 4 .7～ 14 .1) %和 ( 15 .1～ 17.7) % ( P均 <0 .0 5或 0 .0 1)。异丙酚能阻止缺血后 L VEDP进一步升高 ( P<0 .0 1) ,但两组停药时组间 L DH、CPK活性无显著性差异。结论 心肌缺血后对硫喷妥钠负性肌力作用敏感性增强 ;虽然低浓度异丙酚亦加重心肌抑制 。

Objective The different effects of propofol and thiopental on postischemic left ventricular mechanical function were investigated in isolated rabbit heart.Methods Two concentration of propofol(20μmol,50μmol) and thiopental (200μmol,500μmol)were given respectively to non ischemia hearts or hearts experienced 20 min total heart ischemia followed by 15 min reperfusion.The left ventricular systolic index(LVDP,LV+dp/dtmax),diastolic index(LV dp/dtmax,LVEDP) and activities of LDH and CPK in effluence were measured.Results Propofol(20 μmol )induced a more significant negative inotropic effect on LV+dp/dtmax(-12.7%),and LV dp/ptmax(-13 3%)when compared with non ischemic group(P<0 01),but at 50 μmol,no significant difference in negative inotropic effect between groups was found.The inhibitory efficiency of thiopental on postischemic left ventricular increased significantly by 4 7% 14 1%(P<0 05) in LV+dp/dtmax and by 15 1% 17 7%(P<0 01) in LV-dp/dtmax respectively.Propofol,but not thiopental,attenuated the progressive increment of LVEDP after ischemia.No significant differences in actirities of LDH and CPK between groups were found.Conclusion After myocardial ischemia,the hearts sensitivity to the negative inotropic effect of thiopental increases;although 20μmol propofol augments the inhibitory effect postischemically,higher concentration(50 μmol)propofol has a plateau effect.