Evaluation Of The Effect Of Trimetazidine On Myocardial Stunning By Pressure-volume Loops In Rats

ObjectiveTo evaluate the effect of Trimetazidine on myocardial stunning and bypressure-volume loops in rats and its probable mechanism.MethodsThirty SD rats were randomly divided into3groups equally,control groupand myocardial stunning group （physiological saline2ml）， Trimetazidinegroup (Trimetazidine tablet3mg/kg）. All rats，except for those in controlgroup， were subjected to20minutes of left anterior descending arteryocclusion and120minutes reperfusion,while in control group only threadingwithout ligation. Hemodynamic variables (as heart rate,left ventricularend-diastolic pressure,left ventricular end-systolic pressure and so on)weredynamic observed by the pressure-volume loops and were applicatedPowerLab system and software offline to analysis. Myocardial tissue ATPcontent,atpase activity and phosphate fructokinase activity were detected afterreperfusion120min, and the structure and function of myocardial mitochondriaultrastructure was tested using the electron microscope by stereology method.Results（1）Cardiac function of effect on myocardial stunning：Cmoparing withmyocardial stunning group, in trimetazidine group,EDP（8.80±0.49vs10.63±0.42mmHg）、-dp/dtmin(5703±218vs6080±172mmHgs-1)) were significantlyreduced (P <0.01），EDPVR(0.10±0.04vs0.38±0.02) were also decreased （P<0.05）.ESP(125.36±5.55vs91.37±6.64mmHg)、 EDV(148.5±9.46vs113.1±7.50ul)、ESPVR(0.85±0.10vs0.70±0.07)、dp/dtmax(8996±292vs7162±278mmHgs-1) were increased obviously by pressure volume ringanalysis.（2）The influence of the ATP content, atpase, phosphoric acid fructosekinase (PFK)：Cmoparing with myocardial stunning group, in trimetazidinegroup，ATP content7.56±0.63umol/g vs7.02±0.44umol/g）and atpaseactivity elevated(Ca2+-Mg2+ATPase：4.87±0.25u/mgprot vs4.60±0.26u/mgprot，Na+-K+ATPase：4.78±0.26u/mgpro vs4.46±0.21u/mgprot，P <0.05); phosphate fructokinase （PFK） activity lower (0.52±0.04U/mgpro/min vs0.34±0.07U/mgpro/min，P <0.01);。（3）The influencer of myocardial mitochondria ultrastructure in myocardialstunning： Cmoparing with myocardial stunning group, in trimetazidinegroup， myocardial mitochondria ultrastructure significantly ameliorateabnormal changes （Vv：18.35±0.22%vs23.07±0.77%，NA：0.505±0.01um vs0.311±0.01um，δ：37.57±0.32%vs27.84±0.40%，P <0.01）.ConclusionTrimetazidine attenuates myocardial stunning by the energymetabolism, and pressure volume ring could be evaluation cardiac functionaccurately and sensitively.