烫伤后大鼠心肌力学变化及血清心肌肌钙蛋白T在心肌损伤诊断中的应用

Changes in myocardial mechanics of Rats Post Scald and the Application of Serum Myocardial Troponin T in the Diagnosis of Myocardiad Injury

目的 :探索烫伤后大鼠心肌舒缩功能变化及心肌肌钙蛋白T(cTnT)在心肌损伤诊断中的应用。方法 :复制大鼠 30 %TBSAⅢ°烫伤动物模型。观察非烫伤对照组及烫伤后 1、3、6、12、2 4、48、72小时左心室力学参数(LVSP、LVEDP、±dp/dtmax)和血清cTnT、CK、LDH含量变化。结果 :(1)动物烫伤后 1小时 -dp/dtmax显著下降 ,LVEDP明显升高 ;LVSP、+dp/dtmax伤后 3小时显著下降 ,均于 12小时变化最大 ,至 72小时变化仍较明显 (P <0 0 1) ;(2 )cTnT于伤后 1小时显著上升 ,12小时比对照值升高 43倍 ,至 72小时仍保持在高水平 ;而LDH、CK分别于伤后 3小时、6小时开始上升 ,至 72小时已接近正常 (P <0 0 5 )。结论 :(1)烫伤后大鼠左心室舒缩功能明显下降 ,且舒张功能障碍的发生早于收缩功能 ;(2 )cTnT是诊断烧伤后心肌损伤的可靠指标。

Objective:To explore hte changes in myocardial contractile and relaxation functions and the application of serum myocardial troponin T(cTnT) in the diagnosis of myocardial injury of rats post scald.Methods:Wistar rats with 30% TBSA 3 rd degtee scald were used .Fifty six adult rats were randomly divided into 8 groups,one healthy control group and 7 scalded group.The 7 scalded groups were observed at 1?3?6?12?24?48and 72hours post scald groups.The observatoins on each rat included left ventricular systolic pressure(LVSP),left ventricular end diastolic pressure(LVEDP),maximm rising and falling rate of left ventricular pressure(± dp/dtmax),the contents of cardiac troponin T and myocardial enzyme spectrum(CK,LDH)in serum.Results:1.-dp/dtmax was markedly decreased and LVEDP was increased at 1 hr after scald,LNSP and ±dp/dtmax were decreased at 3 hr after scald.All parameters had the maximal changes at 12 hr and the changes remainde obvious up to 72 hr.(P<0 01).2.The cTnT content in serum increased markedly at 1 hr and was about 43 times higher than control velue at 12 hr,remaining at high level at 72 hr after scald.While LDH and CK activities were increased at 3 hr and 6 hr after scald respectively and recovered to normal at 72 hr after scald(P<0 05).Correlation analysis showed that the cTnT content in serum correlated with the change in LVSP?±dp/dtmax negatively and LVEDP positively.Conclusions:1.Myocardial contractile and relaxation function are depressive (The depression of relaxation function is earlier than that of contractile function)after severe scalded in rats.2.cTnT can be used as a reliable index in the diagnosis of postburn myocardial injury with higher specifcity and sensitivity than myocardial enzyme spenctum.