钙分布异常对烧伤早期心肌力学障碍的影响

目的探讨烧伤后早期心肌损伤的机理。方法应用Ｃａ２＋细胞化学探针及Ｘ线电子探针显微分析测定了烧伤后心肌细胞亚细胞Ｃａ２＋定位、定量变化，心肌力学及心肌组织能量代谢变化。结果烧伤后１小时心肌细胞胞浆Ｃａ２＋急剧升高，且先于线粒体Ｃａ２＋增加；伴心肌收缩、松弛能力下降，室壁应力增加。心肌组织ＡＴＰ、能量负荷在伤后６～１２小时显著低于对照组。结论烧伤后心肌细胞钙异常分布可能是引起心肌肌原纤维过强收缩，心肌松弛力降低的主要原因之一。

Effects of abnormal distribution of calcium on impairment of myocardial mechanics in the early stage of thermal injury

\ Objective\ To investigate the effect of abnormalCa 2 distribution on impairment of myocardial mechanics in the early stage of thermal injury.Methods\ Calcium(Ca 2 ) changes were observed within subcellular distribution in situ in rat heart with calcium cytochemical probe and electron probe microanalysic technique.Meanwhile,myocardial mechanics and energy metabolic changes were investigated after thermal injury .Results\ The results demonstrated that levels of cytoplasmic Ca 2 in cardiomyocytes increased at 1 hour,followed by enhanced mitochondrial Ca 2 at 3 hour after burn injury.Parallel to the changes in Ca 2 ,there were decrease of myocardial contraction,relaxation capacity and increase of ventricular wall stiffness in burned rats.A lower level of heart energy changes was observed from 6 to 12 hours,compared with control group.Conclusion\ The results indicate that subcellular Ca 2 abnormal distribution in myocardium caused by burn injury may be associated with rigor contraction and decreased relaxation of myocardium.