体外循环中磷酸肌酸对未成熟心肌的保护作用

Protective effects of phosphocreatine crystalloid cardioplegia on immature heart during cardiopulmonary bypass

目的 研究人未成熟心肌在心肌停跳条件下高能化合物耗竭情况及磷酸肌酸 ( CP)对于未成熟心肌能量代谢的影响 .方法 先心病患儿 18例按体质量、性别、年龄相近似配成 9对 ,对每组中两个个体随机分配给两种处理 , 组为本院使用的改良停搏液 , 组改良停搏液加磷酸肌酸 10 m L .L- 1 ,分别于心肌缺血前后取右心耳心肌组织 HPL C测定心肌能量物质 CP,ATP,ADP及 AMP.结果 两组术前 L A,CK- MB水平无显著差异 ,而比较缺血未复灌 10 ,30 ,5 0 min发现 组L A,CK- MB漏出量均较少 ( P<0 .0 5 ) .两组术前心肌各能量物质 ( ATP,ADP,AMP,CP)水平相似 ;在缺血再灌注后心肌各能量物质 ( ATP,ADP,AMP,CP) 组 ATP,AMP,CP含量均明显高于 组 ,ATP ( 0 .1983 m mol.g- 1 ,0 .10 36 mmol.g- 1 ,P=0 .0 0 8) ,AMP( 0 .10 82 mmol.g- 1 ,0 .0 5 72 mmol.g- 1 ,P=0 .0 11) ,CP( 0 .4974mmol.g- 1 ,0 .3743mmol.g- 1 ,P=0 .0 0 5 )总非扩散核苷酸 TNN* (除 IMP) ( 0 .46 0 9mmol.g- 1 ,0 .2 90 4mmol.g- 1 )的恢复均优于 组 ,但是两组 ADP( 0 .15 98mmol.g- 1 ,0 .12 96 mmol.g- 1 ,P=0 .345 )无差异 . 组超微结构明显优于 组 .结论 目前心肌保护条件下加入 CP对于未成熟心肌能量物质保存有一定意义 ,即通过减少高能磷?

AIM To study protective effects of phosphocreatine (cp) crystalloid cardioplegia on immature heart during cardiopulmonary bypass. METHODS Infants (less than 24 months old) with congenital heart disease were randomly divided into two groups (n=9 each group). There were 12 boys and 6 girls with a mean age of 11.8 months. The mean body mass was 9.7 kg with a range of 3.0 to 12 kg. Group I received modified St. Thomas II solution. Group II with addition of creatine phosphoate (CP: 10 mmol·L -1 ). The level of ATP, ADP, AMP, CP (preoperation, postoperation) in right cardiac atrium and the MB isoenzyme of creatine kinase (CKMB), lactic acid (LA) at each time point (preoperation, the end of arrest, 10 min, 30 min, 50 min of reperfuse) were measured. Postischemic ultrastrature in heart was observed in two groups. RESULTS ①CKMB (at the end of arrest, 10 min, 30 min, 50 min of reperfuse) released in group II were lower than those in group I (P=0.011). ②Although the baseline concentrations of ATP, ADP, AMP, CP were similar during the preischemic in two groups, the rate of highenergy phosphate depletion was attenuated during operation in group II. On reperfusion, the recovery of ATP ( 0.1983 mmol·g -1 , 0.1036 mmol·g -1 , P=0.008) , AMP ( 0.1082 mmol·g -1 , 0.0572 mmol·g -1 , P=0.011), and CP ( 0.4974 mmol·g -1 , 0.3743 mmol·g -1 , P=0.005) was greater in group II than in group I. While no difference was observed in ADP (0.1598 mmol·g -1 , 0.1296 mmol·g -1 , P= 0.345 ), the total non diffusible nucleotides (TNN* except IMP) in group II reach a much greater degree than that of group I ( 0.4609 mmol·g -1 , 0.2904 mmol·g -1 ). ③LA (at the end of arrest, 10 min, 30 min, 50 min of reperfuse) released at lower degree in group II than group I. ④Postischemic myocardial ultrastrature of group II was more excellent than in group I. CONCLUSION CP causes beneficial changes in highenergy phosphate metabolism subjected to cardioplegic arrest and ischemia. It is associated with a decreased rate of highenergy phosphate depletion and the increased recovery of ATP and phosphocreatine levels during reperfusion. Changes in energy metabolism may play a role in the cardioprotection by phosphocreatine during the prolonged hypothermic cardiac arrest.