三种心脏停搏液对未成熟猪体外循环中的心肌保护效果

目的比较St．Thomas停搏液（STH液）、氧合血停搏液和组氨酸一色氨酸一酮戊二酸停搏液fhistidine—tryptophan—ketoglutarate，HTK液）对未成熟猪围体外循环（cardiopulmonarybypass，CPB）期的心肌保护效果。方法21只年龄为（15～20）天、体重为（4．5～8．0）kg的中华小型猪随机分为STH液组、氧合血停搏液组和HTK液组，每组7只。分别于CPB前（T1）、升主动脉阻断（aorticcross—clamping，ACC）后10min（T2）、升主动脉开放（cross—clampingremission，CCR）后5min（T3）、CPB后5min（T4）、CPB后60min（T5）、CPB后120min（T6）抽取颈动脉血，实验结束后取少量右房心肌组织。ELISA法测肌酸激酶同工酶（CK—MB）、肌钙蛋白T（cTnT）和肌钙蛋白Ⅰ（cTnI）的含量，电镜下观察心肌超微结构的变化；同时记录每只动物的用血量。结果停跳前各组血浆CK—MB、cTnI、cTnT组间差异均无统计学意义（P〉0．05）；随着体外循环进行，各组血浆心肌生化标志物含量逐渐增加，HTK液组和氧合血停搏液组心肌生化标志物漏出率小于STH液组，差异有统计学意义（P〈0．05）。氧合血停搏液组和HTK液组相比，血浆心肌生化标志物含量无明显差异（P〉0．05）。氧合血停搏液组、HTK液组动物心肌细胞线粒体超微结构Flameng评分低于sTH液组（P〈0．05）。结论氧合血停搏液和HTK液组心肌细胞线粒体的损伤程度小，对未成熟心肌的保护效果均优于STH液组。

Protective effects of different cardioplegias on myocardium during cardiopulmonary bypass in immature pigs

Objective To compare the protective effects of St.Thomas cardioplegia(STH cardioplegia),oxygenated blood cardioplegia and histidine-tryptophan-ketoglutarate cardioplegia(HTK cardioplegia) on myocardium during cardiopulmonary bypass(CPB) in immature pigs.Methods Chinese minipigs(n=21) aged from 15 days to 20 days and weighed from 4.5 kg to 8.0 kg were randomly divided into STH group,oxygenated blood cardioplegia group(OBC group) and HTK group(each n=7).The samples of arterial blood were collected from minipigs respectively before CPB,10 minutes after aortic cross-clamping(ACC),5 minutes after cross-clamping remission(CCR),5 minutes after CPB,60 minutes after CPB and 120 minutes after CPB,and a little quantity of right atrial tissue was collected after the test finished.The content of CK-MB,cTnT and cTnI were detected by using ELISA.The changes of myocardial ultrastructure were observed with electronic microscope,and at the same time the consumption of blood of each rabbit was recorded.Results There was no statistically significant difference in the content of CK-MB,cTnT and cTnI among all groups(P>0.05).During CPB,the content of myocardial enzymes gradually increased,and the leakage rate was lower in HTK group and OBC group than that in STH group(P<0.05).The content of myocardial enzymes had no significant difference between OBC group and HTK group(P>0.05).The Flameng score of mitochondrial ultrastructure was lower in OBC group and HTK group than that in STH group(P<0.05).Conclusion The damage of myocardial mitochondria was mild and the protective effect on immature myocardium is better in OBC group and HTK group than those in STH group.