摘要
目的:探讨不同浓度的2,3-丁二酮单肟(2,3 butanedione monoxime,BDM)初始复灌对停搏心脏机械功能和氧代谢恢复的影响,确定理想作用浓度并初步探讨其机制。方法:48只Langendorff灌流豚鼠心脏用4℃St.Thomas Hospital液保存12 h,随机分为4组,分别以37℃改良Krebs-Ringer液(CON组)、含20 mmol/L BDM的Krebs液(BDM20组)、含30 mmol/L BDM的Krebs液(BDM30组)和含40 mmol/L BDM的Krebs液(BDM40组)进行初始复灌30 min,随后所有心脏以37℃改良Krebs-Ringer液进行复灌60 min。结果:与CON组比较,BDM组初始灌流后左室作用压、左室压力增加速率峰值(+dP/dtmax)和左室压力减少速率峰值(-dP/dtmax)、氧消耗速度和用氧效率恢复更为迅速,BDM30组最为显著。电镜检查发现,CON组心肌呈明显的肌节过度收缩和线粒体破坏,BDM30组则明显减轻。结论:BDM初始灌流可显著改善停搏心肌的机械功能和氧代谢,且理想作用浓度为30mmol/L,其机制可能与BDM减轻缺血再灌注引起的心肌过度收缩和细胞破坏有关。
Objective: To evaluate the effects of initial reperfusion with different concentration of 2,3 butanedione monoxime(BDM) on the mechanical function and oxygen metabolism in hearts following cold cardioplegic arrest.Methods: 48 Langendorff perfused guinea pig hearts were subjected to 12 h of cardioplegic arrest in 4℃ St.Thomas Hospital solution.Control group(CON group,n=12) were reperfused with a modified Krebs-Ringer solution for 30min immediately.Hearts in BDM20 group,BDM30 group and BDM 40 group(n=12,each group) were initial reperfused with Krebs solution at 37℃ which contained 20 mmol/L,30 mmol/L and 40 mmol/L BDM,respectively,for 30 min.Then the perfusate in all groups were switched to the modified Krebs-Ringer solution for 60min.Reuslts: Compared to CON group,initial reperfusion with BDM enhanced the recovery of left ventricular developed pressure,+dP/dt_(max) and-dP/dt_(max) and alleviate oxygen consumption and cardiac efficacy in utilizing consumed oxygen.The most markedly effect was observed in BDM30 group.Myocardial ultrastructure was best preserved in hearts of BDM30 group too.Conclusion: Initial BDM reperfusion were superior to immediate Krebs-Ringer reperfusion in preserving myocardial mechanical function.30 mmol/L of BDM was the optimal concentration,comparing with either 20 mmol/L or 40 mmol/L.The underlying mechanism of protecting effect of BDM may be its alleviation of myocardial hypercontracture and ultrastructure damage induced by reperfusion injury.
