阿片预处理对兔移植心脏的保护作用

The Protective Effects of Opioid Preconditioning on Rabbit Heart Graft in Hypothermia

目的:研究D-丙2,D-亮5-脑啡肽(DADLE)和吗啡预处理对兔离体心脏的保护作用,并对其作用的可能机制进行探讨。方法:成年家兔36只,随机分为6组,每组6只。3组为供体组,其中2组为预处理组,在心脏获取前分别给予DADLE(D组)和吗啡(M组)预处理,1组予等量生理盐水作为对照组(C组);余3组为受体组。心脏获取后,低温保存4 h行异位心脏移植。观察供心功能的恢复,测定心肌钠-钾ATP酶活性及冠脉回流血中乳酸脱氢酶(LDH)、肌酸激酶(CK)、乳酸(LA)的含量,电镜观察心肌超微结构。结果:预处理组有较好的心功能恢复(P<0.05);钠-钾ATP酶活性好于C组(P<0.05);冠脉回流血中心肌酶的漏出量差异不显著(P>0.05),乳酸含量在复跳后2 h C组明显增加(P<0.05);预处理组心肌超微结构明显优于C组。结论:阿片预处理对低温保存的兔供心有明显的保护作用,短期内有效减轻兔供心的缺血再灌注损伤。冠脉流出液中乳酸含量减低可能是其保护效果的原因。

Objective: To investigate the effects of the selective δ-opioid receptor agonist DADLE(D-Ala2-Leu5-enkephalin) and non-selective opioid receptor agonist morphine preconditioning on rabbit graft in hypothermia. Methods: Isogeneic intraabdominal het-erotopic heart transplantation was performed on rabbits. The donor rabbits were preconditioned with DADLE (1 mg · kg-1) or morphine (1 mg · kg-1) or saline respectively (each group n = 6), rabbit hearts were excised from donors and stored 4 hours at 4℃, then the hearts were transplantated to rabbits. The myocardial functional recovery, left ventricular pressure (LVSP), left ventricular end di-astolic pressure(LVeDP), left ventricular development pressure(LVDP) and heart rate(HR) of donor heart were measured every 30 minutes tor 2 hours after reperfusion. Serial specimen were performed to assess activity of myocardial Na-K ATPase, contents of the perfusate LDH, CK and lactic acid effused from coronary vessel and cardial ultra structure. Results: The recovery of left ventricular functions, the activity of myocardial Na-K ATPase and cardial ultra structure in the groups of precondition with DADLE or morphine were better than the control ( P < 0. 05). Cardiac enzyme leakage (CK, LDH) was similar among the precondition and the control groups. Lactate efflux in the control was more than that in the group of the precondition with opioid during 2 hours after cardial resuscitation ( P < 0. 05). Conclusion: There is a significantly protective role on the exsomatize heart of rabbit with cold storage in the groups of precondition with DADLE and morphine, at least the damage of postischemic reinfusion is availably alleviated in short period. It may be the cause of protective role to decrease the lactic acid of perfuate effused from coronary vessel.