兔烫伤后动脉壁脑啡肽含量的变化

Changes of enkephaline content in artery wall of the burned rabbits

目的 :研究兔烫伤早期发生多器官功能衰竭时 ,动脉壁脑啡肽含量的变化及其意义。方法 :兔乙醚吸入法全身麻醉后 ,以 95℃水烫伤其背部及躯干两侧 30s,造成 30 %体表面积III度烫伤 (III度 30 %TBSA)。测定烫伤 4 8h后的平均动脉血压、中心静脉压、心输出量 ,计算总外周阻力、心指数 ;测定血中肌酸磷酸激酶、谷丙转氨酶、尿素、肌酐、血小板等反映心、肺、肝、肾功能的一系列指标。用放射免疫测定法测定动脉脑啡肽的含量。结果 :烫伤后 4 8h肠系膜动脉、肾动脉、肺动脉中亮氨酸脑啡肽的含量明显减少。血流动力学指标中平均动脉血压无明显变化 ,总外周阻力明显增高 ,心脏指数明显下降。心、肝、肾功能下降达到衰竭标准 ,肺功能下降 ,动物发生MOF。给烫伤动物应用钠洛酮以后 ,动物的心脏指数明显改善 ,血管总外周阻力下降。但是 ,多脏器功能衰竭的各项指标均未见改善。结论 :烫伤后动脉壁内源性脑啡肽含量减少 ,可能是外周微血管痉挛收缩 ,全身总血管阻力增高 。

Objective: To study the changes and its significance of enkephaline content in the early multiple organ failure of the burned rabbits artery wall. Methods All rabbits were anesthetized with etherinhalation. The dorsal skin of rabbits were immersed in 95℃ or 37℃water for 30 s. This procedure produced a full thickness burn of 30% total body surface area (TBSA) or sham burn. At 48 h postburn, mean arterial pressure(MAP), central venous pressure(CVP), cardiac output(CO) were monitored, and systemic vascular resistance(SVR) and cardia cindex(CI) were calculated. Levels of serum creatine phosphokinase(CK), glutamic pyruvic transaminase(GPT), urea(BU), creatinine(Cr) and blood platelet count(PLT) were detected. These data reflected separately the functions of heart, liver, kidney, lung and blood coagulation system. The leucine enkephalin(L-Enk) contents of arteries were measured by radioimmunoassay. Results:The L-Enk contents of the mesenteric artery, renal artery and pulmonary artery were significantly decreased at 48 h postburn. No obvious changes of MAP were observed. SVR increased and the CO declined significantly. Damages of functions of heart, liver and kidney achieved the criterion of MOF, the lungs function declined, animal developed MOF. The CO improved and the SVR declined significontely, but no improvement of the organ function indexes were observed after injection of naloxone. Conclusion: These results suggested that enkephalin contents of arteries decreased in the rabbits after burn. It seems to be an important reason that induced peripheral microvascular spastic contraction, SVR increase and organ functions damage.