亚甲蓝对兔创伤性休克的干预作用

目的 观察亚甲蓝（MB）干预后，创伤性休克兔血浆一氧化氮（NO）、肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）的变化和小肠、肝脏病理形态学改变，探讨MB对创伤性休克的作用机制。方法 18只大白兔随机分为假手术组、创伤性休克生理盐水复苏组（生理盐水复苏组）、创伤性休克MB处理组（MB处理组），每组6只。生理盐水复苏组及MB处理组记录休克前（T1）、休克末（T2）、复苏末（T3），复苏后0．5（T4）、2（T5）、4h（T6）血流动力学的动态变化，并测定血浆NO、TNF-α、IL-6水平，假手术组于相应时间点测定。实验结束后，3组动物均留取小肠、肝脏组织，观察病理形态学变化。结果 MB处理组血流动力学较生理盐水复苏组平稳（P〈0．05或P〈0．01）。创伤性休克后，血浆NO水平明显高于T1水平，生理盐水复苏组复苏后血浆NO进行性增高，于T4时达峰值水平，以后逐渐下降，但仍高于T1水平；MB处理组复苏后血浆NO明显降低；假手术组各时间点血浆NO无明显变化。创伤性休克后TNF-α及IL-6明显升高，而应用MB复苏后TNF-α及IL-6与T1时比较差异均无显著性，假手术组各时间点TNF-α及IL-6差异无显著性。生理盐水复苏组各脏器病理损害明显；MB处理组各脏器病理损害显著减轻；假手术组各脏器无明显病理损害。结论 NO、TNF-α及IL-6在创伤性休克的病理发展过程中起着重要作用，应用MB可降低血浆NO、TNF-α及IL-6的水平，明显改善创伤性休克血流动力学，保护重要脏器，有助于创伤性休克的改善。

Effect of methylene blue on traumatic shock in rabbits

OBJECTIVE: To observe the effect of methylene blue (MB) on the changes in plasma nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and visceral pathologic changes in rabbits with traumatic shock. METHODS: Eighteen rabbits were randomly assigned into 3 groups (n=6): sham operation group, traumatic shock with normal saline (NS) resuscitation group (NS group), and traumatic shock with MB resuscitation group (MB group). In NS group and MB group, hemodynamics was monitored, and plasma contents of NO, TNF-alpha and IL-6 were determined before shock, after shock, after resuscitation, and 0.5, 2 and 4 hours after resuscitation. In sham operation control group, hemodynamics monitoring and plasma contents of NO, TNF-alpha and IL-6 were also determined. Tissue samples of the liver and intestine were obtained after experiments for microscopic examination. RESULTS: Compared with NS group, hemodynamics was stable in MB group. The levels of plasma NO in rabbits after traumatic shock were much higher than those of before shock. In NS group, the levels of plasma NO were progressively increased after resuscitation, reaching peak level at 0.5 hour after resuscitation, then decreased thereafter but still remaining higher than those of before shock. But in MB group, the levels of plasma NO after resuscitation were obviously decreased. In sham operation group, the levels of plasma NO showed no significant changes during the whole course. The levels of plasma TNF-alpha and IL-6 in rabbits after traumatic shock were much higher than those of before shock. But after intravenous administration of MB, the levels of plasma TNF-alpha and IL-6 after resuscitation showed no significant difference compared with the baseline levels. In sham operation group, the levels of plasma TNF-alpha and IL-6 showed no significant changes during the entire course. In NS group, the organs showed prominent pathologic changes. But in MB group, less pathologic changes in the organs were milder, and in sham operation group, there was no obvious pathologic changes in the organs. CONCLUSION: NO, TNF-alpha and IL-6 play important roles in the pathologic process of traumatic shock and the administration of MB after resuscitation can decrease the levels of plasma NO, TNF-alpha and IL-6, improve hemodynamics in traumatic shock, and protect the important organs.