褪黑素对家免肾上腺素所致肺水肿的保护机制初探

Protective Effect of Melatonin on Pneumonary Edema Induced by Adrenaline in Rabbits

目的探讨褪黑素对家兔肾上腺素诱发实验性肺水肿的作用。方法随机将18只家兔分成正常对照组（对照组）、肾上腺素组（模型组）和褪黑素组（预防组），预防组经耳缘静脉注射褪黑素10mg／kg，30min后模型组和预防组耳缘静脉分别注射肾上腺素1mg／只诱发肺水肿，对照组则注射等量生理盐水。观察记录不同时间点呼吸频率的变化，比较肺系数及肺的病理组织学。结果肾上腺素注射后，呼吸急促并维持一段时间；预防组与模型组比较，呼吸频率明显减慢且肺体系数降低。病理组织学检查显示，模型组动物肺泡壁断裂，肺泡隔明显增宽；褪黑素明显减轻上述的症状。结论褪黑素对肾上腺素所致肺水肿具有保护作用。

Objective To investigate the effect of melatonin on adrenaline induced experimental pneumonary edema in rabbits. Methods Eighteen rabbits were randomly divided into normal group, model group, melatonin group. In the melatonin group, rabbits were received an injection of 10 mg/kg melatonin, followed by injection of 1 mg adrenaline （AD） after 30 min. In the model group, after a corresponding bolus of normal saline, AD was administrated. Normal group were injected with a corresponding bolus of normal saline. The effect of melatonin was evaluated by light microscopy, the indications of the animals as breathing and lung index. Results In the model group, respiratory frequency and lung index were significantly higher compared with the normal group. Histopathological alterations presented hemorrhage, edema thickened alveolar septum in alveolar spaces. Melatonin decreased the respiratory frequency remarkably and lung index. Light microscopic analysis disclosed that lung were less deteriorated in the melatonin group than in the model group. Conclusion Melatonin has aprotective effect on adrenaline induced pulmonary edema.