高热应激对机体持续损伤的实验研究

The experimental study of the heat stress on the functional injury and persisting injury

目的探讨高热环境对机体的损伤及持续损伤的特点,为高热环境损伤的防治提供实验依据。方法将动物暴露于高温环境中造成热应激模型,并于热应激打击后的不同时相及不同恢复期,用冷冻蚀刻、电镜酶组织化学和常规电镜等技术,观察动物心肌、肺、小肠等细胞膜的结构与功能。结果电镜观察热应激动物的心、肺、肾、小肠细胞膜均可见到膜内微粒分布异常,出现成簇分布及稀疏分布区,多数器官膜内微粒数量显著减少,动物心肌细胞,肺泡上皮细胞及毛细血管内皮细胞紧密连接结构明显被破坏,硝酸镧通透性增加,细胞膜上Na-K-ATPas活性降低,受热停止4～24h电镜观察无明显改善。结论高热应激可使动物细胞膜的结构与功能明显损伤,程度与高热时间的长短,体温的高低呈反比,受热停止4～24h,各项异常指标无确定的恢复迹象,提示高热应激损伤有明显的持续性。

Objective To open out the characteristics of heat environment damage and persisting injury,for provide the according as experiment and theoretic to prevent and lighten heat stress damage.Methods The objects were made the pattern of the heat stress by exposing in the heat environment.The function and structure of the cy-membrane of heart,lung,small intestine organs were studied during varies time phases after hitting of heat stress and the different recovered stages. Results The distribution of the intra-membranous particles（IMPs）on heart,lung and small intestine in these animals were abnormal,which present characteristics of the clustered and sparse distribution. The quantity of IMPs was reduced in most organic cells.The integrality of tight junction（TJ）on the myocardial cells、alveolar epithelial cells and capillary endothelial cells were destroyed notably and the permeability of Lanthanum-nitrate trace was increased.The Na-K-ATPase reactants on the membrane were decreased.No obvious evidence of recovery was shown in above indexes even 4~24 hours after stopping heat exposure.Conclusion Heat stress can make cytomembranous structural and functional injury obviously.Above indexes showed no notable evidence of recovery even 4~24 hours after stopping heat exposure,the persisting injury was obvious.