植入式生物遥测技术在劳力型热射病大鼠实验模型中的应用

Application of implantable biotelemetry in rat model of exertional heat stroke

背景劳力型热射病(exertional heat stroke,EHS)是一种主要因运动或劳作产生过量的内源性热而引起的重度中暑,目前尚无成熟的EHS实验动物模型建模方法和标准。目的通过植入式生物遥测技术的应用,建立稳定可靠的EHS大鼠模型,阐明高温和运动下EHS大鼠的核心温度(core temperature,Tc)、血压(blood pressure,BP)、心率(heart rate,HR)等基本生理参数的变化规律。方法取体质量250~300 g健康成年雄性Wistar大鼠18只,通过手术将可实时遥测Tc、BP、HR的无线植入子植入大鼠腹腔,恢复1周后进行适应性跑步训练。训练1周后大鼠进入高温、高湿环境模拟舱,实验舱的环境温度设置为(39.5±0.3)℃,相对湿度为55%±5%;大鼠以阶梯式增速方案进行跑步,疲劳后停止,出现重度意识障碍表现后结束热暴露出舱,出舱后自然降温。实验中持续监测大鼠Tc、BP、HR等参数变化,记录生存时间。死亡EHS大鼠即刻解剖,观察病理学变化。结果在18只进行植入子手术的大鼠中,7只大鼠术后恢复良好,手术总体成功率为38.9%。遥测模型完整记录了热应激下大鼠的Tc、BP、HR等生理参数变化过程,随着Tc的迅速上升,BP、HR同步到达峰值并于出舱前急剧下降。病理学检查验证了EHS大鼠的多器官损伤。结论植入式生物遥测技术可以实时监测EHS大鼠实验模型的生理参数,有助于进一步挖掘EHS的病理生理学变化特点和机制,为后续EHS研究提供了必要工具。

Background Exertional heat stroke(EHS) is a kind of severe heat illness caused by excessive endogenous heat mainly generated by exercise or labor.Currently,there is no standard experimental animal model for EHS.Objective To establish a stable and reliable rat model of EHS by using implantable biotelemetry,and elucidate the changes of basic physiological parameters of EHS rats,such as core temperature(Tc),blood pressure(BP),heart rate(HR),in the process of exercise during heat exposure.Methods A total of 18 adult male Wistar rats,weighing 250-300 g,were intraperitoneally implanted with a wireless radiotelemetry transmitter,which provided remote monitoring of Tc,BP,and HR.After one-week recovery,adaptive running exercise was implemented.After one week of training,rats were brought into an artificial climate chamber,in which the ambient temperature was set to 39.5 ± 0.3℃,relative humidity was 55 ± 5 %.Then,the rats underwent an incremental-speed exercise protocol until fatigue was exhibited.The end point was defined by the appearance of severe disturbance of consciousness,after which the rats were removed from the chamber and recovered at a room temperature.Physiological parameters such as Tc,BP,and HR were continuously monitored during the course,and the survival time was recorded.The EHS rats were dissected immediately after the death and pathological changes were observed.Results Seven out of eighteen(38.9%) rats underwent the transmitter surgery successfully.By using the biotelemetry model,Tc,BP,and HR of rats were recorded completely during heat stress.With the rapid rise of Tc,BP and HR simultaneously reached the peak and sharply dropped before the end of heat exposure.The histopathological examination verified multiple organ injuries in EHS rats.Conclusion The application of implantable biotelemetry is helpful in monitoring the physiological parameters,and further investigating the characteristics and mechanism of pathophysiological changes in EHS rats,providing a necessary tool for the follow-up study in EHS.