Furuyama F, Ohara K, Ota A
J Appl Physiol Respir Environ Exerc Physiol. 1984 Oct;57(4):1271-5. doi: 10.1152/jappl.1984.57.4.1271.
A new simple but general estimation method for survival time in a hot environment is presented in this study. Even in heat-tolerant rats showing a triphasic heat response, an accurate estimation of survival time (ST) is possible. Rat groups, which included some heat-tolerant individuals, were exposed to 42.5 degrees C, 40% rh. Colonic temperature (Tco) was measured continuously by copper-constantan thermocouple. The ST (Y) of male and female rats were expressed as a linear function of time (X) until the Tco of 42.5 degrees C was reached: Y = 0.976X + 30.6 and Y = 0.968X + 31.6, respectively. A Tco of 42.5 degrees C at rest was just below the maximum survivable body temperature and above the steady-state equilibrium Tco levels during the second phase of the triphasic heat-response curve. Heat-tolerant individuals showed lower equilibrium temperatures than heat-intolerant rats. All 140 rats survived the Tco of 42.5 degrees C and lived for more than 8 wk, thus enabling them to be used for future experiments on thermoregulation. The heat survivors were able to reproduce, and their genetically controlled offspring could be used for thermoregulatory experiments.
本研究提出了一种新的、简单但通用的热环境下生存时间估算方法。即使在表现出三相热反应的耐热大鼠中，也能够准确估算生存时间（ST）。将包含一些耐热个体的大鼠组暴露于42.5摄氏度、相对湿度40%的环境中。通过铜-康铜热电偶连续测量结肠温度（Tco）。雄性和雌性大鼠的生存时间（Y）表示为达到42.5摄氏度结肠温度之前时间（X）的线性函数：分别为Y = 0.976X + 30.6和Y = 0.968X + 31.6。静息时42.5摄氏度的结肠温度刚好低于最大可耐受体温，且高于三相热反应曲线第二阶段的稳态平衡结肠温度水平。耐热个体的平衡温度低于不耐热大鼠。所有140只大鼠均在结肠温度达到42.5摄氏度后存活，且存活超过8周，因此可用于未来的体温调节实验。热幸存者能够繁殖，其基因控制的后代可用于体温调节实验。
