Hubbard R W, Mager M, Bowers W D, Leav I, Angoff G, Matthew W T, Sils I V
J Appl Physiol Respir Environ Exerc Physiol. 1981 Jul;51(1):8-13. doi: 10.1152/jappl.1981.51.1.8.
A total of 182 male Sprague-Dawley rats weighing 250-300 g were fed either a control (n = 122) diet for 32 days. The diets contained either 125 or 8 meq potassium/kg, respectively. Rats fed the low-K diet gained weight at only one-third the rate of controls (1.7 vs. 5.2 g/day), and their skeletal muscle and plasma potassium levels were reduced by 28 and 47%, respectively. When run to exhaustion at either 15 or 20 degrees C, low K+-fed rats accomplished less than one-half of the work done by the controls (26 vs. 53 kg. m) but exhibited a markedly greater rate of heat gain per kilogram-meter of work than controls (0.12 vs. 0.05 degrees C)ambient temperature of 20 degrees C, the rats of the low-K+ group despite large differences in body weight (-25%), run time temperature and twice (33 vs 17%) the mortality rate of the controls. Postexercise increases in circulating potassium (less than 90%) of heat-injured rats raised the plasma levels of low K+-fed rats to normal (5.9 +/- 2.2 meq/l). These results appear to characterize the existence of an insidious and, therefore, undocumented form of fatal exertion-induced heat illness.
总共182只体重为250 - 300克的雄性斯普拉格 - 道利大鼠被喂食对照饮食（n = 122）32天。这些饮食分别含有125或8毫当量钾/千克。喂食低钾饮食的大鼠体重增加速度仅为对照组的三分之一（1.7对5.2克/天），其骨骼肌和血浆钾水平分别降低了28%和47%。在15或20摄氏度下运动至疲惫时，喂食低钾的大鼠完成的工作量不到对照组的一半（26对53千克·米），但每千克 - 米工作量的产热率明显高于对照组（0.12对0.05摄氏度）。在20摄氏度的环境温度下，低钾组的大鼠尽管体重差异很大（-25%），运动时间和温度不同，但死亡率是对照组的两倍（33%对17%）。热损伤大鼠运动后循环钾的增加（不到90%）使喂食低钾的大鼠血浆水平恢复正常（5.9±2.2毫当量/升）。这些结果似乎表明存在一种隐匿的、因此未被记录的致命性运动诱发热疾病形式。
