Berntman L, Welsh F A, Harp J R
Anesthesiology. 1981 Nov;55(5):495-8. doi: 10.1097/00000542-198111000-00003.
Male Wistar rats with unilateral carotid ligation were exposed to arterial hypoxia (PaO2 20-23 torr for 20 min) while body temperature was controlled at 37 degrees C, 36 degrees C, or 34 degrees C. Brain cortical concentrations of ATP, phosphocreatine (PCr) and lactate were measured microfluorometrically. Normothermic hypoxic rats had severe metabolic changes with low brain ATP and extremely high brain lactate. When rectal temperature was controlled at 36 degrees C during hypoxia, brain ATP was not different from that observed in normothermic, normoxic rats, and brain lactate was significantly lower than during normothermic hypoxia. At 34 degrees C, brain lactate was even less, but still three times higher than that observed in normothermic normoxic rats. PCr was significantly higher following hypoxia at 34 degrees C than at 37 degrees C. In part, this latter finding may reflect preservation of intracellular pH at 34 degrees C. A decrease of body temperature of 1-3 degrees C can minimize or prevent brain energy failure during hypoxia as well as decrease the magnitude of brain tissue acidosis. Thus, in experiments examining "cerebral protective effects" of therapies during brain hypoxia-ischemia, stringent control of body temperature is necessary. Furthermore, a possible clinical benefit resulting from modest reduction in body temperature in patients with marginal cerebral oxygenation is suggested.
对单侧颈动脉结扎的雄性Wistar大鼠进行动脉低氧处理（动脉血氧分压20 - 23托，持续20分钟），同时将体温控制在37℃、36℃或34℃。采用微量荧光法测定大脑皮质中的三磷酸腺苷（ATP）、磷酸肌酸（PCr）和乳酸的浓度。体温正常的低氧大鼠有严重的代谢变化，脑ATP水平低，脑乳酸水平极高。在低氧期间将直肠温度控制在36℃时，脑ATP与体温正常、未缺氧的大鼠所观察到的情况无差异，且脑乳酸水平显著低于体温正常时的低氧状态。在34℃时，脑乳酸水平更低，但仍比体温正常、未缺氧的大鼠高3倍。低氧处理后，34℃时的PCr显著高于37℃时。这一结果部分可能反映了34℃时细胞内pH值的维持情况。体温降低1 - 3℃可在低氧期间将脑能量衰竭降至最低或预防其发生，并减轻脑组织酸中毒的程度。因此，在研究脑缺氧缺血期间治疗方法的“脑保护作用”的实验中，严格控制体温是必要的。此外，这表明对于脑氧合处于临界状态的患者，适度降低体温可能会带来临床益处。
