THE INFLUENCE OF INHALATIONAL ANESTHETICS ON THE ENERGY METABOLISM AND CREATIN KINASE SYSTEM OF BRAIN DURING BRAIN ISCHEMIA

我们以前报道过，氟烷（Hal）延迟脑缺血后的脑细胞内pH值（pHi）和[ATP]的恢复与异氟烷（Iso）和七氟烷（Sev）麻醉相比。结果：Hal对脑缺血时和缺血后的脑能量代谢有明显的影响，但对[无机磷]和[磷酸肌酸（PCr）]的回收率无明显影响，因此我们推测Hal影响了肌酸激酶（CK）的正向反应（PCr+ADP→Cr+ATP）。Wistar大鼠分为3组：1%Hal-、2%Hal-或1.5%Iso-处理组（n=7）。双侧颈总动脉结扎并放血造成脑缺血9分钟后，我们继续观察2小时。结果：Wistar大鼠分为2组，Hal组与Iso组比较，Hal延迟了pHi和[ATP]的恢复，但在2个Hal组中，未发现2个Hal组之间的剂量依赖性效应。两种麻醉条件下的kf值差异无显著性，但有显著性（Hal为0.24±0.05，Iso为0.30±0.04）.结论：氟烷可能损害脑能量平衡，氟烷具有神经麻醉的不良特性，并有脑缺血的危险.

We previously reported that halothane (Hal) delayed the recoveries in cerebral intracellular pH (pHi) and [ATP] in comparison with isoflurane (Iso) and sevoflurane (Sev) anesthesia after cerebral ischemia in the rat model. We did not find any differences in the recoveries in [inorganic P] nor [phosphocreatine (PCr)], therefore we hypothesized that Hal affected the creatine kinase (CK) forward reaction (PCr+ADP→Cr+ATP).METHODS : With using magnetic resonance spectroscopy, we further investigated whether Hal affected the brain energy metabolism during and after cerebral ischemia dose-dependently. Wistar rats were divided into 3 groups : 1% Hal-, 2% Hal-, or 1.5% Iso-treated (n=7). After 9 min of cerebral ischemia by bilateral carotid ligation and blood withdrawal, we continued the observation up to 2 hrs. We then measured the pseudo first-order rate constant (kf) of CK forward reaction in Hal/Iso anesthesia determined by MR saturation transfer technique under normoxic condition.RESULTS : Wistar rats were divided into 2 groups Hal delayed the recoveries in pHi and [ATP] in a comparison with Iso group but in the two Hal groups, we could not find the dose-dependent effect between 2 Hal groups. There were no differences between the both anesthetic conditions but significant difference in the values of kf (0.24±0.05 in Hal and 0.30±0.04 in Iso anesthesia).CONCLUSION : Halothane might impair the brain energy balance and we concluded that halothane has an undesirable property for neuroanesthesia with the risk of cerebral ischemia.