Matsushita M, Ohashi I, Becker G L, Pohorecki R
Department of Anesthesiology, University of Nebraska Medical Center, Omaha 68198-4455, USA.
Anesth Analg. 1996 Jun;82(6):1261-7. doi: 10.1097/00000539-199606000-00028.
The hypothesis that general anesthetics protect energy reserves by decreasing energy demand is widely accepted but poorly substantiated. Isoflurane at clinical doses preserved adenosine triphosphate (ATP) levels in anoxic isolated hepatocytes. Specific inhibitors were used to block mitochondrial and/or glycolytic ATP formation to ascertain whether pathways of energy supply or demand, or both, were involved in ATP preservation by isoflurane. Hepatocytes were isolated from fed adult male rats after perfusing livers with Krebs buffer containing collagenase. Cells were incubated in Krebs buffer for 0-30 min at 25 degrees C under N2/CO2 (95%/5%) +/- isoflurane 0.63 mM in liquid phase. Oligomycin, iodoacetate, or fasting were used to block mitochondrial and glycolytic ATP formation. Under anoxia alone, ATP levels declined more slowly in the presence than in the absence of isoflurane, confirming the ATP-protective effect of isoflurane reported previously. With oligomycin plus iodoacetate blocking all ATP formation, ATP decline (representing pure ATP consumption) was not slowed by isoflurane. Isoflurane's protective effect recurred when glycolytic ATP supply was restored by incubating with oligomycin only. The protective effect was accompanied by increased lactate accumulation, and both effects-ATP preservation and lactate formation-were similarly dependent on isoflurane concentration. We conclude that the protective effect of isoflurane on energy status in anoxic isolated hepatocytes was not associated with reduced ATP demand but with enhanced ATP supply via stimulation of glycolysis.
全身麻醉药通过降低能量需求来保护能量储备这一假说已被广泛接受，但证据不足。临床剂量的异氟烷可维持缺氧分离肝细胞中的三磷酸腺苷（ATP）水平。使用特异性抑制剂阻断线粒体和/或糖酵解ATP生成，以确定能量供应或需求途径，或两者是否参与异氟烷对ATP的维持作用。在用含胶原酶的 Krebs 缓冲液灌注肝脏后，从成年雄性大鼠中分离肝细胞。细胞在 Krebs 缓冲液中于 25℃下在 N2/CO2（95%/5%）中孵育 0 - 30 分钟，液相中添加或不添加 0.63 mM 异氟烷。使用寡霉素、碘乙酸盐或禁食来阻断线粒体和糖酵解ATP生成。仅在缺氧条件下，存在异氟烷时ATP水平下降比不存在时更慢，证实了先前报道的异氟烷对ATP的保护作用。当寡霉素加碘乙酸盐阻断所有ATP生成时，异氟烷并未减缓ATP下降（代表纯ATP消耗）。仅用寡霉素孵育恢复糖酵解ATP供应时，异氟烷的保护作用再次出现。保护作用伴随着乳酸积累增加，并且ATP维持和乳酸生成这两种作用同样依赖于异氟烷浓度。我们得出结论，异氟烷对缺氧分离肝细胞能量状态的保护作用与ATP需求减少无关，而是与通过刺激糖酵解增强ATP供应有关。
