Department of Anesthesiology and Intensive Care, Faculty of Medicine, University of Miyazaki, 5200 Kihara Kiyotake, Miyazaki 889-1692, Japan.
J Anesth. 2011 Feb;25(1):65-71. doi: 10.1007/s00540-010-1071-6. Epub 2010 Dec 10.
An active sleep homeostatic process is present during propofol anesthesia. Activation of the orexin system induces wakefulness, and inhibition of the orexin system causes narcolepsy. We hypothesized that orexin would affect propofol anesthesia.
The effects of an intracerebroventricular (i.c.v.) injection of orexin-A (OXA) or an orexin-1 (OX-1) receptor antagonist, SB-334867, on the times to the loss and return of the righting reflex induced by propofol were examined in Wistar rats. The effects of propofol or OXA on norepinephrine (NE) and dopamine (DA) release from the prefrontal cortex (PFC) were examined using in vivo microdialysis.
An i.c.v. injection of OXA (1 nmol) decreased the time to emergence from propofol anesthesia mediated by the OX-1 receptor without changing anesthetic induction (n = 8). An i.c.v. injection of SB-334867 (5 and 50 nmol) increased the time to emergence from propofol anesthesia without changing anesthetic induction (n = 8). Intravenous infusion of propofol decreased NE (48 ± 8%; n = 8) and DA (61.2 ± 11%; n = 8) release from PFC mediated by the GABA(A) receptor. An i.c.v. injection of OXA reversed the decreases in NE and DA release induced by propofol mediated by the OX-1 receptor (n = 8).
These results indicate that the orexin system may accelerate the emergence from propofol anesthesia associated with increases in the central noradrenergic and dopaminergic activity.
在异丙酚麻醉期间存在活跃的睡眠稳态过程。 激活食欲素系统会引起觉醒，而抑制食欲素系统会导致发作性睡病。 我们假设食欲素会影响异丙酚麻醉。
在 Wistar 大鼠中，通过脑室（i.c.v.）注射食欲素-A（OXA）或食欲素-1（OX-1）受体拮抗剂 SB-334867，研究其对异丙酚诱导的翻正反射丧失和恢复时间的影响。 使用体内微透析研究异丙酚或 OXA 对前额叶皮层（PFC）去甲肾上腺素（NE）和多巴胺（DA）释放的影响。
脑室注射 OXA（1 nmol）可降低 OX-1 受体介导的异丙酚麻醉苏醒时间，而不改变麻醉诱导（n = 8）。脑室注射 SB-334867（5 和 50 nmol）增加了异丙酚麻醉苏醒时间，而不改变麻醉诱导（n = 8）。 异丙酚静脉输注可降低由 GABA（A）受体介导的 PFC 中 NE（48 ± 8％；n = 8）和 DA（61.2 ± 11％；n = 8）的释放。脑室注射 OXA 逆转了由 OX-1 受体介导的异丙酚诱导的 NE 和 DA 释放的减少（n = 8）。
这些结果表明，食欲素系统可能通过增加中枢去甲肾上腺素能和多巴胺能活性来加速异丙酚麻醉的苏醒。
