可乐定对丙泊酚麻醉中海马去甲肾上腺素释放的影响

Effects of clonidine on the noradrenaline release in rat hippocampus daring propofol anesthesia

目的 通过观察大鼠在丙泊酚麻醉中海马去甲基肾上腺素(NA)的释放效应,探讨中枢性NA机制在丙泊酚麻醉中的作用。方法 采用微透析技术检测大鼠海马组织细胞外液NA的浓度。20只雄性大鼠,随机分为两组。单纯丙泊酚(A)组:分别以10和60 mg·kg-1·h-1的速度各静注45min,然后停止静注直至动物清醒。B组在输注丙泊酚的同时腹腔内注射可乐定0.5 mg/kg,余和A组相同。分别比较麻醉前、中及苏醒期的NA值(μg/15min)。结果 与基础值相比,A组60 mg·k-1·h-1丙泊酚时的海马NA为(0.13±0.02)μg/15min,B组海马NA为(0.07±0.04)μg/15min,均显著降低(P<0.05)。结论海马α2-NA受体激动药可乐定与丙泊酚麻醉深度的加深有关,但是否是丙泊酚麻醉的共有机制还有待于深入研究。

Objective To observe the influences of propofol anesthesia on the release of nora-drenaline(NA)in rat hippocampus in order to identify the central NA mechanism of propofol anesthesia. Methods Twenty adult male SD rats were randomly divided into two groups. In group A,the rats were infused intravenously (IV) with propofol at a rate of 10 mg · kg-1 · h-1 for 45 min and 60 mg · kg-1· h-1 for 45 min,and in group B,clonidine 0. 5 mg/kg intraperitoneally and infusion of propofol at the same rate as in group A. The concentrations of NA in the extra-cellular liquid of the hippocampus (μg/15min)were quantified before, during and emergence from anesthesia by microdialysis technique in vivo. Results The NA levels in the hippocampus were decreased by propofol 60 mg · kg-1· h-1 [from (0. 18±0. 04) μg/15min to (0. 13±0. 02) μg/15min],but they were decreased more by cloni-dine [from (0. 14±0. 04 ) μg/15min to (0. 07±0. 04) μg/15min](P<0. 05). Conclusion Clonidine may enhance the depth of propofol anesthesia,but whether clonidine shares the mechanism of propofol anesthesia needs to be studied further.