摘要
目的研究异丙酚不同麻醉深度下兔纹状体多巴胺(DA)及cAMP的变化。方法 随机选取40只日本大耳兔,雌雄不拘。10只兔颈外静脉连接Graseby 3500注射泵进行靶控输注(TCI),异丙酚靶血药浓度最初为6μg/ml,达平衡后2 min以0.3μg/ml速度递增。此期间每30 s观察咀嚼反射,以咀嚼反射消失作为浅麻醉标志,以夹尾后无体动反应为深麻醉标志,确定不同麻醉深度下所需的异丙酚靶控血药浓度(Cp),并用高效液相色谱法测定异丙酚血药浓度(cm),计算预期误差(PE)的百分数(PE％)、预期误差的中位数(MDPE)、预期误差绝对值的中位数(MDAPE),评价TCI系统的准确性。30只兔随机分为三组:对照组、浅麻醉组和深麻醉组各10只。对照组不予以异丙酚,浅麻醉组和深麻醉组应用异丙酚TCI系统,严格控制麻醉于不同深度,持续1h后断头处死,迅速冰上分离纹状体,测定DA、高香草酸(HVA)、cAMP含量。结果浅麻醉和深麻醉状态下异丙酚Cp及BIS分别为:(9.25±0.12)μg·ml-1,63±4;(11.63±0.29)μg·ml-1,32±6。MDPE和MDAPE分别为-25.7％和29.6％,DA代谢水平随麻醉深度的增加而显著性增加(P<0.05),cAMP含量浅麻醉组及深麻醉组均高于对照组(P<0.05),但浅麻醉组与深麻醉组之间差异无显著性(P>0.05)。结论随异丙酚麻醉深度的增加纹状体DA含量增加,并可能通?
Objective To investigate the changes in dopamine (DA) metabolism and cAMP in striatum during different depths of anesthesia produced by TCI of propofol in rabbits. Methods Forty Japanese long-ear rabbits of both sexes, aged 8 months-2 yrs, weighing 2-3 kg were anesthetized with TCI of propofol. The TCI system consisted of a Graseby 3500 infusion pump, a lap-top, a RS 232 connector and the computer program Stelpump 1.06P (by Johan Coetzee) . The target blood propofol concentration was set initially at 6 μg·ml-1 and then gradually increased in 0.3μg·ml-1 increment until loss of chewing reflex (light anesthesia) or loss of response to tail nipping (deep anesthesia). The light or deep anesthesia was maintained for 1h. Blood samples were taken for measurement of blood propofol concentration (Cm) . BIS was continuously monitored during the experiment.The Cm and the predicted blood propofol concentration (Cp) were recorded. The prediction error (PE), median prediction error ( MDPE) and median absolute prediction error ( MDAPE) were calculated. The animals were randomly divided into 3 groups : A control group (n=10); B light anesthesia group (n=10) and C deep anesthesia group ( n=10) . The animals were decapitated at the end of 1 h anesthesia. The striatums were immediately separated on ice and their contents of DA, homovanillic acid (HVA, the end-metabolite of DA in brain, representing the activity of dopaminergic neurons) and cAMP were measured. Results BIS value was 95 ?±7 before anesthesia, 63±4 during light anesthesia and 32±6 during deep anesthesia. Cp was (9.25±0.12) μg·ml-1 during light anesthesia and (11.63±0.29)μg·ml-1 during deep anesthesia. MDPE was -25.7% and MDAPE 29.6 % , indicating higher reliability of the TCI system. The negative value of MDPE indicated that Cp was overestimated compared with Cm. DA, HVA and cAMP contents in striatum increased significantly during light and deep anesthesia (group B and C) compared with those in group A. There was no significant difference in DA and cAMP levels between light and deep anesthesia but HVA level was significantly higher during deep anesthesia than that during light anesthesia (P<0.01) .Conclusion Dopamine metabolism in striatum increases with increasing level of propofol anesthesia. Dopamine may act on D1 receptor, bringing about significant increase in intracellular cAMP level.
出处
《中华麻醉学杂志》
CAS
CSCD
北大核心
2004年第8期615-617,共3页
Chinese Journal of Anesthesiology
