目的 评价右美托咪定对七氟醚麻醉诱发新生大鼠皮层癫痫样脑电图波的影响.方法 清洁健康SD大鼠40只,4~6日龄,体重8~15 g,采用随机数字表法分为5组(n=8):对照组(C组)、七氟醚组(S组)、右美托咪定+七氟醚组(D+S组)、右美托咪定+α2肾上腺素能受体拮抗剂阿替美唑+七氟醚组(D+A+S组)和阿替美唑+七氟醚组(A+S组).正确放置电极,持续监测脑电图,监测58 min时C组腹腔注射生理盐水5 μl∕g,D+S组腹腔注射右美托咪定25 μg∕kg,D+A+S组腹腔注射右美托咪定25 μg∕kg、阿替美唑250 μg∕kg,A+S组腹腔注射阿替美唑250 μg∕kg.持续监测脑电图60 min时,S组、D+S组、D+A+S组和A+S组吸入6%七氟醚3 min进行麻醉诱导,随后吸入2. 1%七氟醚维持麻醉,麻醉时间1 h.记录麻醉期间癫痫波总时长、癫痫波个数和癫痫波平均时长.麻醉结束后左心室取血样,行血气分析;然后断头取血样检测血清皮质酮浓度.结果 C组未见癫痫波发生.与C组比较,其余4组血清皮质酮浓度升高(P<0. 05);与S组比较,D+S组癫痫波总时长缩短,个数减少,血清皮质酮浓度降低(P<0. 05),D+A+S组和A+S组癫痫波总时长、癫痫波个数、癫痫波平均时长和血清皮质酮差异无统计学意义(P>0. 05);与D+S组比较,D+A+S组和A+S组癫痫波总时长延长,个数增加,血清皮质酮浓度升高(P<0. 05).结论 右美托咪定可抑制七氟醚麻醉诱发新生大鼠皮层癫痫样脑电图波的发生,机制可能主要通过激活中枢α2肾上腺素能受体,改善下丘脑-垂体-肾上腺皮质轴功能亢进有关.
Objective To evaluate the effect of dexmedetomidine on sevoflurane anesthesia-in-duced cortical epileptiform electroencephalogram ( EEG) activity in the neonatal rats. Methods Forty clean-grade healthy Sprague-Dawley rats, aged 4-6 days, weighing 8-15 g, were divided into 5 groups (n=8 each) using a random number table method: control group ( C group), sevoflurane group ( S group), dexmedetomidine plus sevoflurane group (D+S group), dexmedetomidine plus alpha 2-adrenocep-tor antagonist atipamezole plus sevoflurane group (D+A+S group), and atipamezole plus sevoflurane group (A+S group). After the electrode was correctly placed, the EEG was continuously monitored, and normal saline 5 μl∕g was intraperitoneally injected at 58 min of monitoring in group C, dexmedetomidine 25 μg∕kg was intraperitoneally injected in group D+S, dexmedetomidine 25 μg∕kg and atipamezole 250 μg∕kg were intraperitoneally injected in group D+A+S, and atipamezole 250 μg∕kg was intraperitoneally injected in group A+S. Anesthesia was induced by inhaling 6% sevoflurane for 3 min starting from 60 min of monitoring and then maintained by inhaling 2. 1% sevoflurane for 1 h. The total duration, the number and average du- ration of epileptic waves were recorded during anesthesia. Blood samples were obtained from the left ventri-cle after the end of anesthesia for blood gas analysis. Rats were then sacrificed and blood samples were col-lected for measurement of the serum corticosterone concentration. Results No epileptic wave was found in group C. The serum concentration of corticosterone was significantly higher in the other four groups than in group C ( P<0. 05). Compared with group S, the total duration of epileptic wave was significantly short-ened, the number of epileptic wave was reduced, and the concentration of corticosterone was decreased in group D+S (P<0. 05), and no significant change was found in the total duration, the number and average duration of epileptic waves or serum concentration of corticosterone in D+A+S and A+S
Chinese Journal of Anesthesilolgy