吗啡对家兔定量药物脑电图β_2频段的影响

Effect of Morphine on β_2-band of quantitative pharmaco-electroencephalogram in rabbits

目的探讨吗啡对家兔定量药物脑电图（QPEEG）B：频段的影响及其与阿片受体的关系。方法取42只成年家兔随机均分为Ns组（1mL·kg-1生理盐水）、吗啡低（LD）、中（MD）、高（HD）剂量组（0．5、1、2mg·kg-1吗啡）、Na组（200μg·kg-1纳洛酮）、NSM组（1mL·kg-1生理盐水＋2mg·kg-1吗啡）和NAM组（200μg·kg-1纳洛酮＋2mg·kg-1吗啡），应用QPEEG，采用功率谱分析家兔在iv药物前后β2频段功率百分比的变化。结果与给药前比较，Ns组、N组和LD组中家兔的p。频段功率百分比无明显变化；MD组和HD组中的B：频段功率百分比在部分脑区0．5～5min时增加（P〈0．05，P〈0．01），此改变在0．5～5min与吗啡剂量呈正相关（r=0．407～0．694，P〈0．01）；NAM组的家兔在给吗啡前后，β2频段功率百分比无明显变化，部分脑区低于NSM组的（P〈0．05）。结论吗啡以剂量依赖方式增加兔QPEEGp：频段功率百分比，纳洛酮可拮抗之，表明吗啡在大脑皮层作用部位广泛，阿片受体介导了这一作用，提示β2频段可能成为反映镇痛程度的指标。

OBJECTIVE To study the effect of Morphine on β2 - band of quantitative pharmaco - electroencephalogram （QPEEG） in the rabbits and the relation with opiate receptor. METHODS 42 grown rabbits were divided into 7 groups （ n = 6 ） ： NS group （ normal saline 1 mL kg - l ） , LD group （ Morphine 0.5 mg- kg - 1 ） , MD group （ Morphine 1 mg kg - 1 ） , HD group （ Morphine 2 mg. kg - 1 ） , Na group （ Naloxone 200 μg kg - 1 ） , NSM group （ normal saline 1 mL- kg - 1 ＋ Morphine 2 rag. kg - 1 ） and NAM group （ Naloxone 200 μg kg-1 ＋ Morphine 2 mg kg-1 ）. QPEEG activity was processed with power spectral analysis in order to analyze the change of 132 - band power percentage before and after the rabbits＇ being administrated drugs. RESULTS Compared with the previous administration, there was no obvious change in β2 - band power percentage of NS group, N group and LD group. In MD group and HD group,β2 - band power percentage had an increased in several brain regions during 0.5 -5 min（P 〈0. 05,P 〈0.01 ）. The change of β2- band power percentage during 0.5 -5 rain had a positive correlation with Morphine dose（ r = 0. 407 - 0. 694,P 〈 0.01 ）. In NAM group,there was no obvious change in β2 - band power percentage before and after the rabbits＇ being administrated Morphine. β2 - band pow- er percentage of NAM group were even lower than that of NSM group in some brain regions （P 〈 0.05 ）. CONCLUSION Morphine can increase β2- band power percentage of QPEEG in a dose dependant manner in rabbits, which can be antagonized by Naloxone. It indicates that Morphine affects the sites in cerebral cortex widely. Opiate receptor mediates this effect and β2- band may become an index that reflects analgesia degree.