大鼠氧惊厥时脑内μ-阿片受体的变化

Changes of μ-opioid receptor in brain of rats during oxygen-induced convulsions

目的 探讨大鼠氧惊厥时脑内 μ-阿片受体的变化。方法 用 [3H]-羟甲芬太尼作为特异性标记配体 ,采用放射配体受体结合实验 (radioligand binding assay,RBA) ,测定在几种不同气体及压力的暴露条件下 ,大鼠脑内 μ-阿片受体的 k D值和 Bmax值的变化。结果 大鼠氧惊厥前 ,脑内 μ-阿片受体的 k D值即有增大趋势 (但 P>0 .0 5 ) ,Bmax值减小 (P<0 .0 1) ;氧惊厥时 k D值进一步升高 (P<0 .0 1) ,Bmax值反而增大 (P<0 .0 1)。结论 结果提示 :(1)氧惊厥发作中 ,μ-阿片受体的数量增多 ,而其结合活性降低。(2 )在高压氧 (HBO)暴露中 。

Objective To investigate the changes of μ opioid receptor in brain of rats during oxygen induced convulsions. Methods The binding of selecitve μ opioid receptor agonist [ 3H] ohmefentanyl(OMF) to brain of rats exposed to different gases and pressures was determined by means of radioligand binding assay(RBA). Results After rats were exposed to approximately normoxic hyperbaric N 2 O 2, the k D and B max of [ 3H] OMF bindings to brain were not apparently altered. After the animals were exposed to HBO for only 5 min(before the appearance of convulsions), the k D values began to increase (but P >0 05). When the animals were exposed to HBO and developed convulsions, the k D increaase became more obvious ( P <0 01). Whereas, the B max values were decreased ( P <0 05) before the appearance of convulsions, but thereafter increased significantly ( P <0 01) with the occurance of convulsions. Conclusions (1) During HBO induced convulsions, the total number of μ opioid receptors was increased but the receptor affinity was decreased. (2) In HBO induced convulsions, the μ opioid receptor was involved.