缺氧条件下梭曼中毒对大鼠脑M受体的影响

Effects of soman intoxication under hypoxia on cerebral M receptors of rats

目的 探讨高原缺氧条件下梭曼中毒大鼠脑组织乙酰胆碱酯酶 (AChE)活性和毒蕈碱样乙酰胆碱 (M)受体变化规律。方法 以DTNB法和受体放射性配基结合法检测大鼠皮层、海马及纹状体AChE活性和M受体密度及亲和力。结果 缺氧使大鼠脑组织AChE活性不同程度升高 ,缺氧 2 4h海马和纹状体M受体密度分别增加 10 .4%和 2 5 .3 % ,M受体的亲和力分别增加 5 5 .6 %和 30 .3 %。单纯梭曼中毒和缺氧复合梭曼中毒均显著抑制脑组织AChE活性 ,但缺氧条件下梭曼对大鼠海马和纹状体的AChE抑制程度减弱。缺氧和缺氧复合梭曼中毒脑损伤以纹状体最明显。结论 高原缺氧和梭曼中毒均明显干扰大鼠脑组织胆碱能神经系统功能。

Objective To study the effects of soman intoxication under high altitude hypoxia on muscarinic acetylcholine receptors (M receptors) and the mechanism of the increase of toxicity in the nervous tissue in high altitude.Methods The activity of acetylcholine esterase (AChE) and the density and affinity of M receptors in the cerebral cortex, hippocampus and striatum were measured with DTNB method and receptor radioligand binding method. Results Hypoxia increased the activity of AChE in different degrees. After 24 hours of hypoxia, the density of M receptors was increased by 10.4% and 25.3% in the hippocampus and striatum respectively and the affinity of M receptors was increased by 55.6% and 30.3%. Both simple soman intoxication and combined soman intoxication and hypoxia inhibited significantly the activity of AChE in brain tissues. But under hypoxia, the inhibition of soman on AChE in the hippocampus and striatum was attenuated. The damages resulting from hypoxia or combined hypoxia and soman intoxication were most severe in the striatum. Conclusion High altitude soman intoxication and hypoxia both significantly interfere in the functions of the cholinergic nervous system in the brain.