嗅球部多巴胺能神经元在帕金森病并发嗅觉障碍中的作用

摘要

目的:探讨嗅球部多巴胺(DA)能神经元在帕金森病并发嗅觉障碍中的作用.方法:雄性3月龄C57BL/6小鼠,腹腔注射1-甲基-4-苯基-1,2,3,6-四氢吡啶(1-methyl-4-phenyl-1,2,3,6-tetrapyridine,MPTP)25 mg/kg,每周2次,共持续5周.再以嗅觉障碍行为学方法检测,从上述小鼠中选出帕金森病并发嗅觉障碍小鼠作为实验组,将帕金森病未并发嗅觉障碍小鼠作为实验对照组,另以一组小鼠腹腔注射生理盐水作为生理盐水组.通过免疫组化免疫荧光染色法检测3组小鼠嗅球部DA能神经细胞数量,Western blot实验检测3组小鼠嗅球部酪氨酸羟化酶(TH)蛋白含量.结果:实验组小鼠较实验对照组小鼠嗅球部DA能神经元数量及嗅球部TH蛋白显著减少(P＜0.05),实验对照组小鼠嗅球部DA能神经元数量及嗅球部TH蛋白较生理盐水组也显著减少(P＜0.05),3组间嗅球部DA能神经元数量及TH蛋白差异有统计学意义(P＜0.05).结论:帕金森病并发嗅觉障碍与嗅球部DA能神经元残存的数量有关.%Objective To investigate the role of olfactory bulb dopamine (DA) neurons in olfactory dysfunction in Parkinson's disease.Methods C57BL/6 mice were treated with 1-methyl-4-phenyl-1,2,3,6-tetrapyridine (MPTP) of 25 mg/kg twice a week for 5 weeks; and were assigned to a group of olfactory dysfunction complicated by Parkinson's disease and a control group based on the result of buried food pellet test.Another group received injections of normal sodium as NS group.The number of tyrosine hydroxylase (TH)-positive cells in olfactory bulb was determined by immunohistochemistry and TH proteins were detected by Western blot.Results As compared with the control group,the number of TH-positive cells and TH proteins in olfactory bulb in the group of olfactory dysfunction in Parkinson's disease were decreased with a significant difference (P ＜ 0.05); and as compared with NS group,the number of TH-positive cells and TH proteins in olfactory bulb were also decreased in control group with a significant difference (P ＜ 0.05).Conclusions Olfactory dysfunction in Parkinson's disease may be related to a decrease in the number of olfactory bulb DA neurons.