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应用免疫组织化学方法研究甲苯四氢吡啶（ＭＰＴＰ）对单胺氧化酶Ｂ的作用。单胺氧化酶Ｂ被认为可使ＭＰＴＰ转化为甲苯吡啶（ＭＰＰ＋ ），而ＭＰＰ＋ 是损毁黑质致密部神经元的细胞毒性物质。在猫腹腔注射ＭＰＴＰ导致选择性的抑制中缝核神经元内的单胺氧化酶Ｂ免疫反应，分布显示中缝吻侧完全被抑制，而尾侧仅存少量免疫染色非常弱的神经元。但是ＭＰＴＰ对下丘脑及各脑区星状胶质细胞内的单胺氧化酶Ｂ无任何作用。这些作用伴随黑质多巴胺能神经元的丢失，但中缝核的细胞数量和形态以及５－羟色胺（５－ＨＴ）免疫组织化学反应与对照组相同。根据上述结果我们认为，ＭＰＴＰ抑制中缝核内单胺氧化酶Ｂ，但不破坏５－ＨＴ能神经元，并且中缝核内单胺氧化酶Ｂ在ＭＰＴＰ导致黑质损伤的过程中不起关键作用。
The effect of MPTP on monoamine oxidase B was studied by immunohistochemistry. Monoamine oxidase B is thought to convert MPTP to toluidine (MPP +), a cytotoxic substance that damages neurons in the substantia nigra compacta. Intraperitoneal injection of MPTP resulted in the selective inhibition of monoamine oxidase B immunoreactivity in the medial raphe nucleus neurons, showing a complete inhibition of the kyphosis in the midrib and only a small number of very weakly immunostained neurons on the caudal side. However, MPTP had no effect on monoamine oxidase B in the hypothalamus and astrocytes in various brain regions. These effects were accompanied by loss of substantia nigra dopaminergic neurons, but the number and morphology of mesencephalic nuclei and serotonin (5-HT) immunohistochemistry were the same as in the control group. Based on the above results, we conclude that MPTP inhibits intranuclear monoamine oxidase B but does not destroy 5-HT neurons and that central mechinanone monoamine oxidase B has no role in the MPTP-induced nigral lesion.