Egashira T, Waddell W J
Histochem J. 1984 Sep;16(9):919-29. doi: 10.1007/BF01003848.
Monoamine oxidase was investigated histochemically in tissues of the mouse by incubating freeze-dried, whole-body sections with tryptamine, serotonin, tyramine, beta-phenylethylamine, or benzylamine as substrate and Nitroblue tetrazolium as the final electron acceptor. The most intense staining with tryptamine was exhibited by intestinal epithelium and adrenal cortex; moderate staining was noted in the epithelium of the nose, bronchi, oesophagus, and upper stomach and in preputial gland, pancreas, nerve, spinal cord and brain. Weak staining was seen in the lung, spleen, liver and kidney. The distribution of the formazan deposition was similar, but much less intense, when serotonin and tyramine were used as the substrates. Only very weak staining was observed when beta-phenylethylamine was the substrate; no staining was seen with benzylamine. Monoamine oxidase activities with tryptamine were greatly inhibited by pretreatment with clorgyline (10 microM), while deprenyl (10 microM) slightly inhibited activities in all tissues except liver. This staining technique should be useful in further studies on the identification of the multiple forms of monoamine oxidase in tissues of the mouse. Nicotine and nitrosonornicotine were not substrates in any of the tissues; consequently, this enzyme system does not appear to produce the proximal carcinogen from this nitrosamine.
通过将冻干的小鼠全身切片与色胺、5-羟色胺、酪胺、β-苯乙胺或苄胺作为底物以及硝基蓝四唑作为最终电子受体一起孵育，对小鼠组织中的单胺氧化酶进行了组织化学研究。色胺染色最强烈的是肠上皮和肾上腺皮质；鼻、支气管、食管和胃上部的上皮以及包皮腺、胰腺、神经、脊髓和脑中可见中度染色。肺、脾、肝和肾中可见弱阳性染色。当使用5-羟色胺和酪胺作为底物时，甲臜沉积的分布相似，但强度要小得多。当以β-苯乙胺为底物时，仅观察到非常微弱的染色；苄胺则无染色。用氯吉兰（10微摩尔）预处理可大大抑制色胺的单胺氧化酶活性，而司来吉兰（10微摩尔）除肝脏外对所有组织的活性均有轻微抑制作用。这种染色技术在进一步研究小鼠组织中单胺氧化酶多种形式的鉴定中应会有用。尼古丁和亚硝基去甲烟碱在任何组织中都不是底物；因此，该酶系统似乎不会从这种亚硝胺产生近端致癌物。
