Demisch L, Demisch K, Seiler N
Metabolism. 1979 Feb;28(2):144-50. doi: 10.1016/0026-0495(79)90079-9.
The specific activity of human platelet monoamine oxidase from control subjects undergoing glucose tolerance tests is reduced drastically. Three hours after intake of 100 g of glucose only 25%-30% of the MAO-baseline activity was measured with tryptamine. beta-phenylethylamine and p-tyramine as substrates. At about 5 hr, platelet MAO activity has increased again. Inhibition was not due to small molecular weight inhibitors or other diffusible factors. Studies of other platelet enzymes, including succinate dehydrogenase and isocitrate dehydrogenase (NADP+ dependent) showed no parallel reductions; hGH, insulin, blood glucose and platelet glycogen concentrations did not correlate with platelet MAO activity. The changes of MAO activity in respect with p-tyramine and tryptamine as substrates 24 hr after glucose ingestion suggest changes of the lipid microenvironment of this enzyme of the outer mitochondrial membrane.
在进行葡萄糖耐量试验的对照受试者中，人血小板单胺氧化酶的比活性急剧降低。摄入100克葡萄糖三小时后，以色胺、β-苯乙胺和对酪胺为底物测量时，MAO的基线活性仅为25%-30%。在大约5小时时，血小板MAO活性再次升高。抑制作用并非由于小分子抑制剂或其他可扩散因子。对其他血小板酶的研究，包括琥珀酸脱氢酶和异柠檬酸脱氢酶（依赖NADP+），未显示出平行降低；hGH、胰岛素、血糖和血小板糖原浓度与血小板MAO活性无关。葡萄糖摄入24小时后，以对酪胺和色胺为底物时MAO活性的变化表明线粒体外膜该酶的脂质微环境发生了变化。
