STUDIES ON MONOAMINE OXIDASE (REPORT 17) EFFECTS OF NaNO2 ON MAO FROM RAT LIVER MITOCHONDRIA

[摘要] References(11)Cited-By(1)There have been few reports on monoamine oxidase (MAO) [EC 1.4.3.4. monoamine: oxygen oxidoreductase (deaminating)] activators and at present it is only known that reserpine (1-3), in vivo and 4-diazo-imidazole-5-carboxamide (4), in vitro cause increase in MAO activity. A previous report from this laboratory showed that sodium nitrite (NaNO2) activated MAO with certain substrates (5). Namely, using benzylamine, butylamine, amylamine, hexylamine or β-phenylethylamine as substrate, MAO activity in rat liver mitochondria was increased by NaNO2, while when using tyramine or serotonin it was inhibited. In rat brain mitochondria, MAO activity was increased by NaNO2 when tyramine or butylamine were used as substrates, however, it was inhibited when other substrates were used. These results suggested the presence of multiple forms of MAO in mitochondria. This paper describes the effects of NaNO2 on the substrate specificities, pS maxima, pH optima and Michaelis constants of MAO in rat liver mitochondria.

[学科分类] 药理学