Differential distribution of type A and B monoamine oxidase in neuronal tissues

Various neuronal tissues of the albino rabbit were assayed for type A and type B monoamine oxidase, using norepinephrine and 2-phenylethylamine as substrates, respectively. There was an apparent positive correlation between the sympathetic character of peripheral nerves and the presence of type A monoamine oxidase activity. Type A enzyme activity was 15 fold higher in the superior cervical ganglion than in the vagus nerve. Type B activity was more uniformly distributed.