β-Carbolines as selective monoamine oxidase inhibitors:In vivo implications
Journal of Neural Transmission
The inhibitory action of a range of β-carbolines on human and rat monoamine oxidase (MAO) A and B has been studied. Concentrations of 5-hydroxytryptamine and phenylethylamine, approximately at their Km values, were used as substrates for MAO A and B respectively. A wide variation in selectivity was found, with harmaline being 10,000 times more potent an inhibitor of A than B whereas, using tetrahydro-β-carboline and harmane, the difference was nearer to ten-fold. Of the carbolines which have been found endogenously, tetrahydro-β-carboline, 6-methoxytetrahydro-β-carboline and harmane are all sufficiently potent inhibitors of human MAO A, with I50 values of 5×10-6, 10-6, 5×10-7M respectively, for this property to be of possible physiological significance. Harmane, with an I50 of 5×10-6M, might also play a role as an inhibitor of MAO B. © 1982 Springer-Verlag.
Glover, V., Liebowitz, J., Armando, I., & Sandler, M. (1982). β-Carbolines as selective monoamine oxidase inhibitors:In vivo implications. Journal of Neural Transmission, 54 (3-4). http://dx.doi.org/10.1007/BF01254930