Cimoxatone is a reversible tight-binding inhibitor of the A form of rat brain monoamine oxidase.

Cimoxatone is a fully reversible inhibitor selective for the A form of monoamine oxidase. The inhibition is so potent against this enzyme form that it acts as a tight-binding inhibitor. Use of this inhibitor indicates that in rat brain homogenates the concentration of monoamine oxidase A is approximately 8-11 pmol . mg protein-1. Values similar to this were obtained by clorgyline titration, and both methods gave values similar to those found with a [3H]harmaline binding assay.