M-signal hypothesis--metabolic modulation of membrane functions in rat brain

1. Monoamine oxidase (amine: oxygen oxidoreductase [deaminating], EC 1.4.3.4) (MAO) and Na+/K+ ATPase (Na+/K+-ATPase, Mg2+-dependent ATP phosphohydrolase, EC 3,1,6,3) showed reciprocal relationship in their activity patterns during experimentally perturbed situations in vivo as well as in vitro. 2. M-signal hypothesis is proposed, which attempts at explaining the regulation of plasma membrane function by the intermediate of metabolic processes in the cell. This metabolic intermediate referred to as M-signal exercise its influence on the plasma membrane Na+/K+ ATPase which is responsible for the uptake process.