[Kinetic studies of melipramine inhibition of Na+, K+-ATPase activity in the synaptosomal fraction of the brain].

The effect of antidepressant melipramine (imipramine) on the Na+, K+-ATPase activity was studied in the brain synaptosomes as dependent on the sodium and potassium ions concentration and pH of the incubation medium. Melipramine in concentrations of 0.05-1.0 mM is shown to inhibit the Na+, K+-ATPase activity. Under pH 7.4 monovalent cations prevent the inhibitory action of melipramine, changing the kinetic of the interaction between melipramine and the enzyme preparation. When changing pH from 7.4 to 8.2 the preventional action of the ions decreases, and the inhibitory action of melipramine on the Na+, K+-ATPase activity increases. Possible mechanisms of the melipramine interaction with Na+, K+-ATPase system are discussed.