[Comparative effect of psychotropic agents on orienting-motor responses and cerebral Na,K-ATPase activity in vivo]. / Sravnitel'noe deistvie psikhotropnykh sredstv na orientirovochno-dvigatel'nye reaktsii i aktivnost' Na, K-ATF-azy mozga in vivo.

Levomepromazine, chlorpromazine (10 and 30 mg/kg), etaperaxine, haloperidol (3 and 10 mg/kg) inhibited the exploratory-motor reactions of rats and the brain Na, K-ATPase activity an hour after their administration. The effects of tranquilizers as well as of antidepressants on the exploratory reactions and on the enzyme activity were not found to stand in a clearcut relation to each other. The stimulating effect of amphethamine (3 mg/kg) was accompanied by activation and suppressive action (10 mg/kg)--by inhibition of the enzyme. It is suggested that the inhibition of the brain Na, K-ATPase activity by psychotropic drugs may play a role in the mechanism of their sedative action.

[Comparative study of the effect of some psychotropic substancces on the activity of brain Na+, K+-ATPase in vitro]. / Sravnitel'noe izuchenie vliianiia nekotorykh psikhotropnykh veshchestv na aktivnost' Na+, K+-ATF-azy mozga in vitro

The activity of Na+, K+-ATPase from bovine brain in vitro was studied as affected by some neuroleptics (levomepromazine, chlorpromazine, perphenazine and haloperidol), antidepressants (imipramine and iproniazid) and psychostimulants (amphetamine) as well as by benactyzine and procaine. The degree of the enzyme inhibition by these drugs estimated by means of I 50 and apparent inhibitor constants (Ki) or rate constants (k) was different. Sensitivity of the brain Na+, K+-ATPase to the drugs decreased in the following order: levomepromazine, chlorpromazine, perphenazine, haloperidol, imipramine, iproniazid, benactyzine, procaine and amphetamine. Competition for the enzyme was revealed between sodium and some of the drugs investigated (levomepromazine, chlorpromazine, perphenazine and impramine) as well as between potassium and other drugs (haloperidol, genactyzine and amphetamine). It is suggested that the inhibition of the brain Na+, K+-ATPase by psychotropic drugs may be a part in the biochemical mechanism of their sedative-tranquilizing activity.