[Pharmacologic activity of pyrimidoindole derivatives].

The spectrum of the psychotropic activity of a number of new pyrimidoindole derivatives and the relation between their chemical structure and activity were studied experimentally. The research was done on mice by employing tests usually applied in estimating neuroleptics and antidepressants of tricyclic structure. The study of indole derivatives are shown to display a sedative action. 5-methyl derivatives of pyrimido- and tetrahydropyrimido [3,4-a] indole without any substituent in the 2nd position are 5-oxytryptophan antagonists. The 2,5-dimethyltetrahydropyrimido [3,4-a] indole derivatives electively potentiate the central effect of 5-oxytryptophan and display in experiments a specific spectrum of the pharmacological action, resembling antidepressants by a number of tests. As concerns their activity these compounds, however, are inferior to amitriptyline and pyrasidol.