Elimination of F'lac plasmid by different psychotropic drugs and some related compounds

Desipramine, trimipramine, protriptyline, noxiptyline, promazine, trimeprazine, triflupromazine and chlorprothixene methoiodide eliminated the F'lac plasmid of Escherichia coli, while thiazinanum, toluidine blue, lidocaine and procaine were ineffective in this respect. The plasmid eliminating action of the drug ceased in the presence of 0.05 M magnesium sulphate. Methylene blue did not inhibit plasmid elimination by the psychotropic drugs, and in presence of the dye even lidocaine and procaine became effective. Based on plasmid elimination in the presence of methylene blue and on the selective effects of the lon- mutant, the plasmid eliminating mechanism of psychotropic drugs seems to differ from that of acridine orange.