The effects of two new amphetamine-like derivatives on the phagocytic ability of the protozoan, Tetrahymena pyriformis

Six new amphetamine-like molecules (2-[2,3-dihydro-4H-1,4-benzoxazine-4-yl]-1-methyl-2-[1-methyl-2-phenylethyiamino] ethanamines) were synthesised and their physicochemical behaviour was studied. The log P values (index of lipophilicity) of the derivatives were calculated according to Rekker's fragmental system. One derivative representative of each series (C-5508 and C-5512) was selected, and their biological effects on the phagocytic ability of the protozoan, Tetrahymena pyriformis, were studied as a basic functional test for an amphetamine-like action. Furthermore, the action of both derivatives when administered concomitantly with haloperidol was also investigated. The data indicate that both derivatives significantly increased the phagocytic ability of the protozoan (p < 0.001), presumably via an alternative pathway to that of one of the dopamine monoaminergic pools. The administration of haloperidol significantly suppressed phagocytosis (p < 0.001). However, cultures exposed to the derivatives and to haloperidol indicated quantitatively different reactions. The lipophilic behaviours of the derivatives provide a possible explanation for such distinct effects.