Sympathomimetic effects of exo- and endo-isomers of 2-aminobenzonorbornene in vitro and in vivo

Article abstract of DOI:10.1111/j.2042-7158.1980.tb12858.x

A stereospecific synthesis of endo-2-aminobenzonorbornene is described. Its sympathomimetic activities and those of its N-methyl derivative were compared with the equivalent exo-isomers using the isolated rat anococcygeus muscle and the anaesthetized rat blood pressure preparations. On the anococcygeus muscle preparation, the endo- and exo-isomers of the primary amines had similar indirectly acting sympathomimetic activities. In contrast, the exo-N-methyl derivative was a far more potent sympathometic in vitro than the endo-N-methyl isomer. In the anaesthetized rat, the exo- and endo-isomers of 2-aminobenzonorbornene and their N-methyl derivatives all had similar pressor activities, though the successive injections of the two exo-derivatives suggested an additional α-adrenoceptor blocking activity. The actions of these rigid sympathomimetics are compared with those of the flexible amphetamine structure.