[Evaluation of the central anticholinergic activity of antidepressants. Comparison of two experimental methods]

The anticholinergic effect of atropine, imipramine, clomipramine and metapramine was evaluated on oxotremorine induced trembling in the mouse as well as on contractions of the isolated guinea pig ileum induced by electrical stimulation of the mesenteric plexus. The ED 50 and IC 50 which expressed the anticholinergic activity of these substances, were found to be identifically distributed for both methods. Activity, in decreasing order was found to be: atropine much greater than imipramine greater than clomipramine greater than metapramine. There was a good correlation between results from the two methods (r = 0.97). The method using the stimulated guinea pig ileum would therefore seem suitable for characterisation of potential anticholinergic activity of a molecule.