Analysis of the mechanism of the protective activity of some sympathomimetic amines in experimental ulcers.

Apomorphine administered in reserpine-induced as well as in restraint ulcers in rats, failed to afford protection. Pimozide, moperone, trifluperidol and chlorpromazine fail to influence the development of the experimental ulcers. Pimozide and moperone although antagonizing the behavioral changes of amphetamine, maintained its antiulcer activity. Amitryptiline, cocaine and morphine had a protective activity. L-Dopa afforded a significant protection which was abolished if this compound was administered together with FLA-63, a specific dopamine-beta-hydroxilase inhibitor. These results were explained by admitting that not dopamine, but noradrenaline was responsible for the antiulcer activity. alpha-Methyl-dopa produced a significant protection in both experimental models.