Antiulcer effects of nomifensine, a new antidepressant, on stress-induced ulcers in the rat.

The effectiveness of the antidepressant agents 8-amino-1,2,3,4-tetrahydro-2-methyl-4-phenyl-isoquinoline (nomifensine, Alival) and amitriptyline on various ulcer models was tested by using at least 300 rats. Oral application of 3 mg/kg nomifensine resulted in a 50% decrease of stress ulcers produced by water immersion. Using an immobilisation ulcer model the ID50 of nomifensine was calculated to be 1.89 mg/kg p.o. Amitriptyline proved to be less active in both models. Neither er of the two compounds had any beneficial effects on ulcers produced by pyloric ligation. Gastric acid secretion stimulated with either histamine or pentagastrin, was not affected by nomifensine. Thus peripheral gastric effects of nomifensine could be ruled out, its antiulcer properties may be of central nervous origin. Affecting noradrenergic mechanisms in the hypothalamus could possibly play an important role.