Dopamine disorder in duodenal ulceration.

Cysteamine-induced duodenal ulcers in rats were prevented by the dopamine agonists bromocriptine, lergotrile, and apomorphine, whereas both the severity of duodenal ulcers and the mortality among cysteamine-treated rats were raised by the dopamine receptor antagonist, haloperiodol. Bromocriptine and lergotrile greatly reduced gastric-acid output in cysteamine-treated rats. A review of the literature shows a high incidence of duodenal ulcers in patients with Parkinson's disease (associated with dopamine deficiency) and a low occurrence in schizophrenics (associated with dopamine excess and/or hyperactivity). Thus, changes in peripheral and/or central dopamine concentrations and/or receptor activity may have a role in the pathogenesis of duodenal ulceration.