An evaluation of the influence of increased gastric acid in the aetiology of reserpine-induced ulcers in rat stomachs

The depletion effects of chlorpromazine, reserpine and ascorbic acid on tissue histamine of guinea-pigs

1. 30 mg kg-1 chlorpromazine (CPZ) depleted more than half of the tissue histamine from lungs, stomach, ileum and skin of the normal guinea-pigs. However, the drug increased the tissue histamine content in scorbutic animals. 2. In contrast, reserpine depleted histamine from the four tested tissues in both normal and scorbutic animals, except those in the lungs of the control animals. 3. Ascorbic acid only depleted histamine from the stomach and ileum. 4. A 24 hr period was the time limit for CPZ to deplete the histamine in all the four tested tissues. 5. Histamine partially or completely recovered in the tissues after the next 24 hr.

The influence of cimetidine, a histamine H2-receptor antagonist, on the gastric effects of reserpine in rats

The effects of graded doses of cimetidine on both resting and reserpine-evoked gastric acid secretion were examined in relation to their influence on reserpine-induced ulceration, mast cell degranulation and mucosal microcirculatory changes in rat stomachs. Cimetidine 10 mg/kg or above reduced resting or reserpine-provoked gastric acid secretion as well as rumenal and glandular ulceration. However, non-acid-inhibiting doses, 5 mg/kg or below, continued to prevent glandular ulceration. Reserpine-evoked gastric glandular mucosal mast cell degranulation was unaffected by both acid-inhibiting and non-acid-inhibiting doses of cimetidine which dose-dependently blocked the superficial glandular mucosal microcirculatory volume changes. These results suggest that cimetidine prevents reserpine-induced glandular ulceration largely by blocking the ulcerogenic effect of histamine H2-receptor-mediated mucosal microcirculatory congestion, in contrast to antagonising rumenal lesions through acid inhibition; they also support the idea tha reserpine may release histamine mainly from the glandular mucosal mast cells. The possibility of another antiulcer mechanism, due to cytoprotection, is discussed.

A comparative study of the gastric ulcerogenic effects of stress and reserpine in rats with decreased stomach wall mast cell populations

Stress-induced gastric glandular ulcers in rats appeared less severe than those evoked by reserpine, although glandular mucosal mast cell counts were equally decreased. Prior depletion of the glandular mucosal mast cell population confirmed the hypothesis that an additional mechanism contributes to reserpine ulceration.