ANTACIDS IN EXPERIMENTAL GASTRIC-ULCER HEALING - PHARMACOKINETICS OF ALUMINUM AND QUALITY OF HEALING

Objective: We studied the adherence of aluminium to ulcerated mucosa a nd the quality of ulcer healing during treatment with aluminium-contai ning topical anti-ulcer drugs. Methods: Aluminium concentrations in ul cerated and non-ulcerated gastric mucosa were assessed in 80 rats with cryo-ulcers treated for 2 days with the antacid hydrotalcite, sucralf ate or placebo. The diameter of ulcers and the mucosal height in ulcer margins and scars were measured histologically in an additional 64 ra ts with cryo-ulcers treated for 8 and 15 days with placebo, antacid, o meprazole or antacid + omeprazole. Results: The aluminium concentratio n-time curve showed a rapid decrease in aluminium in non-ulcerated muc osa and gastric juice in antacid-treated rats. By 1, 4, 8 and 24 h aft er antacid administration, the aluminium concentration was increased i n ulcerated mucosa compared to non-ulcerated mucosa by 1.0-, 3.9-, 5.4 - and 3.3-fold, respectively. By 8 h after sucralfate administration, this ratio was 5.2. Compared to placebo, the height of the mucosal mar gin (day 8) and scar (day 15) was significantly increased in antacid- and significantly decreased in omeprazole- and antacid + omeprazole-tr eated rats. Conclusion: Adherence of aluminium to ulcerated mucosa may contribute to the anti-ulcer activity of antacid and sucralfate. The antacid hydrotalcite provides better restoration of glandular structur e in the ulcer scar than omeprazole; this advantage is lost by cotreat ment with omeprazole.