Gastroprotective Effect of MX1 (a Novel Salt of the Active Metabolite of Roxatidine with a Complex of Bismuth and Citric Acid) Against Stress Ulcers in Rats

We have studied the effect of the newly synthesized agent MX1, a salt of the active metabolite of the H2‐blocker roxatidine with a complex of bismuth and citric acid (N‐[3‐(3‐(1‐piperidinylmethyl)phenoxy)propyl]‐hydroxyacetamide‐2‐hydroxypropane‐1,2,3‐tricarboxilate‐bismuth(3+) complex), against restraint stress ulcers in rats (24 h immobilization). The effects of MX1 (12.5, 50, 125, 184 and 250 mg kg−) were compared with the effects of equimolar doses of roxatidine (6.5, 25, 70, 100 and 140 mg kg−) and bismuth subcitrate (6.5, 25, 70, 100 and 140 mg kg−). The results show that MX1‐pre‐treatment, at all the doses used, significantly reduces the mean number and size of ulcers. Even at the lowest dose the number of ulcers was reduced by 64.3% and the size of the ulcer by 55.9%. Roxatidine (25, 70, 100 and 140 mg kg−) dose‐dependently reduces ulcer size and number by 24.6, 55.6, 85.3 and 890% and by (+ 7.2), 14.3, 571 and 67.9%, respectively. Bismuth subcitrate significantly reduces ulcer size and number only at the highest dose employed (−28.5 and −44.8%, respectively). The morphometric results have been confirmed histomorphologically. The results suggest that MX1 has a gastroprotective effect against stress‐induced ulcers which is similar to that of the parent compound and more pronounced than that of bismuth subcitrate.