GASTROPROTECTIVE EFFECT OF MX1 (A NOVEL SALT OF THE ACTIVE METABOLITEOF 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 H-2-blocker roxatidine with a complex of bismuth and citric acid -2-hydroxypropane-1,2,3-tricarboxilate-bism uth(3+) complex), against restraint stress ulcers in rats (24 h immobi lization). The effects of MX1 (12.5, 50, 125, 184 and 250 mg kg(-1)) w ere compared with the effects of equimolar doses of roxatidine (65, 25 , 70, 100 and 140 mg kg(-1)) and bismuth subcitrate (6.5, 25, 70, 100 and 140 mg kg(-1)). The results show that MX1-pre-treatment, at all th e 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% an d the size of the ulcer by 55.9%. Roxatidine (25, 70, 100 and 140 mg k g(-1)) dose-dependently reduces ulcer size and number by 24.6, 55.6, 8 5.3 and 89.0% and by (+7.2), 14.3, 57.1 and 67.9%, respectively. Bismu th subcitrate significantly reduces ulcer size and number only at the highest dose employed (-28.5 and -44.8%, respectively). The morphometr ic results have been confirmed histomorphologically. The results sugge st that MX1 has a gastroprotective effect against stress-induced ulcer s which is similar to that of the parent compound and more pronounced than that of bismuth subcitrate.