riopan and Stomach-Ulcer

Topics: Aluminum Hydroxide; Antacids; Delayed-Action Preparations; Gastric Acidity Determination; Gastric Mucosa; Humans; Magnesium Hydroxide; Stomach Ulcer; Structure-Activity Relationship

Topics: Adult; Aged; Aged, 80 and over; Aluminum Hydroxide; Antacids; Clinical Trials as Topic; Double-Blind Method; Female; Humans; Magnesium; Magnesium Hydroxide; Male; Middle Aged; Random Allocation; Ranitidine; Stomach Ulcer; Wound Healing

Topics: Aluminum Hydroxide; Antacids; Clinical Trials as Topic; Double-Blind Method; Humans; Magnesium; Magnesium Hydroxide; Random Allocation; Ranitidine; Stomach Ulcer; Wound Healing

The present study was undertaken to investigate the mechanism of cytoprotective effects of magaldrate in aspirin plus pylorus-ligation model and ethanol-induced gastric ulcer model in rats. Magaldrate (60 mg/kg, p.o.) produced a significant reduction in the ulcer index and significant increase in mucus content in ethanol-induced gastric ulceration in rats. In aspirin plus pylorus-ligation model magaldrate produced significant decrease in ulcer index, total acidity and protein content (PR). It did not produce any significant change in volume of gastric secretion. However, it produced significant increase in total carbohydrate (TC) level but not in ratio between TC and proteins. It also produced a significant decrease in lipid peroxidation (as expressed by thiobarbituric acid reactive substance). Our data suggests the cytoprotective action of magaldrate on gastric mucosal cells which may be due to protection of gastric mucosa from lipid peroxidation.

Topics: Aluminum Hydroxide; Animals; Antacids; Anti-Ulcer Agents; Ethanol; Female; Gastric Mucosa; Lipid Peroxidation; Magnesium Hydroxide; Male; Rats; Stomach Ulcer

Topics: Aluminum Hydroxide; Antacids; Delayed-Action Preparations; Gastric Acidity Determination; Gastric Mucins; Gastric Mucosa; Humans; Magnesium Hydroxide; Stomach Ulcer

The antacid ES Riopan was acidified ex vivo to pH 2.5 to completely eliminate its buffering capacity and was then tested as a mucosal protective agent. The pH 2.5 acidified antacid solution was named activated aluminum complex. Activated aluminum complex was 8.2 times more potent than its parent antacid in protecting against acidified aspirin-induced gastric lesions in the rat. Activated aluminum complex had a duration of action greater than 10 h in the ethanol-induced gastric lesion model, while ES Riopan was active for 6 h. Activated aluminum complex was able to inhibit both acid- and nonacid-mediated ulcers in the stomach and intestine. Its mucosal protective activity was not blocked by pretreatment with indomethacin. These results demonstrate that the nonbuffering antacid activated aluminum complex exerted a more potent and longer-lasting mucosal protective activity than its parent antacid. The activity was probably due to the presence of a hexaaquoaluminum cation and supports the argument that antacids possess mucosal protective effects independent of their acid-neutralizing capacity.

Topics: Aluminum Hydroxide; Animals; Antacids; Aspirin; Cysteamine; Duodenal Ulcer; Ethanol; Gastric Mucosa; Hydrogen-Ion Concentration; Indomethacin; Intestinal Mucosa; Ligation; Magnesium Hydroxide; Male; Rats; Rats, Inbred Strains; Stomach Ulcer

The cytoprotective and antiulcer activities of the antacid magaldrate (ES Riopan) as well as its effects on gastric mucosal blood flow and mucus secretions, were determined in the rat. Magaldrate afforded protection against gastric necrotic lesions induced by absolute ethanol (ED50, as magaldrate, 419 mg/kg); gastric ulcers induced by acidified acetylsalicylic acid (ED50 540 mg/kg), stress (cold restraint, ED50 388 mg/kg), indometacin (ED50 281 mg/kg), and pylorus ligation; and intestinal ulcers induced by cysteamine (ED50 243 mg/kg) and indometacin (ED50 184 mg/kg). At a dose of 8 ml/kg (1728 mg/kg magaldrate), the cytoprotective effect of magaldrate against ethanol was evident 1 min after oral administration and lasted more than 8 h. The cytoprotection induced by magaldrate was decreased by pretreatments with the depletor of endogenous thiols, n-ethylmaleimide, or with the cyclooxygenase inhibitor, indometacin. Magaldrate did not affect gastric mucosal blood flow, but it increased gastric mucus secretion. This later effect may be a factor responsible for the cytoprotective activity of the agent. The efficacy of magaldrate may be due not only to its antacid, bile sequestering, and antipeptic activities, but also to its cytoprotective activity. The present results suggest that magaldrate could be effective in preventing gastric damage caused by alcohol and antiinflammatory drugs.

Topics: Aluminum Hydroxide; Animals; Antacids; Anti-Ulcer Agents; Aspirin; Cell Survival; Cysteamine; Dinoprostone; Ethanol; Gastric Juice; Indomethacin; Magnesium; Magnesium Hydroxide; Male; Rats; Rats, Inbred Strains; Serotonin; Stomach Ulcer; Sucralfate

Topics: Aluminum; Aluminum Hydroxide; Antacids; Anti-Ulcer Agents; Gastric Acidity Determination; Gastritis; Humans; Magnesium; Magnesium Hydroxide; Stomach Ulcer