gefarnate and geranylgeranylacetone

We have reported that teprenone (geranylgeranylacetone), an anti-ulcer drug, prevents acute gastric mucosal lesion progression in rats treated once with compound 48/80 (C48/80), a mast cell degranulator, possibly by suppressing mucus depletion, neutrophil infiltration, and oxidative stress in the gastric mucosa. Herein, we examined the preventive effect of gefarnate (geranyl farnesylacetate), an anti-ulcer drug, on acute gastric mucosal lesion progression in rats treated once with C48/80 (0.75 mg/kg, i.p.) in comparison with that of teprenone, because the chemical structure and anti-ulcer action of gefarnate are similar to those of teprenone. Gefarnate (50, 100 or 200 mg/kg) administered orally at 0.5 h after C48/80 treatment, at which time gastric mucosal lesions appeared, reduced progressive gastric mucosal lesions at 3 h dose-dependently. At 3 h after C48/80 treatment, the gastric mucosa had decreased adherent mucus and hexosamine contents and increased myeloperoxdiase (an index of neutrophil infiltration) and xanthine oxidase activities and thiobarbituric acid reactive substances (an index of lipid peroxidation) content. Post-administered gefarnate attenuated all these changes dose-dependently. These preventive effects of gefarnate were similar to those of teprenone at a dose of 200 mg/kg. Post-administered gefarnate did not affect the increases in serum serotonin and histamine concentrations and the decrease in gastric mucosal blood flow at 3 h after C48/80 treatment like teprenone. These results indicate that orally administered gefarnate prevents acute gastric mucosal lesion progression in C48/80-treated rats possibly by suppressing mucus depletion, neutrophil infiltration, and oxidative stress in the gastric mucosa like teprenone.

Topics: Animals; Anti-Ulcer Agents; Cell Degranulation; Diterpenes; Gastric Mucosa; Gefarnate; Hexosamines; Histamine; Male; Mast Cells; p-Methoxy-N-methylphenethylamine; Peroxidase; Rats; Rats, Wistar; Regional Blood Flow; Serotonin; Thiobarbituric Acid Reactive Substances; Xanthine Oxidase

To evaluate the effects of teprenone on acute gastritis, its inhibitory effects on gastric mucosal damage were compared to that of gefarnate in taurocholate/hydrochloric acid-induced acute gastric mucosal lesions in rats. After oral administration of 160 mM taurocholic acid and 250 mM hydrochloric acid, hemorrhage and erosion were macroscopically observed in the gastric mucosal surface layer. Edema in the submucosal tissue and decreased PAS staining in the mucosa were histomorphologically observed. Concerning macroscopic findings, pretreatment with teprenone at a dose of 50 mg/kg or more significantly reduced pathological changes in the mucosa of the fundic glandular area. However, gefarnate slightly inhibited these changes in at a dose of 50 mg/kg and significantly inhibited them at a dose of 200 mg/kg. With regards to histomorphological findings in the fundic glandular area, teprenone slightly inhibited erosion at a dose of 50 mg/kg, and it significantly and slightly inhibited the decrease in PAS staining in this area at doses of 50 and 200 mg/kg, respectively. Gefarnate at doses of 50 and 200 mg/kg showed significant inhibition of decreased PAS staining in the fundic glandular area. In the pyloric mucosa, decreased PAS staining was slightly inhibited by teprenone at both doses but not by gefarnate at either dose. The differences between teprenone and gefarnate observed in this model appear to be due to their differences in mucus production ability. These results suggest that teprenone was more effective than gefarnate for the treatment of gastritis.

Topics: Acute Disease; Animals; Anti-Ulcer Agents; Disease Models, Animal; Diterpenes; Dose-Response Relationship, Drug; Gastric Mucosa; Gastritis; Gefarnate; Hydrochloric Acid; Male; Mucus; Rats; Rats, Wistar; Taurocholic Acid

Topics: Anti-Ulcer Agents; Cyclohexanecarboxylic Acids; Diterpenes; Gefarnate; Humans; Peptic Ulcer; Recurrence; Sucralfate; Tranexamic Acid

The effects of geranylgeranylacetone (GGA), a new acyclic polyisoprenoid with a novel antiulcer action on gastrointestinal secretion were studied in rats. Intraduodenal administration of GGA (1-30 mg/kg) dose-relatedly reduced the gastric acid secretion caused by pentagastrin, histamine or insulin. On the other hand, GGA (3-30 mg/kg i.d.) dose-relatedly increased pancreatic secretion but did not affect biliary secretion. The above-mentioned findings seem consistent with the further findings that GGA depressed a plasma gastrin level enhanced by insulin while in increased the basal level of plasma secretin. These pharmacological features found in the present studies may partially, at least, account for the mechanism of GGA antiulcer action.

Topics: Animals; Bile; Cimetidine; Digestive System; Diterpenes; Drug Interactions; Gastric Acid; Gastrins; Gefarnate; Male; Pancreatin; Rats; Rats, Inbred Strains; Secretin

Antiulcer effects of geranylgeranylacetone (GGA) on aspirin-induced gastric ulcers in rats were studied, comparing them with those of gefarnate. The oral administration of GGA prevented the development of gastric ulcer induced by a single or repeated oral administration (5 consecutive days) of aspirin. The effects of GGA were more potent and more definite than those of gefarnate. The intraduodenal administration of GGA, but not the intragastric administration, also inhibited the ulceration induced by aspirin in pylorus-ligated rats, while the intraduodenal administration of gefarnate did not. GGA prevented the reduction of the H+ concentration and the increment of Na+ concentration in the gastric juice induced by aspirin. In addition, the decrease of hexosamine content in the gastric mucosa induced by aspirin was restored to a normal level by GGA, but not by gefarnate. From these results, it was concluded that the protective actions of GGA on aspirin-induced gastric ulcers might be due to its protection from the weakening of gastric mucosal resistances.

Topics: Animals; Aspirin; Diterpenes; Gastric Mucosa; Gefarnate; Hexosamines; Male; Rats; Rats, Inbred Strains; Stomach Ulcer