Effects of 15(S)-15-Methyl-PGE2 Methyl Ester on Healing of Chronic Gastric and Duodenal Ulcers in Rats

Effects of trimoprostil on healing and recurrence of acetic acid-induced gastric ulcer in rats

Chronic gastric ulcers were produced by injection of 20% acetic acid (0.05 ml) into the submucosal layer of the rat stomach in order to determine the effects of the prostanoid trimoprostil on the healing and recurrence of ulcers. Local injection of acetic acid solution produced large demarcated ulcers in all animals on day 5, which rapidly decreased to reach low levels on days 40-80 and then became exacerbated on day 100. The exacerbation of the ulcer is probably recurrence. Trimoprostil was administered ad libitum in drinking water containing 0.1, 0.3 and 1.0 microgram/ml (average dose 12.4, 37 and 124 micrograms/kg/day) for a period of 14 days (day 1-15) to assess its effect on healing and for a period of 40 days (day 60-100) to assess its ability to prevent recurrence. The higher two doses of trimoprostil accelerated the spontaneous healing of the ulcers. Furthermore, trimoprostil, at both doses, prevented the observed recurrence of this type of ulcer. Trimoprostil dose-dependently (30-300 micrograms/kg, p.o.) inhibited gastric secretion in pylorus-ligated rats. Cimetidine at the antisecretory dose (1 mg/ml, 132 mg/kg/day) failed to affect the healing process of gastric ulcers, but tended to prevent the recurrence of gastric ulcers. Our present study suggests that trimoprostil is a promising antiulcer drug for the treatment of chronic gastric ulcer.

Effects of 15(R)-15-methyl prostaglandin E2 (arbaprostil) on gastric secretion and various gastric lesions induced in rats

We studied the effects of 15(R)-15-methyl prostaglandin E2 (arbaprostil) on gastric secretion and various acute and chronic gastric lesions produced in rats. Arbaprostil significantly inhibited gastric secretion in 4 hr-pylorus-ligated preparations when given intraduodenally in a dose of 30 or 100 micrograms/kg. The agent, however, significantly stimulated gastric secretion of rats with either a ligated or intact pylorus when given orally in doses of 3-100 micrograms/kg. Orally administered arbaprostil dose-dependently prevented the development of HCI-ethanol-, histamine-, water-immersion stress-, or indomethacin-induced gastric erosions. Intraduodenally administered arbaprostil also dose-dependently prevented the development of aspirin-induced gastric erosions in pylorus-ligated rats. Arbaprostil, given orally in doses of 1-100 micrograms/kg twice daily for 2 weeks, had little or no effect on the healing of acetic acid-induced gastric ulcers. However, oral administration of the agent in a dose of 3 or 10 micrograms/kg twice daily for 4 weeks significantly accelerated the healing of acetic acid-induced gastric ulcers. The increase in doses up to 100 micrograms/kg twice daily for 4 weeks had no effect on ulcer healing. These results indicate that arbaprostil, at either antisecretory or even acid stimulating doses, is effective in preventing the development of acute gastric erosions and in accelerating the healing of chronic gastric ulcers.