nocloprost and Stomach-Ulcer

The gastroprotective and ulcer-healing properties of prostaglandins, especially in gastric ulcers induced by non-steroidal anti-inflammatory drugs, are well established. Ulcer healing is an active process of filling the mucosal defect with migrating and proliferating epithelial cells combined with angiogenesis in granulation tissue at the ulcer bed. Growth factors, especially epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) are crucial in the regulation of the reconstruction of damaged mucosal structures.. In this double-blind, randomized, prospective study 40 patients with gastric ulcer were treated with nocloprost, a stable prostaglandin E2 derivative, or with ranitidine. All subjects underwent endoscopy before and after 4 and 8 weeks of anti-ulcer therapy. During endoscopy mucosal biopsies were performed for determination of EGF content in gastric mucosa at the ulcer margin and in the intact mucosa. Additionally, EGF output in saliva and its plasma concentrations were determined in all subjects before and during the treatment.. The gastric ulcer healing rate after 4 weeks was significantly higher in patients treated with nocloprost than in those treated with ranitidine (63% versus 39%, respectively). At initial examination the EGF content in the gastric mucosa obtained from the ulcer edge was significantly higher than that in the intact mucosa. There was a significant increase in the EGF content in both the ulcer margin and the intact mucosa in subjects treated with nocloprost but not in patients under treatment with ranitidine. Similarly, patients treated with nocloprost had significantly higher EGF output in saliva and higher EGF concentration in plasma throughout the anti-ulcer therapy.. Nocloprost is superior to ranitidine in the treatment of chronic gastric ulcers, and these effects could be due, at least in part, to higher expression and mucosal content of EGF in the ulcer area.

Topics: Adult; Anti-Ulcer Agents; Double-Blind Method; Drug Administration Schedule; Epidermal Growth Factor; Female; Gastric Mucosa; Humans; Male; Middle Aged; Prospective Studies; Prostaglandins F, Synthetic; Ranitidine; Stomach Ulcer; Time Factors; Wound Healing

The 24 patients with gastric ulcer were treated ranitidine (2 x 150 mg daily) or nocloprost (2 x 200 micrograms daily). The effects of these drugs on the gastric juice components were measured. We evaluated hydrochloric acid, total protein, pepsin and some carbohydrates components secretion. We showed, that ranitidine decreased significantly total protein, fucose, N-acetylneuraminic acid and hexoses contents in the gastric juice in the basal secretion; the same tendency was observed in the pentagastrin-stimulated secretion. The similar direction of the changes, but weakly expressed was confirmed in the patients treated with nocloprost. It has been shown, that ranitidine modified the gastric mucin components content, what can suggest diminished degradation of mucus directly adhering to the gastric mucosa.

Topics: Anti-Ulcer Agents; Female; Fucose; Gastric Acid; Gastric Juice; Gastric Mucins; Gastric Mucosa; Gastrointestinal Agents; Hexoses; Histamine H2 Antagonists; Humans; Male; N-Acetylneuraminic Acid; Pentagastrin; Pepsin A; Prostaglandins F, Synthetic; Proteins; Ranitidine; Stomach Ulcer

Sucralfate is known to protect gastric mucosa against the damaging action of strong irritants and to accelerate healing of chronic ulcers, but the mechanisms underlying these effects have not been elucidated. Similar gastroprotective and healing effects can be obtained with exogenous donors of nitric oxide (NO) and prostaglandins (PG).. The area of gastric lesions was measured by planimetry. Gastric blood flow was determined using laser Doppler flowmetry. The role of NO in the prevention of ethanol-induced gastric damage and in the healing of gastric ulcerations by sucralfate and nocloprost, a stable PGE2 analog, was therefore assessed.. Pretreatment with NG-nitro-L-arginine (L-NNA), an inhibitor of NO synthase, enhanced ethanol-induced mucosal damage and reduced dose-dependently the gastroprotective and hyperemic effects of sucralfate. The doses of L-NNA attenuating significantly the protective effects of sucralfate were 25-50 mg/kg. The effects of L-NNA were reversed by the addition of L-arginine but not D-arginine. For comparison, the gastroprotective (but not hyperemic) effects of nocloprost were not affected by the pretreatment with L-NNA and/or arginine. Daily treatment with L-NNA (50 mg/kg per day) prolonged the healing of chronic gastric ulcers and significantly reduced the acceleration of healing by sucralfate.. We conclude that (i) the gastroprotective and hyperemic effects of sucralfate involve, at least in part, the NO-arginine pathway, (ii) the ulcer healing effects of sucralfate may also involve NO, probably through the hyperemia around the ulcer, and (iii) NO is not essential for the mucosal protection of PGE2 analog, but may account for the gastric vasodilatory effect of this PG.

Topics: Animals; Anti-Ulcer Agents; Arginine; Dose-Response Relationship, Drug; Ethanol; Gastric Mucosa; Laser-Doppler Flowmetry; Male; Nitric Oxide; Nitroarginine; Prostaglandins F, Synthetic; Rats; Rats, Wistar; Stomach Ulcer; Sucralfate; Vasodilator Agents

We investigated the role of nitric oxide (NO) and prostaglandins (PG) in the prevention by sucralfate of ethanol-induced gastric damage and the decrease of gastric blood flow and compared them with those obtained with nocloprost, a potent locally acting gastroprotective agent. Sucralfate and nocloprost given intragastrically (i.g.) protected dose dependently the gastric mucosa against the damage by absolute ethanol and prevented the decrease in blood flow induced by ethanol. Pretreatment with NG-nitro-L-arginine (L-NNA), an inhibitor of NO synthase decreased dose dependently the protection and the maintenance of blood flow provided by sucralfate but not by nocloprost. This decrease of sucralfate protection was antagonized by L-arginine but not D-arginine. Pretreatment with indomethacin also reversed, in part, the protective and hyperemic effects of sucralfate but the combination of both indomethacin and L-NNA completely abolished these effects. We conclude that sucralfate activates both the NO and PG systems that cooperate in the gastroprotective action of this drug and that NO is not involved in the protection induced by a PGE2 analog.

Topics: Animals; Anti-Ulcer Agents; Arginine; Ethanol; Indomethacin; Male; Nitric Oxide; Nitroarginine; Prostaglandins; Prostaglandins F, Synthetic; Rats; Rats, Inbred Strains; Regional Blood Flow; Stomach; Stomach Ulcer; Sucralfate

Topics: Animals; Anti-Ulcer Agents; Aspirin; Female; Gastric Mucosa; Male; Prostaglandins F, Synthetic; Rats; Rats, Inbred Strains; Stomach Ulcer; Stress, Physiological; Taurocholic Acid

Nocloprost (9 beta-chloro-16,16-dimethyl prostaglandin E2 (PGE2)) was examined for gastroprotective and ulcer-healing activity and compared to 16,16-dimethyl PGE2 (dmPGE) in rats. Nocloprost given intragastrically (i.g.) at various doses (0.01-10 micrograms/kg) 30 min before 100% ethanol, acidified aspirin (ASA), acidified taurocholate, water immersion, or restraint stress dose dependently prevented the formation of gastric lesions, the ID50 values being 0.25, 0.58, 0.06 and 0.12 micrograms/kg, respectively. The gastroprotection provided by nocloprost given i.g. was somewhat enhanced by the presence of acid in the stomach and was reduced by inhibition of gastric acid secretion. Nocloprost given s.c. also showed protective activity against ethanol damage but was ineffective when applied intraduodenally. The protective effect of nocloprost lasted about 8 h whereas that induced by dmPGE lasted 6 h. Nocloprost (0.01-100 micrograms/kg) given i.g. failed to affect gastric acid secretion or intestinal secretion (enteropooling) but prevented the increased gastroduodenal alkaline secretion. Nocloprost alone caused only a transient increase in the mucosal blood flow but prevented the fall in blood flow caused by 100% ethanol. [3H]Nocloprost was absorbed from the small intestine but was then taken up and metabolized by the liver and excreted into the bile so that very little reached the systemic circulation in an unchanged form. Nocloprost, unlike dmPGE, accelerated the healing of chronic gastric ulcerations and enhanced mucosal growth. We conclude that nocloprost is a locally active PGE2 analog with high cytoprotective and ulcer-healing efficacy.

Topics: Animals; Anti-Ulcer Agents; Duodenum; Female; Gastric Acid; Gastric Juice; Gastric Mucosa; Intestinal Absorption; Intestinal Mucosa; Male; Pepsin A; Prostaglandins F, Synthetic; Rats; Rats, Inbred Strains; Regional Blood Flow; Stomach Ulcer; Vasodilator Agents