title: Role of prostaglandins in the early phases of experimental gastric carcinogenesis in the rat.
abstract: The study was initiated to evaluate the effect of N-methyl-N-nitro-N-nitrosoguanidine (NG) on gastric intraluminal prostaglandin release during a 30-day treatment period and to investigate the effect of a stable prostaglandin E1 analogue (misoprostol) on NG-induced gastric mucosal damage during the same time period. Samples of gastric juice (1 h) were obtained from 40 male Sprague-Dawley rats with chronic gastric fistulas, in basal conditions and after 5, 15 and 30 days of continuous oral administration of NG (120 mg/l) or tap water. Aliquots of gastric juice were titrated with 0.1 M NaOH. Other aliquots were extracted with ethyl acetate and subjected to specific radioimmunoassay for prostaglandin E2. The severity of gastric mucosal lesions was evaluated in 60 rats after 5 days and 30 days of continuous oral administration of NG (120 mg/l) or NG plus misoprostol (200 micrograms/kg-1/day-1) or tap water, and a histological study was carried out. Administration of NG induced a significant decrease of gastric intraluminal prostaglandin E2 concentration at 15 and 30 days. Oral administration of misoprostol, at non-antisecretory doses, protected the rats against NG-induced gastric mucosal damage. Prostaglandins may be involved in the early phases of experimental gastric carcinogenesis.
authors.affiliation: II Clinica Chirurgica University La Sapienza, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Materia
authors.forename: G
authors.initials: G
authors.lastname: Silecchia
authors.forename: E
authors.initials: E
authors.lastname: Spaziani
authors.forename: P
authors.initials: P
authors.lastname: Mariani
authors.forename: L
authors.initials: L
authors.lastname: Scucchi
authors.forename: P
authors.initials: P
authors.lastname: Mingazzini
authors.forename: C
authors.initials: C
authors.lastname: Favalli
authors.forename: E
authors.initials: E
authors.lastname: Garaci
authors.forename: N
authors.initials: N
authors.lastname: Basso
mesh_terms: D000818:Animals; D005753:Gastric Mucosa / Q000378:metabolism / Q000473:pathology; D008297:Male; D008769:Methylnitronitrosoguanidine; D011453:Prostaglandins / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013274:Stomach Neoplasms / Q000139:chemically induced*
chemical_list: D011453:Prostaglandins; D008769:Methylnitronitrosoguanidine