Protection by opioids against gastric lesions caused by necrotizing agents.
The synthetic opioid met-enkephalin analog [D-Ala2, MePhe4, Met(0)5ol] enkephalin (DAMME) and the opiate morphine injected intraperitoneally to rats at doses of 0.5-2 and 5-20 mg/kg, respectively, showed a protective effect on gastric damage induced by oral administration of necrotizing agents (0.6 N HCl or 0.2 N NaOH solutions, 1 ml/rat). The protection was prevented by naltrexone (10 mg/kg s.c.), an opioid antagonist with long-lasting activity. Histological sections of mucosal samples from animals pretreated with morphine (10 mg/kg i.p.) and DAMME (1 mg/kg i.p.) showed less alteration of the columnar epithelium, with a normal glandular structure, than untreated rats. A mediation of prostaglandins is suggested, since indomethacin (10 mg/kg s.c.) significantly reduced the protective effects of opioids.
Ferri
S
S
Institute of Pharmacology, University of Bologna, Italy.
Speroni
E
E
Candeletti
S
S
Cavicchini
E
E
Romualdi
P
P
Govoni
P
P
Marchini
M
M
D000818:Animals; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin / Q000627:therapeutic use*; D004723:Endorphins / Q000627:therapeutic use*; D005753:Gastric Mucosa / Q000473:pathology; D006851:Hydrochloric Acid / Q000494:pharmacology; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009271:Naltrexone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012972:Sodium Hydroxide / Q000494:pharmacology; D013276:Stomach Ulcer / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*
D004723:Endorphins; D012972:Sodium Hydroxide; D009271:Naltrexone; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin; D009020:Morphine; D006851:Hydrochloric Acid