Naloxone exerts a dose-dependent gastric cytoprotective effect.
Previous work has shown that naloxone inhibits the ulcerogenic effects of indomethacin and stress, although the site, mechanism or dose are unknown. We investigated whether naloxone possessed gastric cytoprotective properties, generating a dose-response curve existed for both intragastric (IG) and intravenous (IV) administration. One hundred and two rats were subjected to a four hour period of restraint, with the last two hours at 4 degrees C. Naloxone was given hourly during restraint at doses of 0 (Control), 1, 5, 10, 20 mg/kg. After sacrifice, the residual gastric volume, and pH were measured and the number of mucosal lesions scored. The cytoprotection offered by naloxone was different from control (p = 0.0001), with the intravenous route having a greater effect (p = 0.038). While this protective effect did not correlate with changes in gastric acidity, it correlated with the dose of naloxone.
Kleiman
R L
RL
College of Pharmacy, University of Iowa, Iowa City 52242.
Ephgrave
K S
KS
Adair
C G
CG
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D008297:Male; D009270:Naloxone / Q000627:therapeutic use*; D051381:Rats; D011919:Rats, Inbred Strains; D013276:Stomach Ulcer / Q000209:etiology / Q000517:prevention & control*; D013312:Stress, Physiological / Q000150:complications
D009270:Naloxone