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Effects of morphine and naloxone on stress ulcer formation and gastric acid secretion

1986; Elsevier BV; Volume: 124; Issue: 1-2 Linguagem: Inglês

10.1016/0014-2999(86)90131-7

1879-0712

Gary B. Glavin, Kathleen M. Kiernan, Mark R. Hinatowich, Frank S. LaBella,

Pharmacological Effects of Natural Compounds

The effect of both acute and chronic morphine and naloxone on restraint-stress gastric ulcer formation and on basal gastric acid secretion were examined in the conscious rat. Acute morphine administration produced a dose-related decrease in stress ulceration and basal gastric acid secretion. Acute naloxone treatment resulted in a dose-related increase in stress ulcer formation and markedly augmented gastric acid secretion. Naloxone (4.0 mg/kg) antagonized the ulcer-reducing effects at all doses of morphine tested (4.0–32.0 mg/kg). Morphine-dependent rats, restrained during spontaneous or naloxone-precipitated withdrawal, exhibited the most severe ulceration. However, only those subjected to naloxone-precipitated withdrawal produced a significant increase in gastric acid output. Chronic treatment with naloxone or with chronic naloxone followed by morphine (16.0 mg/kg) resulted in augmented stress ulcer formation relative to all acutely treated groups. Both chronic naloxone-treated groups exhibited markedly enhanced gastric secretion. These data suggest that central and/or peripheral opiate receptors can modulate both basal and stress-perturbed gastric function.