Endogenous opioids are not involved in the pathology induced by hyperbaric oxygen treatment.
In mice, oxygen at hyperbaric pressures (515 kPa; 5 ATA) induces convulsions and lung damage (edema and hemorrhage). Morphine treatment (15 mg X kg-1, i.p.) significantly protects against the development of this pathology. The protection is abolished by naloxone (1 mg X kg-1, i.p.). Electric footshock, which induces diverse opioid effects, affords no protection against hyperbaric oxygen damage. Possible mechanisms of the morphine action are discussed.
D000818:Animals; D004723:Endorphins / Q000502:physiology*; D006931:Hyperbaric Oxygenation / Q000009:adverse effects*; D008168:Lung / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009020:Morphine / Q000627:therapeutic use; D009270:Naloxone / Q000627:therapeutic use; D010100:Oxygen / Q000506:poisoning*; D012640:Seizures / Q000473:pathology / Q000517:prevention & control
D004723:Endorphins; D009270:Naloxone; D009020:Morphine; D010100:Oxygen