NATURAL-RESISTANCE TO EFFECTS OF MORPHINE IN OCTODON-DEGUS A SOUTH-AMERICAN RODENT
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Date
1984
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Abstract
O. degus, a South American caviomorph, presents a natural resistance to some effects of morphine. None of the doses of morphine (i.v.) employed produced a significant modification of respiration rate. The administration of morphine leu-enkephalin and .beta.-endorphin to isolated O. degus vas deferens did not significantly change electrically-induced muscular twitches. Brain concentration of 14C morphine in the rat, as compared to O. degus, showed statistically significant differences. Pentazocine modified in EEG of O. degus, while morphine had no effect. Pimozide produced only a partial change of the pentazocine effect on EEG. This result is consistent with the view that pentazocine interacts with different opiate receptors.