In vitro effect of opioid agonist and antagonist on superoxide release by granulocytes.
The effect of the opioid agonist morphine and of the (-) and (+) stereoisomers of the antagonist naloxone were studied on the O2-generation from human granulocytes. Morphine or naloxone had no effect on basal or phorbol myristate acetate (PMA) stimulated O2-generation, while equimolar (-) naloxone and morphine concentrations (1 x 10-13 - 1 x 10-7 M) inhibited the stimulated O2-generation. The effect of (-) naloxone was stereospecific, suggesting the involvement of opioid receptors. The unmasking of non opioid effects of morphine could be responsible for the inhibition of O2-generation. It is suggested that the opioid control of oxidative metabolism in human granulocytes could involve multiple receptors mediating opposite effect.
Pasotti
D
D
Senior Institute of Health, Rome, Italy.
Mazzone
A
A
Rossi
M
M
Ricevuti
G
G
D000328:Adult; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006098:Granulocytes / Q000187:drug effects*; D006801:Humans; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000187:drug effects*; D013481:Superoxides / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D011957:Receptors, Opioid; D013481:Superoxides; D009270:Naloxone; D009020:Morphine; D013755:Tetradecanoylphorbol Acetate