Morphine inhibited respiratory burst of neutrophils and scavenged oxygen free radicals.
OBJECTIVE
To study the effects of morphine on active oxygen free radicals.


METHODS
Chemiluminescence method was used to measure (a) active oxygen generation induced by respiratory burst of neutrophils from human blood stimulated with phorbol myristate acetate (PMA), (b) Superoxide anion (O2.-) induced by xanthine-xanthine oxidase system, (c) hydroxyl radical (.OH) generated by ascorbic acid (AA)-Cu(2+)-zymosan, and (d) the release of H2O2.


RESULTS
The (a), (b), (c), and (d) were scavenged by morphine and their median inhibitory concentrations (IC50 and 95% confidence limits) were 21.1 (13.0-34.0), 54.1 (50.0-58.5), 224.0 (128.2-390.8), and 66.9 (62.9-71.0), nmol L-1, respectively.


CONCLUSIONS
The immunosuppressant effect of morphine was related to its free radicals scavenging action.
Chen
S Y
SY
Department of Pharmacology, First Military Medical University, Guangzhou, China.
Huo
Q L
QL
Huang
J B
JB
Chen
Z L
ZL
Shi
X H
XH
Liao
X L
XL
D000328:Adult; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008163:Luminescent Measurements; D009020:Morphine / Q000494:pharmacology*; D009504:Neutrophils / Q000502:physiology*; D016897:Respiratory Burst / Q000187:drug effects*
D016166:Free Radical Scavengers; D007166:Immunosuppressive Agents; D009020:Morphine