Functional alterations of swine peripheral blood mononuclear cells by methadone.
In vitro exposure of the synthetic opiate drug methadone allowed evaluation of putative immunomodulatory activities of swine peripheral blood mononuclear cells. Respiratory burst, an index of microbicidal activity, was suppressed by methadone in a dose-dependent manner following exposure for 48 h. The suppression was blocked by the opiate antagonist naloxone. Another macrophage function phagosome-lysosome fusion was impaired by exposure to methadone. A primary lymphocyte-mediated function natural killer cell activity was also affected. In contrast, the macrophage function antibody-mediated phagocytosis was not affected. Because the functions affected by methadone are critical to host defenses against pathogenic organisms, our findings suggest that opiate-mediated immunomodulation merits further study. Moreover, our studies suggest that swine may provide an ideal model for the investigation of opiate-mediated suppression of immune cell functions.
Molitor
T W
TW
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul 55108.
Murtaugh
M P
MP
Click
R E
RE
Gekker
G
G
Chao
C
C
Peterson
P K
PK
D000818:Animals; D003602:Cytotoxicity, Immunologic; D011992:Endosomes / Q000502:physiology; D007694:Killer Cells, Natural / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000187:drug effects*; D008247:Lysosomes / Q000502:physiology; D008561:Membrane Fusion; D008691:Methadone / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D010587:Phagocytosis / Q000187:drug effects; D010588:Phagosomes / Q000502:physiology; D014176:Protein Biosynthesis; D012313:RNA / Q000096:biosynthesis; D013481:Superoxides / Q000378:metabolism; D013552:Swine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D013481:Superoxides; D009270:Naloxone; D012313:RNA; D013755:Tetradecanoylphorbol Acetate; D008691:Methadone