Met-enkephalin induced escape from dexamethasone immunosuppression.
The present study was undertaken to examine whether and what type of interaction occurs between a synthetic glucocorticoid, dexamethasone (DEX) and an opioid peptide, met-enkephalin (MENK) upon superoxide anion (O2-) release from human polymorphonuclear cells (PMN). MENK (10(-8) M) abolished suppressed O2- release from PMNs treated with 10(-7) M DEX. This was the case in unstimulated but not in PMNs stimulated with PMA. The effect of MENK was mediated through pertussis-toxin (PTX) sensitive G-protein and since it was abolished by H7 probably involves protein kinase C (PKC) as a second messenger system. Thus, MENK can abolish DEX induced suppression of O2- release from human PMNs possibly through the interaction of second messenger pathways.
Haberstock
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Institute R. Bosković, Department of Experimental Biology and Medicine, Zagreb, Croatia.
Marotti
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D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D003907:Dexamethasone / Q000037:antagonists & inhibitors*; D004744:Enkephalin, Methionine / Q000494:pharmacology*; D019204:GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000502:physiology; D006801:Humans; D007166:Immunosuppressive Agents / Q000037:antagonists & inhibitors*; D007546:Isoquinolines / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D037342:Pertussis Toxin; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000502:physiology; D016897:Respiratory Burst / Q000187:drug effects*; D013481:Superoxides / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D007166:Immunosuppressive Agents; D007546:Isoquinolines; D010879:Piperazines; D010566:Virulence Factors, Bordetella; D013481:Superoxides; D004744:Enkephalin, Methionine; D003907:Dexamethasone; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D037342:Pertussis Toxin; D011493:Protein Kinase C; D019204:GTP-Binding Proteins; D013755:Tetradecanoylphorbol Acetate