Involvement of mu-opioid receptors and alpha-adrenoceptors in the immunomodulatory effects of dihydroetorphine.
The present study investigated the effects of acutely administered dihydroetorphine on mitogen-stimulated lymphocyte proliferation and lymphokine production in mice. These immune functions were significantly suppressed by dihydroetorphine at 24 microg/kg and 128 microg/kg in a dose-dependent fashion. This study further examined the involvement of micro-opioid receptors and alpha-adrenoceptors in the immunomodulatory effects of dihydroetorphine. The micro-opioid receptor antagonist, naloxone (4 mg/kg), and alpha-adrenoceptor antagonist, phentolamine (10 mg/kg), but not the beta-adrenoceptor antagonist, propranolol (10 mg/kg), effectively blocked dihydroetorphine-induced suppression of splenic lymphocyte proliferation and lymphokine production. These results demonstrate that dihydroetorphine has significant immunosuppressive effects in mice and the mechanisms of these effects may lie in its interactions with opioid receptors and adrenergic pathways.
Department of Pharmacology, Xi'an Medical University, China. wrwu@yahoo.com
W R
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Wu
J W
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Zheng
F Y
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Li
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Li
K R
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Zhang
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Bai
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D005048:Etorphine / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007376:Interleukin-2 / Q000096:biosynthesis; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000276:immunology*; D017450:Receptors, Opioid, mu / Q000276:immunology*
D000276:Adjuvants, Immunologic; D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D000701:Analgesics, Opioid; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D009292:Narcotic Antagonists; D011942:Receptors, Adrenergic, alpha; D017450:Receptors, Opioid, mu; D009270:Naloxone; D005048:Etorphine; D011433:Propranolol; C034765:18,19-dihydroetorphine; D010646:Phentolamine