Role of hypothalamic-pituitary axis in morphine-induced alteration in thymic cell distribution using mu-opioid receptor knockout mice.
Mu-opioid receptor knockout mice (MORKO), were used to address two questions: (1) if morphine induced decrease in thymic weight and cell distribution is mediated by the mu-opioid receptor and (2) the role of corticosteroids in morphine mediated alteration in thymic cell distribution. Our result show that morphine mediated increase in plasma corticosterone is mediated by the mu-opioid receptor since morphine at doses as high as 25 mg/kg-body weight does not increase plasma corticosterone levels in the MORKO. In addition, we have also shown that morphine treatment results in the differentiation of CD4+CD8+ (double positive cells) to single positive CD4+ cells while dexamethasone treatment results in the deletion of CD4+CD8+ (double positive) cells.
Roy
S
S
Department of Pharmacology and Surgery, University of Minnesota and Veterans Administration Medical Center, 1 Veterans Drive, 55417, Minneapolis, MN, USA. royxx002@gold.tc.umn.edu
Wang
J H
JH
Balasubramanian
S
S
Sumandeep
Charboneau
R
R
Barke
R
R
Loh
H H
HH
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D003345:Corticosterone / Q000097:blood; D003907:Dexamethasone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005938:Glucocorticoids / Q000494:pharmacology; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D009020:Morphine / Q000494:pharmacology*; D009929:Organ Size; D010902:Pituitary Gland / Q000187:drug effects* / Q000276:immunology; D017465:Receptors, Opioid, delta / Q000037:antagonists & inhibitors; D017473:Receptors, Opioid, kappa / Q000037:antagonists & inhibitors; D017450:Receptors, Opioid, mu / Q000235:genetics* / Q000276:immunology; D013950:Thymus Gland / Q000166:cytology* / Q000187:drug effects
D000701:Analgesics, Opioid; D005938:Glucocorticoids; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D009020:Morphine; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone