Participation of an alpha 2-mediated mechanism in the production of forced swimming-stress induced analgesia in mice.
In mice, both swimming-stress induced analgesia (SW-SIA) and clonidine (CLO) analgesia were dose dependently antagonized by yohimbine, an alpha 2-adrenoceptor antagonist, but not by naloxone, an opioid mu-antagonist. SW-SIA was potentiated by subanalgesic dose of CLO, and CLO analgesia was enhanced by SW-SIA. Animals tolerant to CLO analgesia were tolerant to SW-SIA, in contrast, CLO analgesia was potentiated in SW-SIA tolerant mice. Thus, SW-SIA and CLO analgesia partially share a common alpha 2-adrenergic-dependent mechanism, for their production.
Tokuyama
S
S
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Nagasaki University, Japan.
Takahashi
M
M
Kaneto
H
H
D000698:Analgesia; D000818:Animals; D003000:Clonidine / Q000494:pharmacology*; D004361:Drug Tolerance; D008297:Male; D051379:Mice; D009270:Naloxone / Q000494:pharmacology; D005082:Physical Exertion / Q000502:physiology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology*; D013312:Stress, Physiological / Q000503:physiopathology*; D013550:Swimming; D015016:Yohimbine / Q000494:pharmacology
D011942:Receptors, Adrenergic, alpha; D015016:Yohimbine; D009270:Naloxone; D003000:Clonidine