Antitussive effect of WIN 55212-2, a cannabinoid receptor agonist

Several lines of evidence indicate that the opioid and cannabinoid systems produce synergistic interactions. The present study examined the opioid receptors involved in the antitussive effect of WIN 55212-2 (( R)-(+)-[2,3-dihydro-5-methyl-3-[4-morpholinylmethyl]-pyrrolo-[1,2,3-de]-1,4-benzoxazin-6-y...

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Bibliographic Details
Published inEuropean journal of pharmacology Vol. 474; no. 2; pp. 269 - 272
Main Authors Morita, Kayo, Kamei, Junzo
Format Journal Article
LanguageEnglish
Published Amsterdam Elsevier B.V 08.08.2003
Elsevier
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Summary:Several lines of evidence indicate that the opioid and cannabinoid systems produce synergistic interactions. The present study examined the opioid receptors involved in the antitussive effect of WIN 55212-2 (( R)-(+)-[2,3-dihydro-5-methyl-3-[4-morpholinylmethyl]-pyrrolo-[1,2,3-de]-1,4-benzoxazin-6-yl](1-naphthyl) methanone mesylate), a high-affinity cannabinoid receptor agonist, in mice. WIN 55212-2, at doses of 0.3–3 mg/kg ip, produced a dose-dependent antitussive effect. This antitussive effect of WIN 55212-2 was antagonized by pretreatment with either methysergide (3 mg/kg ip), a 5-HT receptor antagonist, or naloxone (1 mg/kg ip), an opioid receptor antagonist. Furthermore, pretreatment with N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1 H-pyrazole-3-carboxamide hydrochloride (SR141716A, 3 mg/kg ip), a cannabinoid CB 1 receptor antagonist, also significantly reduced the antitussive effect of WIN 55212-2. Blockade of μ-opioid receptors by pretreatment with β-funaltrexamine (40 mg/kg sc) significantly reduced the antitussive effect of WIN 55212-2. However, pretreatment with nor-binaltorphimine (20 mg/kg sc), a κ-opioid receptor antagonist, did not affect the antitussive effect of WIN 55212-2. Pretreatment with naloxonazine (35 mg/kg sc), a μ 1-opioid receptor antagonist, also did not affect the antitussive effect of WIN 55212-2. These results indicate that the antitussive effect of WIN 55212-2 is mediated by the activation of cannabinoid CB 1 receptors and μ 2 (naloxonazine-insensitive)-opioid receptors, but not μ 1 (naloxonazine-sensitive)- or κ-opioid receptors.
ISSN:0014-2999
1879-0712
DOI:10.1016/S0014-2999(03)02009-0