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-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-1H-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 mu-opioid receptors by pretreatment with beta-funaltrexamine (40 mg/kg sc) significantly reduced the antitussive effect of WIN 55212-2. However, pretreatment with nor-binaltorphimine (20 mg/kg sc), a kappa-opioid receptor antagonist, did not affect the antitussive effect of WIN 55212-2. Pretreatment with naloxonazine (35 mg/kg sc), a mu(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 mu(2) (naloxonazine-insensitive)-opioid receptors, but not mu(1) (naloxonazine-sensitive)- or kappa-opioid receptors.
Morita
Kayo
K
School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 4-41 Ebara 2-chome, Shinagawa-ku, 142-8501 Tokyo, Japan.
Kamei
Junzo
J
D000818:Animals; D000996:Antitussive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D048588:Benzoxazines; D063386:Cannabinoid Receptor Agonists; D063387:Cannabinoid Receptor Antagonists; D002186:Cannabinoids / Q000494:pharmacology / Q000627:therapeutic use; D003371:Cough / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009025:Morpholines / Q000494:pharmacology / Q000627:therapeutic use*; D009281:Naphthalenes / Q000494:pharmacology / Q000627:therapeutic use*; D043882:Receptors, Cannabinoid / Q000378:metabolism
D000996:Antitussive Agents; D048588:Benzoxazines; D063386:Cannabinoid Receptor Agonists; D063387:Cannabinoid Receptor Antagonists; D002186:Cannabinoids; D009025:Morpholines; D009281:Naphthalenes; D043882:Receptors, Cannabinoid; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone