title: Possible role of mast cells in cineole-induced scratching behavior in mice.
abstract: We examined the scratch (itch) inducing effect of 1,8-cineole (cineole), a monoterpene oxide present in many plant essential oils and the possible role of mast cells in the response. Subcutaneous injection of cineole (10, 20 and 40 microl/site) or the mast cell degranulating agent, compound 48/80 (25, 50 and 100 microg/site) into the rostral back of mice induced a scratching behavior. This response of cineole as well as that of 48/80 was markedly suppressed in mice subjected to mast cell desensitization by repeated injections of 48/80. The cineole-induced scratching was also significantly diminished in animals pretreated with diphenhydramine, the histamine H1-receptor antagonist or cyproheptadine, the dual histamine/serotonin-receptor antagonist. Furthermore, the scratch-inducing effect of cineole was greatly reduced in mice that received the opioid antagonist naloxone or the selective adenosine A1-receptor agonist, N6-cyclopentyladenosine (CPA), but not the more selective adenosine A2-receptor agonist, 5'-N-ethylcarboxamidoadenosine (NECA). The data suggest a likely role for mast cells in cineole-induced scratching behavior of mice, possibly involving adenosinergic and opioidergic mechanisms.
authors.affiliation: Department of Physiology and Pharmacology, Federal University of Ceará (FM), Fortaleza, Brazil.
authors.forename: F A
authors.initials: FA
authors.lastname: Santos
authors.forename: V S N
authors.initials: VS
authors.lastname: Rao
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D019830:Adenosine-5'-(N-ethylcarboxamide) / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D003511:Cyclohexanols / Q000494:pharmacology; D003533:Cyproheptadine / Q000494:pharmacology; D004155:Diphenhydramine / Q000494:pharmacology; D000077591:Eucalyptol; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D008297:Male; D008407:Mast Cells / Q000502:physiology*; D051379:Mice; D039821:Monoterpenes; D009270:Naloxone / Q000494:pharmacology; D058906:Purinergic P1 Receptor Agonists; D012702:Serotonin Antagonists / Q000494:pharmacology; D013729:Terpenes / Q000494:pharmacology; D013806:Theophylline / Q000031:analogs & derivatives* / Q000494:pharmacology; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
chemical_list: D003511:Cyclohexanols; D006634:Histamine H1 Antagonists; D039821:Monoterpenes; D058906:Purinergic P1 Receptor Agonists; D012702:Serotonin Antagonists; D013729:Terpenes; D003533:Cyproheptadine; D019830:Adenosine-5'-(N-ethylcarboxamide); D009270:Naloxone; D003189:p-Methoxy-N-methylphenethylamine; C048599:N(6)-cyclopentyladenosine; D004155:Diphenhydramine; D013806:Theophylline; C028322:8-phenyltheophylline; D000241:Adenosine; D000077591:Eucalyptol