title: Roles played by histamine in strenuous or prolonged masseter muscle activity in mice.
abstract: Bruxism and/or clenching, resulting in fatigue or dysfunction of masseter muscles (MM), may cause temporomandibular disorders. Functional support of the microcirculation is critical for prolonged muscle activity. Histamine is a regulator of the microcirculation and is supplied by release from its stores and/or by de novo production via the induction of histidine decarboxylase (HDC). Interleukin (IL)-1, a cytokine involved in temporomandibular disorders, is an inducer of HDC. In the present study, we examined the roles of histamine, HDC and IL-1 in MM activity. Experiments were conducted using our R+G+ model. A mouse restrained (R+) inside a narrow cylinder (front end blocked with a thin plastic strip) gnaws away (G+) the strip to escape, with the weight reduction in the strip serving as an index of MM activity. Fexofenadine (a peripherally acting histamine H1 receptor antagonist) reduced MM activity in normal mice. Both H1 receptor-deficient and HDC-deficient mice exhibited low MM activity. Prolonged R+G+ induced HDC activity in MM. Mast cell-deficient mice exhibited strikingly low HDC induction in MM (and also in the quadriceps femoris muscle) in response to muscle activity or IL-1β. Mast cells were present around blood vessels and nerves in the epimysium and perimysium of MM. These results, together with others reported previously, suggest that: (i) peripheral histamine supports strenuous MM activity; (ii) strenuous MM activity stimulates mast cells to release histamine and to induce HDC (which replenishes the histamine pool in mast cells, possibly mediated by IL-1); and (iii) peripheral histamine H1 receptor antagonists may be effective in treating temporomandibular disorders or preventing prolonged clenching and/or bruxism.
authors.affiliation: Division of Oral Molecular Regulation, Graduate School of Dentistry, Tohoku University, Sendai, Japan; Division of Advanced Prosthetic Dentistry, Graduate School of Dentistry, Tohoku University, Sendai, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoneda
authors.forename: Fukie
authors.initials: F
authors.lastname: Niijima-Yaoita
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tsuchiya
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kumamoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Watanbe
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohtsu
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yanai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tadano
authors.forename: Keiichi
authors.initials: K
authors.lastname: Sasaki
authors.forename: Shunji
authors.initials: S
authors.lastname: Sugawara
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Endo
mesh_terms: D000818:Animals; D002012:Bruxism / Q000378:metabolism / Q000517:prevention & control; D006632:Histamine / Q000378:metabolism / Q000502:physiology*; D006634:Histamine H1 Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D006640:Histidine Decarboxylase / Q000235:genetics / Q000378:metabolism; D008297:Male; D008406:Masseter Muscle / Q000098:blood supply / Q000187:drug effects* / Q000378:metabolism; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D011969:Receptors, Histamine H1 / Q000235:genetics / Q000378:metabolism; D012149:Restraint, Physical
chemical_list: D006634:Histamine H1 Antagonists; D011969:Receptors, Histamine H1; D006632:Histamine; D006640:Histidine Decarboxylase
keywords: histamine; histidine decarboxylase; interleukin 1; masseter muscle; muscle fatigue; quadriceps femoris muscle