Ghrelin and obestatin promote the allergic action in rat peritoneal mast cells as basic secretagogues.
Ghrelin is an endogenous ligand of the type 1a growth hormone secretagogue receptor (GHSR1a) that regulates energy balance. Ghrelin and obestatin, derived from the post-translational processing of preproghrelin, are involved in a diverse range of biological activities, yet their effect on the immune system is not fully understood. In the present study, we investigated the roles of ghrelin and obestatin on mast cell degranulation and found that both ghrelin and obestatin induce the release of histamine from rat peritoneal mast cells. This induced histamine release was inhibited by the pertussis toxin, an inhibitor of Gα(i) protein, and extracellular Ca(2+). Rat peritoneal mast cells and rat basophilic leukemia (RBL-2H3) cells did not express the ghrelin receptor GHSR1a, suggesting that histamine release induced by ghrelin occurs via a receptor-independent mechanism. We report here that ghrelin and obestatin, belonging to the family of basic secretagogues, stimulate mast cells independent of a receptor, and this may play a crucial role at the site of allergy or inflammation.
Hirayama
Tatsuya
T
Department of Medical Technology, Nagoya University School of Health Sciences, 1-1-20 Daikou-minami, Higashi-ku, Nagoya 461-8673, Japan.
Kawabe
Tsutomu
T
Matsushima
Miyoko
M
Nishimura
Yuko
Y
Kobe
Yuko
Y
Ota
Yui
Y
Baba
Kenji
K
Takagi
Kenzo
K
D000818:Animals; D054439:Ghrelin / Q000494:pharmacology*; D006636:Histamine Release / Q000187:drug effects*; D006967:Hypersensitivity / Q000503:physiopathology; D008407:Mast Cells / Q000187:drug effects*; D036361:Peptide Hormones / Q000494:pharmacology*; D037342:Pertussis Toxin / Q000494:pharmacology; D051381:Rats; D054440:Receptors, Ghrelin / Q000096:biosynthesis
D054439:Ghrelin; D036361:Peptide Hormones; D054440:Receptors, Ghrelin; C505798:obestatin, rat; D037342:Pertussis Toxin