Des-Arg9-bradykinin increases intracellular Ca2+ in bronchoalveolar eosinophils from ovalbumin-sensitized and -challenged mice.
The effects of the selective bradykinin B1 receptor agonist, des-Arg9-bradykinin and the bradykinin B2 receptor agonist, bradykinin were studied on the intracellular free Ca2+ concentration ([Ca2+]i) in murine bronchoalveolar lavage cells from control and ovalbumin-sensitized mice using fura-2 microfluorimetry. The bronchoalveolar lavage cells of control mice, which were predominantly alveolar macrophages, showed an increase in [Ca2+]i in response to bradykinin (1 microM) but not to des-Arg9-bradykinin (1 microM), indicating the presence of functional bradykinin B2 receptors and the absence of B1 receptors. Such elevation in [Ca2+]i induced by bradykinin was totally inhibited by the selective bradykinin B2 receptor antagonist, D-Arg0-Hyp3-Thi5-D-Tic7-Oic8-bradykinin (HOE-140; 10 microM). In contrast, bronchoalveolar lavage cells from ovalbumin-sensitized and -challenged mice significantly responded to both bradykinin and des-Arg9-bradykinin, indicating the presence of both functional bradykinin B1 and B2 receptors. Eosinophils exhibited higher response to des-Arg9-bradykinin (1 microM; 485% increase in [Ca2+]i) compared to bradykinin (1 microM; 163% increase in [Ca2+]i). This des-Arg9-bradykinin-induced [Ca2+]i increase was markedly inhibited by the selective bradykinin B1 receptor antagonist, Ac-Lys-[D-betaNal7, Ile8]des-Arg9-bradykinin (R-715; 10 microM). Des-Arg9-bradykinin neither modified the basal [Ca2+]i in lymphocytes nor in mononuclear cells from ovalbumin-sensitized and challenged mice, while bradykinin produced a [Ca2+]i increase in both cell types. Our results further support the implication of the inducible bradykinin B1 receptors in airway inflammatory response in ovalbumin-sensitized and challenged mice.
Eric
Jadranka
J
Institute of Pharmacology of Sherbrooke, School of Medicine, University of Sherbrooke, PQ, J1H 5N4, Sherbrooke, Canada
Bkaily
Ghassan
G
Bkaily
Ghassan B
GB
Volkov
Leonid
L
Gabra
Bichoy H
BH
Sirois
Pierre
P
D000818:Animals; D001920:Bradykinin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D002118:Calcium / Q000378:metabolism*; D004804:Eosinophils / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D007424:Intracellular Fluid / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000494:pharmacology
C024626:bradykinin, des-Arg(9)-; D010047:Ovalbumin; D001920:Bradykinin; D002118:Calcium