Rehn M, Diener M. Cysteinyl leukotrienes mediate the response of submucosal ganglia from rat colon to bradykinin.
Eur J Pharmacol 2012;
681:100-6. [PMID:
22366210 DOI:
10.1016/j.ejphar.2012.02.001]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 01/30/2012] [Accepted: 02/06/2012] [Indexed: 11/24/2022]
Abstract
The aim of the present study was to find out the mechanism by which the inflammatory mediator, bradykinin, induces an increase of the cytosolic Ca(2+) concentration ([Ca(2+)](i)) in enteric neurons. For this purpose, ganglia in the isolated submucosa from rat colon were loaded with the Ca(2+)-sensitive dye, fura-2, and were exposed to bradykinin (2·10(-8)mol/l). Under control conditions, the kinin evoked a transient increase in [Ca(2+)](i). Preincubation with quinacrine or arachidonyltrifluoromethylketone (AACOCF(3)), i.e. blockers of cytosolic phospholipase A(2), prevented the raise of [Ca(2+)](i). This inhibition was mimicked by 5,8,11,14-eicosatetrayonic acid (ETYA), an inhibitor of cyclooxygenases as well as lipoxygenases, and by BWA4C, a selective inhibitor of lipoxygenases, whereas indomethacin was ineffective, suggesting the mediation of the kinin response by a lipoxygenase metabolite. Indeed, a leukotriene, leukotriene D(4) (LTD(4)), mimicked the effect of bradykinin. The LTD(4) receptor blocker, MK-571, inhibited the increase in [Ca(2+)](i) evoked by LTD(4) and by bradykinin. Consequently, bradykinin receptors in submucosal ganglia from rat colon are coupled to a stimulation of phospholipase A(2), the release of arachidonic acid and the production of LTD(4), which seems to be finally responsible for the change in the cytosolic Ca(2+) concentration.
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