Journal article

Publication year: 2010

Pages: 87-95

Journal: European Journal of Pharmacology

Volume number: 635

Issue number: 1-3

ISSN: 0014-2999

DOI Link: https://doi.org/10.1016/j.ejphar.2010.03.009

Publisher: Elsevier

Abstract: 

The aim of the present study was the investigation of the mechanism, by which bradykinin B-2 receptor stimulation evokes an increase of the cytosolic Ca2+ concentration in rat submucosal plexus. In ganglionic cells within the intact submucosal plexus, the Ca2+-response evoked by bradykinin was suppressed by Ni2+, suggesting that Ca2+ enters the cell through voltage-gated Ca2+ channels (Ca-v channels). Inhibition of Ca-v channel subtypes P, T and R with omega-agatoxin IVA, flunarizine, and SNX-482 did not affect the response to bradykinin. In contrast, verapamil, omega-conotoxin GVIA, and omega-conotoxin MVIIC attenuated the actions of bradykinin, indicating the involvement of the L-, N- and omega-subtypes of Ca-v channels. The combination of these three blockers had a strong inhibitory action on the bradykinin response. In order to study the mechanism of activation of Ca-v channels by bradykinin, isolated submucosal neurons in culture were used. Immunocytochemical stainings revealed that these neurons expressed the bradykinin B-2 receptor, while the B-1 receptor was absent. Isolated submucosal glial cells did not express the bradykinin B-2 receptor. Whole-cell patch-clamp measurements of submucosal neurons showed that bradykinin induced a depolarisation of the membrane in average of 14 mV. The ionic mechanism underlying the depolarisation was identified with current measurements at two different membrane potentials (-81 and 0 mV). The current associated to Na+ influx was not changed by bradykinin, whereas the current representing K+ outflux was reduced by 26%. The present results suggest that at submucosal neurons from the rat colon bradykinin induces a depolarisation by decreasing the K+ conductance, followed by activation of the Ca-v channels, which mediates the increase of the cytosolic Ca2+ concentration.

Harvard Citation style: Avemary, J. and Diener, M. (2010) Bradykinin-induced depolarisation and Ca2+ influx through voltage-gated Ca2+ channels in rat submucosal neurons, European Journal of Pharmacology, 635(1-3), pp. 87-95. https://doi.org/10.1016/j.ejphar.2010.03.009

APA Citation style: Avemary, J., & Diener, M. (2010). Bradykinin-induced depolarisation and Ca2+ influx through voltage-gated Ca2+ channels in rat submucosal neurons. European Journal of Pharmacology. 635(1-3), 87-95. https://doi.org/10.1016/j.ejphar.2010.03.009