Journal article

Publication year: 1999

Pages: 75-80

Journal: European Journal of Pharmacology

Volume number: 377

Issue number: 1

ISSN: 0014-2999

DOI Link: https://doi.org/10.1016/S0014-2999(99)00416-1

Publisher: Elsevier

Abstract: 

The cholinergic agonist carbachol stimulates the apical H+-K+-ATPase and apical as well as basolateral K+ channels in the rat distal colon. The effect of carbachol was tested in the presence of different inhibitors of the Ca2+ signaling pathway in order to characterize the intracellular mechanisms involved. Both carbachol-stimulated Rb+-efflux as well as carbachol-stimulated mucosal Rb+-uptake were dependent on the presence of serosal Ca2+. The Ca2+-calmodulin antagonist calmidazolium (10(-7) mol l(-1)) inhibited the stimulation of mucosal and serosal Rb+ efflux by carbachol. A similar effect had KN-62 (10(-5) mol l(-1)), an inhibitor of the Ca2+-calmodulin-dependent kinase II, suggesting the regulation of basolateral and apical K+ channels by this kinase. Staurosporine (10(-6) mol l(-1)), which potently inhibits protein kinase C, did not alter the effect of carbachol on Rb+ efflux, although the stimulation of apical Rb+ efflux by carbachol seemed to be less prolonged, indicating that protein kinase C is not involved in the regulation of K+ permeability. In contrast, mucosal Rb+ uptake, which is determined by the ouabain- and vanadate-sensitive K+ transport via the apical H+-K+-ATPase, was decreased to nearly one third of control values in the presence of calmidazolium. Both calmidazolium and staurosporine, but not KN-62, prevented the stimulatory action of carbachol on the H+-K+-ATPase, suggesting a synergistic control of this ion pump by both Ca2+-calmodulin and protein kinase C.

Harvard Citation style: Heinke, B., Ribeiro, R. and Diener, M. (1999) Involvement of calmodulin and protein kinase C in the regulation of K+ transport by carbachol across the rat distal colon, European Journal of Pharmacology, 377(1), pp. 75-80. https://doi.org/10.1016/S0014-2999(99)00416-1

APA Citation style: Heinke, B., Ribeiro, R., & Diener, M. (1999). Involvement of calmodulin and protein kinase C in the regulation of K+ transport by carbachol across the rat distal colon. European Journal of Pharmacology. 377(1), 75-80. https://doi.org/10.1016/S0014-2999(99)00416-1