Journal article

Publication year: 1999

Pages: 39-48

Journal: Pflügers Archiv European Journal of Physiology

Volume number: 439

Issue number: 1-2

ISSN: 0031-6768

DOI Link: https://doi.org/10.1007/s004249900159

Publisher: Springer

Abstract: 
Capacitative Ca2+ entry in isolated rat colonic crypts was induced by dialysing the cells in the whole-cell patch-clamp mode with a pipette solution having a high Ca2+-buffering capacity. Under these conditions crypt cell resting potential was lower than normal. Flufenamate, La3+ and Gd3+, blockers of non-selective cation channels, hyperpolarized the crypt cells and decreased membrane current. This current exhibited a cation selectivity of Na+>Ca2+. In contrast to Na+, Ca2+ inhibited the current at concentrations exceeding 1 mmol/l. Indirect evidence suggests that the non-selective cation conductance is activated after stimulation of muscarinic receptors. Carbachol, a cholinergic agonist, evoked a transient hyperpolarization and an increase in membrane outwards current. The half-time of the decay of the carbachol response was shortened strongly in the presence of La3+ Fura-2 experiments with isolated crypts confirmed that La3+ inhibited: the carbachol-induced increase in intracellular Ca2+. In Parallel Ussing chamber experiments, La3+ suppressed the induction of Cl- secretion by carbachol. These-results demonstrate that a non-selective cation conductance activated by store depletion may be involved in the regulation of electrolyte transport by agonists of the Ca2+ signalling pathway.

Harvard Citation style: Frings, M., Schultheiss, G. and Diener, M. (1999) Electrogenic Ca2+ entry in the rat colonic epithelium, Pflügers Archiv European Journal of Physiology, 439(1-2), pp. 39-48. https://doi.org/10.1007/s004249900159

APA Citation style: Frings, M., Schultheiss, G., & Diener, M. (1999). Electrogenic Ca2+ entry in the rat colonic epithelium. Pflügers Archiv European Journal of Physiology. 439(1-2), 39-48. https://doi.org/10.1007/s004249900159