Carbachol regulates pacemaker activities in cultured interstitial cells of Cajal from the mouse small intestine

• Published in: Molecules and cells 2009, 27(5), , pp.525-531
• Main Authors: So, K.Y. (Chosun University, Gwangju, Republic of Korea), Kim, S.H. (Chosun University, Gwangju, Republic of Korea), Sohn, H.M. (Chosun University, Gwangju, Republic of Korea), Choi, S.J. (Gachon University, Inchon, Republic of Korea), Parajuli, Shankar Prasad (Chosun University, Gwangju, Republic of Korea), Choi, S. (Chosun University, Gwangju, Republic of Korea), Yeum, C.H. (Chosun University, Gwangju, Republic of Korea), Yoon, P.J. (Chosun University, Gwangju, Republic of Korea), Jun, J.Y. (Chosun University, Gwangju, Republic of Korea), E-mail: [e-mail]
• Format: Article
• Language: English
• Subjects: Animals; Anti-Inflammatory Agents - pharmacology; Biochemistry; Biological Clocks - drug effects; Biological Clocks - physiology; Biomedical and Life Sciences; Biomedicine; Biotechnology; Calcium - metabolism; Calcium-Transporting ATPases - antagonists & inhibitors; Carbachol - pharmacology; Cation Transport Proteins - antagonists & inhibitors; Cell Biology; Cells, Cultured; Diamines - pharmacology; Flufenamic Acid - pharmacology; Guanosine Diphosphate - analogs & derivatives; Guanosine Diphosphate - pharmacology; interstitial cells of Cajal; INTESTIN; Intestine, Small - physiology; INTESTINES; INTESTINOS; Life Sciences; MEDICAMENT NEUROTROPE; MEDICAMENTOS NEUROTROPICOS; Membrane Potentials - drug effects; Membrane Potentials - physiology; Mice; Mice, Inbred BALB C; muscarinic receptor; Neuromuscular Depolarizing Agents - pharmacology; NEUROTROPIC DRUGS; Patch-Clamp Techniques; Piperidines - pharmacology; Plant Roots; Receptor, Muscarinic M2 - antagonists & inhibitors; Receptor, Muscarinic M3 - antagonists & inhibitors; Thapsia; Thapsigargin - pharmacology; Thionucleotides - pharmacology; 생물학
• ISSN: 1016-8478; 0219-1032
• DOI: 10.1007/s10059-009-0076-1

We studied the effect of carbachol on pacemaker currents in cultured interstitial cells of Cajal (ICC) from the mouse small intestine by muscarinic stimulation using a whole cell patch clamp technique and Ca²+-imaging. ICC generated periodic pacemaker potentials in the current-clamp mode and generated spontaneous inward pacemaker currents at a holding potential of -70 mV. Exposure to carbachol depolarized the membrane and produced tonic inward pacemaker currents with a decrease in the frequency and amplitude of the pacemaker currents. The effects of carbachol were blocked by 1-dimethyl-4-diphenylacetoxypiperidinium, a muscarinic M₃ receptor antagonist, but not by methotramine, a muscarinic M₂ receptor antagonist. Intracellular GDP-β-S suppressed the carbachol-induced effects. Carbachol-induced effects were blocked by external Na+-free solution and by flufenamic acid, a non-selective cation channel blocker, and in the presence of thapsigargin, a Ca²+-ATPase inhibitor in the endoplasmic reticulum. However, carbachol still produced tonic inward pacemaker currents with the removal of external Ca²+. In recording of intracellular Ca²+ concentrations using fluo 3-AM dye, carbachol increased intracellular Ca²+ concentrations with increasing of Ca²+ oscillations. These results suggest that carbachol modulates the pacemaker activity of ICC through the activation of non-selective cation channels via muscarinic M₃ receptors by a G-protein dependent intracellular Ca²+ release mechanism.