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Updated: May 30, 2026

Applications of Spatio-temporal Mapping and Particle Analysis Techniques to Quantify Intracellular Ca2+ Signaling In Situ
Published on: January 7, 2019
5-hydroxytryptamine generates tonic inward currents on pacemaker activity of interstitial cells of cajal from mouse
Pawan Kumar Shahi1, Seok Choi, Dong Chuan Zuo
1Department of Physiology, College of Medicine, Chosun University, Gwangju 501-759, Korea.
Abstract:
In this study we determined whether or not 5-hydroxytryptamine (5-HT) has an effect on the pacemaker activities of interstitial cells of Cajal (ICC) from the mouse small intestine. The actions of 5-HT on pacemaker activities were investigated using a whole-cell patch-clamp technique, intracellular Ca(2+) ([Ca(2+)](i)) analysis, and RT-PCR in ICC. Exogenously-treated 5-HT showed tonic inward currents on pacemaker currents in ICC under the voltage-clamp mode in a dose-dependent manner. Based on RT-PCR results, we found the existence of 5-HT(2B, 3, 4, and 7) receptors in ICC. However, SDZ 205557 (a 5-HT(4) receptor antagonist), SB 269970 (a 5-HT7 receptor antagonist), 3-tropanylindole - 3 - carboxylate methiodide (3-TCM; a 5-HT(3) antagonist) blocked the 5-HT-induced action on pacemaker activity, but not SB 204741 (a 5-HT(2B) receptor antagonist). Based on [Ca(2+)](i) analysis, we found that 5-HT increased the intensity of [Ca(2+)](i). The treatment of PD 98059 or JNK II inhibitor blocked the 5-HT-induced action on pacemaker activity of ICC, but not SB 203580. In summary, these results suggest that 5-HT can modulate pacemaker activity through 5-HT(3, 4, and 7) receptors via [Ca(2+)](i) mobilization and regulation of mitogen-activated protein kinases.
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