Located within the tunica muscularis of the gastrointestinal (GI) tract are networks of cells known as interstitial cells of Cajal (ICC). ICC are critical for important basic functions of GI motility such as generation and propagation of slow-wave pacemaker activity and reception of regulatory inputs from the enteric nervous system. We have developed a novel procedure to identify and isolate individual ICC from freshly dispersed cell preparations of the murine small intestine and gastric fundus and to determine differential transcriptional expression We have compared the expression profiles of pacemaker ICC isolated from the murine small intestine (IC-MY) and ICC involved in neurotransmission from the gastric fundus (IC-IM). We have also compared expression profiles between ICC and smooth muscle cells (SMC) and between freshly isolated ICC and cultured ICC. Cultured ICC express smooth muscle myosin, whereas freshly dispersed ICC do not. All cell types express muscarinic receptor types M(2) and M(3), neurokinin receptors NK(1) and NK(3), and inhibitory receptor VIP-1, whereas only cultured ICC and SMC express VIP-2. Both cultured and freshly dispersed IC-IM and IC-MY express the soluble form of stem cell factor, whereas SMC from the gastric fundus express only the membrane-bound form.
Voltage-activated K+(KV) channels play an important role in regulating the membrane potential in excitable cells. In gastrointestinal (GI) smooth muscles, these channels are particularly important in modulating spontaneous electrical activities. The purpose of this study was to identify the molecular components that may be responsible for the KV currents found in the canine GI tract. In this report, we have examined the qualitative expression of eighteen different KV channel genes in canine GI smooth muscle cells at the transcriptional level using RT-PCR analysis. Our results demonstrate the expression of KV1.4, KV1.5, KV1.6, KV2.2, and KV4.3 transcripts in all regions of the GI tract examined. Transcripts encoding KV1.2, KVβ1.1, and KVβ1.2 subunits were differentially expressed. KV1.1, KV1.3, KV2.1, KV3.1, KV3.2, KV3.4, KV4.1, KV4.2, and KVβ2.1 transcripts were not detected in any GI smooth muscle cells. We have also determined the protein expression for a subset of these KV channel subunits using specific antibodies by immunoblotting and immunohistochemistry. Immunoblotting and immunohistochemistry demonstrated that KV1.2, KV1.4, KV1.5, and KV2.2 are expressed at the protein level in GI tissues and smooth muscle cells. KV2.1 was not detected in any regions of the GI tract examined. These results suggest that the wide array of electrical activity found in different regions of the canine GI tract may be due in part to the differential expression of KV channel subunits.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.