Ginsenoside Re inhibits pacemaker potentials via adenosine triphosphate-sensitive potassium channels and the cyclic guanosine monophosphate/nitric oxide-dependent pathway in cultured interstitial cells of Cajal from mouse small intestine

Abstract

BackgroundGinseng belongs to the genus Panax. Its main active ingredients are the ginsenosides. Interstitial cells of Cajal (ICCs) are the pacemaker cells of the gastrointestinal (GI) tract. To understand the effects of ginsenoside Re (GRe) on GI motility, the authors investigated its effects on the pacemaker activity of ICCs of the murine small intestine.MethodsInterstitial cells of Cajal were dissociated from mouse small intestines by enzymatic digestion. The whole-cell patch clamp configuration was used to record pacemaker potentials in cultured ICCs. Changes in cyclic guanosine monophosphate (cGMP) content induced by GRe were investigated.ResultsGinsenoside Re (20–40μM) decreased the amplitude and frequency of ICC pacemaker activity in a concentration-dependent manner. This action was blocked by guanosine 5′-[β-thio]diphosphate [a guanosine-5'-triphosphate (GTP)-binding protein inhibitor] and by glibenclamide [an adenosine triphosphate (ATP)-sensitive K+ channel blocker]. To study the GRe-induced signaling pathway in ICCs, the effects of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (a guanylate cyclase inhibitor) and RP-8-CPT-cGMPS (a protein kinase G inhibitor) were examined. Both inhibitors blocked the inhibitory effect of GRe on ICC pacemaker activity. L-NG-nitroarginine methyl ester (100μM), which is a nonselective nitric oxide synthase (NOS) inhibitor, blocked the effects of GRe on ICC pacemaker activity and GRe-stimulated cGMP production in ICCs.ConclusionIn cultured murine ICCs, GRe inhibits the pacemaker activity of ICCs via the ATP-sensitive potassium (K+) channel and the cGMP/NO-dependent pathway. Ginsenoside Re may be a basis for developing novel spasmolytic agents to prevent or alleviate GI motility dysfunction.

The Traditional Medicine Banhasasim-Tang Depolarizes Pacemaker Potentials of Cultured Interstitial Cells of Cajal through M3 Muscarinic and 5-HT3 Receptors in Murine Small Intestine

“…Next, the cells were cultured at 37 ° C in a 95% O 2-5% CO 2 incubator in smooth muscle growth medium (Clonetics, San Diego, CA, USA) supplemented with 2% antibiotics/antimycotics (Gibco, Grand Island, NY, USA) and 5 ng/mL murine stem cell factor (Sigma-Aldrich). First, ICCs were cultured only for < 12 h and then immunologically examined using anti-c-Kit antibody (eBioscience, San Diego, CA, USA) at a dilution of 1: 50 for 20 min [19]. However, in this case, we could not conduct the patchclamp experiment because of the bad state of the ICCs.…”

Effects of Chaihu-Shugan-San on Small Intestinal Interstitial Cells of Cajal in Mice

“…32) ATP-sensitive K + channels have also been reported in GI smooth muscle cells, and act as targets of neurotransmitters and peptides. 33,34) In this study, CSS acted as neurotransmitters and peptides in ICCs and regulated the pacemaker potentials by modulating the ATP-sensitive K + channels (Fig. 5).…”

Modulation of Pacemaker Potentials in Murine Small Intestinal Interstitial Cells of Cajal by Gamisoyo-San, a Traditional Chinese Herbal Medicine

“…Additional studies are required to identify the ion channels involved, specifically K + channels that may be involved in the GSS-induced pacemaker potential depolarizations. There are many K + channels that possibly regulate ICC or GI motility, such as voltage-dependent K + channels (Kv channels) [42], Na + -K + -Cl – cotransporters [43], ATP-sensitive K + channels [44], voltage-gated Kv11.1 (hERG) channels [45], K V 7.5 channels [46], transient outward K + channels [47], Ca 2+ -activated K + channels [48], E-4031-sensitive K + channels [49], 4-AP-sensitive K + channels [50], and clotrimazole-sensitive K + channels [51]. GSS may have an effect on K + channels in ICCs and the possible effect of this on the pacemaker potential depolarization requires investigation.…”