Estrogen regulates the expression of small-conductance Ca-activated K+ channels in colonic smooth muscle cells

Digestion
Yu-rong TangLin Lin

Abstract

This study aimed to determine the effects of small-conductance Ca(2+)-activated K(+) (SK) channels in colonic relaxation and the regulation of SK channels by estrogen. The contractile activity of muscle strips from male rats was estimated, and drugs including vehicle (DMSO), 17β-estradiol (E2), or apamin (SK blocker) were added, respectively. In a further experiment, muscle strips were preincubated with apamin before exposure to E2. The levels of the SK2 and SK3 protein expression in the colonic smooth muscle cells (SMCs) were detected. SMCs were treated with ICI 182780 (estrogen receptor [ER] antagonist) plus E2, BSA-E2, PPT (ERα agonist), or DPN (ERβ agonist). SK3 mRNA and protein expression levels were detected. The muscle strips responded to E2 with a decrease and to apamin with a transient increase in tension. Preincubation with apamin partially prevented E2-induced relaxation. Two SK channel subtypes, SK2 and SK3, were coexpressed with α-actin in colonic SMCs. The quantitative ratio of the SK transcriptional expression in colonic SMCs was SK3 > SK2. The SK3 expression was upregulated by E2, and was downregulated by ICI 182780, but was not influenced by BSA-E2. Furthermore, the effect of PPT on the expression of SK3 was al...Continue Reading

Citations

Dec 23, 2016·Journal of Digestive Diseases·Christine BaumgartnerJuergen Gschossmann
Oct 24, 2018·Europace : European Pacing, Arrhythmias, and Cardiac Electrophysiology : Journal of the Working Groups on Cardiac Pacing, Arrhythmias, and Cardiac Cellular Electrophysiology of the European Society of Cardiology·Katja E OdeningHikmet Yorgun
Jan 17, 2021·Neurogastroenterology and Motility : the Official Journal of the European Gastrointestinal Motility Society·Xiaoxue ShenTing Yu
Mar 21, 2021·European Journal of Pharmacology·Iris LimRuss Chess-Williams

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