Participation of BK_Ca2+ and K_ATP potassium ion channels in the contractility of human term pregnant myometrium in in vitro conditions

Abstract

In our experimental study we found that the participation of BK(Ca2+) and K(ATP) potassium ion channels in the contractility of human term pregnant myometrium in labor is probably different.

Effect of cytochrome P‐450 epoxygenase and hydroxylase metabolites on rat myometrium contractility in non‐pregnancy, late pregnancy and late pregnancy under inflammatory conditions

“…It could be proposed that EET may modulate either spontaneous cell membrane excitation (delayed triggering of action potential) or pharmaco‐mechanical coupling (membrane receptor activation), which usually involves Ca 2+ entry and Ca 2+ release from internal stores in uterine smooth muscle cells . EET are also known to act on BK ca channels as proposed in published work . BK ca channels have been shown to be involved in the control of uterine relaxation whereas their inhibition may facilitate the initiation of labor .…”

Functional insights into modulation of BKCa channel activity to alter myometrial contractility

“…For example, mice lacking the BK Ca channel gene, mSlo1 , give birth to smaller pups and litters, although they reach term successfully (Meredith et al, 2004); however, compensatory mechanisms to systemic channel ablation have not been addressed. Additionally, a few studies have shown a minimal effect of BK Ca channel blockers or openers on rodent and human myometrial contraction in vitro (Aaronson et al, 2006; Smith et al, 2007; Sadlonova et al, 2011). However, as we shall see below, this channel is modulated by multiple factors that are difficult to replicate in vitro .…”

Orai1 protein expression and the role of calcium release‐activated calcium channels in the contraction of human term‐pregnant and non‐pregnant myometrium

“…The contractility of myometrium was investigated by an organ tissue bath method described previously. 17 Briefly, isolated uterine smooth muscle strips (15 × 7 × 5 mm) were immediately placed into tissue bath chambers filled with Krebs-Henseleit buffer of the following composition (nM): NaCl, 112.9; KCl, 4.7; CaCl2, 2.8; MgSO4, 0.5; NaHCO3, 24.9; and glucose, 11.1. The chambers were saturated by pneumoxide (95% O2 + 5% CO2) at a temperature of 36 ± 0.5°C and maintained at pH 7.5 ± 0.1.…”