Sadlonova Vladimira, Franova Sona, Dokus Karol, Janicek Frantisek, Visnovsky Jozef, Sadlonova Jurina
Department of Pharmacology, Jessenius Faculty of Medicine, Comenius University, Martin, Slovakia.
J Obstet Gynaecol Res. 2011 Mar;37(3):215-21. doi: 10.1111/j.1447-0756.2010.01340.x. Epub 2011 Jan 27.
The aim of this study was to assess the participation of ligand-sensitive potassium large conductance calcium-activated ion channels (BK(Ca2+) ) and adenosine triphosphate (ATP)-sensitive potassium ion channels (K(ATP) ) using its openers (NS1619 and pinacidil) in the contractility of human term pregnant myometrium in in vitro conditions.
Human myometrium tissue samples were collected from term pregnant laboring women who had to undergo cesarean section. The contractility of myometrium was induced by the application of oxytocin into the organ bath. Myometrial strips were incubated with the opener of BK(Ca2+) potassium ion channels NS1619 and its antagonist tetraethylammonium or with the opener of K(ATP) potassium ion channels pinacidil and its antagonist glibenclamide.
K(ATP) potassium ion channel's opener pinacidil significantly decreased amplitude of myometrial contractions (P < 0.05) as well as frequency of myometrial contractions (P < 0.05) provoked by oxytocin in human term pregnant myometrium in in vitro conditions. The inhibition of the human myometrial contractions of pinacidil was significantly antagonized by its specific antagonist glibenclamide (P < 0.05). BK(Ca2+) potassium ion channel's opener NS1619 did not significantly affect the contractile activity of human term pregnant myometrium induced by the application of oxytocin in in vitro conditions.
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.
本研究旨在评估配体敏感性大电导钙激活钾离子通道（BK(Ca2+) ）和三磷酸腺苷（ATP）敏感性钾离子通道（K(ATP) ）通过其开放剂（NS1619和吡那地尔）在体外条件下对足月妊娠人子宫肌层收缩性的影响。
从足月妊娠且需行剖宫产的产妇中收集人子宫肌层组织样本。通过向器官浴槽中加入缩宫素诱导子宫肌层收缩。将子宫肌条与BK(Ca2+) 钾离子通道开放剂NS1619及其拮抗剂四乙铵一起孵育，或与K(ATP) 钾离子通道开放剂吡那地尔及其拮抗剂格列本脲一起孵育。
在体外条件下，K(ATP) 钾离子通道开放剂吡那地尔显著降低了足月妊娠人子宫肌层由缩宫素诱发的子宫肌层收缩幅度（P < 0.05）以及子宫肌层收缩频率（P < 0.05）。吡那地尔对人子宫肌层收缩的抑制作用被其特异性拮抗剂格列本脲显著拮抗（P < 0.05）。BK(Ca2+) 钾离子通道开放剂NS1619在体外条件下对缩宫素诱导的足月妊娠人子宫肌层收缩活性没有显著影响。
在我们的实验研究中，我们发现BK(Ca2+) 和K(ATP) 钾离子通道在分娩时足月妊娠人子宫肌层收缩性中的作用可能不同。
