Myometrial relaxation of mice via expression of two pore domain acid sensitive K⁺ (TASK-2) channels.
10.4196/kjpp.2016.20.5.547
- Author:
Kyu Sang KYEONG
1
;
Seung Hwa HONG
;
Young Chul KIM
;
Woong CHO
;
Sun Chul MYUNG
;
Moo Yeol LEE
;
Ra Young YOU
;
Chan Hyung KIM
;
So Yeon KWON
;
Hikaru SUZUKI
;
Yeon Jin PARK
;
Eun Hwan JEONG
;
Hak Soon KIM
;
Heon KIM
;
Seung Woon LIM
;
Wen Xie XU
;
Sang Jin LEE
;
Il Woon JI
Author Information
1. Department of Obstetrics and Gynecology, Chungbuk National University College of Medicine, Cheongju 28644, Korea. iwji@chungbuk.ac.kr
- Publication Type:Original Article
- Keywords:
Longitudinal muscle;
Myometrium;
Relaxation;
TASK-2
- MeSH:
Acidosis;
Animals;
Blotting, Western;
Bupivacaine;
Estrogens;
Female;
Isometric Contraction;
Lidocaine;
Methionine;
Mice*;
Microscopy, Confocal;
Muscle, Smooth;
Myometrium;
Oxytocin;
Pregnancy;
Quinidine;
Relaxation*;
Tea;
Uterine Contraction;
Uterus
- From:The Korean Journal of Physiology and Pharmacology
2016;20(5):547-556
- CountryRepublic of Korea
- Language:English
-
Abstract:
Myometrial relaxation of mouse via expression of two-pore domain acid sensitive (TASK) channels was studied. In our previous report, we suggested that two-pore domain acid-sensing K⁺ channels (TASK-2) might be one of the candidates for the regulation of uterine circular smooth muscles in mice. In this study, we tried to show the mechanisms of relaxation via TASK-2 channels in marine myometrium. Isometric contraction measurements and patch clamp technique were used to verify TASK conductance in murine myometrium. Western blot and immunehistochemical study under confocal microscopy were used to investigate molecular identity of TASK channel. In this study, we showed that TEA and 4-AP insensitive non-inactivating outward K⁺ current (NIOK) may be responsible for the quiescence of murine pregnant longitudinal myometrium. The characteristics of NIOK coincided with two-pore domain acid-sensing K⁺ channels (TASK-2). NIOK in the presence of K⁺ channel blockers was inhibited further by TASK inhibitors such as quinidine, bupivacaine, lidocaine, and extracellular acidosis. Furthermore, oxytocin and estrogen inhibited NIOK in pregnant myometrium. When compared to non-pregnant myometrium, pregnant myometrium showed stronger inhibition of NIOK by quinidine and increased immunohistochemical expression of TASK-2. Finally, TASK-2 inhibitors induced strong myometrial contraction even in the presence of L-methionine, a known inhibitor of stretch-activated channels in the longitudinal myometrium of mouse. Activation of TASK-2 channels seems to play an essential role for relaxing uterus during pregnancy and it might be one of the alternatives for preventing preterm delivery.
