Mechanism of Relaxation Via TASK-2 Channels in Uterine Circular Muscle of Mouse.
10.4196/kjpp.2013.17.4.359
- Author:
Seung Hwa HONG
1
;
Rohyun SUNG
;
Young Chul KIM
;
Hikaru SUZUKI
;
Woong CHOI
;
Yeon Jin PARK
;
Ill Woon JI
;
Chan Hyung KIM
;
Sun Chul MYUNG
;
Moo Yeol LEE
;
Tong Mook KANG
;
Ra Young YOU
;
Kwang Ju LEE
;
Seung Woon LIM
;
Hyo Yung YUN
;
Young Jin SONG
;
Wen Xie XU
;
Hak Soon KIM
;
Sang Jin LEE
Author Information
1. Department of Obstetrics and Gynecology, Chungbuk National University College of Medicine, Cheongju 361-763, Korea. hakskim@chungbuk.ac.kr
- Publication Type:Original Article
- Keywords:
Relaxation;
TASK-2;
Uterus
- MeSH:
4-Aminopyridine;
Acidosis;
Animals;
Contracts;
Female;
Hydrogen-Ion Concentration;
Lidocaine;
Membranes;
Methionine;
Mice;
Muscle, Smooth;
Muscles;
Myometrium;
Plasma;
Pregnancy;
Quinidine;
Relaxation;
Uterine Contraction;
Uterus
- From:The Korean Journal of Physiology and Pharmacology
2013;17(4):359-365
- CountryRepublic of Korea
- Language:English
-
Abstract:
Plasma pH can be altered during pregnancy and at labor. Membrane excitability of smooth muscle including uterine muscle is suppressed by the activation of K+ channels. Because contractility of uterine muscle is regulated by extracellular pH and humoral factors, K+ conductance could be connected to factors regulating uterine contractility during pregnancy. Here, we showed that TASK-2 inhibitors such as quinidine, lidocaine, and extracellular acidosis produced contraction in uterine circular muscle of mouse. Furthermore, contractility was significantly increased in pregnant uterine circular muscle than that of non-pregnant muscle. These patterns were not changed even in the presence of tetraetylammonium (TEA) and 4-aminopyridine (4-AP). Finally, TASK-2 inhibitors induced strong myometrial contraction even in the presence of L-methionine, a known inhibitor of stretchactivated channels in myometrium. When compared to non-pregnant myometrium, pregnant myometrium showed increased immunohistochemical expression of TASK-2. Therefore, TASK-2, seems to play a key role during regulation of myometrial contractility in the pregnancy and provides new insight into preventing preterm delivery.
