Subcellular Ca2+ Mobilization in Gastric Smooth Muscle Contraction.
10.4097/kjae.2002.43.1.101
- Author:
Kwang Soo KIM
1
;
Nam Sik WOO
;
Ye Chul LEE
;
Bo Kyung KIM
;
Jung Hwan KIM
;
Sung Il CHO
Author Information
1. Department of Anesthesiology, College of Medicine, Konkuk University, Seoul, Korea. nswoo@konkuk.ac.kr
- Publication Type:Original Article
- Keywords:
Contraction;
intracellular Ca2+;
muscarin agonist;
stomach
- MeSH:
Animals;
Carbachol;
Mice;
Muscle, Smooth*;
Receptors, Muscarinic;
Stomach;
Verapamil
- From:Korean Journal of Anesthesiology
2002;43(1):101-106
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: The stomach can be generally classified anatomically into three parts; fundus, corpus, and antrum. It has not been well demonstrated how the three regions contribute to specified gastric motility. In the present study, the regional differences on contractile response and intracellular Ca2+ levels ([Ca2+]i) were investigated in a mouse gastric muscle. METHODS: An isometrical contraction was measured with a computerized physiograph, and [Ca2+]i was measured with fura-PE3/AM, a fluorescent Ca2+ indicator in gastric smooth muscle from mice. RESULTS: Carbachol (CCh), a potent muscarinic receptor agonist, generated rhythmic contractions in a dose dependent manner, superimposed on tonic components in the antral muscle. Whereas similar contractile responses to CCh was obtained in the antrum, CCh evoked tonic components predominantly. CCh increased [Ca2+]i in a dose dependent manner in both the antral and fundic smooth muscle. However, the increment of [Ca2+]i in the fundus was greater than that of the antrum. Verapamil (10nM), a l-type Ca2+ channel blocker, inhibited completely the contraction and [Ca2+]i induced by CCh in the antral strips, whereas the responses in the fundus showed a resistance to verapamil. CONCLUSIONS: These results suggest that muscarinic stimulation has a regional difference on muscle contractility and [Ca2+]i, which is mediated by differences of Ca2+ movement in mouse gastric muscle.
