Muscarinic receptor subtype controlling the carbachol-induced muscle contraction in guinea pig gastric antrum.
- Author:
Jong Chul RHEE
1
;
Dae Yong UHM
;
Tong Mook KANG
Author Information
1. Department of Medicine, Sungkyunkwan University School of Medicine, Suwon, South Korea.
- Publication Type:Original Article
- Keywords:
Muscarinic receptor subtype;
Carbachol;
Smooth muscle
- MeSH:
Animals;
Baths;
Carbachol;
Guinea Pigs*;
Guinea*;
Muscarinic Antagonists;
Muscle Contraction*;
Muscle, Smooth;
Pirenzepine;
Pyloric Antrum*;
Receptors, Muscarinic*
- From:The Korean Journal of Physiology and Pharmacology
2000;4(2):105-111
- CountryRepublic of Korea
- Language:English
-
Abstract:
Stimulation of muscarinic receptors by carbachol (CCh) in the circular smooth muscle of the guinea pig gastric antrum causes muscle contraction. In the present study, muscarinic receptor subtype controlling the muscle contraction in response to CCh was studied using putative muscarinic receptor antagonists. Isometric force of the isolated circular muscle strips was measured in an organ bath. CCh contracted the muscle in a dose-dependent way, and each of the three muscarinic receptor antagonists, 4-diphenylacetoxy-N-methylpeperdine methiodide (4-DAMP), methoctramine and pirenzepine shifted the concentration-response curves to the right without significantly reducing the maximum force. The affinities of the muscarinic antagonists (pA2 values) obtained from Schild plot analysis were 10.15, 7.05 and 6.84 for 4-DAMP, methoctramine and pirenzepine, respectively. These results suggest that the M3-subtype mainly mediate the muscle contraction in response to CCh in guinea pig gastric antrum.
