Muscarinic Receptor Subtype Controlling the Carbachol-Induced Muscle Contraction in Guinea Pig Gastric Antrum
Muscarinic Receptor Subtype Controlling the Carbachol-Induced Muscle Contraction in Guinea Pig Gastric Antrum
- 대한생리학회-대한약리학회
- The Korean Journal of Physiology & Pharmacology
- 제4권 제2호
- : SCOPUS, SCIE, KCI등재
- 2000.01
- 105 - 111 (7 pages)
<P> 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 (pA<SUB>2</SUB> 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 M<SUB>3</SUB>-subtype mainly mediate the muscle contraction in response to CCh in guinea pig gastric antrum.