Am J Physiol Cell Physiol Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Cell Physiol 258: C787-C793, 1990;
0363-6143/90 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Mitsui, M.
Right arrow Articles by Karaki, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mitsui, M.
Right arrow Articles by Karaki, H.

AJP - Cell Physiology, Vol 258, Issue 5 C787-C793, Copyright © 1990 by American Physiological Society

ARTICLES

Dual effects of carbachol on cytosolic Ca2+ and contraction in intestinal smooth muscle

M. Mitsui and H. Karaki
Department of Veterinary Pharmacology, Faculty of Agriculture, University of Tokyo, Japan.

The effects of carbachol on muscle tension and cytosolic Ca2+ concentrations ([Ca2+]cyt), measured with fura-2, were examined in the guinea pig intestinal smooth muscle. Carbachol induced an initial transient increase followed by a sustained increase in [Ca2+]cyt and muscle tension. Higher concentrations of carbachol induced larger transient changes and smaller sustained changes. In the presence of carbachol, application of Ca2+ to a Ca2(+)-depleted muscle induced a contraction that was smaller in the presence of higher concentrations of carbachol. High concentrations of carbachol inhibited the high-K(+)-stimulated muscle tension and [Ca2+]cyt. Contractile and inhibitory effects of carbachol were inhibited by a muscarinic M2 antagonist. Increase in the external Ca2+ concentration or addition of BAY K 8644, a Ca2(+)-channel activator, antagonized the inhibitory effect. There was a linear correlation between log [Ca2+]cyt and muscle tension under the conditions employed in the present experiments (r = 0.949). These results suggest that lower concentrations of carbachol increase [Ca2+]cyt and induce contraction, whereas high concentrations of carbachol have an additional effect to decrease [Ca2+]cyt and inhibit contraction by a Ca2(+)-channel blocker-like action.


This article has been cited by other articles:


Home page
 J. Pharmacol. Exp. Ther.Home page
S. Horio, T. Nagare, Y. Ishida, and H. Moritoki
Effects of Local Anesthetics on Acetylcholine-Induced Desensitization of Guinea Pig Ileal Longitudinal Muscle
J. Pharmacol. Exp. Ther., July 1, 1998; 286(1): 221 - 227.
[Abstract] [Full Text]

Home page
 Pharmacol. Rev.Home page
H. Karaki, H. Ozaki, M. Hori, M. Mitsui-Saito, K.-I. Amano, K.-I. Harada, S. Miyamoto, H. Nakazawa, K.-J. Won, and K. Sato
Calcium Movements, Distribution, and Functions in Smooth Muscle
Pharmacol. Rev., June 1, 1997; 49(2): 157 - 230.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online