|
|
||||||||
AJP - Gastrointestinal and Liver Physiology, Vol 259, Issue 1 1-G5, Copyright © 1990 by American Physiological Society
ARTICLES |
L. M. Renzetti, M. B. Wang and J. P. Ryan
Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
Studies were performed to evaluate the contribution of intracellular Ca2+ to gallbladder smooth muscle contraction under acetylcholine (ACh) or potassium stimulation. Gallbladder smooth muscle strips from adult guinea pigs were placed in tissue baths containing N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES)-buffered physiological salt solution (PSS) and set to optimal length for contraction (Lo). The results were as follows, 1) A 20-min equilibration in zero Ca2(+)-0.1 mM ethylene glycol-bis( beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) PSS virtually abolished the response to potassium but not to ACh. 2) Substitution of strontium, an inhibitor of intracellular Ca2+ release, for Ca2+ significantly decreased the contractile response to ACh (3 X 10(-5), 10(-4), and 3 X 10(-4) M). Strontium had no effect on the response to 40 and 80 mM potassium. 3) Intracellular Ca2+ depletion significantly decreased gallbladder smooth muscle contraction to ACh (10(-4) M) but had no effect on the response to potassium (80 mM). 4) Ryanodine, a compound that inhibits Ca2+ storage by the sarcoplasmic reticulum, significantly decreased the contractile response to ACh (10(-4) M) but not to potassium (80 mM). These data support the observation that the use of intracellular Ca2+ by gallbladder smooth muscle for contraction is agonist dependent.
This article has been cited by other articles:
![]() |
S. Morales, P. J. Camello, G. M. Mawe, and M. J. Pozo Characterization of intracellular Ca2+ stores in gallbladder smooth muscle Am J Physiol Gastrointest Liver Physiol, March 1, 2005; 288(3): G507 - G513. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. P. Parkman, A. N. James, and J. P. Ryan The contractile action of platelet-activating factor on gallbladder smooth muscle Am J Physiol Gastrointest Liver Physiol, July 1, 2000; 279(1): G67 - G72. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. S. Myers, J. S. Martin, D. T. Dempsey, H. P. Parkman, R. M. Thomas, and J. P. Ryan Acute experimental colitis decreases colonic circular smooth muscle contractility in rats Am J Physiol Gastrointest Liver Physiol, October 1, 1997; 273(4): G928 - G936. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |