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Long-term regulation of contractility and calcium current in smooth muscle

Gomez, Maria LU and Swärd, Karl LU (1997) In American Journal of Physiology 273(5). p.1714-1720
Abstract
Longitudinal smooth muscle strips from guinea pig ileum were cultured in vitro for 5 days, and the relationship between extracellular Ca2+ and force in high-K+ medium was evaluated. In strips cultured with 10% fetal calf serum (FCS), this relationship was shifted to the right (50% effective concentration changed by 2-3 mM) compared with strips cultured without FCS. The shift was prevented by inclusion of verapamil (1 microM) during culture and mimicked by ionomycin in the absence of FCS. The intracellular Ca2+ concentration ([Ca2+]i) during stimulation with high-K+ solution or carbachol was reduced after culture with FCS, whereas the [Ca2+]i-force relationship was unaffected. Cells were isolated from cultured strips, and whole cell... (More)
Longitudinal smooth muscle strips from guinea pig ileum were cultured in vitro for 5 days, and the relationship between extracellular Ca2+ and force in high-K+ medium was evaluated. In strips cultured with 10% fetal calf serum (FCS), this relationship was shifted to the right (50% effective concentration changed by 2-3 mM) compared with strips cultured without FCS. The shift was prevented by inclusion of verapamil (1 microM) during culture and mimicked by ionomycin in the absence of FCS. The intracellular Ca2+ concentration ([Ca2+]i) during stimulation with high-K+ solution or carbachol was reduced after culture with FCS, whereas the [Ca2+]i-force relationship was unaffected. Cells were isolated from cultured strips, and whole cell voltage-clamp experiments were performed. Maximum inward Ca2+ current (10 mM Ba2+), normalized to cell capacitance, was almost three times smaller in cells isolated from strips cultured with FCS. Culture with 1 microM verapamil prevented this reduction. These results suggest that increased [Ca2+]i during culture downregulates Ca2+ current density, with associated effects on contractility. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
fura 2, verapamil, patch clamp, ionomycin, tissue culture
in
American Journal of Physiology
volume
273
issue
5
pages
1714 - 1720
publisher
American Pysiological Society
external identifiers
  • pmid:9374659
  • scopus:0030722259
ISSN
0002-9513
language
English
LU publication?
yes
id
c4519778-b5e6-4a2b-8cc0-01afe38d3e99 (old id 1111933)
alternative location
http://ajpcell.physiology.org/cgi/content/full/273/5/C1714
date added to LUP
2008-07-21 10:29:56
date last changed
2017-01-01 07:26:00
@article{c4519778-b5e6-4a2b-8cc0-01afe38d3e99,
  abstract     = {Longitudinal smooth muscle strips from guinea pig ileum were cultured in vitro for 5 days, and the relationship between extracellular Ca2+ and force in high-K+ medium was evaluated. In strips cultured with 10% fetal calf serum (FCS), this relationship was shifted to the right (50% effective concentration changed by 2-3 mM) compared with strips cultured without FCS. The shift was prevented by inclusion of verapamil (1 microM) during culture and mimicked by ionomycin in the absence of FCS. The intracellular Ca2+ concentration ([Ca2+]i) during stimulation with high-K+ solution or carbachol was reduced after culture with FCS, whereas the [Ca2+]i-force relationship was unaffected. Cells were isolated from cultured strips, and whole cell voltage-clamp experiments were performed. Maximum inward Ca2+ current (10 mM Ba2+), normalized to cell capacitance, was almost three times smaller in cells isolated from strips cultured with FCS. Culture with 1 microM verapamil prevented this reduction. These results suggest that increased [Ca2+]i during culture downregulates Ca2+ current density, with associated effects on contractility.},
  author       = {Gomez, Maria and Swärd, Karl},
  issn         = {0002-9513},
  keyword      = {fura 2,verapamil,patch clamp,ionomycin,tissue culture},
  language     = {eng},
  number       = {5},
  pages        = {1714--1720},
  publisher    = {American Pysiological Society},
  series       = {American Journal of Physiology},
  title        = {Long-term regulation of contractility and calcium current in smooth muscle},
  volume       = {273},
  year         = {1997},
}