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Polyamines increase Ca2+ sensitivity in permeabilized smooth muscle of guinea pig ileum

Swärd, Karl LU ; Nilsson, Bengt-Olof LU orcid and Hellstrand, Per LU (1994) In American Journal of Physiology: Cell Physiology 266(6). p.1754-1763
Abstract
The effects of polyamines were investigated in strips of smooth muscle from guinea pig ileum permeabilized with beta-escin (0.005%). Spermine (1 mM) inhibited transient contractions induced in Ca(2+)-free medium by carbachol (0.1 mM) and GTP gamma S (0.1 mM) but potentiated responses to caffeine (20 mM) and D-myo-inositol 1,4,5-trisphosphate (40 microM). At high ethylene glycol-bis(beta-amino-ethyl ether)-N,N,N',N'-tetraacetic acid concentration (10 mM) and in the presence of A-23187 (10 microM), force at optimal and suboptimal Ca2+ concentrations was increased both by spermine and by carbachol. Spermine did not potentiate contraction in Ca(2+)-free medium or after full thiophosphorylation of the regulatory 20-kDa myosin light chains but... (More)
The effects of polyamines were investigated in strips of smooth muscle from guinea pig ileum permeabilized with beta-escin (0.005%). Spermine (1 mM) inhibited transient contractions induced in Ca(2+)-free medium by carbachol (0.1 mM) and GTP gamma S (0.1 mM) but potentiated responses to caffeine (20 mM) and D-myo-inositol 1,4,5-trisphosphate (40 microM). At high ethylene glycol-bis(beta-amino-ethyl ether)-N,N,N',N'-tetraacetic acid concentration (10 mM) and in the presence of A-23187 (10 microM), force at optimal and suboptimal Ca2+ concentrations was increased both by spermine and by carbachol. Spermine did not potentiate contraction in Ca(2+)-free medium or after full thiophosphorylation of the regulatory 20-kDa myosin light chains but slightly potentiated contractions produced by partial thiophosphorylation. Also, spermidine and putrescine, as well as the aminoglycoside antibiotic neomycin, increased sensitivity to Ca2+, with potency correlating with number of positive charges. After permeabilization by a high concentration (0.1%) of beta-escin, the sensitivity to Ca2+ was increased by spermine but not by GTP gamma S. In preparations permeabilized by Triton X-100, spermine slightly increased Ca2+ sensitivity but not maximal force. Tissue contents of putrescine, spermidine, and spermine in intact ileum muscle were 8, 98, and 184 nmol/g, respectively. Permeabilization by 0.005 and 0.1% beta-escin reduced spermine contents by 40 and 53%, respectively. Effects of added polyamines in permeabilized preparations may thus reflect physiological effects of endogenous polyamines modulating contraction in the intact tissue. (Less)
Please use this url to cite or link to this publication:
author
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Contribution to journal
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published
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in
American Journal of Physiology: Cell Physiology
volume
266
issue
6
pages
1754 - 1763
publisher
American Physiological Society
external identifiers
  • pmid:8023905
  • scopus:0028227132
ISSN
1522-1563
language
English
LU publication?
yes
id
868934b5-996f-40fa-9886-6eb219b21d75 (old id 1107894)
alternative location
http://ajpcell.physiology.org/cgi/reprint/266/6/C1754
date added to LUP
2016-04-01 15:25:28
date last changed
2023-06-26 04:25:44
@article{868934b5-996f-40fa-9886-6eb219b21d75,
  abstract     = {{The effects of polyamines were investigated in strips of smooth muscle from guinea pig ileum permeabilized with beta-escin (0.005%). Spermine (1 mM) inhibited transient contractions induced in Ca(2+)-free medium by carbachol (0.1 mM) and GTP gamma S (0.1 mM) but potentiated responses to caffeine (20 mM) and D-myo-inositol 1,4,5-trisphosphate (40 microM). At high ethylene glycol-bis(beta-amino-ethyl ether)-N,N,N',N'-tetraacetic acid concentration (10 mM) and in the presence of A-23187 (10 microM), force at optimal and suboptimal Ca2+ concentrations was increased both by spermine and by carbachol. Spermine did not potentiate contraction in Ca(2+)-free medium or after full thiophosphorylation of the regulatory 20-kDa myosin light chains but slightly potentiated contractions produced by partial thiophosphorylation. Also, spermidine and putrescine, as well as the aminoglycoside antibiotic neomycin, increased sensitivity to Ca2+, with potency correlating with number of positive charges. After permeabilization by a high concentration (0.1%) of beta-escin, the sensitivity to Ca2+ was increased by spermine but not by GTP gamma S. In preparations permeabilized by Triton X-100, spermine slightly increased Ca2+ sensitivity but not maximal force. Tissue contents of putrescine, spermidine, and spermine in intact ileum muscle were 8, 98, and 184 nmol/g, respectively. Permeabilization by 0.005 and 0.1% beta-escin reduced spermine contents by 40 and 53%, respectively. Effects of added polyamines in permeabilized preparations may thus reflect physiological effects of endogenous polyamines modulating contraction in the intact tissue.}},
  author       = {{Swärd, Karl and Nilsson, Bengt-Olof and Hellstrand, Per}},
  issn         = {{1522-1563}},
  language     = {{eng}},
  number       = {{6}},
  pages        = {{1754--1763}},
  publisher    = {{American Physiological Society}},
  series       = {{American Journal of Physiology: Cell Physiology}},
  title        = {{Polyamines increase Ca2+ sensitivity in permeabilized smooth muscle of guinea pig ileum}},
  url          = {{http://ajpcell.physiology.org/cgi/reprint/266/6/C1754}},
  volume       = {{266}},
  year         = {{1994}},
}