Polyamines increase Ca2+ sensitivity in permeabilized smooth muscle of guinea pig ileum
Swärd, Karl LU ; Nilsson, Bengt-Olof LU
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:
https://lup.lub.lu.se/record/1107894
- author
- Swärd, Karl
LU
; Nilsson, Bengt-Olof
LU
and Hellstrand, Per
LU
- organization
- publishing date
- 1994
- type
- Contribution to journal
- publication status
- published
- subject
- 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}},
}