Effects of 2,3-butanedione monoxime on activation of contraction and crossbridge kinetics in intact and chemically skinned smooth muscle fibres from guinea pig taenia coli
(1993) In Journal of Muscle Research and Cell Motility 14(2). p.186-194- Abstract
- The effects of 2,3-butanedione monoxime (BDM) were studied in smooth muscle fibres from guinea pig taenia coli. In intact muscle, active force during contractions induced by high-K+ was inhibited by about 10% in 1 mM BDM and by approximately 70% in 10 mM BDM. Intracellular [Ca2+] during contraction, measured with the fura-2 technique, was reduced in the presence of BDM. The reduction in force and [Ca2+] in the presence of 1 and 10 mM BDM could be reproduced by reduction in extracellular Ca2+, suggesting that BDM influences the Ca2+ entry or release. In skinned muscle preparations, BDM decreased the Ca2+ sensitivity of active force. This change could be explained by a decreased level of myosin light chain phosphorylation. In fibres... (More)
- The effects of 2,3-butanedione monoxime (BDM) were studied in smooth muscle fibres from guinea pig taenia coli. In intact muscle, active force during contractions induced by high-K+ was inhibited by about 10% in 1 mM BDM and by approximately 70% in 10 mM BDM. Intracellular [Ca2+] during contraction, measured with the fura-2 technique, was reduced in the presence of BDM. The reduction in force and [Ca2+] in the presence of 1 and 10 mM BDM could be reproduced by reduction in extracellular Ca2+, suggesting that BDM influences the Ca2+ entry or release. In skinned muscle preparations, BDM decreased the Ca2+ sensitivity of active force. This change could be explained by a decreased level of myosin light chain phosphorylation. In fibres maximally activated by thiophosphorylation, the effect of BDM on force occurred at higher concentrations; 10 mM gave no reduction of force and 60 mM 15% reduction. The maximal shortening velocity (Vmax) and force were unaffected by 30 mM BDM in thiophosphorylated muscle and decreased almost in parallel in Ca(2+)-activated contractions. The present results suggest that BDM inhibits myosin light chain phosphorylation, directly decreases force generation at the crossbridge level and inhibits the Ca2+ translocation in smooth muscle. The effect on force in skinned fibres is observed at higher BDM concentrations than those reported to be required for inhibition of force in striated muscle. The inhibition of force in intact smooth muscle could be explained by an influence on Ca2+ translocation. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1107557
- author
- Österman, Å ; Arner, Anders LU and Malmqvist, Ulf LU
- organization
- publishing date
- 1993
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Muscle Research and Cell Motility
- volume
- 14
- issue
- 2
- pages
- 186 - 194
- publisher
- Springer
- external identifiers
-
- pmid:8315022
- scopus:0027160263
- ISSN
- 0142-4319
- DOI
- 10.1007/BF00115453
- language
- English
- LU publication?
- yes
- id
- 2419c960-1949-4ed3-97c9-878329e888f2 (old id 1107557)
- date added to LUP
- 2016-04-01 15:54:16
- date last changed
- 2021-12-23 08:14:43
@article{2419c960-1949-4ed3-97c9-878329e888f2,
abstract = {{The effects of 2,3-butanedione monoxime (BDM) were studied in smooth muscle fibres from guinea pig taenia coli. In intact muscle, active force during contractions induced by high-K+ was inhibited by about 10% in 1 mM BDM and by approximately 70% in 10 mM BDM. Intracellular [Ca2+] during contraction, measured with the fura-2 technique, was reduced in the presence of BDM. The reduction in force and [Ca2+] in the presence of 1 and 10 mM BDM could be reproduced by reduction in extracellular Ca2+, suggesting that BDM influences the Ca2+ entry or release. In skinned muscle preparations, BDM decreased the Ca2+ sensitivity of active force. This change could be explained by a decreased level of myosin light chain phosphorylation. In fibres maximally activated by thiophosphorylation, the effect of BDM on force occurred at higher concentrations; 10 mM gave no reduction of force and 60 mM 15% reduction. The maximal shortening velocity (Vmax) and force were unaffected by 30 mM BDM in thiophosphorylated muscle and decreased almost in parallel in Ca(2+)-activated contractions. The present results suggest that BDM inhibits myosin light chain phosphorylation, directly decreases force generation at the crossbridge level and inhibits the Ca2+ translocation in smooth muscle. The effect on force in skinned fibres is observed at higher BDM concentrations than those reported to be required for inhibition of force in striated muscle. The inhibition of force in intact smooth muscle could be explained by an influence on Ca2+ translocation.}},
author = {{Österman, Å and Arner, Anders and Malmqvist, Ulf}},
issn = {{0142-4319}},
language = {{eng}},
number = {{2}},
pages = {{186--194}},
publisher = {{Springer}},
series = {{Journal of Muscle Research and Cell Motility}},
title = {{Effects of 2,3-butanedione monoxime on activation of contraction and crossbridge kinetics in intact and chemically skinned smooth muscle fibres from guinea pig taenia coli}},
url = {{http://dx.doi.org/10.1007/BF00115453}},
doi = {{10.1007/BF00115453}},
volume = {{14}},
year = {{1993}},
}