Free cytosolic calcium during spontaneous contractions in smooth muscle of the guinea-pig mesotubarium
(1990) In Pflügers Archiv 417(4). p.404-409- Abstract
- The free intracellular calcium ion concentration ([Ca2+]i) was measured simultaneously with isometric force in strips of guinea-pig mesotubarium using the Fura-2 technique. During the relaxed period (5-15 min) between spontaneous contractions [Ca2+]i continues to decrease after full mechanical relaxation to reach a minimal level of 86 +/- 8 nM (n = 9) just before the start of the next contraction. During the spontaneous contractions (5-15 min) [Ca2+]i reached a maximum of 211 +/- 19 nM and then oscillated between 155 +/- 16 nM and 194 +/- 9 nM. Increased extracellular Ca2+ concentration to 10 mM from the standard concentration of 1.5 mM caused a decreased frequency of spontaneous contractions and an increase in [Ca2+]i both in the relaxed... (More)
- The free intracellular calcium ion concentration ([Ca2+]i) was measured simultaneously with isometric force in strips of guinea-pig mesotubarium using the Fura-2 technique. During the relaxed period (5-15 min) between spontaneous contractions [Ca2+]i continues to decrease after full mechanical relaxation to reach a minimal level of 86 +/- 8 nM (n = 9) just before the start of the next contraction. During the spontaneous contractions (5-15 min) [Ca2+]i reached a maximum of 211 +/- 19 nM and then oscillated between 155 +/- 16 nM and 194 +/- 9 nM. Increased extracellular Ca2+ concentration to 10 mM from the standard concentration of 1.5 mM caused a decreased frequency of spontaneous contractions and an increase in [Ca2+]i both in the relaxed and contracted states. In 10 mM extracellular Ca2+, addition of AlF4-, as 1 mM NaF + 10 microM AlCl3, caused a sustained increase in [Ca2+]i and maintained force. Addition of verapamil (10 microM) in this situation decreased [Ca2+]i to the resting level. The results suggest that the cyclic appearance of trains of action potentials is related to variation in [Ca2+]i, possibly via inactivation of Ca2(+)-dependent K+ channels. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1105281
- author
- Himpens, B ; Lydrup, M L ; Hellstrand, Per LU and Casteels, R
- organization
- publishing date
- 1990
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- [Ca2+]i, Smooth muscle, Mesotubarium, Pacemaker activity
- in
- Pflügers Archiv
- volume
- 417
- issue
- 4
- pages
- 404 - 409
- publisher
- Springer
- external identifiers
-
- pmid:2080105
- scopus:0025610677
- ISSN
- 0031-6768
- DOI
- 10.1007/BF00370660
- language
- English
- LU publication?
- yes
- id
- 7494aee9-6fb3-447c-91cf-2f628259d995 (old id 1105281)
- date added to LUP
- 2016-04-01 16:35:36
- date last changed
- 2021-01-03 09:27:10
@article{7494aee9-6fb3-447c-91cf-2f628259d995,
abstract = {{The free intracellular calcium ion concentration ([Ca2+]i) was measured simultaneously with isometric force in strips of guinea-pig mesotubarium using the Fura-2 technique. During the relaxed period (5-15 min) between spontaneous contractions [Ca2+]i continues to decrease after full mechanical relaxation to reach a minimal level of 86 +/- 8 nM (n = 9) just before the start of the next contraction. During the spontaneous contractions (5-15 min) [Ca2+]i reached a maximum of 211 +/- 19 nM and then oscillated between 155 +/- 16 nM and 194 +/- 9 nM. Increased extracellular Ca2+ concentration to 10 mM from the standard concentration of 1.5 mM caused a decreased frequency of spontaneous contractions and an increase in [Ca2+]i both in the relaxed and contracted states. In 10 mM extracellular Ca2+, addition of AlF4-, as 1 mM NaF + 10 microM AlCl3, caused a sustained increase in [Ca2+]i and maintained force. Addition of verapamil (10 microM) in this situation decreased [Ca2+]i to the resting level. The results suggest that the cyclic appearance of trains of action potentials is related to variation in [Ca2+]i, possibly via inactivation of Ca2(+)-dependent K+ channels.}},
author = {{Himpens, B and Lydrup, M L and Hellstrand, Per and Casteels, R}},
issn = {{0031-6768}},
keywords = {{[Ca2+]i; Smooth muscle; Mesotubarium; Pacemaker activity}},
language = {{eng}},
number = {{4}},
pages = {{404--409}},
publisher = {{Springer}},
series = {{Pflügers Archiv}},
title = {{Free cytosolic calcium during spontaneous contractions in smooth muscle of the guinea-pig mesotubarium}},
url = {{http://dx.doi.org/10.1007/BF00370660}},
doi = {{10.1007/BF00370660}},
volume = {{417}},
year = {{1990}},
}