Exercise training attenuates coronary smooth muscle phenotypic modulation and nuclear Ca2+ signaling
1 Departments of Physiology and 2 Internal Medicine, School of Medicine, 3 Department of Veterinary Biomedical Sciences, School of Veterinary Medicine, 4 Dalton Cardiovascular Research Center, and 5 Diabetes and Cardiovascular Biology Program, University of Missouri, Columbia, Missouri 65212 Ph...
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Published in | American journal of physiology. Heart and circulatory physiology Vol. 283; no. 6; pp. H2397 - H2410 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
01.12.2002
|
Subjects | |
Online Access | Get full text |
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Summary: | 1 Departments of Physiology and
2 Internal Medicine, School of Medicine,
3 Department of Veterinary Biomedical Sciences, School
of Veterinary Medicine, 4 Dalton Cardiovascular Research
Center, and 5 Diabetes and Cardiovascular Biology
Program, University of Missouri, Columbia, Missouri 65212
Physical
inactivity is an independent risk factor for coronary heart disease,
yet the mechanism(s) of exercise-related cardioprotection remains
unknown. We tested the hypothesis that coronary smooth muscle after
exercise training would have decreased mitogen-induced phenotypic
modulation and enhanced regulation of nuclear Ca 2+ . Yucatan
swine were endurance exercise trained (EX) on a treadmill for
16-20 wk. EX reduced endothelin-1-induced DNA content by 40% compared with sedentary (SED) swine ( P < 0.01). EX
decreased single cell peak endothelin-1-induced cytosolic
Ca 2+ responses compared with SED by 16% and peak nuclear
Ca 2+ responses by 33% ( P < 0.05), as
determined by confocal microscopy. On the basis of these results, we
hypothesized that sarco(endo)plasmic reticulum Ca 2+ -ATPase
(SERCA) and intracellular Ca 2+ stores in native smooth
muscle are spatially localized to dissociate cytosolic Ca 2+
and nuclear Ca 2+ . Subcellular localization of SERCA in
living and fixed cells revealed a distribution of SERCA near the
sarcolemma and on the nuclear envelope. These results show that EX
enhances nuclear Ca 2+ regulation, possibly via SERCA, which
may be one mechanism by which coronary smooth muscle cells from EX are
less responsive to mitogen-induced phenotypic modulation.
endothelin-1; sarco(endo)plasmic reticulum
Ca 2+ -ATPase; electron microscopy; fluorescence microscopy; swine
Deceased 7 May 2002. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0363-6135 1522-1539 |
DOI: | 10.1152/ajpheart.00371.2001 |