Universität zu Köln

Gehlert, Sebastian ORCID: 0000-0001-6940-3084, Bungartz, Gerd, Willkomm, Lena, Korkmaz, Yueksel, Pfannkuche, Kurt, Schiffer, Thorsten, Bloch, Wilhelm and Suhr, Frank (2012). Intense Resistance Exercise Induces Early and Transient Increases in Ryanodine Receptor 1 Phosphorylation in Human Skeletal Muscle. PLoS One, 7 (11). SAN FRANCISCO: PUBLIC LIBRARY SCIENCE. ISSN 1932-6203

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Abstract

Background: While ryanodine receptor 1 (RyR1) critically contributes to skeletal muscle contraction abilities by mediating Ca(2+)ion oscillation between sarcoplasmatic and myofibrillar compartments, AMP-activated protein kinase (AMPK) senses contraction-induced energetic stress by phosphorylation at Thr(172). Phosphorylation of RyR1 at serine(2843) (pRyR1Ser(2843)) results in leaky RyR1 channels and impaired Ca2+ homeostasis. Because acute resistance exercise exerts decreased contraction performance in skeletal muscle, preceded by high rates of Ca2+-oscillation and energetic stress, intense myofiber contractions may induce increased RyR1 and AMPK phosphorylation. However, no data are available regarding the time-course and magnitude of early RyR1 and AMPK phosphorylation in human myofibers in response to acute resistance exercise. Purpose: Determine the effects and early time-course of resistance exercise on pRyR1Ser(2843) and pAMPKThr(172) in type I and II myofibers. Methods: 7 male subjects (age 23 +/- 2 years, height: 185 +/- 7 cm, weight: 82 +/- 5 kg) performed 3 sets of 8 repetitions of maximum eccentric knee extensions. Muscle biopsies were taken at rest, 15, 30 and 60 min post exercise. pRyR1Ser(2843) and pAMPKThr(172) levels were determined by western blot and semi-quantitative immunohistochemistry techniques. Results: While total RyR1 and total AMPK levels remained unchanged, RyR1 was significantly more abundant in type II than type I myofibers. pRyR1Ser(2843) increased 15 min and peaked 30 min (p<0.01) post exercise in both myofiber types. Type I fibers showed relatively higher increases in pRyR1Ser(2843) levels than type II myofibers and remained elevated up to 60 min post resistance exercise (p<0.05). pAMPKThr(172) also increased 15 to 30 min post exercise (p<0.01) in type I and II myofibers and in whole skeletal muscle. Conclusion: Resistance exercise induces acutely increased pRyR1Ser(2843) and concomitantly pAMPKThr(172) levels for up to 30 min in resistance exercised myofibers. This provides a time-course by which pRyR1Ser(2843) can mechanistically impact Ca2+ handling properties and consequently induce reduced myofiber contractility beyond immediate fatiguing mechanisms.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Gehlert, Sebastian UNSPECIFIED orcid.org/0000-0001-6940-3084 UNSPECIFIED Bungartz, Gerd UNSPECIFIED UNSPECIFIED UNSPECIFIED Willkomm, Lena UNSPECIFIED UNSPECIFIED UNSPECIFIED Korkmaz, Yueksel UNSPECIFIED UNSPECIFIED UNSPECIFIED Pfannkuche, Kurt UNSPECIFIED UNSPECIFIED UNSPECIFIED Schiffer, Thorsten UNSPECIFIED UNSPECIFIED UNSPECIFIED Bloch, Wilhelm UNSPECIFIED UNSPECIFIED UNSPECIFIED Suhr, Frank UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-478850
DOI:	10.1371/journal.pone.0049326
Journal or Publication Title:	PLoS One
Volume:	7
Number:	11
Date:	2012
Publisher:	PUBLIC LIBRARY SCIENCE
Place of Publication:	SAN FRANCISCO
ISSN:	1932-6203
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language CALCIUM-RELEASE; FATIGUE; FIBERS; RECRUITMENT; ACTIVATION; EXPRESSION; PLASTICITY; VOLUNTARY; RESPONSES; CHANNELS Multiple languages Multidisciplinary Sciences Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/47885