Increase of skeletal muscle relaxation speed by direct injection of parvalbumin cDNA.

Fish species exhibit great diversity rating of aging (from negligible to rapid), which gives a unique possibility for the discovery of the molecular mechanisms that determine the differences in the rate of aging. A mass spectrometric metabolic profiling of skeletal muscle of fish with various aging rates was carried out by direct injection to a quadrupole time-of-flight mass spectrometer. The first group includes long-lived fish species (pike (Esox Lucius) and sterlet (Acipenser ruthenus); the second group—species with gradual senescence such as that observed in many mammalian species of similar size (zander (Sandra lucioperca) and perch (Perca fluviatilis)) and the third group—species with very short life cycle (chum salmon (Oncorhynchus keta) and pink salmon (Oncorhynchus gorbuscha)). Multivariate analysis of metabolic profiles allowed the detecting of about 80 group-specific features associated with amino acids, lipids, biogenic amines, intermediates of glycolysis, glycogenolysis, and citric acid cycle. Possible roles in the aging process are hypothesized for the biochemical pathways of the metabolites that were altered in the different groups.

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Effect of Treatment on Skeletal Muscle Dysfunction in Hypothyroidism

Clinical Science ◽

10.1042/cs0660063 ◽

1984 ◽

Vol 66 (1) ◽

pp. 63-68 ◽

Cited By ~ 26

Author(s):

A. A. Khaleeli ◽

R. H. T. Edwards

Keyword(s):

Skeletal Muscle ◽

Time Course ◽

Muscle Relaxation ◽

Thyroid Stimulating Hormone ◽

Skeletal Muscle Function ◽

Skeletal Muscle Dysfunction ◽

Effect Of Treatment ◽

Quadriceps Force ◽

Serum Tsh ◽

Total Muscle

1. Abnormalities in skeletal muscle function were characterized in 19 hypothyroid subjects and the extent and time course of recovery in these abnormalities after treatment determined. 2. Slow muscle relaxation was observed on examination in 11 patients and 12 out of 16 patients had a reduced quadriceps maximum relaxation rate (MRR) and 11 out of 15 had a prolonged ankle jerk relaxation time (AJRT). 3. Measurements of quadriceps force revealed significant muscle weakness when comparison with 15 age matched healthy subjects was made (P<0.001). This weakness was often not evident on clinical examination. 4. A raised plasma creatine kinase (CK) activity was characteristic. 5. With treatment the plasma CK activity and the AJRT rapidly became normal often long before the serum thyroid-stimulating hormone (TSH) was normal, but the quadriceps MRR was slower to recover. It was rarely normal before the serum TSH became normal. Weakness was slow to recover and seven patients remained weak at the end of the study despite being euthyroid for a mean period of 1 year, but strength increased modestly overall (P < 0.01). The urinary creatinine/height index was unchanged, indicating that total muscle mass does not alter with therapy.

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Enhanced Ca2+ transport and muscle relaxation in skeletal muscle from sarcolipin-null mice

AJP Cell Physiology ◽

10.1152/ajpcell.00409.2010 ◽

2011 ◽

Vol 301 (4) ◽

pp. C841-C849 ◽

Cited By ~ 35

Author(s):

A. Russell Tupling ◽

Eric Bombardier ◽

Subash C. Gupta ◽

Dawar Hussain ◽

Chris Vigna ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Relaxation ◽

Force Frequency ◽

Relaxation Rates ◽

Wild Type ◽

Inhibitory Effects ◽

Tetanic Force ◽

Plasmic Reticulum ◽

Force Relaxation ◽

Frequency Curves

Sarcolipin (SLN) inhibits sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) pumps. To evaluate the physiological significance of SLN in skeletal muscle, we compared muscle contractility and SERCA activity between Sln-null and wild-type mice. SLN protein expression in wild-type mice was abundant in soleus and red gastrocnemius (RG), low in extensor digitorum longus (EDL), and absent from white gastrocnemius (WG). SERCA activity rates were increased in soleus and RG, but not in EDL or WG, from Sln-null muscles, compared with wild type. No differences were seen between wild-type and Sln-null EDL muscles in force-frequency curves or maximum rates of force development (+dF/d t). Maximum relaxation rates (−dF/d t) of EDL were higher in Sln-null than wild type across a range of submaximal stimulation frequencies, but not during a twitch or peak tetanic contraction. For soleus, no differences were seen between wild type and Sln-null in peak tetanic force or +dF/d t; however, force-frequency curves showed that peak force during a twitch and 10-Hz contraction was lower in Sln-null. Changes in the soleus force-frequency curve corresponded with faster rates of force relaxation at nearly all stimulation frequencies in Sln-null compared with wild type. Repeated tetanic stimulation of soleus caused increased (−dF/d t) in wild type, but not in Sln-null. No compensatory responses were detected in analysis of other Ca2+ regulatory proteins using Western blotting and immunohistochemistry or myosin heavy chain expression using immunofluorescence. These results show that 1) SLN regulates Ca2+-ATPase activity thereby regulating contractile kinetics in at least some skeletal muscles, 2) the functional significance of SLN is graded to the endogenous SLN expression level, and 3) SLN inhibitory effects on SERCA function are relieved in response to repeated contractions thus enhancing relaxation rates.

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EARLY AND LATE PHASES OF SKELETAL MUSCLE RELAXATION RESPOND DIFFERENTLY TO FATIGUE 831

Medicine & Science in Sports & Exercise ◽

10.1097/00005768-199605001-00829 ◽

1996 ◽

Vol 28 (Supplement) ◽

pp. 140

Author(s):

A. Jask??lska ◽

A. Jask??lski

Keyword(s):

Skeletal Muscle ◽

Muscle Relaxation

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Extensive alternative splicing transitions during postnatal skeletal muscle development are required for calcium handling functions

10.1101/124230 ◽

2017 ◽

Cited By ~ 1

Author(s):

Amy E. Brinegar ◽

Zheng Xia ◽

James A. Loehr ◽

Wei Li ◽

George G. Rodney ◽

...

Keyword(s):

Skeletal Muscle ◽

Alternative Splicing ◽

Postnatal Development ◽

Muscle Development ◽

Muscle Relaxation ◽

Calcium Handling ◽

Muscle Physiology ◽

Mouse Muscle ◽

Calcium Dependent ◽

Calcineurin A

AbstractPostnatal development of skeletal muscle is a highly dynamic period of tissue remodeling. Here we used RNA-seq to identify transcriptome changes from late embryonic to adult mouse muscle and demonstrate that alternative splicing developmental transitions impact muscle physiology. The first two weeks after birth are particularly dynamic for differential gene expression and AS transitions, and calciumhandling functions are significantly enriched among genes that undergo alternative splicing. We focused on the postnatal splicing transitions of three calcineurin A genes, calcium-dependent phosphatases that regulate multiple aspects of muscle biology. Redirected splicing of calcineurin A to the fetal isoforms in adult muscle and in differentiated C2C12 slows the timing of muscle relaxation, promotes nuclear localization of calcineurin targets Nfatc3 and Nfatc2, and affects expression of Nfatc transcription targets. The results demonstrate a previously unknown specificity of calcineurin isoforms as well as the broader impact of AS during muscle postnatal development.

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