scholarly journals Fibre-type-specific and Mitochondrial Biomarkers of Muscle Damage after Mountain Races

2019 ◽  
Vol 40 (04) ◽  
pp. 253-262 ◽  
Author(s):  
Gerard Carmona ◽  
Emma Roca ◽  
Mario Guerrero ◽  
Roser Cussó ◽  
Cristina Bàrcena ◽  
...  

AbstractConsequences of running mountain races on muscle damage were investigated by analysing serum muscle enzymes and fibre-type-specific sarcomere proteins. We studied 10 trained amateur and 6 highly trained runners who ran a 35 km and 55 km mountain trail race (MTR), respectively. Levels of creatine kinase (CK), CK-MB isoform (CK-MB), sarcomeric mitochondrial CK (sMtCK), transaminases (AST and ALT), cardiac troponin I (cTnI) and fast (FM) and slow myosin (SM) isoforms, were assessed before, 1 h, 24 h and 48 h after the beginning of MTR. Significant SM increases were found at 24 h in the 55 km group. Levels of CK, CK-MB, AST and cTnI were significantly elevated in both groups following MTR, but in the 55 km group they tended to stabilize in at 48 h. Using pooled data, time-independent serum peaks of SM and CK-MB were significantly correlated. Moreover, concentration of sMtCK was significantly elevated at 1 and 24 h after the race in the 35 km group. Although training volume could confer protection on the mitochondria, the increase in serum CK-MB and SM in the 55 km group might be related to damage to the contractile apparatus type I fibres. Competing in long-distance MTRs might be related to deeper type I muscle fibre damage, even in highly trained individuals

1985 ◽  
Vol 115 (1) ◽  
pp. 31-42
Author(s):  
S. V. Perry

The differences in performance that exist between skeletal muscles are in part determined by the presence of different forms of most of the contractile and regulatory proteins of the myofibril - isoforms. These isoforms have common properties but their amino acid sequences are not identical and they exhibit slight differences in biological activities, such as ATPase, affinity for calcium, etc., that are appropriate for the physiological properties of the muscle in which they are present. With the exception of actin, all the major proteins present in the I and A filaments of skeletal muscle have been shown to exist in two or more isoforms. Whereas proteins such as troponin I and troponin C are present as a single isoform in each fibre type in normal muscle, others such as myosin and tropomyosin are present as two or more isoforms, usually in relative amounts characteristic for the fibre type. Type I and type II muscle fibres possess the capacity of synthesizing all the skeletal muscle isoforms of the myofibrillar proteins. The complement of isoforms present in a muscle fibre, however, depends on a number of factors such as the stage of development or regeneration, type of innervation, hormonal effects, etc. Complex mechanisms involving the coordinated control of gene expression must operate to ensure that the set of isoforms of the myofibrillar proteins present is characteristic for the cell type.


Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 926
Author(s):  
Daniela M. Meléndez ◽  
Sonia Marti ◽  
Luigi Faucitano ◽  
Derek B. Haley ◽  
Timothy D. Schwinghamer ◽  
...  

Lactate is a product of anaerobic glycolysis, used in animal research as an indicator of muscle fatigue. Therefore, it has been used as an indicator of cattle response to long distance transportation. The aim of this study was to assess the relationship of L-lactate concentrations measured using a Lactate Scout+ analyzer and a traditional lactate assay colorimetric kit. Blood samples were collected by venipuncture from 96 steers (Black or Red Angus × Hereford/Simmental and Black or Red Angus × Charolais; 247 ± 38.2 kg BW) prior to loading (LO1) and after 36 h of transport, and prior to reloading and after an additional 4 h of road transportation, and on d 1, 2, 3, 5, 14, and 28 after transport. The Lactate Scout+ analyzer strip was dipped in blood at the time of sampling, while blood samples were collected into sodium fluoride tubes for use in the colorimetric analysis. Pearson correlations were calculated to assess the strength of the relationship between the experimental methods for the quantification of L-lactate concentrations. The magnitude and direction of the correlation, and the level of statistical significance varied over the observed time points, ranging from r = −0.03 (p = 0.75; LO1) to r = 0.75 (p < 0.0001; d 3). The correlation for the pooled data was weak but statistically significant (r = 0.33, p < 0.0001). Based on the low magnitude of the correlation due to variability across sampling time points in this study, the Lactate Scout+ analyzer is not a suitable alternative to a lab-based assay (considered the gold standard) for measuring L-lactate in transported cattle.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
David P. McBey ◽  
Michelle Dotzert ◽  
C. W. J. Melling

Abstract Background Intensive-insulin treatment (IIT) strategy for patients with type 1 diabetes mellitus (T1DM) has been associated with sedentary behaviour and the development of insulin resistance. Exercising patients with T1DM often utilize a conventional insulin treatment (CIT) strategy leading to increased insulin sensitivity through improved intramyocellular lipid (IMCL) content. It is unclear how these exercise-related metabolic adaptations in response to exercise training relate to individual fibre-type transitions, and whether these alterations are evident between different insulin strategies (CIT vs. IIT). Purpose: This study examined glycogen and fat content in skeletal muscle fibres of diabetic rats following exercise-training. Methods Male Sprague-Dawley rats were divided into four groups: Control-Sedentary, CIT- and IIT-treated diabetic sedentary, and CIT-exercised trained (aerobic/resistance; DARE). After 12 weeks, muscle-fibre lipids and glycogen were compared through immunohistochemical analysis. Results The primary findings were that both IIT and DARE led to significant increases in type I fibres when compared to CIT, while DARE led to significantly increased lipid content in type I fibres compared to IIT. Conclusions These findings indicate that alterations in lipid content with insulin treatment and DARE are primarily evident in type I fibres, suggesting that muscle lipotoxicity in type 1 diabetes is muscle fibre-type dependant.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Rachel Ruckdeschel Smith ◽  
Isotta Chimenti ◽  
Eduardo Marbán

Cardiosphere-derived cells (CDCs), a naturally heterogeneous mixture of cell sub-populations, were grown from percutaneous endomyocardial adult human biopsy specimens (n=6). c-Kit + and CD90 + CDCs were selected using magnetic-activated cell sorting with excellent purity as determined by flow cytometry. Immunostaining revealed that ~30% of c-Kit + CDCs expressed Nkx2.5, ~100% of CD90 + CDCs expressed procollagen type I, and ~100% of both sub-populations expressed CD105. When placed in co-culture with neonatal myocytes and fibroblasts, c-Kit + CDCs expressed cardiac troponin I, while CD90 + CDCs expressed vimentin. In order to assess the therapeutic potential of purified CDCs, acute myocardial infarcts (MIs) were created in immunodeficient mice and c-Kit + (n=16), CD90 + (n=14), or CD105 + (n=3) CDCs were injected into the border zone. Echocardiograms were performed 3 weeks post-MI to measure left ventricular ejection fraction (LVEF). CD105-injected mice were comparable to an historical control group of mixed CDC-injected mice (LVEF = 41.3±2.9% CD105 vs. 42.8±10.4% CDC [n=11], p=0.60), indicating that the sorting process did not itself impair the therapeutic potential of CDCs. c-Kit- and CD90-injected mice were indistinguishable from one another (LVEF=31.7±8.2% c-Kit vs. 32.1±11.8% CD90, p=0.92), and both groups were significantly outperformed by the CD105-injected mice (p=0.01 and p=0.03, respectively). All groups were then compared to two other historical control groups, mice treated with normal human dermal fibroblasts (NHDFs [n=7]) and mice treated with phosphate-buffered saline (PBS [n=11]). c-Kit-injected mice did significantly outperform both NHDF- (p=0.04) and PBS-injected mice (p=0.03), while more variability in the CD90-injected group resulted in nearly significant comparisons with the NHDF (p=0.08) and PBS groups (p=0.08). While the therapeutic mechanisms of action of these two distinct sub-populations are undoubtedly different, both offer similar global functional benefits in the setting of acute MI. We conclude that the spontaneously-emerging unselected CDC population serves as a therapeutic cell cocktail, and that no functional advantage is conferred by the extra step of sorting for c-Kit + or CD90 + sub-populations.


2018 ◽  
Vol 6 (1) ◽  
pp. 232596711775081 ◽  
Author(s):  
Jacopo Preziosi Standoli ◽  
Francesco Fratalocchi ◽  
Vittorio Candela ◽  
Tiziano Preziosi Standoli ◽  
Giuseppe Giannicola ◽  
...  

Background: Overhead athletes are at a greater risk of developing scapular dyskinesis (SD). Although swimming is considered an overhead sport, information regarding SD in these athletes is scarce. Purpose: To determine the prevalence of SD in young, asymptomatic elite swimmers. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 661 asymptomatic elite swimmers were enrolled in this study (344 male, 317 female; mean age, 15.83 ± 2.20 years). Anthropometric characteristics, training routine, and stroke specialty were recorded. SD was assessed using a dynamic test consisting of an examination of the shoulder blades throughout synchronous forward flexion motion in the sagittal plane and was deemed to be either present or absent. Each movement was repeated 5 times. These evaluations were performed with athletes at rest, before any training or competition. Statistical analysis was performed. Results: SD was detected in 56 (8.5%) participants. Type I SD was the most common (46.5%); male participants were 2 times as likely to have SD as female participants (39 male, 17 female; P < .01). No correlation was found between the dominant limb and side affected ( P = .258); rather, a correlation was found between the breathing side and side affected, in that swimmers with a preferred breathing side were more prone to develop SD in the opposite shoulder ( P < .05). Swimmers involved in long-distance races were found to have a greater risk of developing SD ( P = .01). Conclusion: SD may be an asymptomatic condition in elite young swimmers and is present in 8.5% of these athletes. Early diagnosis may be useful for asymptomatic athletes with SD and to avoid its possible evolution to a symptomatic condition.


1996 ◽  
Vol 8 (3) ◽  
pp. 391 ◽  
Author(s):  
MD Fratacci ◽  
M Levame ◽  
A Rauss ◽  
H Bousbaa ◽  
G Atlan

The changes occurring in the histochemical characteristics of the rat diaphragm during the postnatal period were examined. Fibre-type distribution, fibre oxidative capacity, i.e. succinate-dehydrogenase (SDH) activity, and cross-sectional area were compared in the costal (COS) and crural (CRU) regions, and across their abdominal and thoracic surfaces. The proportions of type I and IIb fibres in both COS and CRU increased with age, while the proportion of type IIa fibres progressively decreased. For COS, fibre distribution was homogeneous over the entire muscle and did not change after 4 weeks. For CRU, it was heterogeneous with a higher proportion of type I fibres on the thoracic surface as from the first week. All fibre types significantly increased in cross-sectional area between 1 and 8 weeks, with no significant differences in COS and CRU. Mean SDH activity did not differ between COS and CRU or across the muscles. Mean SDH activities-were low and identical in all fibre types at birth, and then increased, peaking at the 6th week in type I and IIa fibres. When total muscle fibre oxidative capacity was calculated from an index including fibre-type proportion, cross-sectional area and mean SDH activity, it was significantly higher at 1 than at 8 weeks after birth; this might have functional implications for the newborn.


2012 ◽  
Vol 590 (6) ◽  
pp. 1443-1463 ◽  
Author(s):  
J. P. Mollica ◽  
T. L. Dutka ◽  
T. L. Merry ◽  
C. R. Lamboley ◽  
G. K. McConell ◽  
...  

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