Contraction-induced injury to single fiber segments from fast and slow muscles of rats by single stretches

Macpherson, Peter; Schork, M. Anthony

doi:10.1152/ajpcell.1996.271.5.c1438

Cited by 150 publications

(167 citation statements)

References 24 publications

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“…This will increase the series compliance of the muscle, leading to a shift of the angle-force curve to the right . Work on animal muscle fibres by Macpherson et al (1996) has provided electron micrographs which support this hypothesis by Fig. 1 Angle-force curves reconstructed using the fitted quadratic polynomial parameters for each day for the ISO and ECC groups.…”

Section: Discussionmentioning

confidence: 81%

Changes in the angle-force curve of human elbow flexors following eccentric and isometric exercise

et al. 2004

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The aim of this study was to explore and compare the magnitude and time-course of the shift in the angle-force curves obtained from maximal voluntary contractions of the elbow flexors, both before and 4 consecutive days after eccentric and isometric exercise. The maximal isometric force of the elbow flexors of fourteen young male volunteers was measured at five different elbow angles between 50°and 160°. Subjects were then divided into two groups: the eccentric group (ECC, n=7) and the isometric group (ISO, n=7). Subjects in the ECC group performed 50 maximal voluntary eccentric contractions of the elbow flexors on an isokinetic dynamometer (30°.s )1 ), while subjects in the ISO group performed 50 maximal voluntary isometric muscle contractions with the elbow flexors at a lengthened position. Following the ECC and ISO exercise protocols, maximal isometric force at the five angles, muscle soreness, and the relaxed (RANG) and flexed (FANG) elbow angles were measured at 24 h intervals for 4 days. All results were presented as the mean and standard error, and a quadratic curve was used to model the maximal isometric force data obtained at the five elbow angles. This approach not only allowed us to mathematically describe the angle-force curves and estimate the peak force and optimum angle for peak force generation, but also enabled us to statistically compare the shift of the angle-force curves between and within groups. A large and persistent shift of the angle-force curve towards longer muscle lengths was observed 1 day after eccentric exercise (P<0.01). This resulted in a $16°s hift of the optimum angle for force generation, which remained unchanged for the whole observation period. A smaller but also persistent shift of the angle-force curve was seen after isometric exercise at long muscle length (P<0.05; shift in optimum angle $5°). ECC exercise caused more muscle damage than ISO exercise, as indicated by the greater changes in RANG and ratings of muscle soreness (P<0.05). It was suggested that the shift in the angle-force curve was proportional to the degree of muscle damage and may be explained by the presence of overstretched sarcomeres that increased in series compliance of the muscle.

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Section: Discussionmentioning

confidence: 81%

Changes in the angle-force curve of human elbow flexors following eccentric and isometric exercise

et al. 2004

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“…Note that force and length calibrations are the same across all panels but that the time scale is compressed in b or predictor variables. These predictors were chosen because they have been shown in a previous work to be correlated with eccentric damage (Macpherson et al 1996) or because we had previously shown that they described post-eccentric force of skinned fibers of younger subjects (Choi and Widrick 2010).…”

Section: Methodsmentioning

confidence: 99%

“…Following the physiological measurements, each fiber segment was recovered for electrophoretic analysis. This allowed us to differentiate responses of muscle cells based upon their myosin heavy chain (MHC) isoform expression, an important consideration as muscle cells isolated from faster muscles of adult laboratory rodents appear be more sensitive to injury at the level of the myofilament lattice than fibers isolated from slower muscles (Warren et al 1994;Macpherson et al 1996).…”

Section: Introductionmentioning

confidence: 99%

Eccentric contraction-induced injury to type I, IIa, and IIa/IIx muscle fibers of elderly adults

Choi

Lim

Nibaldi

et al. 2011

AGE

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Muscles of old laboratory rodents experience exaggerated force losses after eccentric contractile activity. We extended this line of inquiry to humans and investigated the influence of fiber myosin heavy chain (MHC) isoform content on the injury process. Skinned muscle fiber segments, prepared from vastus lateralis biopsies of elderly men and women (78± 2 years, N=8), were subjected to a standardized eccentric contraction (strain, 0.25 fiber length; velocity, 0.50 unloaded shortening velocity). Injury was assessed by evaluating pre-and post-eccentric peak Ca 2+ -activated force per fiber cross-sectional area (F max ). Over 90% of the variability in post-eccentric F max could be explained by a multiple linear regression model consisting of an MHC-independent slope, where injury was directly related to pre-eccentric F max , and MHC-dependent y-intercepts, where the susceptibility to injury could be described as type IIa/IIx fibers>type IIa fibers>type I fibers. We previously reported that fiber type susceptibility to the same standardized eccentric protocol was type IIa/IIx>type IIa=type I for vastus lateralis fibers of 25-year-old adults (Choi and Widrick, Am J Physiol Cell Physiol 299:C1409-C1417, 2010). Modeling combined data sets revealed significant age by fiber type interactions, with posteccentric F max deficits greater for type IIa and type IIa/ IIx fibers from elderly vs. young subjects at constant pre-eccentric F max . We conclude that the resistance of the myofilament lattice to mechanical strain has deteriorated for type IIa and type IIa/IIx, but not for type I, vastus lateralis fibers of elderly adults.

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“…Single permeabilized LVP muscle fibers were obtained from congenitally-clefted palates of goats before and after surgical repair. The testing of permeabilized fibers allowed for the analysis of the behavior of sarcomeres by eliminating the effects associated with the intact plasma membrane (Macpherson et al, 1996). The hypothesis tested was that repair decreases the percentage of type 2 fibers and the susceptibility to injury to levels that are less than those for nonrepaired cleft palates.…”

Section: Abstract Levator Veli Palatini; Velopharyngeal Incompetencementioning

confidence: 99%

“…The mean cross-sectional area was used to estimate the overall fiber cross-sectional area (CSA). Muscle mass was estimated as the product of L f , CSA, and the density of 1 mg/mm 3 (Macpherson et al, 1996). …”

mentioning

confidence: 99%

Effect of Cleft Palate Repair on the Susceptibility to Contraction-Induced Injury of Single Permeabilized Muscle Fibers from Congenitally-Clefted Goat Palates

Rader

Cederna

McClellan

et al. 2008

The Cleft Palate Craniofacial Journal

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Objective-Despite cleft palate repair, velopharyngeal competence is not achieved in ~15% of patients, often necessitating secondary surgical correction. Velopharyngeal competence postrepair may require the conversion of levator veli palatini muscle fibers from injury-susceptible type 2 fibers to injury-resistant type 1 fibers. As an initial step to determining the validity of this theory, we tested the hypothesis that, in most cases, repair induces the transformation to type 1 fibers, thus diminishing susceptibility to injury.Interventions-Single permeabilized levator veli palatini muscle fibers were obtained from normal palates and nonrepaired congenitally-clefted palates of young (2 months old) and adult (14 to 15 months old) goats and from repaired palates of adult goats (8 months old). Repair was done at 2 months of age using a modified von Langenbeck technique. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptMain Outcome Measures-Fiber type was determined by contractile properties and susceptibility to injury was assessed by force deficit, the decrease in maximum force following a lengthening contraction protocol expressed as a percentage of initial force.Results-For normal palates and cleft palates of young goats, the majority of the fibers were type 2 with force deficits of ~40%. Following repair, 80% of the fibers were type 1 with force deficits of 20% ± 2%; these deficits were 45% of those for nonrepaired cleft palates of adult goats (p < .0001). (Elahi et al., 2004;Forrester and Merz, 2004; CDC, 2006). Following surgical repair, 10% to 20% of patients are still not able to achieve velopharyngeal closure (Marrinan et al., 1998), resulting in abnormal speech and other functional deficits that often necessitate secondary surgical correction. This outcome is typically a consequence of either inadequate palatal length or insufficient movement of the pharyngeal walls or soft palate. Soft palatal movement is dependent on the proper functioning of soft palate musculature (Kogo et al., 1996;Marrinan et al., 1998;Berry et al., 1999). Levator veli palatini (LVP; abbreviations listed in Table 1) muscle fibers from normal palates are aligned transversely across the posterior soft palate and when activated during velopharyngeal closure, retrodisplace and elevate the palate (Kogo et al., 1996;Marrinan et al., 1998;Berry et al., 1999). Impairment of LVP muscles of patients with cleft palates may contribute to the incidence of velopharyngeal dysfunction postrepair. Conclusion-TheThe functionality of the LVP muscle is dependent on the fiber-type composition (Hanes et al., 2006; Rader et al., 2006). For normal palates of adult humans (Stal and Lindman, 2000;Lindman et al., 2001) and goats (Hanes et al., 2006; Rader et al., 2006), LVP muscles consist primarily of slow oxidative (type 1) fibers. In contrast, the LVP muscles in nonrepaired cleft palates are oriented in a longitudinal direction, abnormally insert on the posterior hard palate, and at least for adult goats, are predominantly...

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Contraction-induced injury to single fiber segments from fast and slow muscles of rats by single stretches

Cited by 150 publications

References 24 publications

Changes in the angle-force curve of human elbow flexors following eccentric and isometric exercise

Changes in the angle-force curve of human elbow flexors following eccentric and isometric exercise

Eccentric contraction-induced injury to type I, IIa, and IIa/IIx muscle fibers of elderly adults

Effect of Cleft Palate Repair on the Susceptibility to Contraction-Induced Injury of Single Permeabilized Muscle Fibers from Congenitally-Clefted Goat Palates

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