Unloaded shortening of skinned mammalian skeletal muscle fibres: effects of the experimental approach and passive force

Galler, Stefan; Hilber, Karlheinz

doi:10.1007/bf00122114

Cited by 44 publications

(49 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The experimental apparatus and the method for mechanical measurements have been described previously (14). The attachment points for the muscle fibers (active length ϳ0.8 -2.5 mm, mean diameter 25-55 m) on the mechanical apparatus were two ϳ2-mm-long vertically oriented epoxy carbon fiber needles of ϳ100-m tip diameter.…”

Section: Methodsmentioning

confidence: 99%

Kinetic properties of myosin heavy chain isoforms in mouse skeletal muscle: comparison with rat, rabbit, and human and correlation with amino acid sequence

Andruchov

Andruchova

Wang

et al. 2004

American Journal of Physiology-Cell Physiology

Self Cite

View full text Add to dashboard Cite

Galler. Kinetic properties of myosin heavy chain isoforms in mouse skeletal muscle: comparison with rat, rabbit, and human and correlation with amino acid sequence. Am J Physiol Cell Physiol 287: C1725-C1732, 2004. First published August 11, 2004 doi:10.1152/ ajpcell.00255.2004.-Stretch activation kinetics were investigated in skinned mouse skeletal muscle fibers of known myosin heavy chain (MHC) isoform content to assess kinetic properties of different myosin heads while generating force. The time to peak of stretchinduced delayed force increase (t3) was strongly correlated with MHC isoforms [t3 given in ms for fiber types containing specified isoforms; means Ϯ SD with n in parentheses: MHCI 680 Ϯ 108 (13) For rat, rabbit, and human skeletal muscles the same type of correlation was found previously. The kinetics decreases slightly with increasing body mass. Available amino acid sequences were aligned to quantify the structural variability of MHC isoforms of different animal species. The variation in t3 showed a correlation with the structural variability of specific actin-binding loops (so-called loop 2 and loop 3) of myosin heads (r ϭ 0.74). This suggests that alterations of amino acids in these loops contribute to the different kinetics of myosin heads of various MHC isoforms.isoform structure-function relationship; stretch activation; muscle mechanics SKELETAL MUSCLES ARE COMPOSED of different fiber types to fulfill various functional needs. This diversity relates to the existence of specific myofibrillar protein isoforms in different fiber types (for review, see Refs. 41 and 46). Muscle fiber types are generally categorized according to their specific myosin heavy chain (MHC) isoforms. The head portion of this protein is the essential component of the force-generating mechanism of muscle (for review, see Ref. 30). Three fast fiber types (type II) have been identified in limb muscles of adult rodents: types IIB, IIX (or IID), and IIA, containing the isoforms MHCIIb, MHCIIx(d), and MHCIIa, respectively. Conversely, only one slow fiber type (type I) has to date been characterized by its MHC isoform, called MHCI, but there is increasing evidence that the type I fibers do not represent a homogeneous population (2,11,15).MHC isoform content determines the contractile properties of muscle fibers (for review see Ref. 4). The relation between MHC content, stretch activation kinetics, and unloaded shortening velocity (V u ) has been clearly established for rat, rabbit, and human skeletal muscle fibers (4,7,9,17,35). Although the mouse is the most important mammalian model for genetic manipulations, the skeletal muscle fibers of this species have been investigated to a much lesser degree. The relationship between shortening velocity and load has been determined in different mouse muscle fiber types. Furthermore, V u was compared with the actin filament sliding propelled by the different myosin isoforms (28, 39). The kinetics of stretch activation has never been investigated in mouse skeletal muscle fibers, although a...

show abstract

Section: Methodsmentioning

confidence: 99%

Kinetic properties of myosin heavy chain isoforms in mouse skeletal muscle: comparison with rat, rabbit, and human and correlation with amino acid sequence

Andruchov

Andruchova

Wang

et al. 2004

American Journal of Physiology-Cell Physiology

Self Cite

View full text Add to dashboard Cite

show abstract

“…The apparatus and the methods for mechanical measurements have been described previously (Galler and Hilber, 1994). A force sensor AE 801 (SensoNor, Horten, Norway) with a resonance frequency of ~7.5·kHz was used.…”

Section: Experimental Setup and Proceduresmentioning

confidence: 99%

Effect of pH on the rate of myosin head detachment in molluscan catch muscle: are myosin heads involved in the catch state?

Höpflinger

Andruchova

Andruchov

et al. 2006

Journal of Experimental Biology

Self Cite

View full text Add to dashboard Cite

Moderate alkalisation is known to terminate the catch state of bivalve mollusc smooth muscles such as the anterior byssus retractor muscle (ABRM) of Mytilus edulis L. In the present study, we investigated the effect of moderate alkalisation (pH 7.2-7.7 vs control pH 6.7) on the myosin head detachment rate in saponin-skinned fibre bundles of ABRM in order to investigate the possible role of myosin heads in the force maintenance during catch. The detachment rate of myosin heads was deduced from two types of experiments. (1) In stretch experiments on maximally Ca 2+ -activated fibre bundles (pCa 4.5), the rate of force decay after stepwise stretch was assessed. (2) In ATP step experiments, the rate of force decay from high force rigor (pCa>8) was evaluated. The ATP step was induced by photolysis of caged ATP. We found that moderate alkalisation induces relaxation of skinned fibres in catch, thereby reducing both force and stiffness, whereas it does not accelerate the rate of myosin head detachment. This acceleration, however, would be expected if catch would be simply due to myosin heads remaining sustainably attached to actin filaments. Thus, the myosin heads may be less involved in catch than generally assumed. Catch may possibly depend on a different kind of myofilament interconnections, which are abolished by moderate alkalisation.

show abstract

“…AL was plotted against At and linear regression was used to construct a straight line; its slope represents the unloaded shortening velocity. In a separate study, the reliability of Vmax determination was investigated (Galler & Hilber, 1994 velocity measurements based on sarcomere shortening by continuously monitoring the laser diffraction pattern were similar to the results of measurements based on the determination of fibre shortening. The velocity of relative sarcomere shortening varied within a range of + 5% of the corresponding relative fibre shortening.…”

Section: Mechanical Experimentsmentioning

confidence: 99%

Stretch activation, unloaded shortening velocity, and myosin heavy chain isoforms of rat skeletal muscle fibres.

Galler

Schmitt

Pette

1994

The Journal of Physiology

152

151

View full text Add to dashboard Cite

1. Contractile properties were investigated on single skinned-fibre preparations from rat leg muscles. Following the mechanical measurements, the myosin heavy chain (HC) composition of the same fibre was analysed by gradient gel electrophoresis. 2. Fibres were typed according to their myosin HC isoform composition (HCI, type I; HCIIA, type IIA; HCIID, type IID; HCIIB, type IIB). Many fibres showed the co-existence of two myosin HC isoforms (hybrid fibres). 3. A strong correlation was found between fibre type and time characteristics of stretchinduced delayed force increase (stretch activation) of fully Ca2"-activated fibres.4. The maximal unloaded shortening velocity (Vmax), as measured with the slack test, was lowest in type I fibres. Within the type II group, a continuum of Vmax values was found, with large overlaps of the different fibre types. 5. The results suggest that the kinetics of stretch activation is determined by the myosin HCs whereas unloaded fibre shortening seems to be determined by other myofibrillar proteins in addition to the myosin HCs. Assuming that stretch activation represents certain steps of the cross-bridge turnover under isometric conditions and Vmax reflects cross-bridge detachment under unloaded conditions it can be deduced that different myofibrillar proteins are responsible for different steps within the cross-bridge turnover.

show abstract

Unloaded shortening of skinned mammalian skeletal muscle fibres: effects of the experimental approach and passive force

Cited by 44 publications

References 32 publications

Kinetic properties of myosin heavy chain isoforms in mouse skeletal muscle: comparison with rat, rabbit, and human and correlation with amino acid sequence

Kinetic properties of myosin heavy chain isoforms in mouse skeletal muscle: comparison with rat, rabbit, and human and correlation with amino acid sequence

Effect of pH on the rate of myosin head detachment in molluscan catch muscle: are myosin heads involved in the catch state?

Stretch activation, unloaded shortening velocity, and myosin heavy chain isoforms of rat skeletal muscle fibres.

Contact Info

Product

Resources

About