scholarly journals Quantitative electrophoretic analysis of myosin heavy chains in single muscle fibers

2001 ◽  
Vol 90 (5) ◽  
pp. 1927-1935 ◽  
Author(s):  
Boris A. Tikunov ◽  
H. Lee Sweeney ◽  
Lawrence C. Rome
Keyword(s):  
Muscle Fibers ◽  
Electrophoretic Analysis ◽  
Single Fiber ◽  
Fiber Types ◽  
Single Muscle ◽  
Myosin Heavy Chains ◽  
Single Fibers ◽  
Heavy Chains ◽  
Cross Bridges ◽  
Whole Muscle

To better understand the molecular basis of the large variation in mechanical properties of different fiber types, there has been an intense effort to relate the mechanical and energetic properties measured in skinned single fibers to those of their constituent cross bridges. There is a significant technical obstacle, however, in estimating the number of cross bridges in a single fiber. In this study, we have developed a procedure for extraction and quantification of myosin heavy chains (MHCs) that permits the routine and direct measurement of the myosin content in single muscle fibers. To validate this method, we also compared MHC concentration measured in single fibers with the MHC concentration in whole fast-twitch (psoas and gracilis) and slow-twitch (soleus) muscles of rabbit. We found that the MHC concentration in intact psoas (184 μM) was larger than that in soleus (144 μM), as would be expected from their differing mitochondrial content and volume of myofibrils. We obtained excellent agreement between MHC concentration measured at the single fiber level with that measured at the whole muscle level. This not only verifies the efficacy of our procedure but also shows that the difference in concentration at the whole muscle level simply reflects the concentration differences in the constituent fiber types. This new procedure should be of considerable help in future attempts to determine kinetic differences in cross bridges from different fiber types.

scholarly journals Shortening velocity and myosin heavy chains of developing rabbit muscle fibers.

1985 ◽  
Vol 260 (27) ◽  
pp. 14403-14405 ◽  
Author(s):  
P J Reiser ◽  
R L Moss ◽  
G G Giulian ◽  
M L Greaser
Keyword(s):  
Muscle Fibers ◽  
Rabbit Muscle ◽  
Myosin Heavy Chains ◽  
Shortening Velocity ◽  
Heavy Chains

scholarly journals Myosin types and fiber types in cardiac muscle. II. Atrial myocardium.

1982 ◽  
Vol 95 (3) ◽  
pp. 838-845 ◽  
Author(s):  
L Gorza ◽  
S Sartore ◽  
S Schiaffino
Keyword(s):  
Right Atrium ◽  
Muscle Fibers ◽  
Interatrial Septum ◽  
Myosin Heavy Chains ◽  
Atrial Myocardium ◽  
Crista Terminalis ◽  
Heavy Chains ◽  
Bovine Heart ◽  
Atrial Muscle ◽  
The Right

Antibodies were produced against myosins isolated from the left atrial myocardium (anti-bAm) and the left ventricular myocardium (anti-bVm) of the bovine heart. Cross-reactive antibodies were removed by cross-absorption. Absorbed anti-bAm and anti-bVm were specific for the myosin heavy chains when tested by enzyme immunoassay combined with SDS gel electrophoresis. Indirect immunofluorescence was used to determine the reactivity of atrial muscle fibers to the two antibodies. Three populations of atrial muscle fibers were distinguished in the bovine heart: (a) fibers reactive with anti-bAm and unreactive with anti-bVm, like most fibers in the left atrium; (b) fibers reactive with both antibodies, especially numerous in the right atrium; (c) fibers reactive with anti-bVm and unreactive with anti-bAm, present only in the interatrial septum and in specific regions of the right atrium, such as the crista terminalis. These findings can be accounted for by postulating the existence of two distinct types of atrial myosin heavy chains, one of which is antigenically related to ventricular myosin. The tendency for fibers labeled by anti-bVm to occur frequently in bundles and their preferential distribution in the crista terminalis, namely along one of the main conduction pathways between the sinus node and the atrioventricular node, and in the interatrial septum, where different internodal tracts are known to converge, suggests that these fibers may be specialized for faster conduction.

Treatment with beta bungarotoxin blocks muscle spindle formation in fetal rats

Development ◽  
1990 ◽  
Vol 110 (2) ◽  
pp. 483-489
Author(s):  
J. Kucera ◽  
J.M. Waldro
Keyword(s):  
Peripheral Nerves ◽  
Muscle Fibers ◽  
Muscle Spindles ◽  
Myosin Isoforms ◽  
Myosin Heavy Chains ◽  
Heavy Chains ◽  
Intrafusal Fibers ◽  
Intramuscular Nerves ◽  
Fetal Rats ◽  
Intramuscular Nerve

Sensory and motor fibers of peripheral nerves were irreversibly destroyed in fetal rats by administering beta bungarotoxin (BTX) on embryonic day 16 or 17, after assembly of primary myotubes, but before the formation of muscle spindles. Soleus muscles of toxin-treated fetuses and their untreated littermates were removed just prior to birth and were examined by light microscopy of serial transverse sections for the presence of spindles and immunocytochemical expression of several isoforms of myosin heavy chains (MHC). Untreated muscles exhibited numerous spindles that were innervated by branches of intramuscular nerves and contained muscle fibers expressing a slow-tonic MHC isoform characteristic of the intrafusal but not extrafusal fibers. Toxin-treated muscles were devoid of intramuscular nerve bundles and perineurial structures. Encapsulations of muscle fibers resembling spindles were absent and no myotubes expressed the slow-tonic MHC isoform associated with intrafusal fibers in beta BTX-treated muscles. Thus, the assembly of muscle spindles, formation of the spindle capsule, and transformation of undifferentiated myotubes into the intrafusal fibers that contain spindle-specific myosin isoforms all depend on the presence of innervation in prenatal rat muscles.

scholarly journals A Histochemical Study of Normal and Denervated Red and White Muscles of the Rat

1958 ◽  
Vol 4 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Vivianne T. Nachmias ◽  
Helen A. Padykula
Keyword(s):  
Adenosine Triphosphatase ◽  
Histochemical Study ◽  
Muscle Fibers ◽  
Succinic Dehydrogenase ◽  
Biceps Femoris ◽  
Fiber Types ◽  
Albino Rat ◽  
Whole Muscle ◽  
Red And White Muscles

The distribution and characterization of the fibers of normal and denervated red and white muscles of the albino rat are reported in this study. Histochemical procedures for succinic dehydrogenase, lipides, adenosinetriphosphatase, esterase, and glycogen were utilized to differentiate muscle fibers, and these methods facilitated the study of the distribution of fiber types within whole muscle. Muscle fibers of the granular type (dark or red fibers) can be clearly distinguished from those with clearer sarcoplasm (light or white fibers) by methods for demonstrating succinic dehydrogenase, lipides, and esterase. The method for adenosine-triphosphatase reveals differences only under the special conditions described in the text. Additional fiber types are described in the cat's diaphragm and in the extrinsic ocular muscles of the rat. Succinic dehydrogenase and adenosinetriphosphatase activities of the soleus and biceps femoris were studied 14 days after denervation of these muscles. The histochemical findings are discussed principally in the light of current biochemical knowledge of these enzymes.

scholarly journals Myosin content of individual human muscle fibers isolated by laser capture microdissection

2016 ◽  
Vol 310 (5) ◽  
pp. C381-C389 ◽  
Author(s):  
Charles A. Stuart ◽  
William L. Stone ◽  
Mary E. A. Howell ◽  
Marianne F. Brannon ◽  
H. Kenton Hall ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Type I ◽  
Fiber Types ◽  
Myosin Heavy Chains ◽  
Heavy Chains ◽  
Slow Twitch ◽  
Type I Fibers ◽  
Fast Twitch ◽  
Laser Capture

Muscle fiber composition correlates with insulin resistance, and exercise training can increase slow-twitch (type I) fibers and, thereby, mitigate diabetes risk. Human skeletal muscle is made up of three distinct fiber types, but muscle contains many more isoforms of myosin heavy and light chains, which are coded by 15 and 11 different genes, respectively. Laser capture microdissection techniques allow assessment of mRNA and protein content in individual fibers. We found that specific human fiber types contain different mixtures of myosin heavy and light chains. Fast-twitch (type IIx) fibers consistently contained myosin heavy chains 1, 2, and 4 and myosin light chain 1. Type I fibers always contained myosin heavy chains 6 and 7 (MYH6 and MYH7) and myosin light chain 3 (MYL3), whereas MYH6, MYH7, and MYL3 were nearly absent from type IIx fibers. In contrast to cardiomyocytes, where MYH6 (also known as α-myosin heavy chain) is seen solely in fast-twitch cells, only slow-twitch fibers of skeletal muscle contained MYH6. Classical fast myosin heavy chains (MHC1, MHC2, and MHC4) were present in variable proportions in all fiber types, but significant MYH6 and MYH7 expression indicated slow-twitch phenotype, and the absence of these two isoforms determined a fast-twitch phenotype. The mixed myosin heavy and light chain content of type IIa fibers was consistent with its role as a transition between fast and slow phenotypes. These new observations suggest that the presence or absence of MYH6 and MYH7 proteins dictates the slow- or fast-twitch phenotype in skeletal muscle.

scholarly journals Immunocytochemical localization of aldolase in normal, denervated, and dystrophic chicken muscles.

1988 ◽  
Vol 36 (3) ◽  
pp. 227-235
Author(s):  
T H Oh ◽  
B W Rosser ◽  
C R Shear ◽  
Y C Kim ◽  
G J Markelonis
Keyword(s):  
Latissimus Dorsi ◽  
Muscle Fibers ◽  
Sodium Dodecyl ◽  
Immunocytochemical Localization ◽  
Myosin Heavy Chains ◽  
Dystrophic Muscle ◽  
Adult Chicken ◽  
Heavy Chains ◽  
Chicken Muscles ◽  
Fast Twitch

To investigate whether immunocytochemical localization of muscle-specific aldolase can be used for fiber phenotype determination, we produced specific antibodies against the enzyme and studied its distribution in adult chicken skeletal muscles by indirect immunofluorescence microscopy. Monoclonal antibodies against the myosin heavy chains of fast-twitch (MF-14) and slow-tonic (ALD-58) muscle fibers were also used to correlate aldolase levels with the fiber phenotype. The goat anti-aldolase antibody was found to be specific for the A form of aldolase, as evidenced by sodium dodecyl sulfate gel electrophoresis, immunotitration experiments, and immunoblot analysis. The antibody reacted strongly with the fast-twitch myofibers of normal pectoralis and posterior latissimus dorsi muscles; the phenotype of these muscle fibers was confirmed by a positive immunofluorescent reaction after incubation with MF-14 antibody. By contrast, the slow-tonic myofibers of normal anterior latissimus dorsi, which react positively with ALD-58 antibody, reacted weakly with anti-aldolase antibodies. In denervated chicken muscles, reaction to anti-aldolase antibodies was markedly reduced in fast-twitch fibers, although reaction to MF-14 was not diminished. By contrast, in dystrophic muscle, fast-twitch fibers showed reduced reactivity to anti-aldolase and marked to moderate reduction in MF-14 reactivity. Our results show that: (a) in normal muscles, reactivity to anti-aldolase matches the phenotype obtained by using anti-fast or anti-slow myosin heavy chain antibodies, and therefore can serve to identify mature fibers as fast or slow; and (b) in denervated or dystrophic muscles, the intracellular expressions of aldolase and fast-twitch myosin heavy chains are regulated independently.

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