Functional significance of myosin transitions in single fibers of developing soleus muscle

1988 ◽  
Vol 254 (5) ◽  
pp. C605-C613 ◽  
Author(s):  
P. J. Reiser ◽  
C. E. Kasper ◽  
M. L. Greaser ◽  
R. L. Moss
Keyword(s):  
Soleus Muscle ◽  
Muscle Development ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Slow Muscle ◽  
Maximal Velocity ◽  
Single Fibers ◽  
Adult Rat ◽  
Velocity Of Shortening ◽  
Rat Soleus Muscle

The maximal velocity of shortening and myosin heavy chain (MHC) composition of single, chemically skinned fibers from neonatal and adult rat soleus muscles were examined to determine the relationship between these parameters during slow muscle development in the rat. In addition, the MHC composition of bundles of fibers from soleus muscles at the same ages was studied. The MHC compositions were examined using sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The results from the bundles of fibers indicate that from 3 days to 5 mo postnatal, the rat soleus contains predominantly MHCs that migrate in the vicinity of the MHC from adult slow muscle. From 14 days to 2 mo postnatal, there are also significant amounts of additional MHCs that comigrate on SDS gels with those characteristic of adult rat fast muscle. All the fibers studied at 3 and 7 days postnatal and at 5 mo and the majority of fibers from 14 days to 2 mo postnatal had relatively low shortening velocities. A few fibers from the latter group had significantly higher velocities. The faster fibers at each age had greater amounts of the MHCs that comigrate with the adult fast-type MHC on SDS gels. Thus the velocity of shortening of single fibers from the rat soleus muscle appears to be related to MHC composition during postnatal development.

scholarly journals Effect of hindlimb unweighting on single soleus fiber maximal shortening velocity and ATPase activity

1993 ◽  
Vol 74 (6) ◽  
pp. 2949-2957 ◽  
Author(s):  
K. S. McDonald ◽  
R. H. Fitts
Keyword(s):  
Atpase Activity ◽  
Soleus Muscle ◽  
Time Course ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Maximal Velocity ◽  
Shortening Velocity ◽  
Hindlimb Unweighting ◽  
Fast Myosin ◽  
Highly Correlated

This study characterizes the time course of change in single soleus muscle fiber size and function elicited by hindlimb unweighting (HU) and analyzes the extent to which varying durations of HU altered maximal velocity of shortening (Vo), myofibrillar adenosinetriphosphatase (ATPase), and relative content of slow and fast myosin in individual soleus fibers. After 1, 2, or 3 wk of HU, soleus muscle bundles were prepared and stored in skinning solution at -20 degrees C. Single fibers were isolated and mounted between a motor arm and a transducer, and fiber force, Vo, and ATPase activity were measured. Fiber myosin content was determined by one-dimensional sodium dodecyl sulfate- (SDS) polyacrylamide gel electrophoresis. After 1, 2, and 3 wk of HU, soleus fibers exhibited a progressive reduction in fiber diameter (16, 22, and 42%, respectively) and peak force (42, 48, and 72%, respectively). Peak specific tension was significantly reduced after 1 wk of HU (18%) and showed no further change in 2–3 wk of HU. During 1 and 3 wk of HU, fiber Vo and ATPase showed a significant increase. By 3 wk, Vo had increased from 1.32 +/- 0.04 to 2.94 +/- 0.17 fiber lengths/s and fiber ATPase from 291 +/- 16 to 1,064 +/- 128 microM.min-1 x mm-3. The percent fibers expressing fast myosin heavy chain increased from 4% to 29% by 3 wk of HU, and Vo and ATPase activity within a fiber were highly correlated.(ABSTRACT TRUNCATED AT 250 WORDS)

Myosin subunits and contractile properties of single fibers from hypokinetic rat muscles

1987 ◽  
Vol 63 (6) ◽  
pp. 2293-2300 ◽  
Author(s):  
P. J. Reiser ◽  
C. E. Kasper ◽  
R. L. Moss
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Contractile Properties ◽  
Hindlimb Suspension ◽  
Maximal Velocity ◽  
Adult Rats ◽  
Single Fibers ◽  
Myosin Subunits ◽  
Change In The Mean ◽  
The Mean

The effects of prolonged hypokinesia on the contractile properties and myosin isozymes of single fibers from the synergistic fast-twitch plantaris (PL) and slow-twitch soleus (SOL) skeletal muscles of adult rats were studied after 28 days of hindlimb suspension. There was a 31% increase in the mean maximal velocity of unloaded shortening (Vmax) among fibers from SOL with no change in the mean Vmax of fibers from PL after suspension. The myosin heavy and light chain (MHC and MLC) composition of bundles and the MHC composition of single fibers from control and suspended muscles were examined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. There was a marked increase in the relative amount of fast-type MHC's in hypokinetic SOL and a smaller increase in the amount of fast-type MHC's in the PL. Relatively minor changes occurred in the MLC's during hypokinesia. As Vmax increased among individual fibers from control and suspended muscles, the relative amount of fast-type MHC's increased. The results demonstrate that the myosin isozyme composition of skeletal muscle, especially the heavy chains, is altered during hypokinesia, and this finding provides an explanation for changes in Vmax of rat single muscle fibers under the same conditions.

Myosin and troponin changes in rat soleus muscle after hindlimb suspension

1993 ◽  
Vol 74 (3) ◽  
pp. 1156-1160 ◽  
Author(s):  
M. Campione ◽  
S. Ausoni ◽  
C. Y. Guezennec ◽  
S. Schiaffino
Keyword(s):  
Soleus Muscle ◽  
Troponin I ◽  
Troponin T ◽  
High Mobility ◽  
Calcium Sensitivity ◽  
Hindlimb Suspension ◽  
Type I ◽  
Maximal Velocity ◽  
Rat Soleus Muscle ◽  
Fast Twitch

We examined the myosin heavy-chain (MHC), troponin T (TnT), and troponin I (TnI) isoform composition in the rat soleus muscle after 21 days of hindlimb suspension using electrophoretic and immunoblotting analysis with specific monoclonal antibodies. The suspended soleus showed a shift in the MHC isoform distribution with a marked increase (from 1.0 to 33%) in the relative amount of type IIa and IIx MHC and a corresponding decrease in type I MHC. However, type IIb MHC, which represents a major component in fast-twitch muscles, was not detected in suspended soleus muscles. TnT and TnI isoform composition was also changed with the appearance of fast-type TnI and TnT bands. However, a high-mobility TnT band, which represents a major component in fast-twitch muscles, was not expressed in suspended soleus. These isoform transitions may be related to the increased maximal velocity of shortening and higher calcium sensitivity previously reported in the rat soleus after hindlimb suspension.

scholarly journals Changes in myosin heavy chain mRNA and protein isoforms in single fibers of unloaded rat soleus muscle

FEBS Letters ◽  
1999 ◽  
Vol 463 (1-2) ◽  
pp. 15-18 ◽  
Author(s):  
Laurence Stevens ◽  
Bärbel Gohlsch ◽  
Yvonne Mounier ◽  
Dirk Pette
Keyword(s):  
Myosin Heavy Chain ◽  
Soleus Muscle ◽  
Heavy Chain ◽  
Protein Isoforms ◽  
Single Fibers ◽  
Rat Soleus Muscle

scholarly journals Phosphorylation of rat muscle acetyl-CoA carboxylase by AMP-activated protein kinase and protein kinase A

1997 ◽  
Vol 82 (1) ◽  
pp. 219-225 ◽  
Author(s):  
W. W. Winder ◽  
H. A. Wilson ◽  
D. G. Hardie ◽  
B. B. Rasmussen ◽  
C. A. Hutber ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Maximal Velocity ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Rat Muscle ◽  
Amp Activated Protein Kinase ◽  
Kinase A

Winder, W. W., H. A. Wilson, D. G. Hardie, B. B. Rasmussen, C. A. Hutber, G. B. Call, R. D. Clayton, L. M. Conley, S. Yoon, and B. Zhou. Phosphorylation of rat muscle acetyl-CoA carboxylase by AMP-activated protein kinase and protein kinase A. J. Appl. Physiol. 82(1): 219–225, 1997—This study was designed to compare functional effects of phosphorylation of muscle acetyl-CoA carboxylase (ACC) by adenosine 3′,5′-cyclic monophosphate-dependent protein kinase (PKA) and by AMP-activated protein kinase (AMPK). Muscle ACC (272 kDa) was phosphorylated and then subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by autoradiography. Functional effects of phosphorylation were determined by measuring ACC activity at different concentrations of each of the substrates and of citrate, an activator of the enzyme. The maximal velocity ( V max) and the Michaelis constants ( K m) for ATP, acetyl-CoA, and bicarbonate were unaffected by phosphorylation by PKA. Phosphorylation by AMPK increased the K m for ATP and acetyl-CoA. Sequential phosphorylation by PKA and AMPK, first without label and second with label, appeared to reduce the extent of label incorporation, regardless of the order. The activation constant ( K a) for citrate activation was increased to the same extent by AMPK phosphorylation, regardless of previous or subsequent phosphorylation by PKA. Thus muscle ACC can be phosphorylated by PKA but with no apparent functional effects on the enzyme. AMPK appears to be the more important regulator of muscle ACC.

Coordinate changes in C protein and myosin expression during skeletal muscle hypertrophy

1994 ◽  
Vol 267 (2) ◽  
pp. C443-C449 ◽  
Author(s):  
K. M. McCormick ◽  
K. M. Baldwin ◽  
F. Schachat
Keyword(s):  
Skeletal Muscle ◽  
Muscle Hypertrophy ◽  
Peptide Mapping ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Thick Filament ◽  
Protein Isoforms ◽  
Plantaris Muscle ◽  
C Protein ◽  
Adult Rat

In this study, two new C protein isoforms in adult rat skeletal muscle were resolved using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These isoforms migrated between previously identified fast (Cf) and slow (Cs) C protein isoforms; hence they were named intermediate C proteins (Ci1 and Ci2). Cyanogen bromide peptide mapping and Western blotting showed that the intermediate isoforms were more similar to Cs than Cf. The distribution of specific C protein and myosin heavy chain (MHC) isoforms was highly correlated in several hindlimb muscles, suggesting that the expression of these two thick-filament proteins is coordinated. This notion was tested by determining whether specific C protein and MHC isoforms change in parallel during muscle hypertrophy. Eight weeks after ablation of its synergists, the overloaded plantaris muscle showed significant increases in type IIa MHC and intermediate C protein, with corresponding decreases in type IIb MHC and Cf protein. These results indicate that C protein expression is linked to MHC expression during plantaris muscle hypertrophy.

Increased Na(+)-H+ antiporter activity in apical membrane vesicles from mutant LLC-PK1 cells

1991 ◽  
Vol 260 (4) ◽  
pp. C738-C744 ◽  
Author(s):  
R. F. Reilly ◽  
J. G. Haggerty ◽  
P. S. Aronson ◽  
E. A. Adelberg ◽  
C. W. Slayman
Keyword(s):  
Apical Membrane ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Membrane Vesicles ◽  
Epithelial Cell Line ◽  
Marker Enzyme ◽  
Maximal Velocity ◽  
Apical Surface ◽  
Membrane Level ◽  
Apical Membrane Vesicles

In whole cell experiments, the PKE20 mutant of the renal epithelial cell line LLC-PK1 displays a severalfold elevation of Na(+)-H+ antiporter activity at the apical surface (J.G. Haggerty, N. Agarwal, R.F. Reilly, E. A. Adelberg, and C.W. Slayman. Proc. Natl. Acad. Sci. USA 85: 6797-6801, 1988). The present study was undertaken to explore the properties of the mutant at the membrane level. Apical membrane vesicles were prepared by the magnesium-aggregation technique, with a similar enrichment (ca. 10-fold) of the marker enzyme gamma-glutamyltranspeptidase in vesicles from parent and mutant cell lines. In both cases, 22Na influx was stimulated by an inside-acid pH gradient, inhibited by ethylisopropylamiloride (EIPA), and unaffected by valinomycin, indicating that it was mediated by Na(+)-H+ antiport. Quantitatively, PKE20 vesicles showed a 4.2-fold increase in the maximal velocity of Na(+)-H+ antiporter activity compared with the parent, with only minor increases in the activity of two other Na(+)-dependent transporters (14-56% for alpha-methylglucoside and L-glutamate). Dose-response curves for EIPA indicated that the increased Na(+)-H+ antiport activity in PKE20 vesicles was due to an increased activity of the relatively amiloride-resistant form of the Na(+)-H+ antiporter with little or no change in the amiloride-sensitive form. No differences in polypeptide composition of the two vesicle preparations could be detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Taken together, the results indicate that the mutation in PKE20 is expressed at the membrane level and is specific for the relatively amiloride-resistant Na(+)-H+ antiporter.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of Titin in Skeletal Muscle Varies with Hind-Limb Unloading

2000 ◽  
Vol 2 (2) ◽  
pp. 107-115 ◽  
Author(s):  
Christine E. Kasper ◽  
Lin Xun
Keyword(s):  
Skeletal Muscle ◽  
Hind Limb ◽  
Laser Scanning ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Adult Rats ◽  
Single Fibers ◽  
Fast Twitch ◽  
Hind Limb Unloading ◽  
Antibody Localization

The effects of prolonged hind-limb unloading on titin antibody localization and expression of titin isozymes of single fibers from the synergistic slow-twitch soleus (SOL) and fast-twitch plantaris (PLN) of adult rats were studied after 14 and 28 days of hind-limb unloading (HU). Titin antibody localization and expression was not altered at 14 days of HU. However, there was a 4% loss in antibody to Z-band distance (Ab-Z) in the SOL and an increase of 8% in PLN Ab-Z after 28 days of HU. The titin and myosin heavy chain composition of single fibers and small bundles of fibers from control and unloaded muscles were examined using 2% to 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. There was a marked loss of relative amounts of titin in both SOL and PLN following 28 days of HU. As the protein loads for these measures were identical, the authors conclude that these findings represent an actual loss of titin density rather than a decreased value due to a loss of total muscle mass. Laser scanning densitometry of the titin bands show a marked decrease in density and molecular weight in unloaded SOL. In the PLN, marked losses of titin density were accompanied by decreased electrophoretic motility. The results demonstrate that the titin isoform composition and titin antibody localization of skeletal muscle is altered during hind-limb unloading. Furthermore, as titin is responsible for positional stability of the sarcomere and the fiber during contraction, change in isoforms during HU may predispose atrophied muscle to injury during reuse and recovery.

Hypothyroidism alters diaphragm muscle development

1996 ◽  
Vol 81 (5) ◽  
pp. 1965-1972 ◽  
Author(s):  
Gary C. Sieck ◽  
Louise E. Wilson ◽  
Bruce D. Johnson ◽  
Wen-Zhi Zhan
Keyword(s):  
Muscle Development ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Diaphragm Muscle ◽  
Rat Diaphragm ◽  
Shortening Velocity ◽  
Pregnant Rats ◽  
Isoform Expression ◽  
The Impact

Sieck, Gary C., Louise E. Wilson, Bruce D. Johnson, and Wen-Zhi Zhan. Hypothyroidism alters diaphragm muscle development. J. Appl. Physiol. 81(5): 1965–1972, 1996.—The impact of hypothyroidism (Hyp) on myosin heavy chain (MHC) isoform expression, maximum specific force (Po), fatigability, and maximum unloaded shortening velocity ( V o) was determined in the rat diaphragm muscle (Dia) at 0, 7, 14, 21, and 28 days of age. Hyp was induced by treating pregnant rats with 6- n-propyl-2-thiouracil (0.05% in drinking water) beginning at gestational day 10 and was confirmed by reduced plasma levels of 3,5,3′-triiodothyronine and thyroxine. MHC isoforms were separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels and analyzed by densitometry. Isometric Po and fatigue resistance of the Dia were measured in vitro at 26°C, and V o was determined at 15°C with the slack test. Compared with control muscles, expression of MHC-slow was higher and expression of adult fast MHC isoforms was lower in Hyp Dia at all ages. The neonatal isoform of MHC continued to be expressed in the Hyp Dia until day 28. At each age, Po and fatigability were reduced and V o was slower in the Hyp Dia. We conclude that Hyp-induced alterations in MHC isoform expression do not fully predict the changes in Dia contractile properties.

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