Sodium compartmentalization in single muscle fibers of the giant barnacle

1970 ◽  
Vol 48 (2) ◽  
pp. 139-146 ◽  
Author(s):  
R. D. Allen ◽  
J. A. M. Hinke
Keyword(s):  
Muscle Fibers ◽  
Flux Analysis ◽  
Single Muscle ◽  
Activity Measurements ◽  
Microelectrode Measurements

The influx and efflux of 22Na+ was measured in single muscle fibers of the giant barnacle, Balanus nubilus. These experiments show that intracellular Na+ is divided into two compartments. A rapidly exchanging compartment, identified as myoplasmic free Na+, was evident in both influx and efflux experiments. A very slowly exchanging compartment was evident only in the influx experiments. The size of the rapidly exchanging compartment, expressed as the percentage of total intracellular Na, was estimated from the 22Na+ influx experiments and from intracellular Na+ activity measurements made with Na+-specific glass microelectrodes. Influx measurements showed 58.5% free Na+, and Na+ microelectrode measurements showed 51.6% free Na+. Both the 22Na+ flux analysis and Na+ activity measurements indicate at least two compartments for intracellular Na+.

Single Influx Rate for 42K+ in the Single Fiber of the Barnacle

1971 ◽  
Vol 49 (6) ◽  
pp. 624-626 ◽  
Author(s):  
R. D. Allen ◽  
J. A. M. Hinke
Keyword(s):  
Muscle Fibers ◽  
Single Fiber ◽  
Single Muscle ◽  
Influx Rate ◽  
Activity Measurements

The influx of 42K+ was measured in single muscle fibers of the giant barnacle Balanus nubilus. In influx experiments for 54 h, only one exchange component was evident for up to 90% intracellular K+. A comparison of this result with intracellular K+ activity measurements using K+-selective microelectrodes indicates at least 90% of the intracellular K+ is free in the myoplasm.

scholarly journals DISSECTION AND ELECTROPHORETIC PROTEIN ANALYSIS OF SINGLE MUSCLE FIBERS FROM HISTOLOGICALLY IDENTIFIED FREEZE-DRIED SECTIONS: APPLICATION TO MUSCLE FIBERS WITH RIMMED VACUOLES

1983 ◽  
Vol 4 (5) ◽  
pp. 459-466 ◽  
Author(s):  
ITARU TOYOSHIMA ◽  
KEIKO TANAKA ◽  
NOBUYOSHI FUKUHARA ◽  
TOSHIHIDE KUMAMOTO ◽  
TADASHI MIYATAKE
Keyword(s):  
Muscle Fibers ◽  
Protein Analysis ◽  
Single Muscle ◽  
Freeze Dried

Contraction-induced injury to single muscle fibers: velocity of stretch does not influence the force deficit

1998 ◽  
Vol 275 (6) ◽  
pp. C1548-C1554 ◽  
Author(s):  
Gordon S. Lynch ◽  
John A. Faulkner
Keyword(s):  
Null Hypothesis ◽  
Muscle Injury ◽  
Isometric Force ◽  
Muscle Fibers ◽  
Single Muscle ◽  
Control Value ◽  
Severity Of Injury ◽  
Before And After ◽  
The Difference ◽  
Permeabilized Fibers

We tested the null hypothesis that the severity of injury to single muscle fibers following a single pliometric (lengthening) contraction is not dependent on the velocity of stretch. Each single permeabilized fiber obtained from extensor digitorum longus muscles of rats was maximally activated and then exposed to a single stretch of either 5, 10, or 20% strain [% of fiber length ( L f)] at a velocity of 0.5, 1.0, or 2.0 L f /s. The force deficit, the difference between maximum tetanic isometric force (Po) before and after the stretch expressed as a percentage of the control value for Po before the stretch, provided an estimate of the magnitude of muscle injury. Despite a fourfold range from the lowest to the highest velocities, force deficits were not different among stretches of the same strain. At stretches of 20% strain, even an eightfold range of velocities produced no difference in the force deficit, although 40% of the fibers were torn apart at a velocity of 4 L f /s. We conclude that, within the range of velocities tolerated by single permeabilized fibers, the severity of contraction-induced injury is not related to the velocity of stretch.

MHC and sarcoplasmic reticulum protein isoforms in functionally overloaded cat plantaris muscle fibers

1996 ◽  
Vol 80 (4) ◽  
pp. 1296-1303 ◽  
Author(s):  
R. J. Talmadge ◽  
R. R. Roy ◽  
G. R. Chalmers ◽  
V. R. Edgerton
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Heavy Chain ◽  
Muscle Fibers ◽  
Protein Isoforms ◽  
Type I ◽  
Single Muscle ◽  
Plantaris Muscle ◽  
Plasmic Reticulum ◽  
Deep Region ◽  
Isoform Expression

To determine whether the adaptations in myosin heavy chain (MHC) isoform expression after functional overload (FO) are accompanied by commensurate adaptations in protein isoforms responsible for relaxation [sarco(endo)plasmic reticulum (SR) Ca(2+)-adenosinetriphosphatase (SERCA) and phospholamban (PHL)] in single muscle fibers, the isoforms of MHC and SERCA and the presence or absence of PHL were determined for cat plantaris fibers 3 mo after FO. In control plantaris the relative MHC isoform composition was 23% type I, 21% type IIa, and 56% type IIb. FO resulted in a shift toward slower isoforms (33% type I, 44% type IIa, and 23% type IIb). In the deep region of the plantaris the proportions of type I MHC and hybrid MHC fibers (containing type I and II MHCs) were 40 and 200% greater in FO cats, respectively. FO resulted in a 47% increase in the proportion of fibers containing only the slow SERCA isoform (SERCA2) and a 41% increase in the proportion of fibers containing PHL. The proportions of fibers containing type I MHC, SERCA2, and PHL in control and FO plantaris were linearly correlated. These data show that adaptations in MHC isoform expression are accompanied by commensurate adaptations in sarcoplasmic reticulum protein isoforms in single muscle fibers after FO.

The mutations m.5628T>C and m.8348A>G in single muscle fibers of a patient with chronic progressive external ophthalmoplegia

2012 ◽  
Vol 320 (1-2) ◽  
pp. 131-135 ◽  
Author(s):  
Juliana Gamba ◽  
Beatriz Hitomi Kiyomoto ◽  
Acary Souza Bulle de Oliveira ◽  
Alberto Alain Gabbai ◽  
Beny Schmidt ◽  
...  
Keyword(s):  
Muscle Fibers ◽  
Progressive External Ophthalmoplegia ◽  
Chronic Progressive External Ophthalmoplegia ◽  
Single Muscle

Size changes in single muscle fibers during fixation and embedding

1975 ◽  
Vol 7 (2) ◽  
pp. 383-387 ◽  
Author(s):  
Brenda R. Eisenberg ◽  
Bert A. Mobley
Keyword(s):  
Muscle Fibers ◽  
Single Muscle

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.

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