Ryanodine receptor in different malignant hyperthermia-susceptible porcine muscles

1991 ◽  
Vol 260 (1) ◽  
pp. C58-C66 ◽  
Author(s):  
J. M. Ervasti ◽  
M. A. Strand ◽  
T. P. Hanson ◽  
J. R. Mickelson ◽  
C. F. Louis

The sarcoplasmic reticulum (SR) ryanodine receptor was studied in SR vesicles isolated from the vastus intermedius skeletal muscle and cardiac muscle of malignant hyperthermia-susceptible (MHS) and normal pigs. MHS and normal heavy SR preparations isolated from the vastus intermedius muscle had similar yields, polyacrylamide gel electrophoretic patterns, Ca2(+)-ATPase activities, mitochondrial enzyme activities, calsequestrin contents, and maximal [3H]ryanodine-binding activities. However, while half-maximal calcium concentrations (Ca0.5) for stimulation of MHS and normal vastus intermedius SR [3H]ryanodine binding were not significantly different, the Ca0.5 for inhibition of [3H]ryanodine binding to MHS vastus intermedius SR (76 +/- 17 microM) was significantly greater than to normal SR (16 +/- 9 microM). MHS vastus intermedius SR also exhibited a significantly lower Kd value (62 +/- 15 nM) for [3H]ryanodine binding compared with normal SR (Kd = 284 +/- 102 nM). These values for MHS and normal vastus intermedius SR are similar to those reported using SR isolated from a muscle composed of predominantly fast-twitch fibers, indicating the similarity of the ryanodine receptor in fast- and slow-twitch skeletal muscles. In contrast, there were no differences in the properties of the ryanodine receptor of porcine cardiac SR isolated from MHS and normal pigs. We therefore conclude that there is a defect in the SR ryanodine receptor of both slow- and fast-twitch skeletal muscle fiber types but not in cardiac muscle of MHS individuals.

1977 ◽  
Vol 42 (2) ◽  
pp. 267-272 ◽  
Author(s):  
K. M. Baldwin ◽  
D. A. Cooke ◽  
W. G. Cheadle

The effects of chronic “steady-state” and high-speed interval running were investigated on time-course changes in certain biochemical properties of cardiac and skeletal muscle fiber types of rats. Nine weeks of the interval program resulted in significant increased (15%) in both cardiac enlargement and ATPase activity of myofibrils; whereas increases in these parameters were only transient and not significant at the termination of the program involving steady-state running. Neither program induced appreciable alterations in citrate synthase and phosphofructokinase activity in cardiac muscle. In fast-twitch white fibers, “steady-state” training induced only a transient 45% increase in citrate synthase activity in contrast to a progressive twofold change with interval training. Both programs resulted in similar increases (45–50%) in citrate synthase activity in fast-twitch and slow-twitch red fibers. However, the patterns of increase for both fiber types differed between the two programs. These findings suggest that training programs incorporating elements of both “steady-state” incline and high-speed interval running can potentially induce respiratory enzyme adaptations in the greatest spectrum of rodent skeletal muscle fibers in addition to inducing adaptations to enhance contractile potential in cardiac muscle.


1983 ◽  
Vol 245 (2) ◽  
pp. H265-H275 ◽  
Author(s):  
B. G. Mackie ◽  
R. L. Terjung

Blood flow to fast-twitch red (FTR), fast-twitch white (FTW), and slow-twitch red (STR) muscle fiber sections of the gastrocnemius-plantaris-soleus muscle group was determined using 15 +/- 3-microns microspheres during in situ stimulation in pentobarbital-anesthetized rats. Steady-state blood flows were assessed during the 10th min of contraction using twitch (0.1, 0.5, 1, 3, and 5 Hz) and tetanic (7.5, 15, 30, 60, and 120/min) stimulation conditions. In addition, an earlier blood flow determination was begun at 3 min (twitch series) or at 30 s (tetanic series) of stimulation. Blood flow was highest in the FTR (220-240 ml X min-1 X 100 g-1), intermediate in the STR (140), and lowest in the FTW (70-80) section during tetanic contraction conditions estimated to coincide with the peak aerobic function of each fiber type. These blood flows are fairly proportional to the differences in oxidative capacity among fiber types. Further, their absolute values are similar to those predicted from the relationship between blood flow and oxidative capacity found by others for dog and cat muscles. During low-frequency contraction conditions, initial blood flow to the FTR and STR sections were excessively high and not dependent on contraction frequency. However, blood flows subsequently decreased to values in keeping with the relative energy demands. In contrast, FTW muscle did not exhibit this time-dependent relative hyperemia. Thus, besides the obvious quantitative differences between skeletal muscle fiber types, there are qualitative differences in blood flow response during contractions. Our findings establish that, based on fiber type composition, a heterogeneity in blood flow distribution can occur within a whole muscle during contraction.


1985 ◽  
Vol 249 (4) ◽  
pp. E360-E365 ◽  
Author(s):  
E. G. Noble ◽  
C. D. Ianuzzo

Muscle homogenates representing slow-twitch oxidative, fast-twitch oxidative-glycolytic, fast-twitch glycolytic, and mixed fiber types were prepared from normal, diabetic, and insulin-treated diabetic rats. Diabetes was induced by injection of 80 mg . kg-1 of streptozotocin. The activities of citrate synthase, succinate dehydrogenase, and 3-hydroxyacyl-CoA dehydrogenase were employed as markers of oxidative potential, whereas phosphorylase, hexokinase, and phosphofructokinase activities were used as an indication of glycolytic capacity. Diabetes was associated with a general decrement in the activity of oxidative marker enzymes for all fiber types except the fast-twitch glycolytic fiber. In contrast, the fast-twitch glycolytic fibers demonstrated the greatest decline in glycolytic enzymatic activity. Insulin-treated animals, either trained or untrained, exhibited enzyme activities similar to their normal counterparts. Exercise training of diabetic rats mimicked the effect of insulin treatment and caused a near normalization of the activity of the marker enzymes. These findings suggest that the enzymatic potential of all skeletal muscle fiber types of diabetic rats may be normalized by exercise training even in the absence of significant amounts of insulin.


1975 ◽  
Vol 229 (2) ◽  
pp. 394-397 ◽  
Author(s):  
J Borensztajn ◽  
MS Rone ◽  
SP Babirak ◽  
JA McGarr ◽  
LB Oscai

Lipoprotein lipase activity was measured in the three skeletal muscle fiber types of untrained rats and in those of rats subjected to a 12-wk program of treadmill running. Lipoprotein lipase activity in slow-twitch red fibers was approximately 14- to 20-fold higher (P less than 0.001) than that in fast-twitch white and approximately 2-fold higher (P less than 0.001) than that in fast-twitch red fibers in the untrained animals. These results suggest that, in sedentary animals, mainly slow-twitch red and fast-twitch red fibers are capable of taking up plasma triglyceride fatty acids. Regularly performed endurance exercise resulted in significant increase (2- to 4.5-fold) in lipoprotein lipase activity in the three muscle fiber types examined. The increase in lipoprotein lipase activity in response to treadmill running suggests that exercise increases the capacity of these fibers to take up and oxidize plasma triglyceride fatty acids. Cardiac muscle did not undergo an exercise-induced increase in the levels of activity of lipoprotein lipase similar to that seen in skeletal muscle.


2005 ◽  
Vol 25 (15) ◽  
pp. 6629-6638 ◽  
Author(s):  
Misook Oh ◽  
Igor I. Rybkin ◽  
Victoria Copeland ◽  
Michael P. Czubryt ◽  
John M. Shelton ◽  
...  

ABSTRACT Skeletal muscles are a mosaic of slow and fast twitch myofibers. During embryogenesis, patterns of fiber type composition are initiated that change postnatally to meet physiological demand. To examine the role of the protein phosphatase calcineurin in the initiation and maintenance of muscle fiber types, we used a “Flox-ON” approach to obtain muscle-specific overexpression of the modulatory calcineurin-interacting protein 1 (MCIP1/DSCR1), an inhibitor of calcineurin. Myo-Cre transgenic mice with early skeletal muscle-specific expression of Cre recombinase were used to activate the Flox-MCIP1 transgene. Contractile components unique to type 1 slow fibers were absent from skeletal muscle of adult Myo-Cre/Flox-MCIP1 mice, whereas oxidative capacity, myoglobin content, and mitochondrial abundance were unaltered. The soleus muscles of Myo-Cre/Flox-MCIP1 mice fatigued more rapidly than the wild type as a consequence of the replacement of the slow myosin heavy chain MyHC-1 with a fast isoform, MyHC-2A. MyHC-1 expression in Myo-Cre/Flox-MCIP1 embryos and early neonates was normal. These results demonstrate that developmental patterning of slow fibers is independent of calcineurin, while the maintenance of the slow-fiber phenotype in the adult requires calcineurin activity.


1986 ◽  
Vol 251 (3) ◽  
pp. C395-C402 ◽  
Author(s):  
S. P. Kirkwood ◽  
E. A. Munn ◽  
G. A. Brooks

High-voltage electron microscopy at 1,500 kV was used to examine mitochondrial morphology in three skeletal muscles of the rat. The soleus, deep portion of the vastus lateralis, and superficial portion of the vastus lateralis muscles were examined to represent slow-twitch oxidative, fast-twitch oxidative, glycolytic, and fast-twitch glycolytic skeletal muscle fiber types, respectively. Muscle samples were removed from six female Wistar rats. The tissues were fixed using standard electron microscopic techniques and were sectioned transversely with respect to muscle fiber orientation to approximately 0.5-micron thickness. The sections were stained on grids with uranyl acetate and Reynolds' lead citrate. Results revealed a mitochondrial reticulum in all three skeletal muscle fiber types. Stereological analyses of the electron micrographs were performed to measure volume densities and surface-to-volume ratios of mitochondria in the muscle samples. Cross-sectional volume densities of mitochondria in the soleus (15.5 +/- 1%) and deep portion of the vastus lateralis (16.1 +/- 2%) were significantly greater (P less than 0.05) than in the superficial portion of the vastus lateralis (8.7 +/- 1%). Surface-to-volume ratios of mitochondria were not significantly different between fiber types. It was concluded that the mitochondria in mammalian limb skeletal muscle are a reticulum, or network.


1993 ◽  
Vol 41 (7) ◽  
pp. 1013-1021 ◽  
Author(s):  
S Boudriau ◽  
M Vincent ◽  
C H Côté ◽  
P A Rogers

We used immunochemical quantification and indirect immunofluorescence to investigate the cell content, distribution, and organization of microtubules in adult rat slow-twitch soleus and fast-twitch vastus lateralis muscles. An immunoblotting assay demonstrated that the soleus muscle (primarily Type I fibers) was found to have a 1.7-fold higher relative content of alpha-tubulin compared with the superficial portion of the vastus lateralis muscle (primarily Type IIb fibers). Both physiological muscle types revealed a complex arrangement of microtubules which displayed oblique, longitudinal, and transverse orientations within the sarcoplasmic space. The predominance of any one particular orientation varied significantly from one muscle tissue section to another. Nuclei were completely surrounded by a dense net-like structure of microtubules. Both muscle fiber types were found to possess a higher density of microtubules in the subsarcolemmal region. These microtubules followed the contour of the sarcolemma in slightly contracted fibers and showed a fine punctate appearance indicative of a restricted distribution. The immunofluorescence results indicate that microtubules are associated with the sarcolemma and therefore may form a part of the membrane cytoskeletal domain of the muscle fiber. We conclude that the microtubule network of the adult mammalian skeletal muscle fiber constitutes a bone fide component of the exosarcomeric cytoskeletal lattice domain along with the intermediate filaments, and as such could therefore participate in the mechanical integration of the various organelles of the myofibers during the contraction-relaxation cycle.


2001 ◽  
Vol 49 (8) ◽  
pp. 1033-1044 ◽  
Author(s):  
Guillermo H. Graziotti ◽  
Clara M. Ríos ◽  
José-Luis L. Rivero

Skeletal muscle fiber types classified on the basis of their content of different myosin heavy chain (MHC) isoforms were analyzed in samples from hindlimb muscles of adult sedentary llamas ( Lama glama) by correlating immunohistochemistry with specific anti-MHC monoclonal antibodies, myofibrillar ATPase (mATPase) histochemistry, and quantitative histochemistry of fiber metabolic and size properties. The immunohistochemical technique allowed the separation of four pure (i.e., expressing a unique MHC isoform) muscle fiber types: one slow-twitch (Type I) and three fast-twitch (Type II) phenotypes. The same four major fiber types could be objectively discriminated with two serial sections stained for mATPase after acid (pH 4.5) and alkaline (pH 10.5) preincubations. The three fast-twitch fiber types were tentatively designated as IIA, IIX, and IIB on the basis of the homologies of their immunoreactivities, acid denaturation of their mATPase activity, size, and metabolic properties expressed at the cellular level with the corresponding isoforms of rat and horse muscles. Acid stability of their mATPase activity increased in the rank order IIA>IIX>IIB. The same was true for size and glycolytic capacity, whereas oxidative capacity decreased in the same rank order IIA>IIX>IIB. In addition to these four pure fibers (I, IIA, IIX, and IIB), four other fiber types with hybrid phenotypes containing two (I + IIA, IIAX, and IIXB) or three (IIAXB) MHCs were immunohistochemically delineated. These frequent phenotypes (40% of the semitendinosus muscle fiber composition) had overlapped mATPase staining intensities with their corresponding pure fiber types, so they could not be delineated by mATPase histochemistry. Expression of the three fast adult MHC isoforms was spatially regulated around islets of Type I fibers, with concentric circles of fibers expressing MHC-IIA, then MHC-IIX, and peripherally MHC-IIB. This study demonstrates that three adult fast Type II MHC isoproteins are expressed in skeletal muscle fibers of the llama. The general assumption that the very fast MHC-IIB isoform is expressed only in small mammals can be rejected. (J Histochem Cytochem 49:1033–1044, 2001)


1988 ◽  
Vol 255 (3) ◽  
pp. C271-C277 ◽  
Author(s):  
P. C. Tullson ◽  
H. B. John-Alder ◽  
D. A. Hood ◽  
R. L. Terjung

Management of adenine nucleotide catabolism differs among skeletal muscle fiber types. This study evaluated whether there are corresponding differences in the rates of de novo synthesis of adenine nucleotide among fiber type sections of skeletal muscle using an isolated perfused rat hindquarter preparation. Label incorporation into adenine nucleotides from the [1-14C]glycine precursor was determined and used to calculate synthesis rates based on the intracellular glycine specific radioactivity. Results show that intracellular glycine is closely related to the direct precursor pool. Rates of de novo synthesis were highest in fast-twitch red muscle (57.0 +/- 4.0, 58.2 +/- 4.4 nmol.h-1.g-1; deep red gastrocnemius and vastus lateralis), relatively high in slow-twitch red muscle (47.0 +/- 3.1; soleus), and low in fast-twitch white muscle (26.1 +/- 2.0 and 21.6 +/- 2.3; superficial white gastrocnemius and vastus lateralis). Rates for four mixed muscles were intermediate, ranging between 32.3 and 37.3. Specific de novo synthesis rates exhibited a strong correlation (r = 0.986) with muscle section citrate synthase activity. Turnover rates (de novo synthesis rate/adenine nucleotide pool size) were highest in high oxidative muscle (0.82-1.06%/h), lowest in low oxidative muscle (0.30-0.35%/h), and intermediate in mixed muscle (0.44-0.55%/h). Our results demonstrate that differences in adenine nucleotide management among fiber types extends to the process of de novo adenine nucleotide synthesis.


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