Effects of an anabolic steroid and sprint training on selected histochemical and morphological observations in rat skeletal muscle types

1976 ◽  
Vol 35 (4) ◽  
pp. 251-259 ◽  
Author(s):  
Robert C. Hickson ◽  
William W. Heusner ◽  
Wayne D. Van Huss ◽  
James F. Taylor ◽  
Rexford E. Carrow
Keyword(s):  
Skeletal Muscle ◽  
Anabolic Steroid ◽  
Sprint Training ◽  
Rat Skeletal Muscle ◽  
Muscle Types ◽  
Skeletal Muscle Types

scholarly journals Age- and activity-related changes in three proteinase enzymes of rat skeletal muscle

1985 ◽  
Vol 230 (3) ◽  
pp. 833-836 ◽  
Author(s):  
D F Goldspink ◽  
S E Lewis
Keyword(s):  
Skeletal Muscle ◽  
Old Age ◽  
Protein Breakdown ◽  
Rat Skeletal Muscle ◽  
Foetal Life ◽  
Muscle Types ◽  
Specific Activities ◽  
Skeletal Muscle Types

The specific activities of three proteinases, cathepsins B, D and H, were measured in two skeletal-muscle types as a function of age (i.e. from large foetal life to old age), and in muscles immobilized at various lengths for 3 days. The activities of the lysosomal endopeptidases B and D, but not H, consistently changed in parallel with previously determined rates of protein breakdown, indicating a good and potentially useful correlation between the two.

Characterization of insulin receptor kinase activity and autophosphorylation in different skeletal muscle types

1991 ◽  
Vol 260 (1) ◽  
pp. E1-E7 ◽  
Author(s):  
S. Azhar ◽  
J. C. Butte ◽  
R. F. Santos ◽  
C. E. Mondon ◽  
G. M. Reaven
Keyword(s):  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Tyrosine Kinase ◽  
Insulin Receptor ◽  
Kinase Activity ◽  
Insulin Binding ◽  
Tyrosine Kinase Activity ◽  
Fiber Composition ◽  
Muscle Types ◽  
Skeletal Muscle Types

We have examined insulin binding, autophosphorylation, and tyrosine kinase activity in detergent-solubilized and wheat germ agglutinin-purified insulin receptor preparations from four rat muscles of different fiber composition (i.e., tensor fascia latae, soleus, vastus intermedius, and plantaris). Insulin binding activity was similar in three of the four muscles but lower in tensor fascia latae. No significant differences were noted in the affinity of insulin for its receptor from various muscle types. Insulin receptor tyrosine kinase activity measured in the absence (basal) and presence of insulin (0.3-300 nM) was comparable in all muscle types (normalized to the amount of insulin bound). Insulin sensitivity, measured as the dose of insulin required for half-maximal activation of kinase activity, was also similar in all muscle types. Likewise, incubation of receptor preparations with [gamma-32P]ATP, Mn2+, and insulin (0.25-100 nM) resulted in a dose-dependent autophosphorylation of the beta-subunit (relative molecular weight approximately 95 kDa) with similar kinetics in all muscle types. In conclusion, these results show that the functional behavior of the insulin receptor autophosphorylation-kinase system (in vitro) is not changed by alterations in muscle fiber composition, indicating that differences in insulin sensitivity between different skeletal muscle types is probably not due to modulation of the insulin receptor phosphorylation system.

scholarly journals PGC-1β prevents statin-associated myotoxicity in oxidative skeletal muscle

2017 ◽  
Author(s):  
François Singh ◽  
Joffrey Zoll ◽  
Urs Duthaler ◽  
Anne-Laure Charles ◽  
Gilles Laverny ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
Rat Skeletal Muscle ◽  
Oxidative Defense ◽  
Muscle Types ◽  
And Function

AbstractStatins are generally well-tolerated, but can induce myopathy. Statins are associated with impaired expression of PGC-1β in human and rat skeletal muscle. The current study was performed to investigate the relation between PGC-1β expression and function and statin-associated myopathy. In WT mice, atorvastatin impaired mitochondrial function in glycolytic, but not in oxidative muscle. In PGC-1β KO mice, atorvastatin induced a shift from oxidative type IIA to glycolytic type IIB myofibers mainly in oxidative muscle and mitochondrial dysfunction was observed in both muscle types. In glycolytic muscle of WT and KO mice and in oxidative muscle of KO mice, atorvastatin suppressed mitochondrial proliferation and oxidative defense, leading to apoptosis. In contrast, mitochondrial function was maintained or improved and apoptosis decreased by atorvastatin in oxidative muscle of WT mice. In conclusion, PGC-1β has an important role in preventing damage to oxidative muscle in the presence of a mitochondrial toxicant such as atorvastatin.

scholarly journals Thyroid receptor plasticity in striated muscle types: effects of altered thyroid state

1998 ◽  
Vol 274 (6) ◽  
pp. E1018-E1026 ◽  
Author(s):  
Fadia Haddad ◽  
Anqi X. Qin ◽  
Samuel A. McCue ◽  
Kenneth M. Baldwin
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Type I ◽  
Thyroid State ◽  
Muscle Types ◽  
Slow Twitch ◽  
Thyroid Receptor ◽  
Altered Thyroid ◽  
Fast Twitch ◽  
Skeletal Muscle Types

This study examined nuclear thyroid receptor (TR) maximum binding capacity (Bmax), dissociation constant ( K d), and TR isoform (α1, α2, β1) mRNA expression in rodent cardiac, “fast-twitch white,” “fast-twitch red,” and “slow-twitch red” muscle types as a function of thyroid state. These analyses were performed in the context of slow-twitch type I myosin heavy-chain (MHC) expression, a 3,5,3′-triiodothyronine (T3)-regulated gene that displays varying responsiveness to T3 in the above tissues. Nuclear T3 binding analyses show that the skeletal muscle types express more TRs per unit DNA than cardiac muscle, whereas the latter has a lower K d than the former. Altered thyroid state had little effect on either cardiac Bmax or K d, whereas hypothyroidism increased Bmax in the skeletal muscle types without affecting its K d. Cardiac muscle demonstrated the greatest mRNA signal of TR-β1 compared with the other muscle types, whereas the TR-α1mRNA signals were more abundant in the skeletal muscle types, especially fast-twitch red. Hyperthyroidism increased the ratio of β1 to α1 and decreased the ratio of α2- to α1+β1-mRNA signal across the muscle types, whereas hypothyroidism caused the opposite effects. The nuclear T3affinity correlated significantly with the TR-β1 mRNA expression but not with TR-α1 mRNA expression. Collectively, these findings suggest that, despite a divergent pattern of TR mRNA expression in the different muscle types, these patterns follow similar qualitative changes under altered thyroid state. Furthermore, TR expression pattern cannot account for the quantitative and qualitative changes in type I MHC expression that occur in the different muscle types.

Activation of the ubiquitin pathway in rat skeletal muscle by catabolic doses of glucocorticoids

1997 ◽  
Vol 272 (3) ◽  
pp. C1007-C1016 ◽  
Author(s):  
D. Auclair ◽  
D. R. Garrel ◽  
A. Chaouki Zerouala ◽  
L. H. Ferland
Keyword(s):  
Skeletal Muscle ◽  
Muscular Atrophy ◽  
Specific Marker ◽  
Rat Skeletal Muscle ◽  
Mrna Accumulation ◽  
Ubiquitin Pathway ◽  
Subunit Mrna ◽  
Muscle Types ◽  
Two Peaks ◽  
Ubiquitin Conjugate

To evaluate whether catabolic levels of glucocorticoids activate the ubiquitin pathway in conjunction with their known proteolytic effect in skeletal muscle, rats were injected daily with corticosterone (CTC; 10 mg/100 g body wt) for 7 days. Two peaks of urinary excretion of 3-methylhistidine (3-MH), a specific marker of myofibrillar proteolysis, were observed at days 1 and 3 (165 and 295% of controls, respectively). Levels of ubiquitin pathway mRNAs in skeletal muscle were assessed around the 3-MH peaks. In the extensor digitorum longus, a first rise of two polyubiquitin (pUb) mRNAs was seen at day 1 (183 and 162% of control for the UbB and UbC transcripts, respectively, P < 0.01). An accumulation of both E2-14k mRNAs (140%, P < 0.02, and 157% of controls, P < 0.01) and proteasome C8 subunit mRNA (222% of control, P < 0.05) was seen at day 2. A second more important peak of induction of pUb mRNA was seen at day 3 (251 and 217% of controls for the UbB and UbC transcripts, respectively, P< 0.001). All transcripts returned to near control levels by day 4. In the soleus, induction of E2-14k mRNA started at day 3 and reached 216 and 208% of controls at day 4 (P < 0.001), whereas an increase of pUb mRNA was observed at days 3 (213 and 241%, P < 0.05) and 4 (211 and 221%, P < 0.001). A rise of proteasome C8 subunit mRNA accumulation was also seen in the soleus at days 3 (217%, P< 0.05) and 4 (157%, P < 0.05). Reduced ubiquitin conjugate levels, possibly due to their rapid degradation through increased proteasome activity, were observed in both muscle types at day 3. The parallel between the catabolic effects of CTC and activation of the ubiquitin pathway in muscles of CTC-treated rats strongly suggests the involvement of this system in glucocorticoid-induced muscular atrophy.

scholarly journals Creatine transporter protein content, localization, and gene expression in rat skeletal muscle

2001 ◽  
Vol 280 (3) ◽  
pp. C415-C422 ◽  
Author(s):  
R. Murphy ◽  
G. McConell ◽  
D. Cameron-Smith ◽  
K. Watt ◽  
L. Ackland ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Protein Content ◽  
Cross Sections ◽  
Cellular Localization ◽  
Immunohistochemical Analysis ◽  
Rat Skeletal Muscle ◽  
Creatine Transporter ◽  
Transporter Protein ◽  
Muscle Types

The present study examined the gene expression and cellular localization of the creatine transporter (CreaT) protein in rat skeletal muscle. Soleus (SOL) and red (RG) and white gastrocnemius (WG) muscles were analyzed for CreaT mRNA, CreaT protein, and total creatine (TCr) content. Cellular location of the CreaT protein was visualized with immunohistochemical analysis of muscle cross sections. TCr was higher ( P ≤ 0.05) in WG than in both RG and SOL, and was higher in RG than in SOL. Total CreaT protein content was greater ( P ≤ 0.05) in SOL and RG than in WG. Two bands (55 and 70 kDa) of the CreaT protein were found in all muscle types. Both the 55-kDa (CreaT-55) and the 70-kDa (CreaT-70) bands were present in greater ( P ≤ 0.05) amounts in SOL and RG than in WG. SOL and RG had a greater amount ( P ≤ 0.05) of CreaT-55 than CreaT-70. Immunohistochemical analysis revealed that the CreaT was mainly associated with the sarcolemmal membrane in all muscle types. CreaT mRNA expression per microgram of total RNA was similar across the three muscle types. These data indicate that rat SOL and RG have an enhanced potential to transport Cr compared with WG, despite a higher TCr in the latter.

scholarly journals Characterization of α-actin isoforms in white and red skeletal muscle types of Leporinus macrocephalus (Characiformes, Anostomidae)

2015 ◽  
Vol 87 (4) ◽  
pp. 2055-2066 ◽  
Author(s):  
FERNANDA A. ALVES-COSTA ◽  
MAELI D.P. SILVA ◽  
ADRIANE P. WASKO
Keyword(s):  
Skeletal Muscle ◽  
Actin Isoforms ◽  
Qrt Pcr ◽  
Muscle Types ◽  
Skeletal Muscle Types

RESUMO Dois genes de α-actina do peixe Leporinus macrocephalus, referindo-se aos tecidos musculares branco e vermelho, foram isolados. Isoformas de actinas, que principalmente diferiram por uma substituição Ser/Ala155, podem ter uma significância funcional relacionada à interação entre actina e ATP. Um resíduo de Ala155, como observado na α-actina esquelética do músculo vermelho, resulta em uma diminuição da afinidade da actina pelo ATP, o que também pode estar associado à ação contrátil lenta desse tecido. Adicionalmente, uma substituição Phe/Ile262 na actina do músculo vermelho leva a uma variação na hidrofobicidade no "plug-D" da proteína, o que pode alterar sua estabilidade. Dados de qRT-PCR evidenciaram significante maior nível de actina RNAm em músculo branco, quando comparado ao músculo vermelho (T=105 Mann Whitney; p=<0,001). Este resultado pode estar relacionado às demandas energéticas do tecido muscular branco, com fibras de contração rápida e metabolismo glicolítico para fornecimento de energia. Os dados disponíveis sobre actinas musculares levam a propor que as α-actinas esqueléticas dos músculos branco e vermelho são geneticamente e funcionalmente distinguíveis em espécies de peixes, uma característica não encontrada em outros grupos de vertebrados.

Calcium uptake in mitochondria from different skeletal muscle types

1985 ◽  
Vol 59 (1) ◽  
pp. 137-141 ◽  
Author(s):  
W. L. Sembrowich ◽  
J. J. Quintinskie ◽  
G. Li
Keyword(s):  
Skeletal Muscle ◽  
Muscle Relaxation ◽  
Muscular Contraction ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Uptake Process ◽  
Muscle Types ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Skeletal Muscle Types

The kinetics of calcium (Ca2+) uptake have been studied in mitochondria isolated from the different types of skeletal muscle. These studies demonstrate that the Ca2+ uptake properties of skeletal mitochondria are similar to those from liver and cardiac mitochondria. The Ca2+ carriers apparently have a high affinity for Ca2+ (Michaelis constants in the microM range). The relationship between Ca2+ uptake and initial Ca2+ concentration (10(-5) to 10(-7) M) is sigmoid in all mitochondria from the different skeletal muscle types suggesting that the uptake process is cooperative. Hill plots reveal coefficients of approximately 2 for mitochondria from fast-twitch muscle and 3.5 for slow-twitch muscle, adding further evidence to the concept that the uptake process is cooperative. An analysis of the potential role of mitochondria in the sequestration of Ca2+ during muscular contraction demonstrated that mitochondria from slow-twitch muscle of both rats and rabbits can potentially account for 100% of the relaxation rate at a low frequency of stimulation (5 Hz). In fast-twitch muscle, the mitochondria appear unable to play a significant role in muscle relaxation, particularly at stimulation frequencies that are considered in the normal physiological range. In summary, it appears that Ca2+ uptake by mitochondria from slow-twitch skeletal muscle has kinetic characteristics which make it important as a potential regulator of Ca2+ within the muscle cell under normal physiological conditions.

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