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

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.

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

European Journal of Applied Physiology and Occupational Physiology ◽

10.1007/bf00423284 ◽

1976 ◽

Vol 35 (4) ◽

pp. 251-259 ◽

Cited By ~ 20

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

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Hypertrophy of Rat Skeletal Muscle Is Associated with Increased SIRT1/Akt/mTOR/S6 and Suppressed Sestrin2/SIRT3/FOXO1 Levels

International Journal of Molecular Sciences ◽

10.3390/ijms22147588 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7588

Author(s):

Zoltan Gombos ◽

Erika Koltai ◽

Ferenc Torma ◽

Peter Bakonyi ◽

Attila Kolonics ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Hypertrophy ◽

Male Rats ◽

Cellular Interactions ◽

Molecular Signaling ◽

Protein Breakdown ◽

Rat Skeletal Muscle ◽

Plantaris Muscle ◽

Skeletal Muscle Hypertrophy ◽

Intensive Investigation

Despite the intensive investigation of the molecular mechanism of skeletal muscle hypertrophy, the underlying signaling processes are not completely understood. Therefore, we used an overload model, in which the main synergist muscles (gastrocnemius, soleus) of the plantaris muscle were surgically removed, to cause a significant overload in the remaining plantaris muscle of 8-month-old Wistar male rats. SIRT1-associated pro-anabolic, pro-catabolic molecular signaling pathways, NAD and H2S levels of this overload-induced hypertrophy were studied. Fourteen days of overload resulted in a significant 43% (p < 0.01) increase in the mass of plantaris muscle compared to sham operated animals. Cystathionine-β-synthase (CBS) activities and bioavailable H2S levels were not modified by overload. On the other hand, overload-induced hypertrophy of skeletal muscle was associated with increased SIRT1 (p < 0.01), Akt (p < 0.01), mTOR, S6 (p < 0.01) and suppressed sestrin 2 levels (p < 0.01), which are mostly responsible for anabolic signaling. Decreased FOXO1 and SIRT3 signaling (p < 0.01) suggest downregulation of protein breakdown and mitophagy. Decreased levels of NAD+, sestrin2, OGG1 (p < 0.01) indicate that the redox milieu of skeletal muscle after 14 days of overloading is reduced. The present investigation revealed novel cellular interactions that regulate anabolic and catabolic processes in the hypertrophy of skeletal muscle.

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

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1991.260.1.e1 ◽

1991 ◽

Vol 260 (1) ◽

pp. E1-E7 ◽

Cited By ~ 1

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.

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Total and myofibrillar protein breakdown in different types of rat skeletal muscle: Effects of sepsis and regulation by insulin

Metabolism ◽

10.1016/0026-0495(89)90100-5 ◽

1989 ◽

Vol 38 (7) ◽

pp. 634-640 ◽

Cited By ~ 111

Author(s):

Per-Olof Hasselgren ◽

J.Howard James ◽

Daniel W. Benson ◽

Marianne Hall-Angerås ◽

Ulf Angerås ◽

...

Keyword(s):

Skeletal Muscle ◽

Myofibrillar Protein ◽

Protein Breakdown ◽

Rat Skeletal Muscle ◽

Different Types

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

10.1101/218636 ◽

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.

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

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1998.274.6.e1018 ◽

1998 ◽

Vol 274 (6) ◽

pp. E1018-E1026 ◽

Cited By ~ 13

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.

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

AJP Cell Physiology ◽

10.1152/ajpcell.1997.272.3.c1007 ◽

1997 ◽

Vol 272 (3) ◽

pp. C1007-C1016 ◽

Cited By ~ 106

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.

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The differing responses of four muscle types to dexamethasone treatment in the rat

Biochemical Journal ◽

10.1042/bj2080147 ◽

1982 ◽

Vol 208 (1) ◽

pp. 147-151 ◽

Cited By ~ 72

Author(s):

Frank J. Kelly ◽

David F. Goldspink

Keyword(s):

Skeletal Muscle ◽

Growth Patterns ◽

Protein Accumulation ◽

Protein Breakdown ◽

Dexamethasone Treatment ◽

Slow Twitch Muscle ◽

Muscle Types ◽

Slow Twitch ◽

Induced Changes ◽

Fast Twitch

The glucocorticoid dexamethasone dramatically altered growth patterns in four muscle types, inducing atrophy of smooth and fast-twitch skeletal muscle, suppressing protein accumulation in slow-twitch muscle and enhancing growth in the heart. These differing responses were explained by steroid-induced changes in RNA content, protein synthesis and protein breakdown.

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