Upregulation of HARP during in vitro myogenesis and rat soleus muscle regeneration

The effects of the diuretic furosemide on the sensitivity of glucose disposal to insulin were investigated in rat soleus muscle in vitro. At basal levels of insulin, the rates of 3-O-methylglucose transport, 2-deoxyglucose phosphorylation and lactate formation were not affected significantly by furosemide (0.5 mmol/l). However, furosemide significantly decreased these rates at physiological and maximal levels of insulin. The contents of 2-deoxyglucose and glucose 6-phosphate in the presence of furosemide were not significantly different from those in control muscles at all levels of insulin studied. It is concluded that furosemide decreases the sensitivity of glucose utilization to insulin in skeletal muscle by directly inhibiting the glucose transport process.

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Palmitic acid uptake by the rat soleus muscle in vitro

Biochemistry and Cell Biology ◽

10.1139/o01-028 ◽

2001 ◽

Vol 79 (4) ◽

pp. 419-424 ◽

Cited By ~ 5

Author(s):

M Górecka ◽

M Synak ◽

L Budohoski ◽

J Langfort ◽

S Moskalewski ◽

...

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Palmitic Acid ◽

Soleus Muscle ◽

Fatty Acid Uptake ◽

Cellular Fatty Acid ◽

Acid Uptake ◽

Acid Complex ◽

Rat Soleus Muscle

The rate of fatty acid uptake, oxidation, and deposition in skeletal muscles in relation to total and unbound to albumin fatty acids concentration in the medium were investigated in the incubated rat soleus muscle. An immunohistochemical technique was applied to demonstrate whether the albumin-bound fatty acid complex from the medium penetrates well within all areas of the muscle strips. It was found that the percentage of incorporation of palmitic acid into intramuscular lipids was fairly constant, independently of the fatty acid concentration in the medium, and amounted to 6372% for triacylglycerols, 712% for diacylglycerols-monoacylglycerols, and 1926% for phospholipids. Both palmitic acid incorporation into the muscle triacylglycerol stores and its oxidation to CO2closely correlated with an increase in both total and unbound to albumin fatty acid concentrations in the incubation medium. Under conditions of increased total but constant unbound to albumin palmitic acid concentrations, the incorporation of palmitic acid into triacylglycerols and its oxidation to CO2were also increased, but to a lower extent. This supports the hypothesis that the cellular fatty acid metabolism depends not only on the availability of fatty acids unbound to albumin, but also on the availability of fatty acids complexed to albumin.Key words: skeletal muscle, fatty acids, triacylglycerols, phospholipids.

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Heparan sulfate mimetics modulate calpain activity during rat Soleus muscle regeneration

Journal of Cellular Physiology ◽

10.1002/jcp.1106 ◽

2001 ◽

Vol 188 (2) ◽

pp. 178-187 ◽

Cited By ~ 15

Author(s):

M. Zimowska ◽

D. Szczepankowska ◽

W. Streminska ◽

D. Papy ◽

M.C. Tournaire ◽

...

Keyword(s):

Heparan Sulfate ◽

Soleus Muscle ◽

Muscle Regeneration ◽

Calpain Activity ◽

Rat Soleus Muscle

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Long term culture of rat soleus muscle in vitro

FEBS Letters ◽

10.1016/0014-5793(90)81058-v ◽

1990 ◽

Vol 273 (1-2) ◽

pp. 91-94 ◽

Cited By ~ 12

Author(s):

Pamela B. Stace ◽

David R. Marchington ◽

Alan L. Kerbey ◽

Philip J. Randle

Keyword(s):

Soleus Muscle ◽

Long Term Culture ◽

Rat Soleus Muscle

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Effects of insulin and phorbol esters on MARCKS (myristoylated alanine-rich C-kinase substrate) phosphorylation (and other parameters of protein kinase C activation) in rat adipocytes, rat soleus muscle and BC3H-1 myocytes

Biochemical Journal ◽

10.1042/bj2950155 ◽

1993 ◽

Vol 295 (1) ◽

pp. 155-164 ◽

Cited By ~ 20

Author(s):

T P Arnold ◽

M L Standaert ◽

H Hernandez ◽

J Watson ◽

H Mischak ◽

...

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Soleus Muscle ◽

Plasma Membranes ◽

Phorbol Esters ◽

Kinase Substrate ◽

Rat Adipocytes ◽

Kinase C ◽

Rat Soleus Muscle

To evaluate the question of whether or not insulin activates protein kinase C (PKC), we compared the effects of insulin and phorbol esters on the phosphorylation of the PKC substrate, i.e. myristoylated alanine-rich C-kinase substrate (MARCKS). In rat adipocytes, rat soleus muscle and BC3H-1 myocytes, maximally effective concentrations of insulin and phorbol esters provoked comparable, rapid, 2-fold (on average), non-additive increases in the phosphorylation of immunoprecipitable MARCKS. These effects of insulin and phorbol esters on MARCKS phosphorylation in intact adipocytes and soleus muscles were paralleled by similar increases in the phosphorylation of an exogenous, soluble, 85 kDa PKC substrate (apparently a MARCKS protein) during incubation of post-nuclear membrane fractions in vitro. Increases in the phosphorylation of this 85 kDa PKC substrate in vitro were also observed in assays of both plasma membranes and microsomes obtained from rat adipocytes that had been treated with insulin or phorbol esters. These insulin-induced increases in PKC-dependent phosphorylating activities of adipocyte plasma membrane and microsomes were associated with increases in membrane contents of diacylglycerol, PKC-beta 1 and PKC-beta 2. Our findings suggest that insulin both translocates and activates PKC in rat adipocytes, rat soleus muscles and BC3H-1 myocytes.

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The short-term influence of catecholamines on acid-base balance of rat soleus muscle in vitro

Pflügers Archiv - European Journal of Physiology ◽

10.1007/bf00582595 ◽

1984 ◽

Vol 401 (3) ◽

pp. 272-276

Author(s):

F. Huguenin

Keyword(s):

Soleus Muscle ◽

Acid Base Balance ◽

Acid Base ◽

Short Term ◽

Base Balance ◽

Rat Soleus Muscle

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Coordinate activation of lysosomal, Ca2+-activated and ATP-ubiquitin-dependent proteinases in the unweighted rat soleus muscle

Biochemical Journal ◽

10.1042/bj3160065 ◽

1996 ◽

Vol 316 (1) ◽

pp. 65-72 ◽

Cited By ~ 203

Author(s):

Daniel TAILLANDIER ◽

Eveline AUROUSSEAU ◽

Dominique MEYNIAL-DENIS ◽

Daniel BECHET ◽

Marc FERRARA ◽

...

Keyword(s):

Soleus Muscle ◽

Enzyme Activities ◽

Muscle Wasting ◽

Hindlimb Suspension ◽

Mrna Levels ◽

Protein Breakdown ◽

Equal Distribution ◽

Rat Soleus Muscle ◽

A Minor

Nine days of hindlimb suspension resulted in atrophy (55%) and loss of protein (53%) in rat soleus muscle due to a marked elevation in protein breakdown (66%, P < 0.005). To define which proteolytic system(s) contributed to this increase, soleus muscles from unweighted rats were incubated in the presence of proteolytic inhibitors. An increase in lysosomal and Ca2+-activated proteolysis (254%, P < 0.05) occurred in the atrophying incubated muscles. In agreement with the measurements in vitro, cathepsin B, cathepsins B+L and m-calpain enzyme activities increased by 111%, 92% and 180% (P < 0.005) respectively in the atrophying muscles. Enhanced mRNA levels for these proteinases (P < 0.05 to P < 0.001) paralleled the increased enzyme activities, suggesting a transcriptional regulation of these enzymes. However, the lysosomal and Ca2+-dependent proteolytic pathways accounted for a minor part of total proteolysis in both control (9%) and unweighted rats (18%). Furthermore the inhibition of these pathways failed to suppress increased protein breakdown in unweighted muscle. Thus a non-lysosomal Ca2+-independent proteolytic process essentially accounted for the increased proteolysis and subsequent muscle wasting. Increased mRNA levels for ubiquitin, the 14 kDa ubiquitin-conjugating enzyme E2 (involved in the ubiquitylation of protein substrates) and the C2 and C9 subunits of the 20 S proteasome (i.e. the proteolytic core of the 26 S proteasome that degrades ubiquitin conjugates) were observed in the atrophying muscles (P < 0.02 to P < 0.001). Analysis of C9 mRNA in polyribosomes showed equal distribution into both translationally active and inactive mRNA pools, in either unweighted or control rats. These results suggest that increased ATP-ubiquitin-dependent proteolysis is most probably responsible for muscle wasting in the unweighted soleus muscle.

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Skeletal muscle Ca2+ flux and catabolic response during sepsis

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1993.265.3.r487 ◽

1993 ◽

Vol 265 (3) ◽

pp. R487-R493 ◽

Cited By ~ 2

Author(s):

J. Bhattacharyya ◽

K. D. Thompson ◽

M. M. Sayeed

Keyword(s):

Skeletal Muscle ◽

Soleus Muscle ◽

Experimental Sepsis ◽

Protein Catabolism ◽

Sprague Dawley ◽

Sprague Dawley Rats ◽

Rat Soleus Muscle ◽

Catabolic Response ◽

Net Protein

Membrane Ca2+ flux and net protein catabolism were studied in the skeletal muscle during experimental sepsis. Sterilized rat fecal pellets with (septic) or without (sterile) gram-negative bacteria, Escherichia coli [10(2) colony-forming units (cfu)] and Bacteroides fragilis (2 x 10(3) cfu), were implanted into the abdomens of male Sprague-Dawley rats (110-120 g). Septic and sterile rats were febrile and hyperlactacidemic on day 1 postimplantation. These responses subsided by day 2 in sterile but not septic rats. Initial Ca2+ flux, estimated from measurements of 45Ca uptake by soleus muscles in vitro, was elevated on day 1 in both sterile and septic rats and on day 2 and 3 in septic rats only. The septic rat soleus muscle showed a significantly increased net protein catabolic response (measured as tyrosine release by soleus muscle, in vitro) over that found in muscles of sterile rats on day 1-3 postimplantation. The increase in Ca2+ flux in septic (day 1-3 postimplantation) and sterile (day 1 only) rats was abolished when the rats were treated with the calcium channel blocker diltiazem. In unoperated control rat soleus muscles the Ca2+ ionophore, ionomycin, concomitantly caused an increase in Ca2+ flux and net protein catabolism. Overall, the present study suggested that altered cellular Ca2+ regulation plays a role in the net protein catabolic response in the skeletal muscle during sepsis.

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