Enhancement of the lipolytic activity of skeletal muscle in certain physiological states

1970 ◽  
Vol 48 (5) ◽  
pp. 547-552 ◽  
Author(s):  
Donald P. Wallach
Keyword(s):  
Skeletal Muscle ◽  
Ground Squirrel ◽  
Skeletal Muscles ◽  
Specific Activity ◽  
Lipolytic Activity ◽  
Ground Squirrels ◽  
Lipolytic Enzyme ◽  
Rat Skeletal Muscle ◽  
Enzyme Preparations ◽  
Dystrophic Mice

Four lipolytic enzyme preparations, whose existence was previously demonstrated in rat skeletal muscle, have been shown to be present in preparations from skeletal muscles of the golden hamster, the 13-lined ground squirrel, and three strains of mice. When compared with appropriate controls, statistically significant increases in specific activity of all four lipase preparations were observed in hibernating hamsters and muscular dystrophic mice. In obese hyperglycemic mice, three monoglyceride lipases were significantly increased; there was no significant increase, however, in tricaproin lipase. In hibernating 13-lined ground squirrels and aurothioglucose-treated hyperphagic mice, only the monopalmitin lipase was significantly increased.

Pancreatic triacylglycerol lipase in a hibernating mammal. II. Cold-adapted function and differential expression

2003 ◽  
Vol 16 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Teresa L. Squire ◽  
Mark E. Lowe ◽  
Vernon W. Bauer ◽  
Matthew T. Andrews
Keyword(s):  
Low Temperature ◽  
High Activity ◽  
Ground Squirrel ◽  
Mammalian Cells ◽  
Lipolytic Activity ◽  
Tissue Expression ◽  
Ground Squirrels ◽  
Mrna Levels ◽  
Western Blots ◽  
Triacylglycerol Lipase

Thirteen-lined ground squirrels ( Spermophilus tridecemlineatus) exploit the low-temperature activity of pancreatic triacylglycerol lipase (PTL) during hibernation. Lipolytic activity at body temperatures associated with hibernation was examined using recombinant ground squirrel and human PTLs expressed in yeast. Both the human and ground squirrel enzymes displayed high activity at temperatures as low as 0°C and showed Q10 values of 1.2–1.5 over a range of 37–7°C. These studies indicate that low-temperature lipolysis is a general property of PTL and does not require protein modifications unique to mammalian cells and/or the hibernating state. Western blots show elevated levels of PTL protein during hibernation in both heart and white adipose tissue (WAT). Significant increases in PTL gene expression are seen in heart, WAT, and testes; but not in pancreas, where PTL mRNA levels are highest. Upregulation of PTL in testes is also accompanied by expression of the PTL-specific cofactor, colipase. The multi-tissue expression of PTL during hibernation supports its role as a key enzyme that shows high activity at low temperatures.

Biochemical changes in progressive muscular dystrophy. XIII. Nucleic acids, proteins, and total nucleotides in the thymus and spleen of dystrophic mice

1985 ◽  
Vol 63 (5) ◽  
pp. 325-332 ◽  
Author(s):  
Uma Srivastava ◽  
Mikael Sebag ◽  
Manohar Thakur
Keyword(s):  
Skeletal Muscle ◽  
Amino Acid ◽  
Muscular Dystrophy ◽  
Free Amino Acid ◽  
Free Amino ◽  
Specific Activity ◽  
Cellular Growth ◽  
Free Amino Acid Pool ◽  
Acid Pool ◽  
Dystrophic Mice

Assessments were made of the thymus and spleen weights and the total nucleotide, nucleic acid, and protein content as well as the incorporation of [14C]leucine into protein and of [3H]orotate into RNA, in the thymus, spleen, liver, brain, kidney, lungs, heart, pancreas, and skeletal muscle of normal (+/+) and dystrophic (dy/dy) 129 ReJ mice aged 40, 60, or 90 days. The weights of the thymus and spleen were lower at all stages of dystrophy. Total nucleotide and RNA levels per thymus were reduced at 90 days, while total DNA content was decreased at 60 and 90 days. Protein concentrations per thymus were diminished at each stage of the disease. The specific activity of the free amino acid pool and total free nucleotide pool did not show any significant variations in the thymus at any phase of dystrophy. Incorporation of [14C]leucine into protein and of [3H]orotate into RNA was considerably lower in the thymus at each stage of the disease. Total nucleotide content per spleen was decreased at 40 days, with no change at 60 days and followed by an increase at 90 days in the dystrophic mice. DNA, RNA, and protein levels were all reduced in the spleen at each stage of the disease. The specific activity of the free amino acid pool and total free nucleotide pool, as well as the incorporation of [14C]leucine into protein and of [3H]orotate into RNA, showed similar changes in the spleen as noted in the thymus at each phase of dystrophy. These observations indicate that significant alterations in cellular growth occur not only in skeletal muscle and other nonlymphoid organs, but also in the lymphoid organs of dystrophic mice. Such changes in the cellular growth of lymphoid organs could be responsible for an impairment of immunologic responses reflecting thymic atrophy in murine muscular dystrophy.

scholarly journals Alkaline phosphatase and dipeptidylpeptidase IV staining of tissue components of skeletal muscle: a comparative study.

1990 ◽  
Vol 38 (12) ◽  
pp. 1907-1912 ◽  
Author(s):  
M Grim ◽  
B M Carlson
Keyword(s):  
Skeletal Muscle ◽  
Alkaline Phosphatase ◽  
Skeletal Muscles ◽  
Laboratory Animals ◽  
Staining Reaction ◽  
Rat Skeletal Muscle ◽  
Dipeptidylpeptidase Iv ◽  
Dpp Iv ◽  
Intramuscular Nerves ◽  
Interspecies Variability

A combined alkaline phosphatase (AP) and dipeptidlypeptidase IV (DPP IV) staining reaction has demonstrated enzymatic heterogeneity of the arterial and venous segments of capillaries in rat skeletal muscle. This study compared the staining reactions of skeletal muscles in many commonly used laboratory animals, including the axolotl, chick, quail, Monodelphys, rat, mouse, hamster, guinea pig, rabbit, dog, monkey, and human. DPP IV activity was found in the venous ends of the capillaries and in the endothelium of some larger veins in many of the species but was never demonstrated in the arterial side of the circulation. AP was found in the arterial ends of capillaries in all species except the axolotl, and it was also found in the endothelium of larger arteries of most species. AP activity was absent in venous endothelium of all species except for birds and Monodelphys. DPP IV activity was found in the perineurium of intramuscular nerves of most species, and AP activity was commonly seen in tendons and intramuscular connective tissue. The interspecies variability found in this study shows that care must be taken in comparing experimental data involving this technique from one species to another, but within a species the technique allows a fine level of discrimination between functionally distinct compounds of skeletal muscle tissue.

scholarly journals Ca-ATPase Activity and Protein Composition of Sarcoplasmic Reticulum Membranes Isolated from Skeletal Muscles of Typical Hibernator, the Ground Squirrel Spermophilus undulatus

2001 ◽  
Vol 21 (6) ◽  
pp. 831-838 ◽  
Author(s):  
Anna N. Malysheva ◽  
Kenneth B. Storey ◽  
Olga D. Lopina ◽  
Alexander M. Rubstov
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Atpase Activity ◽  
Electrophoretic Mobility ◽  
Ground Squirrel ◽  
Skeletal Muscles ◽  
Binding Proteins ◽  
Protein Composition ◽  
Ground Squirrels ◽  
Ground Squirrel Spermophilus Undulatus ◽  
Spermophilus Undulatus

Ca-ATPase activity in sarcoplasmic reticulum (SR) membranes isolated from skeletal muscles of the typical hibernator, the ground squirrel Spermophilus undulatus, is about 2-fold lower than that in SR membranes of rats and rabbits and is further decreased 2-fold during hibernation. The use of carbocyanine anionic dye Stains-All has revealed that Ca-binding proteins of SR membranes, histidine-rich Ca-binding protein and sarcalumenin, in ground squirrel, rat, and rabbit SR have different electrophoretic mobility corresponding to apparent molecular masses 165, 155, and 170 kDa and 130, 145, and 160 kDa, respectively; the electrophoretic mobility of calsequestrin (63 kDa) is the same in all preparations. The content of these Ca-binding proteins in SR membranes of the ground squirrels is decreased 3–4 fold and the content of 55, 30, and 22 kDa proteins is significantly increased during hibernation.

scholarly journals Increase in Subcellular GSK-3 Clusters in Insulin- and Adrenaline-treated Differentiated Rat Skeletal Muscle Fibres

2020 ◽  
Author(s):  
Katja Fink ◽  
Mateja Lobe Prebil ◽  
Nina Vardjan ◽  
Jorgen Jensen ◽  
Robert Zorec ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Skeletal Muscles ◽  
Metabolic Regulation ◽  
Glycogen Synthase ◽  
Glycogen Synthase Kinase 3 ◽  
Muscle Fibres ◽  
Optical Section ◽  
Rat Skeletal Muscle ◽  
Average Size ◽  
Skeletal Muscle Fibres

Glycogen synthase kinase 3 (GSK-3) plays an important role in metabolic regulation in skeletal muscles, and both insulin and adrenaline stimulate   GKS-3 phosphorylation. The aim of the present study was to study the effect of insulin and adrenaline on GSK-3 localisation in skeletal muscles.We characterized subcellular localization of (GSK-3) signal protein in fully differentiated muscle fibre by immunofluorescence and confocal microscopy. We stimulated muscle fibres with insulin and/or adrenaline. Images were analysed by segmentation of single central optical section of the muscle.We found GSK-3 to be localised in clusters. The number of GSK-3 clusters and their average size were increased after stimulation with insulin and/or adrenaline. Average GSK-3 particle size is linearly related to their quantity.We conclude that subcellular GSK-3 in isolated skeletal muscle fibres is localized in clusters and clustering increased after stimulation with insulin and/or adrenaline.

Molecular characterization of rat skeletal muscle myosin light chain kinase

1989 ◽  
Vol 256 (2) ◽  
pp. C399-C404 ◽  
Author(s):  
B. P. Herring ◽  
M. H. Nunnally ◽  
P. J. Gallagher ◽  
J. T. Stull
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Skeletal Muscles ◽  
Myosin Light Chain ◽  
Cardiac Tissue ◽  
Rat Skeletal Muscle ◽  
Skeletal Muscle Myosin ◽  
Slow Twitch ◽  
Muscle Myosin

A 1.85-kilobase (kb) cDNA has been isolated that encodes the catalytic and calmodulin binding domains of rat skeletal muscle myosin light chain kinase. The cDNA hybridized to a 3.3-kb RNA present in fast- and slow-twitch skeletal muscles. The reported enzymatic activity (3-fold greater in fast- than slow-twitch skeletal muscles) reflects the relative abundance of this RNA in the two types of skeletal muscle. No hybridization of the cDNA was detected to RNA isolated from smooth or nonmuscle tissues. The clone cross hybridized to a 2.2-kb RNA present in cardiac tissue. Ribonuclease protection analysis of skeletal and cardiac muscle RNA revealed major differences in the two hybridizing RNAs. Thus rat skeletal muscle contains a single myosin light chain kinase isoform, which is distinct from the cardiac, smooth, and nonmuscle forms.

scholarly journals Isolation of Relaxing Particles from Rat Skeletal Muscles in Zonal Centrifuges

1965 ◽  
Vol 48 (5) ◽  
pp. 737-752 ◽  
Author(s):  
H. Schuel ◽  
L. Lorand ◽  
R. Schuel ◽  
N. G. Anderson
Keyword(s):  
Skeletal Muscle ◽  
Cytochrome Oxidase ◽  
Oxidase Activity ◽  
Skeletal Muscles ◽  
Microsomal Fraction ◽  
Differential Centrifugation ◽  
Rat Skeletal Muscle ◽  
Cytochrome Oxidase Activity ◽  
Soluble Phase ◽  
Enzymatic Marker

Supernatants of rat skeletal muscle homogenates were fractionated by differential centrifugation and by zonal centrifugation in sucrose density gradients. Cytochrome oxidase was employed as an enzymatic marker for locating mitochondria. The subcellular fractions were also assayed for their ability to prevent the ATP-induced contraction of myofibrils. Both the mitochondrial and microsomal fractions obtained by differential fractionation were found to be rich in such relaxing activity, and the microsomal fraction was appreciably contaminated by mitochondria. In contrast to this, when fractionation was carried out by means of zonal centrifugation (4200 RPM x 205 min. to 40,000 RPM x 60 min.), relaxing activity was found to be associated only with particles having the sedimentation characteristics of microsomes (s20,w estimated to be between 370 and 1880S). Relaxing activity was not detected in the regions of the gradient containing either the starting sample zone (soluble phase) or the mitochondrial peak. The microsomal relaxing particles showed negligible cytochrome oxidase activity.

Phosphate uptake in rat skeletal muscle is reduced during isometric contractions

2004 ◽  
Vol 97 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Kirk A. Abraham ◽  
Ronald L. Terjung
Keyword(s):  
Skeletal Muscle ◽  
Inorganic Phosphate ◽  
Phosphate Uptake ◽  
Specific Activity ◽  
Fiber Type ◽  
Rat Skeletal Muscle ◽  
Energy Expenditures ◽  
Contraction Duration ◽  
Uptake Rates ◽  
White Gastrocnemius

During contractions, there is a net efflux of phosphate from skeletal muscle, likely because of an elevated intracellular inorganic phosphate (Pi) concentration. Over time, contracting muscle could incur a substantial phosphate deficit unless Pi uptake rates were increased during contractions. We used the perfused rat hindquarter preparation to assess [32P]Pi uptake rates in muscles at rest or over a range of energy expenditures during contractions at 0.5, 3, or 5 Hz for 30 min. Pi uptake rates were reduced during contractions in a pattern that was dependent on contraction frequency and fiber type. In soleus and red gastrocnemius, [32P]Pi uptake rates declined by ∼25% at 0.5 Hz and 50–60% at 3 and 5 Hz. Uptake rates in white gastrocnemius decreased by 65–75% at all three stimulation frequencies. These reductions in Pi uptake are not likely confounded by changes in precursor [32P]Pi specific activity in the interstitium. In soleus and red gastrocnemius, declines in Pi uptake rates were related to energy expenditure over the contraction duration. These data imply that Pi uptake in skeletal muscle is acutely modulated during contractions and that decreases in Pi uptake rates, in combination with expected increases in Pi efflux, exacerbate the net loss of phosphate from the cell. Enhanced uptake of Pi must subsequently occur because skeletal muscle typically maintains a relatively constant total phosphate pool.

Genes controlling the metabolic switch in hibernating mammals

2004 ◽  
Vol 32 (6) ◽  
pp. 1021-1024 ◽  
Author(s):  
M.T. Andrews
Keyword(s):  
Low Temperature ◽  
Pyruvate Dehydrogenase ◽  
Ground Squirrel ◽  
Mammalian Cells ◽  
Lipolytic Activity ◽  
Tricarboxylic Acid Cycle ◽  
Ground Squirrels ◽  
Pyruvate Dehydrogenase Kinase ◽  
Body Temperatures ◽  
Triacylglycerol Lipase

Hibernating mammals have the ability to decrease their metabolic rate and survive up to 6 months without food in an inactive state where body temperatures approach 0°C. In hibernating 13-lined ground squirrels (Spermophilus tridecemlineatus), oxygen consumption holds at 1/30 to 1/50 of the aroused condition and heart rates are as low as 3–10 beats/min, compared with 200–300 beats/min when the animal is active. This seasonal adaptation requires a metabolic shift away from the oxidation of carbohydrates and towards the combustion of stored fatty acids as the primary source of energy. A key element in this fuel switch is the differential expression of the gene encoding pyruvate dehydrogenase kinase isoenzyme 4. Pyruvate dehydrogenase kinase isoenzyme 4 inhibits pyruvate dehydrogenase and thus minimizes carbohydrate oxidation by preventing the flow of glycolytic products into the tricarboxylic acid cycle. Hibernators also exploit the low-temperature activity of PTL (pancreatic triacylglycerol lipase) in both heart and white adipose tissue. Lipolytic activity at body temperatures associated with hibernation was examined using recombinant ground squirrel and human PTL expressed in yeast. Enzymes from both humans and ground squirrel displayed high activity at temperatures as low as 0°C and showed Q10=1.2–1.5 over the temperature range 37–7°C. These studies indicate that low-temperature lipolysis is a general property of PTL and does not require protein modifications unique to mammalian cells and/or the hibernating state.

scholarly journals Glutamine metabolism in skeletal muscles from the broiler chick (Gallus domesticus) and the laboratory rat (Rattus norvegicus)

1991 ◽  
Vol 274 (3) ◽  
pp. 769-774 ◽  
Author(s):  
G Wu ◽  
J R Thompson ◽  
V E Baracos
Keyword(s):  
Skeletal Muscle ◽  
Rattus Norvegicus ◽  
Skeletal Muscles ◽  
Species Difference ◽  
Plasma Concentrations ◽  
Subcellular Location ◽  
Glutamine Metabolism ◽  
Oxidative Decarboxylation ◽  
Rat Skeletal Muscle ◽  
Glutaminase Activity

Oxidative decarboxylation of L-[1-14C]glutamine was studied in isolated chick and rat skeletal muscles incubated in the presence of glucose, insulin and plasma concentrations of amino acids. (1) The rate of oxidative decarboxylation of L-[1-14C]glutamine was high, and exceeded that of L-[1-14C]leucine in all muscles. (2) The rate of oxidative decarboxylation of L-[1-14C]glutamine increased with increasing intracellular concentrations of glutamine. (3) The activities of glutamine aminotransferases K and L were more than 10-fold greater in rat than in chick skeletal muscles. (4) Mitochondrial phosphate-activated glutaminase activity was approx. 10-fold greater in chick than in rat skeletal muscles and increased with increasing glutamine concentrations. (5) An inhibitor of glutaminase, 6-diazo-5-oxo-L-norleucine, inhibited the rate of glutamine decarboxylation in chick, but not in rat, skeletal muscle. These findings suggest that glutamine degradation in skeletal muscle may be substantial and may make an important contribution to the regulation of intramuscular glutamine concentrations. A species difference in the pathways and the subcellular location for the conversion of glutamine into 2-oxoglutarate in rat and chick skeletal muscles is implied by the relative activities of glutamine-degrading enzymes.

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