Effect of extracellular osmolality on metabolism in contracting mammalian skeletal muscle in vitro

2009 ◽  
Vol 34 (6) ◽  
pp. 1055-1064 ◽  
Author(s):  
Naomi M. Cermak ◽  
Paul J. LeBlanc ◽  
Sandra J. Peters ◽  
Rene Vandenboom ◽  
Brian D. Roy
Keyword(s):  
Skeletal Muscle ◽  
Enzyme Activity ◽  
Water Content ◽  
Muscle Metabolism ◽  
Organ Bath ◽  
Mammalian Skeletal Muscle ◽  
Muscle Water Content ◽  
Muscle Water ◽  
Future Work

Extensive research has been conducted on hepatocyte metabolism perturbed under the influence of anisosmotic stress. However, much less is known about the behaviour of skeletal muscle metabolism under similar conditions. After establishing a working model to study anisosmotic stress in resting mammalian skeletal muscle, the current study tested the hypothesis that hyperosmotic (HYPER) stress would lead to increased creatine, lactate, and measured enzyme activity, whereas hypo-osmotic (HYPO) stress would lead to decreased metabolites and enzyme activity vs. iso-osmotic (ISO) stress post contraction. Rat soleus (SOL) and extensor digitorum longus (EDL) were isolated and incubated in an organ bath (95% O2, 5% CO2, pH 7.4, 25 °C) altered to targeted osmotic conditions (ISO, 290 osmol·L–1; HYPO, 180 osmol·L–1; HYPER, 400 osmol·L–1). Muscle samples were flash frozen after 10 min of contraction. Post contraction, muscle water content in the SOL HYPO condition was 18% greater than ISO, and HYPER had approximately 14% less water content than ISO (p < 0.05). In the HYPO condition, EDL had 21% greater water content than ISO, and HYPER had 17% less water content than ISO (p < 0.05). SOL HYPO resulted in higher phosphocreatine and lower lactate and creatine vs. HYPER (p < 0.05) but there were no differences in EDL between HYPO and HYPER. Pyruvate dehydrogenase activity increased in SOL HYPER vs. HYPO, whereas glycogen phosphorylase a increased in EDL HYPER vs. HYPO. In conclusion, fibre-type-specific responses exist after contraction such that when SOL muscle is perturbed in HYPER, as compared with HYPO, media, metabolic activity increases. Future work should focus on glucose uptake–regulation during anisosmotic conditions.

Extracellular hyperosmotic stress stimulates glucose uptake in incubated fast-twitch rat skeletal muscle

2013 ◽  
Vol 38 (6) ◽  
pp. 605-612 ◽  
Author(s):  
Chris M. Farlinger ◽  
Adrian J. Lui ◽  
Rose C. Harrison ◽  
Paul J. LeBlanc ◽  
Sandra J. Peters ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Energy Charge ◽  
Hyperosmotic Stress ◽  
Male Rats ◽  
Organ Bath ◽  
Mammalian Skeletal Muscle ◽  
Relative Water ◽  
Fast Twitch

The influence of hyperosmotic stress on glucose uptake, handling, and signaling processes remains unclear in mammalian skeletal muscle. Thus, the purpose of this study was to investigate alterations in glucose uptake and handling during extracellular hyperosmotic stress in isolated fast-twitch mammalian skeletal muscle. Using an established in vitro isolated whole-muscle model, extensor digitorum longus (EDL) muscles were dissected from male rats (4–6 weeks of age) and incubated (30–60 min) in an organ bath, containing Sigma Medium-199 with 8 mmol·L−1D-glucose, and mannitol was added to the targeted osmolalities (ISO, iso-osmotic, 290 mmol·kg−1; HYPER, hyperosmotic, 400 mmol·kg−1). Results demonstrate that relative water content decreased in HYPER. HYPER resulted in significant alterations in muscle metabolite concentrations (lower glycogen, elevated lactate, and glucose-6-phosphate), suggesting a decrease in energy charge. Glucose uptake was also found to be higher in HYPER, and AS160 (implicated in insulin- and contraction-mediated glucose uptake) was found to be significantly more phosphorylated in HYPER than in ISO after 30 min. In conclusion, glucose uptake and handling is altered with hyperosmotic extracellular stress in the fast-twitch EDL. The increases in glucose uptake might be facilitated through alterations in AS160 signaling after 30 to 60 min of osmotic stress.

Development of Hypoosmoregulatory Capacity in Arctic char (Salvelinus alpinus) Reared under either Continuous Light or Natural Photoperiod

1992 ◽  
Vol 49 (2) ◽  
pp. 229-237 ◽  
Author(s):  
Arne M. Arnesen ◽  
Morten Halvorsen ◽  
Kjell J. Nilssen
Keyword(s):  
Water Content ◽  
Salvelinus Alpinus ◽  
Plasma Osmolality ◽  
Continuous Light ◽  
Arctic Char ◽  
Direct Transfer ◽  
Seawater Tolerance ◽  
Natural Photoperiod ◽  
Muscle Water Content ◽  
Muscle Water

Two groups of Arctic char (Salvelinus alpinus) were reared in freshwater (5–6 °C) under either continuous light (LDL) from first feeding (March) or LDL until July and then natural photoperiod (NDL, 70°N). Direct transfer to seawater (5.5 °C, 35 ppt) in February resulted in both groups exhibiting increases in blood plasma osmolality, Na+, and Mg2+ concentrations and a significant decrease in muscle water content. When tested in May, an improvement in seawater tolerance was evident in both groups. In June, only the NDL fish showed further improvements in hypoosmoregulatory capacity, since they exhibited only minor fluctuations in plasma constituents and muscle water content following direct transfer to seawater. Increased body size could partially explain the improved seawater tolerance in the experimental groups. Acclimation to brackish water prior to transfer to 35 ppt seawater in June improved seawater tolerance only in fish reared under continuous light. The results indicate that the seasonal increase in photoperiod stimulates the development of hypoosmoregulatory capacity whilst the fish are still resident in freshwater.

scholarly journals Purification of desmin from adult mammalian skeletal muscle

1981 ◽  
Vol 195 (2) ◽  
pp. 345-356 ◽  
Author(s):  
J M O'Shea ◽  
R M Robson ◽  
M K Hartzer ◽  
T W Huiatt ◽  
W E Rathbun ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Average Diameter ◽  
Intermediate Filament Protein ◽  
Mammalian Skeletal Muscle ◽  
Cytoskeletal Function ◽  
10 Nm Filaments ◽  
And Function ◽  
Filament Protein

A method has been developed for preparation of purified desmin from mature mammalian (porcine) skeletal muscle. A crude desmin-containing fraction was prepared by modification of procedures used for isolation of smooth-muscle intermediate-filament protein [Small & Sobieszek (1977) J. Cell Sci. 23, 243-268]. The desmin was extracted in 1 M-acetic acid/20 mM-NaCl at 4 degrees C for 15h from the residue remaining after actomyosin extraction from washed myofibrils. Successive chromatography on hydroxyapatite and DEAE-Sepharose CL-6B in 6M-urea yielded desmin that was routinely more than 97% 55 000-dalton protein and that had no detectable actin contamination. Removal of urea by dialysis against 10mM-Tris/acetate (pH 8.5)/1 mM dithioerythritol and subsequent clarification at 134 000 g (rav. 5.9 cm) for 1 h results in a clear desmin solution. Dialysis of purified desmin against 100 mM-NaCl/1 mM-MgCl2/10 mM-imidazole/HCl, pH 7.0, at 2 degrees C resulted in the formation of synthetic desmin filaments have an average diameter of 9-11.5 nm. The present studies demonstrate that the relatively small amount of desmin in mature skeletal muscle can be isolated in sufficient quantity and purity to permit detailed studies of its properties and function. Although 10nm filaments have not been unequivocally demonstrated in mature muscle in vivo, that the purified skeletal-muscle desmin will form 10 nm filaments in vitro lends support to their possible existence and cytoskeletal function in mature skeletal-muscle cells.

In vivo and in vitro characterization of skeletal muscle metabolism in patients with statin-induced adverse effects

2006 ◽  
Vol 55 (4) ◽  
pp. 551-557 ◽  
Author(s):  
S. Guis ◽  
D. Figarella-branger ◽  
J. P. Mattei ◽  
F. Nicoli ◽  
Y. Le Fur ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Adverse Effects ◽  
Muscle Metabolism ◽  
Skeletal Muscle Metabolism ◽  
In Vitro Characterization

scholarly journals Skeletal muscle metabolism in sea-acclimatized king penguins. I. Thermogenic mechanisms

2020 ◽  
Vol 223 (21) ◽  
pp. jeb233668
Author(s):  
Damien Roussel ◽  
Marion Le Coadic ◽  
Jean-Louis Rouanet ◽  
Claude Duchamp
Keyword(s):  
Skeletal Muscle ◽  
Muscle Metabolism ◽  
Exact Nature ◽  
Skeletal Muscle Metabolism ◽  
Energy Demands ◽  
Skeletal Muscle Contraction ◽  
Drastic Increase ◽  
Shivering Thermogenesis

ABSTRACTAt fledging, king penguin juveniles undergo a major energetic challenge to overcome the intense and prolonged energy demands for thermoregulation and locomotion imposed by life in cold seas. Among other responses, sea acclimatization triggers fuel selection in skeletal muscle metabolism towards lipid oxidation in vitro, which is reflected by a drastic increase in lipid-induced thermogenesis in vivo. However, the exact nature of skeletal muscle thermogenic mechanisms (shivering and/or non-shivering thermogenesis) remains undefined. The aim of the present study was to determine in vivo whether the capacity for non-shivering thermogenesis was enhanced by sea acclimatization. We measured body temperature, metabolic rate, heart rate and shivering activity in fully immersed king penguins (Aptenodytes patagonicus) exposed to water temperatures ranging from 12 to 29°C. Results from terrestrial pre-fledging juveniles were compared with those from sea-acclimatized immature penguins (hereafter ‘immatures’). The capacity for thermogenesis in water was as effective in juveniles as in immatures, while the capacity for non-shivering thermogenesis was not reinforced by sea acclimatization. This result suggests that king penguins mainly rely on skeletal muscle contraction (shivering or locomotor activity) to maintain endothermy at sea. Sea-acclimatized immature penguins also exhibited higher shivering efficiency and oxygen pulse (amount of oxygen consumed or energy expended per heartbeat) than pre-fledging juvenile birds. Such increase in shivering and cardiovascular efficiency may favor a more efficient activity–thermoregulatory heat substitution providing penguins with the aptitude to survive the tremendous energetic challenge imposed by marine life in cold circumpolar oceans.

Effect of method of sale and various water regimens at saleyards on the liveweight, carcass traits and muscle properties of cattle

1983 ◽  
Vol 23 (122) ◽  
pp. 235 ◽  
Author(s):  
JR Wythes ◽  
MJ Brown ◽  
WR Shorthose ◽  
MR Clarke
Keyword(s):  
Water Content ◽  
Carcass Traits ◽  
The Other ◽  
Carcass Weight ◽  
Muscle Properties ◽  
Muscle Water Content ◽  
Access To Water ◽  
Muscle Water ◽  
Dressing Percentage ◽  
Water Contents

In two experiments, we examined the effects on liveweight, carcass traits and muscle properties of (a) sending cattle to the abattoir either direct from a farm or via a saleyard, and (b) different curfew and sale procedures at a saleyard. During the 12 h curfew and 10 h sale periods, cattle were held with or without water, but always denied feed. In experiment 1, after a journey of 1320 km, 252 bullocks (mean liveweight 558 kg) were subjected to one of seven treatments. The groups transported direct to the abattoir were (1) denied water between arrival and slaughter (26 h), (2) offered water for 26 h, or (3) offered water and feed for 50 h and then water alone for 24 h. Those sent to the saleyard were given access to water (4) at all times, (5) only during the curfew and sale periods, (6) only before the curfew began, or (7) were denied water until after the sale, when all groups were offered water for 36 h until slaughter. Among the bullocks sent direct to the abattoir, the group with water for 26 h until slaughter had heavier (P< 0.0 1 ) carcasses than those denied water (331 kg vs 312 kg) and also a greater (P < 0.0 1) muscle water content, while the carcasses of the group slaughtered 2 d later were intermediate for both. Whether dressing percentages were calculated on liveweights at the start or end of the simulated sale for the four saleyard groups, the differences in mean dressing percentages between groups offered water (0.7 and 0.3 percentage units) were less than the differences between the means of the groups denied water (3.7 and 3.5 units). The increases in dressing percentage during the sale for groups with water (0.7 and 0.3 units) were less than those for the groups denied water (1.5 and 1.7 units). Differences in mean liveweights and mean muscle water contents between groups followed the same trends. Mean carcass weights did not differ significantly between saleyard groups (318-323 kg). In experiment 2, after a journey of 90 km, 152 cows (mean liveweight 323 kg) were subjected to one of four treatments. The group going direct to the abattoir was offered water for 4.5 h, fasted for 16 h and then slaughtered. For the other three groups, the saleyard treatments 4,6, or 7 of experiment 1were imposed, followed by 21 h on water and a 16 h pre-slaughter fast. Trends in dressing percentage and liveweight were similar to those recorded in experiment 1. Mean carcass weight varied (P<0. 05) between groups and tended to increase with muscle water content. Method of sale was important because it affected the time from mustering to slaughter, and thus, carcass weight. At saleyards, the practice of giving cattle continuous access to water reduced significantly the variation in liveweight, dressing percentage and muscle water content between groups with similar initial liveweights. This practice at abattoirs avoided dehydration of carcass tissues at slaughter

Regulation of phosphatidylinositol 3-kinase by insulin in rat skeletal muscle

1993 ◽  
Vol 265 (5) ◽  
pp. E736-E742 ◽  
Author(s):  
K. S. Chen ◽  
J. C. Friel ◽  
N. B. Ruderman
Keyword(s):  
Skeletal Muscle ◽  
Soleus Muscle ◽  
Protein Tyrosine Kinase ◽  
Kinase Activity ◽  
Receptor Protein ◽  
Mammalian Skeletal Muscle ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphatidylinositol 3

The presence of phosphatidylinositol 3-kinase (PI 3-kinase) in mammalian skeletal muscle and its response to insulin stimulation were investigated. PI kinase, immunoprecipitated from rat soleus muscle with antibodies directed toward its 85-kDa subunit phosphorylated PI, phosphatidylinositol 4-phosphate [PI(4)P], and phosphatidylinositol 4,5,-bisphosphate [PI(4,5)P2] to yield phosphatidylinositol 3-phosphate [PI(3)P], phosphatidylinositol 3,4,-bisphosphate, and phosphatidylinositol trisphosphate in vitro. PI 3-kinase activity was also immunoprecipitated with antiphosphotyrosine [alpha-Tyr(P)] antibodies and with antibodies raised against IRS-1, a substrate of the insulin receptor protein tyrosine kinase that associates with and activates PI 3-kinase. Incubation of the soleus with insulin in vitro, or injection of insulin into rats in vivo, produced three- to fivefold increases in alpha-Tyr(P)- and alpha-IRS-1-immunoprecipitable PI 3-kinase activity. In nonstimulated soleus muscle, PI 3-kinase activity immunoprecipitated with alpha-IRS-1 or with alpha-Tyr(P) antibodies was evenly distributed between particulate (200,000-g pellet) and soluble fractions. Insulin treatment increased immunoprecipitable PI 5-kinase activity in both fractions, but the increase in alpha-Tyr-(P)-precipitable activity was greater in the particulate fraction, whereas the increase in alpha-IRS-1-precipitable activity was greater in the soluble fraction. In intact soleus muscles incubated with 32PO4, insulin increased the labeling of PI(3)P but did not affect the labeling of PI(4)P or PI(4,5)P2. Activation of PI 3-kinase by insulin was unaffected by prior denervation of the muscle, a manipulation that has been shown to cause both insulin resistance and hypersensitivity in muscles, depending on the parameter measured.(ABSTRACT TRUNCATED AT 250 WORDS)

Endothelial cell products alter mammalian skeletal muscle function in vitro

1995 ◽  
Vol 73 (6) ◽  
pp. 736-741 ◽  
Author(s):  
C. L. Murrant ◽  
J. K. Barclay
Keyword(s):  
Skeletal Muscle ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Mammalian Skeletal Muscle ◽  
Skeletal Muscle Function ◽  
Endothelin 1 ◽  
Control Value ◽  
Endothelin 3 ◽  
Fast Twitch

We tested the hypothesis that endothelin and nitric oxide (NO) alter the force developed by fast-twitch and slow-twitch mammalian skeletal muscle, using a mouse skeletal muscle preparation trimmed to approximately 50% of the original diameter to decrease diffusion distances. We suspended trimmed soleus (SOL) and extensor digitorum longus (EDL) muscles in Krebs–Henseleit buffer (27 °C; pH 7.4) gassed with 95% O2 – 5% CO2. Muscles were stimulated once every 90 s for 500 ms at 50 Hz for SOL and 100 Hz for EDL. The force developed by trimmed SOL was 223.8 ± 9.1 mN/mm2 and by EDL was 247.3 ± 9.4 mN/mm2. Endothelin 1 (ET-1) had no effect on EDL but significantly accelerated the rate of decrease of developed force of SOL at concentrations of 10−10 mol/L and higher within 10 contractions. When ET-1 was removed, force returned toward control value. Endothelin 3 (ET-3) had no effect on either muscle. S-Nitroso-N-acetylpenicillamine (SNAP), a source of NO, increased developed force over time in both muscles, with a threshold of 10−6 mol/L. The effect was evident within 5 contractions in both muscles. Force remained elevated above control values after the removal of SNAP. Thus ET-1 attenuated and NO amplified mammalian skeletal muscle function.Key words: soleus, extensor digitorum longus, tetanic contractions, endothelin 1, endothelin 3, S-nitroso-N-acetylpenicillamine.

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