THE EFFECT OF ETHER, PENTOBARBITAL, AND DECAPITATION ON VARIOUS METABOLITES OF RAT SKELETAL MUSCLE

1967 ◽  
Vol 45 (9) ◽  
pp. 1323-1327 ◽  
Author(s):  
Ana Marquez-Julio ◽  
I. W. French
Keyword(s):  
Skeletal Muscle ◽  
Creatine Phosphate ◽  
Hexose Monophosphate ◽  
Rat Skeletal Muscle ◽  
Pentobarbital Anesthesia ◽  
Anesthetized Rats ◽  
Lactate And Pyruvate

The concentrations of creatine phosphate, ATP, ADP, AMP, lactate, pyruvate, hexose monophosphate, and glycogen were examined in skeletal muscle obtained from decapitated rats, or animals anesthetized with ether or pentobarbital.The concentrations of ATP, creatine phosphate, and glycogen were highest in muscles from pentobarbital-treated rats, whereas those of AMP, ADP, lactate, and pyruvate were the lowest in these animals. The data suggest that changes in the concentration of metabolites in skeletal muscle were less when the tissue was isolated under pentobarbital anesthesia than when it was isolated from decapitated or ether-anesthetized rats.

Characteristics of phosphate-induced Ca2+ efflux from the SR in mechanically skinned rat skeletal muscle fibers

2000 ◽  
Vol 278 (1) ◽  
pp. C126-C135 ◽  
Author(s):  
Adrian M. Duke ◽  
Derek S. Steele
Keyword(s):  
Skeletal Muscle ◽  
Creatine Kinase ◽  
Muscle Fibers ◽  
Cyclopiazonic Acid ◽  
Creatine Phosphate ◽  
Ruthenium Red ◽  
Rat Skeletal Muscle ◽  
Atpase Inhibitor ◽  
Skeletal Muscle Fibers ◽  
Efflux Pathway

The effects of Pi on sarcoplasmic reticulum (SR) Ca2+ regulation were studied in mechanically skinned rat skeletal muscle fibers. Brief application of caffeine was used to assess the SR Ca2+ content, and changes in concentration of Ca2+([Ca2+]) within the cytosol were detected with fura 2 fluorescence. Introduction of Pi (1–40 mM) induced a concentration-dependent Ca2+ efflux from the SR. In solutions lacking creatine phosphate (CP), the amplitude of the Pi-induced Ca2+ transient approximately doubled. A similar potentiation of Pi-induced Ca2+ release occurred after inhibition of creatine kinase (CK) with 2,4-dinitrofluorobenzene. In the presence of ruthenium red or ryanodine, caffeine-induced Ca2+ release was almost abolished, whereas Pi-induced Ca2+ release was unaffected. However, introduction of the SR Ca2+ ATPase inhibitor cyclopiazonic acid effectively abolished Pi-induced Ca2+ release. These data suggest that Pi induces Ca2+ release from the SR by reversal of the SR Ca2+ pump but not via the SR Ca2+ channel under these conditions. If this occurs in intact skeletal muscle during fatigue, activation of a Ca2+efflux pathway by Pi may contribute to the reported decrease in net Ca2+ uptake and increase in resting [Ca2+].

L(+)-Lactate Binding to a Protein in Rat Skeletal Muscle Plasma Membranes

1995 ◽  
Vol 20 (1) ◽  
pp. 112-124 ◽  
Author(s):  
Karl J. A. McCullagh ◽  
Arend Bonen
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membranes ◽  
Mass Range ◽  
Dependent Manner ◽  
Rat Skeletal Muscle ◽  
Lactate Transport ◽  
Sds Page ◽  
Lactate And Pyruvate ◽  
Potential Inhibitors ◽  
Dose Dependent

Biochemical studies were conducted to determine the location of a putative lactate transport protein in rat skeletal muscle plasma membranes (PM). PM (50-100 μg protein) were incubated with [U-14C] L(+)-lactate, in the presence or absence of unlabeled monocarboxylates or potential inhibitors, after which proteins were separated by SDS-PAGE. Gel slices (2 mm) were cut and analyzed for14C. [U-14C] L(+)-lactate was bound to plasma membranes in the 30 to 40 kDa molecular mass range. Binding of [U-14C] L(+)-lactate was inhibited by N-ethylmaleimide, unlabeled L-lactate and pyruvate, and in a dose dependent manner by α-cyano-4-hydroxycinnamate (r = 0.995), but not by cytochalasin-B. The inhibition of [U-14C] L(+)-lactate binding was similar to the inhibition of lactate transport. Therefore the transport of L(+)-lactate across skeletal muscle plasma membranes involves a polypeptide of 30 to 40 kDa. Key words: transport, affinity labeling

scholarly journals Reconstitution of the lactate carrier from rat skeletal-muscle sarcolemma

1994 ◽  
Vol 299 (2) ◽  
pp. 533-537 ◽  
Author(s):  
F Wibrand ◽  
C Juel
Keyword(s):  
Skeletal Muscle ◽  
Time Course ◽  
Rat Skeletal Muscle ◽  
Lactate Transport ◽  
Exchange Inhibitor ◽  
Transport Inhibitors ◽  
Lactate And Pyruvate ◽  
Lactate Uptake ◽  
Fold Excess ◽  
Sarcolemmal Vesicles

The lactate carrier was solubilized from purified rat skeletal-muscle sarcolemma with the detergent decanoyl-N-methyl-glucamide and the solubilized carrier was reconstituted into phospholipid vesicles. Reconstituted proteoliposomes showed a faster time course of L-lactate uptake than did protein-free liposomes. The rate of L-lactate uptake into the proteoliposomes was inhibited by the lactate-transport inhibitors p-chloromercuribenzenesulphonate, diethyl pyrocarbonate, alpha-cyano-4-hydroxycinnamate and quercetin. In contrast, the anion-exchange inhibitor DIDS (4,4′-di-isothiocyanostilbene-2,2′-disulphonate) had almost no effect on the uptake. The extent of L-lactate uptake at equilibrium was not affected by the presence of the transport inhibitors, but was sensitive to osmotic strength. L-Lactate and pyruvate, but not D-lactate, inhibited L-lactate uptake when present at 10-fold excess. The properties of L-lactate transport in reconstituted proteoliposomes were similar to those observed in native sarcolemmal vesicles, i.e. the lactate carrier seems to retain its transport characteristics during the solubilization and reconstitution steps.

scholarly journals Post-mortem glycolysis in ox skeletal muscle. Effect of temperature on the concentrations of glycolytic intermediates and cofactors

1967 ◽  
Vol 105 (1) ◽  
pp. 127-136 ◽  
Author(s):  
R. P. Newbold ◽  
R. K. Scopes
Keyword(s):  
Skeletal Muscle ◽  
Creatine Phosphate ◽  
Effect Of Temperature ◽  
Soluble Phosphate ◽  
Hexose Monophosphate ◽  
Post Mortem ◽  
Total Acid ◽  
Atp Turnover ◽  
Glycolytic Intermediates ◽  
Phosphofructokinase Activity

1. Post-mortem changes in the concentrations of the following compounds in ox sternomandibularis muscles stored in nitrogen at 1°, 5° and 15° are reported: Pi creatine phosphate, hexose monophosphates, fructose diphosphate, triose phosphates, α-glycerophosphate, phosphoglycerates, lactate, ATP, ADP, AMP, NAD+ and total nucleotides. Some results obtained with muscles stored at 37° are included. 2. At the time the muscles were placed at controlled temperatures (about 1·5hr. post mortem) the phosphorus in the compounds measured accounted for 91±6% (s.d.) of the total acid-soluble phosphate. 3. The results indicated that at all temperatures the activities of the phosphorylase and phosphofructokinase steps limited the rate and the extent of post-mortem glycolysis. 4. The large variations in hexose monophosphate concentrations during storage indicated that the ratio of phosphorylase to phosphofructokinase activity varied considerably with time and temperature. 5. Between 3·5 and 7hr. post mortem the rates of glycolysis and of ATP turnover were not slower at 5° that at 15°, and were probably faster at 1°. The significance of this finding is discussed.

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