Red Skeletal Muscle Research Articles

Oxidation of DL-alpha-glycerophosphate and beta-hydroxybutyrate in red and white skeletal muscle.

Oxidation of DL-alpha-glycerophosphate and beta-hydroxybutyrate in red and white skeletal muscle.

Studies on Myosin from Red and White Skeletal Muscles of the Rabbit: I. ADENOSINE TRIPHOSPHATASE ACTIVITY

Abstract Myosin obtained from red skeletal muscle of rabbit has a lower adenosine triphosphatase activity than myosin from white skeletal muscle. Structural differences between the two types of myosin are suggested by the higher apparent activation energy of the calcium-activated adenosine triphosphatase reaction catalyzed by red muscle myosin, by the higher rate of inactivation at pH 7.5 to 9.5, and by the previously reported slower rate of tryptic digestion of myosin from red muscle. No evidence has been found for the presence in red muscle, or in myosin prepared from red muscle, of inhibitors or inactivators of myosin adenosine triphosphatase. The two types of myosin also differ with respect to the pattern of activation of adenosine triphosphatase by sulfhydryl reagents. At low ionic strength myosin from red muscles is activated by N-ethylmaleimide and myosin from white muscles is unaffected, whereas at high ionic strength both myosins are activated. Four moles of p-chloromercuribenzoate per 105 g of myosin are needed for maximal activation of fresh myosin from red muscles, but only 2 moles are required per 105 g of myosin from white muscles. This difference disappears in a few days, suggesting a change in the availability of sulfhydryl groups.

Adenosinetriphosphatase activity of cardiac myosin. Comparison of the enzymatic activities and activation by actin of dog cardiac, rabbit cardiac, rabbit white skeletal and rabbit red skeletal muscle myosins.

Examination of the ATPase activities of rabbit cardiac, rabbit red skeletal and rabbit white skeletal muscle myosins has demonstrated the existence of two types of myosin. One type, characterized by the higher ATPase activity, is present in white skeletal muscle; the other is found in red skeletal and cardiac muscle. The differences between myosin preparations could not be attributed to varying degrees of actin contamination nor to changes occurring in the myosins during the preparative procedure. Chromatography of dog cardiac myosin on DEAE-cellulose showed a single component. No differences were observed between the cardiac myosins of the dog and rabbit. Activation of the ATPase activity of cardiac myosin by Ca ++ was less than that of white skeletal myosin while the extent of inhibition by Mg ++ was similar for both. The stoichiometry of the interaction with actin of both cardiac and white skeletal myosins was similar but actin caused less activation of the cardiac myosin ATPase. Cardiac and white skeletal actins showed no differences in their abilities to activate myosin ATPase activity, which is in accord with previously documented similarities in the structures of these actins. Comparison of the present findings with previously reported mechanical measurements made with intact muscles does not indicate that the intrinsic level of myosin ATPase activity determines the maximal tension developed during the active state. On the other hand, there may be a direct relationship between shortening velocity and myosin ATPase activity.

Glycogen and CO-2 production from glucose and lactate by red and white skeletal muscle.

Diaphragm and external oblique muscle of the abdomen were identified histochemically as red and white muscles, respectively, in the rat. Administration of glucose orally to fasted rats 3 hr before sacrifice increased the glycogen in the red but not in the white muscle. Paired red and white muscles were incubated 2 hr in oxygen at 29 C in Krebs-Ringer phosphate medium at pH 74 containing 11 mm glucose and 40 mm dl-lactate. Glycogen increased in all the samples except in the red muscle specimens with high initial glycogen levels. The glycogen change and glucose-U-C14 incorporation into glycogen were both inversely related to the initial glycogen and were both greater in red than in white muscle. These differences between the muscles were suppressed by increasing the oral glucose dose. C14O2 production from glucose-U-C14 and lactate-1-C14 was greater in red than in white muscle.

GLYCOGEN PHOSPHORYLASE AND GLYCOGEN SYNTHETASE ACTIVITY IN RED AND WHITE SKELETAL MUSCLE OF THE GUINEA PIG.

Glycogen phosphorylase (α-1,4-glucan:orthophosphate glucosyltransferase) and glycogen synthetase (UDPG:α-1,4-glucan α-4-glucosyltransferase) have been examined in red and white skeletal muscle of the guinea pig. Histochemically phosphorylase was found to be more active in white than in red muscle fibers but no difference in glycogen synthetase could be detected between the fiber types. However, quantitative determinations showed that total glycogen synthetase activity (I + D) was higher in red than in white muscle (1.46 ± 0.14 S.E.M. vs. 0.71 ± 0.09 μmoles/minute per g wet weight at 37°). The converse relationship held for total phosphorylase activity (a + b), which was greater in white than in red muscle (19.24 ± 2.93 vs. 10.43 ± 2.34 μmoles/minute per g wet weight at 30°). The phosphorylase a level of 3.63 ± 0.96 in red muscle at rest was similar to that of 5.44 ± 1.19 in resting white muscle. Stimulation produced a significant conversion of phosphorylase b to a only in white muscle. After 30 seconds stimulation with 1-volt impulses of 20 milliseconds duration at a rate of 20 pulses per second, the phosphorylase a activities of red and white muscle were respectively 3.72 ± 1.88 and 16.66 ± 1.79. After stimulation the glycogen synthetase values in white and red muscle were 1.02 ± 0.07 and 1.72 ± 0.11 respectively.

Comparative studies of myofibrils, myosin, and actomyosin from red and white rabbit skeletal muscle

Comparative studies of myofibrils, myosin, and actomyosin from red and white rabbit skeletal muscle

RESPIRATION OF MITOCHONDRIA OF RED AND WHITE SKELETAL MUSCLE.

Mitochondria of guinea pig red and white skeletal muscle were isolated in a medium containing 0.25 m sucrose, 1 mm ethylenediamine tetraacetate, and 1% fraction V bovine albumin. Oxidative phosphorylation with pyruvate-malate as substrate was tightly coupled in both types of mitochondria when oxygen uptake was measured over a 2- to 4-min period with a platinum electrode. The P/O ratios approached the theoretical value of 3. Oxygen consumption was also determined manometrically with the substrates 10 mm pyruvate—1 mm malate, 10 mm succinate, 6 mm reduced nicotinamide adenine dinucleotide (NADH2), 20 mm dl-lactate, and 12–20 mm dl-α-glycerophosphate. White muscle mitochondria had a higher rate of oxygen consumption with α-glycerophosphate than with lactate, succinate, and NADH2. Those of red muscle were less active with α-glycerophosphate than with the other substrates. These results indicate that an α-glycerophosphate shuttle may couple the reactions generating NADH2 in the cytoplasm of white muscle with the mitochondrial respiratory chain. The properties of the red muscle mitochondria suggest that the direct oxidation of NADH2 may be more important in this tissue than the α-glycerophosphate shuttle.

THE OXIDATION OF LACTATE AND α-GLYCEROPHOSPHATE BY RED AND WHITE SKELETAL MUSCLE: II. HISTOCHEMICAL STUDIES

The use of phenazine methosulfate (PMS) in the histochemical demonstration of lactate and α-glycerophosphate dehydrogenases in skeletal muscle has been examined. When PMS is added to the conventional dehydrogenase reagents, these enzymes appear to be at least as active in the white fibers as in the red. In the absence of PMS, the red fibers appear to be much richer than the white in lactate and α-glycerophosphate dehydrogenase. The conventional methods without PMS apparently give a false impression of the distribution of diphosphopyridine nucleotide (DPN)-linked dehydrogenases in skeletal muscle because of their dependence on the indigenous tissue level and intracellular localization of reduced DPN (DPNH)-diaphorase. A leakage of both enzymes from the sections into the histochemical dehydrogenase reagents occurred both in the presence and absence of PMS. When allowances are made for such losses, it appears that the PMS results are compatible with other evidence that the glycolytic dehydrogenases are more active in white than in red skeletal muscle fibers and that these enzymes are largely confined to the cytoplasm.

THE OXIDATION OF LACTATE AND α-GLYCEROPHOSPHATE BY RED AND WHITE SKELETAL MUSCLE: I. QUANTITATIVE STUDIES

Quantitative estimations indicate that the white muscle of the guinea pig has more than twice as much lactate and α-glycerophosphate dehydrogenase activity as red muscle and that both enzymes are largely cytoplasmic rather than particulate in distribution. In a related study it was shown that diametrically opposite conclusions can be drawn from the application of conventional histochemical methods to the same material. The discrepancy between the quantitative and histochemical findings appears to be due to the dependence of the histochemical methods upon local intracellular diaphorase activity. Low diaphorase levels in white muscle fibers produce the erroneous impression that the two dehydrogenases are also relatively inactive in these fibers. This artifact does not arise with α-glycerophosphate oxidase since it is not diaphorase-coupled. Quantitative determinations confirmed an earlier histochemical report that this enzyme is associated with particulate matter in muscle and is much more active in white than in red skeletal muscle fibers.

Distribution of Co and radio-chromium in blood and tissues of rabbit and dog. I. Carbon monoxide.

Summary1. Carbon monoxide gas and autogenous red cells tagged with Cr51 were administered simultaneously to rabbits and to dogs. Blood and homogenized tissues from various organs were analyzed for radioactivity and for CO content. 2. The volume of distribution of CO was 13% larger than the volume of distribution of Cr51 in the rabbit. The discrepancy is the same as that found in man and the splenectomized dog. 3. CO accumulated in red skeletal muscle and myocardium in amounts sufficient to account for the discrepancy between distribution volumes. 4. Evidence was found pointing to slight accumulation of Cr51 in spleen and lung. Further studies of this phenomenon are described in part II of this report.

The Relationship between Summated Tissue Respiration and Metabolic Rate in the Mouse and Dog

The Relationship between Summated Tissue Respiration and Metabolic Rate in the Mouse and Dog

Étude électrophorétique d'extraits de muscles doués de différentes propriétés morphologiques et fonctionnelles

The total extracts obtained by different ionic forces from the following have been studied by means of electrophoresis: white and red skeletal muscles of rabbits, muscles of domestically bred rabbits, myocardia of rabbits and dogs, uterus of female rabbits and heifers, calfs' bladder, and skeletal muscles of foetus of rabbits. There is a close connection between certain aspects of the proteinic composition of different muscles and their particular functioning properties. In passing from quickly contracting muscles to slowly contracting muscles, a very progressive modification occurs in the quantitative yield between the constituents of the myogen group, which diminish, and the myoalbumin, which increases. The globulins of smooth muscles differ very much from those of striated muscles; those of skeletal muscle of foetus, although apparently very similar to the α- and β-myosines of striated muscles, differ distinctly in their mobilities.