The time course of plasma enzyme changes accompanying skeletal muscle stimulation

ABSTRACT The distribution of oxytocin in the kidneys, liver, uterus and skeletal muscle of the rat was followed during 10 min after intravenous injection of tritium labelled oxytocin. Oxytocin was found to be taken up and degraded mainly in the kidneys and the liver. After 150 seconds no intact oxytocin could be detected in these organs. The time course of the distribution of the radioactivity in the liver and the skeletal muscle showed no noteworthy characteristics, whereas a different course was found in the kidneys and in the uterus. In the kidneys, the radioactivity increased continuously from 60 to 200 seconds after the injection, indicating an accumulation of oxytocin or its metabolites in the kidneys. In the uterus a high initial uptake was observed, followed by a decrease of the radioactivity from 60 to 100 seconds after the injection. This distribution pattern was specific to oxytocin, since the uptake of tritiated tyrosine and tritiated water was almost constant during the same time period. These findings may indicate a preferential distribution of oxytocin to the uterus.

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A Time-Course Comparison of Skeletal Muscle Metabolomic Alterations in Walker-256 Tumour-Bearing Rats at Different Stages of Life

Metabolites ◽

10.3390/metabo11060404 ◽

2021 ◽

Vol 11 (6) ◽

pp. 404

Author(s):

Gabriela de Matuoka e Chiocchetti ◽

Leisa Lopes-Aguiar ◽

Natália Angelo da Silva Miyaguti ◽

Lais Rosa Viana ◽

Carla de Moraes Salgado ◽

...

Keyword(s):

Skeletal Muscle ◽

Time Course ◽

Cancer Cachexia ◽

Tumour Bearing ◽

Walker 256 Tumour ◽

Walker 256 ◽

Muscle Changes ◽

The Right ◽

Biomarker Research ◽

Host Metabolism

Cancer cachexia is a severe wasting condition that needs further study to find ways to minimise the effects of damage and poor prognosis. Skeletal muscle is the most impacted tissue in cancer cachexia; thus, elucidation of its metabolic alterations could provide a direct clue for biomarker research and be applied to detect this syndrome earlier. In addition, concerning the significant changes in the host metabolism across life, this study aimed to compare the metabolic muscle changes in cachectic tumour-bearing hosts at different ages. We performed 1H-NMR metabolomics in the gastrocnemius muscle in weanling and young adult Walker-256 tumour-bearing rats at different stages of tumour evolution (initial, intermediate, and advanced). Among the 49 metabolites identified, 24 were significantly affected throughout tumour evolution and 21 were significantly affected regarding animal age. The altered metabolites were mainly related to increased amino acid levels and changed energetic metabolism in the skeletal muscle, suggesting an expressive catabolic process and diverted energy production, especially in advanced tumour stages in both groups. Moreover, these changes were more severe in weanling hosts throughout tumour evolution, suggesting the distinct impact of cancer cachexia regarding the host’s age, highlighting the need to adopting the right animal age when studying cancer cachexia.

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Time course of skeletal muscle loss and oxidative stress in rats with walker 256 solid tumor

Muscle & Nerve ◽

10.1002/mus.21798 ◽

2010 ◽

Vol 42 (6) ◽

pp. 950-958 ◽

Cited By ~ 38

Author(s):

Flávia A. Guarnier ◽

Alessandra L. Cecchini ◽

Andréia A. Suzukawa ◽

Ana Leticia G.C. Maragno ◽

Andréa N.C. Simão ◽

...

Keyword(s):

Oxidative Stress ◽

Skeletal Muscle ◽

Solid Tumor ◽

Time Course ◽

Muscle Loss ◽

Skeletal Muscle Loss ◽

Walker 256 ◽

And Oxidative Stress

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Time Course of Enzyme Changes After a Switch From a High-Fat to a Low-Fat Diet

Comparative Biochemistry and Physiology Part B Biochemistry and Molecular Biology ◽

10.1016/s0305-0491(97)00163-6 ◽

1997 ◽

Vol 118 (2) ◽

pp. 359-365 ◽

Cited By ~ 7

Author(s):

Stephen P.J Brooks ◽

Brian J Lampi

Keyword(s):

Time Course ◽

High Fat ◽

Low Fat ◽

Low Fat Diet ◽

Enzyme Changes

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Pulsatile Pressure and Flow in the Skeletal Muscle Microcirculation

Journal of Biomechanical Engineering ◽

10.1115/1.2891208 ◽

1990 ◽

Vol 112 (4) ◽

pp. 437-443 ◽

Cited By ~ 5

Author(s):

Shou-Yan Lee ◽

G. W. Schmid-Scho¨nbein

Keyword(s):

Skeletal Muscle ◽

Arterial Pressure ◽

Time Course ◽

Venous Pressure ◽

Time Dependent ◽

Physiological Importance ◽

Pulsatile Pressure ◽

Theoretical Predictions ◽

Skeletal Muscle Microcirculation

Although blood flow in the microcirculation of the rat skeletal muscle has negligible inertia forces with very low Reynolds number and Womersley parameter, time-dependent pressure and flow variations can be observed. Such phenomena include, for example, arterial flow overshoot following a step arterial pressure, a gradual arterial pressure reduction for a step flow, or hysteresis between pressure and flow when a pulsatile pressure is applied. Arterial and venous flows do not follow the same time course during such transients. A theoretical analysis is presented for these phenomena using a microvessel with distensible viscoelastic walls and purely viscous flow subject to time variant arterial pressures. The results indicate that the vessel distensibility plays an important role in such time-dependent microvascular flow and the effects are of central physiological importance during normal muscle perfusion. In-vivo whole organ pressure-flow data in the dilated rat gracilis muscle agree in the time course with the theoretical predictions. Hemodynamic impedances of the skeletal muscle microcirculation are investigated for small arterial and venous pressure amplitudes superimposed on an initial steady flow and pressure drop along the vessel.

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Differential patterns of transcript accumulation during human myogenesis

Molecular and Cellular Biology ◽

10.1128/mcb.7.11.4100-4114.1987 ◽

1987 ◽

Vol 7 (11) ◽

pp. 4100-4114

Author(s):

P Gunning ◽

E Hardeman ◽

R Wade ◽

P Ponte ◽

W Bains ◽

...

Keyword(s):

Skeletal Muscle ◽

Carbonic Anhydrase ◽

Myosin Heavy Chain ◽

Heavy Chain ◽

Time Course ◽

Human Skeletal Muscle ◽

Transcript Accumulation ◽

Mrna Accumulation ◽

Adult Human ◽

Alpha Actin

We evaluated the extent to which muscle-specific genes display identical patterns of mRNA accumulation during human myogenesis. Cloned satellite cells isolated from adult human skeletal muscle were expanded in culture, and RNA was isolated from low- and high-confluence cells and from fusing cultures over a 15-day time course. The accumulation of over 20 different transcripts was compared in these samples with that in fetal and adult human skeletal muscle. The expression of carbonic anhydrase 3, myoglobin, HSP83, and mRNAs encoding eight unknown proteins were examined in human myogenic cultures. In general, the expression of most of the mRNAs was induced after fusion to form myotubes. However, several exceptions, including carbonic anhydrase and myoglobin, showed no detectable expression in early myotubes. Comparison of all transcripts demonstrated little, if any, identity of mRNA accumulation patterns. Similar variability was also seen for mRNAs which were also expressed in nonmuscle cells. Accumulation of mRNAs encoding alpha-skeletal, alpha-cardiac, beta- and gamma-actin, total myosin heavy chain, and alpha- and beta-tubulin also displayed discordant regulation, which has important implications for sarcomere assembly. Cardiac actin was the only muscle-specific transcript that was detected in low-confluency cells and was the major alpha-actin mRNA at all times in fusing cultures. Skeletal actin was transiently induced in fusing cultures and then reduced by an order of magnitude. Total myosin heavy-chain mRNA accumulation lagged behind that of alpha-actin. Whereas beta- and gamma-actin displayed a sharp decrease after initiation of fusion and thereafter did not change, alpha- and beta-tubulin were transiently induced to a high level during the time course in culture. We conclude that each gene may have its own unique determinants of transcript accumulation and that the phenotype of a muscle may not be determined so much by which genes are active or silent but rather by the extent to which their transcript levels are modulated. Finally, we observed that patterns of transcript accumulation established within the myotube cultures were consistent with the hypothesis that myoblasts isolated from adult tissue recapitulate a myogenic developmental program. However, we also detected a transient appearance of adult skeletal muscle-specific transcripts in high-confluence myoblast cultures. This indicates that the initial differentiation of these myoblasts may reflect a more complex process than simple recapitulation of development.

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Effect of diabetes and insulin treatment of diabetic rats on total RNA, poly(A)+ RNA, and mRNA in skeletal muscle

AJP Cell Physiology ◽

10.1152/ajpcell.1991.260.3.c409 ◽

1991 ◽

Vol 260 (3) ◽

pp. C409-C416 ◽

Cited By ~ 8

Author(s):

J. D. Kent ◽

S. R. Kimball ◽

L. S. Jefferson

Keyword(s):

Skeletal Muscle ◽

Ribosomal Rna ◽

Time Course ◽

Diabetic Rats ◽

In Vitro Translation ◽

Specific Gene ◽

Insulin Administration ◽

Tissue Mass ◽

Total Rna

We have assessed the time course of alterations in several biochemical parameters and expression of specific mRNAs in gastrocnemius muscle following both the induction of diabetes and the administration of insulin to diabetic rats. Muscle mass, total RNA, and total protein were reduced, whereas poly(A)+ RNA relative to total RNA was increased following the induction of diabetes. All the above parameters, with the exception of poly(A)+ RNA, were reciprocally and rapidly altered following administration of insulin to 3-day diabetic animals. These changes suggest that during the induction of diabetes 1) total cellular protein is reduced at a rate that is less than the reduction in gastrocnemius mass, whereas RNA is reduced at a rate 1.5 times the reduction in tissue mass, and 2) poly(A)+ RNA is elevated relative to total RNA. After insulin administration, there appears to be coordinate synthesis of both poly(A)+ RNA and ribosomal RNA, assuming 85% of total RNA is ribosomal. Therefore, we conclude that poly(A)+ RNA is more stable than ribosomal RNA during diabetes, whereas the amounts of poly(A)+ RNA and ribosomal RNA are increased at the same rates following insulin administration to diabetic animals. Analysis of expression of specific gene products over the same time course, as assessed by in vitro translation of total RNA followed by two-dimensional gel analysis, suggests that there are a few mRNAs that are very rapidly altered in response to insulin administration. The mRNAs that are altered demonstrate variable temporal patterns of either repression or full or transient expression. These rapid, but limited, alterations in gene expression may prove important in the development of the defects that occur in skeletal muscle in response to diabetes.

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Interfering with calcium release suppresses I gamma, the "hump" component of intramembranous charge movement in skeletal muscle.

The Journal of General Physiology ◽

10.1085/jgp.97.5.845 ◽

1991 ◽

Vol 97 (5) ◽

pp. 845-884 ◽

Cited By ~ 27

Author(s):

L Csernoch ◽

G Pizarro ◽

I Uribe ◽

M Rodríguez ◽

E Ríos

Keyword(s):

Skeletal Muscle ◽

Time Course ◽

Calcium Release ◽

Time Derivative ◽

Ruthenium Red ◽

Total Charge ◽

Charge Movement ◽

Release Channel ◽

Release Flux ◽

Highly Correlated

Four manifestations of excitation-contraction (E-C) coupling were derived from measurements in cut skeletal muscle fibers of the frog, voltage clamped in a Vaseline-gap chamber: intramembranous charge movement currents, myoplasmic [Ca2+] transients, flux of calcium release from the sarcoplasmic reticulum (SR), and the intrinsic optical transparency change that accompanies calcium release. In attempts to suppress Ca release by direct effects on the SR, three interventions were applied: (a) a conditioning pulse that causes calcium release and inhibits release in subsequent pulses by Ca-dependent inactivation; (b) a series of brief, large pulses, separated by long intervals (greater than 700 ms), which deplete Ca2+ in the SR; and (c) intracellular application of the release channel blocker ruthenium red. All these reduced calcium release flux. None was expected to affect directly the voltage sensor of the T-tubule; however, all of them reduced or eliminated a component of charge movement current with the following characteristics: (a) delayed onset, peaking 10-20 ms into the pulse; (b) current reversal during the pulse, with an inward phase after the outward peak; and (c) OFF transient of smaller magnitude than the ON, of variable polarity, and sometimes biphasic. When the total charge movement current had a visible hump, the positive phase of the current eliminated by the interventions agreed with the hump in timing and size. The component of charge movement current blocked by the interventions was greater and had a greater inward phase in slack fibers with high [EGTA] inside than in stretched fibers with no EGTA. Its amplitude at -40 mV was on average 0.26 A/F (SEM 0.03) in slack fibers. The waveform of release flux determined from the Ca transients measured simultaneously with the membrane currents had, as described previously (Melzer, W., E. Ríos, and M. F. Schneider. 1984. Biophysical Journal. 45:637-641), an early peak followed by a descent to a steady level during the pulse. The time at which this peak occurred was highly correlated with the time to peak of the current suppressed, occurring on average 6.9 ms later (SEM 0.73 ms). The current suppressed by the above interventions in all cases had a time course similar to the time derivative of the release flux; specifically, the peak of the time derivative of release flux preceded the peak of the current suppressed by 0.7 ms (SEM 0.6 ms). The magnitude of the current blocked was highly correlated with the inhibitory effect of the interventions on Ca2+ release flux.(ABSTRACT TRUNCATED AT 400 WORDS)

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