Glycogen depletion in mouse intrafusal fibres after different durations of swimming

Two different cell lines (Be-Wo and Jar) of human gestational choriocarcinoma have been maintained in continuous tissue culture for a period of four and two years respectively without losing the ability to elaborate human chorionic gonadotropin (HCG). Tissue cultures, as revealed by electron microscopy, consisted of small cells with single nuclei. In some instances cell surfaces were provided with microvilli but more often the intercellular spaces were narrow and bridged by desmosomes. However, syncytium was not formed. Endoplasmic reticulum (ER) was poorly developed in both cell lines, except in some Be-Wo cells it was prominent. Golgi complex, lysosomes and numerous free ribosomes, as well as excessive cytoplasmic glycogen, were present in all cells (Fig. 1). Glycogen depletion and concomitant increase of ER were observed in many cells following a single dose of 10 ugm/ml of adrenalin added to medium (Fig. 2).

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Respiratory capacity and glycogen depletion in thyroid-deficient muscle

Journal of Applied Physiology ◽

10.1152/jappl.1980.49.1.102 ◽

1980 ◽

Vol 49 (1) ◽

pp. 102-106 ◽

Cited By ~ 20

Author(s):

K. M. Baldwin ◽

A. M. Hooker ◽

R. E. Herrick ◽

L. F. Schrader

Keyword(s):

Skeletal Muscle ◽

Fatty Acid ◽

Free Fatty Acid ◽

Plasma Free Fatty Acid ◽

Endurance Capacity ◽

Glycogen Depletion ◽

Respiratory Capacity ◽

Rest And Exercise

This study was undertaken to determine the effects of propylthiouracil-induced thyroid deficiency on a) the capacity of muscle homogenates to oxidize [2-14C]pyruvate and [U-14C]palmitate and b) glycogen depletion during exercise in liver and in fast-oxidative-glycogenolytic (FOG), fast-glycogenolytic (FG), and slow-oxidative (SO) muscle. Relative to the rates for normal rats, oxidation with pyruvate was reduced by 53, 68, and 58%, and palmitate by 40, 50, and 48% in FOG, FG, and SO muscle, respectively (P less than 0.05). Normal rats ran longer than thyroid-deficient rats at 26.7 m/min (87 ± 8 vs. 37 ± 5 min). After 40 min of running (22 m/min), the amount of glycogen consumed in normal FOG, FG, and SO muscle and in liver amounted to only 23, 12, 66, and 52%, respectively, of that for their thyroid-deficient counterparts. Also, normal rats maintained higher plasma free fatty acid levels than thyroid-deficient rats during both rest and exercise (P less than 0.05). These findings suggest that thyroid deficiency causes a reduced potential for FFA utilization in skeletal muscle that enhances its consumption of glycogen, thereby limiting endurance capacity.

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Effects of Nutrient Intake Timing on Post-Exercise Glycogen Accumulation and its Related Signaling Pathways in Mouse Skeletal Muscle

Nutrients ◽

10.3390/nu11112555 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2555 ◽

Cited By ~ 1

Author(s):

Takahashi ◽

Matsunaga ◽

Banjo ◽

Takahashi ◽

Sato ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Glycogen ◽

Nutrient Intake ◽

Matched Control ◽

Control Group ◽

Glycogen Depletion ◽

Post Exercise ◽

Glycogen Accumulation ◽

Matched Control Group ◽

Significant Difference

We investigated the effects of nutrient intake timing on glycogen accumulation and its related signals in skeletal muscle after an exercise that did not induce large glycogen depletion. Male ICR mice ran on a treadmill at 25 m/min for 60 min under a fed condition. Mice were orally administered a solution containing 1.2 mg/g carbohydrate and 0.4 mg/g protein or water either immediately (early nutrient, EN) or 180 min (late nutrient, LN) after the exercise. Tissues were harvested at 30 min after the oral administration. No significant difference in blood glucose or plasma insulin concentrations was found between the EN and LN groups. The plantaris muscle glycogen concentration was significantly (p < 0.05) higher in the EN group—but not in the LN group—compared to the respective time-matched control group. Akt Ser473 phosphorylation was significantly higher in the EN group than in the time-matched control group (p < 0.01), while LN had no effect. Positive main effects of time were found for the phosphorylations in Akt substrate of 160 kDa (AS160) Thr642 (p < 0.05), 5'-AMP-activated protein kinase (AMPK) Thr172 (p < 0.01), and acetyl-CoA carboxylase Ser79 (p < 0.01); however, no effect of nutrient intake was found for these. We showed that delayed nutrient intake could not increase muscle glycogen after endurance exercise which did not induce large glycogen depletion. The results also suggest that post-exercise muscle glycogen accumulation after nutrient intake might be partly influenced by Akt activation. Meanwhile, increased AS160 and AMPK activation by post-exercise fasting might not lead to glycogen accumulation.

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Evaluation of period of fasting and mixing of steers prior to slaughter on meat eating quality

Proceedings of the British Society of Animal Science ◽

10.1017/s175275620002977x ◽

2009 ◽

Vol 2009 ◽

pp. 138-138

Author(s):

F O Lively ◽

B W Moss ◽

T W J Keady ◽

L Farmer ◽

N F S Gault ◽

...

Keyword(s):

Shear Force ◽

Eating Quality ◽

Longissimus Dorsi ◽

Glycogen Depletion ◽

Meat Eating ◽

Quadratic Relationship

Mixing of cattle prior to slaughter which results in aggressive activity (Mohan Raj et al 1992) leads to glycogen depletion pre-slaughter and subsequently meat with a higher ultimate pH (pHu). Purchas et al (1990) reported a quadratic relationship between pHu and tenderness with highest shear force values recorded between pHu 5.8 to 6.2. The aim of this study was to determine the effect of fasting and mixing of steers prior to slaughter on the meat eating quality of longissimus dorsi (LD) muscle.

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Failure of glycogen depletion to improve left ventricular function of the rabbit heart after hypothermic ischemic arrest.

Circulation Research ◽

10.1161/01.res.63.1.81 ◽

1988 ◽

Vol 63 (1) ◽

pp. 81-86 ◽

Cited By ~ 34

Author(s):

C F Lagerstrom ◽

W E Walker ◽

H Taegtmeyer

Keyword(s):

Left Ventricular Function ◽

Ventricular Function ◽

Rabbit Heart ◽

Left Ventricular ◽

Glycogen Depletion

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The differentiation of two types of intrafusal fibres in rabbit muscle spindles

Pflügers Archiv - European Journal of Physiology ◽

10.1007/bf00586503 ◽

1970 ◽

Vol 317 (3) ◽

pp. 187-197 ◽

Cited By ~ 7

Author(s):

N. Corvaja ◽

O. Pompeiano

Keyword(s):

Muscle Spindles ◽

Rabbit Muscle ◽

Intrafusal Fibres

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Motor unit territories supplied by primary branches of the phrenic nerve

Journal of Applied Physiology ◽

10.1152/jappl.1989.66.1.61 ◽

1989 ◽

Vol 66 (1) ◽

pp. 61-71 ◽

Cited By ~ 30

Author(s):

C. G. Hammond ◽

D. C. Gordon ◽

J. T. Fisher ◽

F. J. Richmond

Keyword(s):

Motor Unit ◽

Phrenic Nerve ◽

Motor Units ◽

Glycogen Depletion ◽

Precise Analysis ◽

The Central Nervous System ◽

Evoked Activity ◽

Crural Diaphragm ◽

Emg Electrodes ◽

Stimulation Of

Recent studies have demonstrated that, under certain circumstances, the diaphragm does not contract as a homogeneous unit. These observations suggest that motor units may not be randomly distributed throughout the muscle but confined to localized subvolumes. In the present study, electromyographic (EMG) and glycogen depletion methods were combined to investigate the organization of motor units supplied by the primary branches of the phrenic nerve in the cat. Four primary branches are generally present, one branch to the crus and three branches to the sternocostal region. The gross motor-unit territory of each of the four phrenic primary branches was determined by stimulating each nerve separately, while recording from nine EMG electrodes distributed over the hemidiaphragm. Stimulation of the crural branch evoked activity in the ipsilateral crus, whereas stimulation of each of the remaining branches evoked activity in discrete but overlapping areas of the sternocostal diaphragm. A more precise analysis of the distribution and borders of the motor territories was obtained by mapping regions depleted of muscle glycogen due to stimulation of each primary branch for 90 min. Glycogen depletion results closely matched the EMG findings of a localized distribution of motor units served by single primary branches. Stimulation of the crural branch typically caused depletion of the ipsilateral crus, whereas the sternocostal branches each served a striplike compartment. In the majority of cases, the borders of the sternocostal compartments were relatively abrupt and consisted of a 1- to 2-mm transition zone of depleted and nondepleted fibers. These studies demonstrate that motor unit territories of the primary branches of the phrenic nerve are highly delineated. This compartmentalization provides the central nervous system with the potential for a more precise regional motor control of costal and crural diaphragm than previously suspected.

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