Skeletal muscle glycogen concentration and metabolic responses following a high glycaemic carbohydrate breakfast

2004 ◽  
Vol 22 (11-12) ◽  
pp. 1065-1071 ◽  
Author(s):  
Costas Chryssanthopoulos ◽  
Clyde Williams ◽  
Andrea Nowitz ◽  
Gregory Bogdanis
Keyword(s):  
Skeletal Muscle ◽  
Muscle Glycogen ◽  
Metabolic Responses ◽  
Glycogen Concentration ◽  
Skeletal Muscle Glycogen ◽  
Muscle Glycogen Concentration

Skeletal muscle glycogen content: diurnal variation and effects of fasting

1976 ◽  
Vol 231 (2) ◽  
pp. 614-618 ◽  
Author(s):  
RK Conlee ◽  
MJ Rennie ◽  
WW Winder
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Diurnal Variation ◽  
Muscle Glycogen ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Glycogen Concentration ◽  
Skeletal Muscle Glycogen ◽  
Ad Libitum ◽  
Muscle Glycogen Concentration

To test whether skeletal muscle glycogen concentration is related to food consumption, glycogen content was determined in red (R) and white (W) vastus lateralis and in soleus (S) muscles from six groups of ad libitum-fed rats killed at 4-h intervals and from 24-h-fasted animals killed at 0800 and 1600 h. The animal quarters were illuminated between 0700 and 1900 h. Glycogen values exhibited a peak at 0800 h and a nadir at 2000 h. These changes bore no relationship to blood glucose and lactate or plasma free fatty acids, glucagon, insulin, and corticosterone concentrations. Fasting resulted in reductions of glycogen content of 49% (S), 47% (R), and 29% (W) in animals killed at 0800h, but at 1600h changes were only 23% (RY), 17% (W), and 8% (S). The smaller changes at 1600 h were apparently due to lower glycogen levels in the tissues of the fed animals. It was concluded that skeletal muscle exhibits a diurnal variation in glycogen content, and that, contrary to accepted belief, fating significantly alters muscle glycogen concentration.

scholarly journals Mechanism linking glycogen concentration and glycogenolytic rate in perfused contracting rat skeletal muscle

1992 ◽  
Vol 284 (3) ◽  
pp. 777-780 ◽  
Author(s):  
P Hespel ◽  
E A Richter
Keyword(s):  
Skeletal Muscle ◽  
Muscle Glycogen ◽  
Rat Skeletal Muscle ◽  
Phosphorylase Activity ◽  
Tension Development ◽  
Glycogen Concentration ◽  
The Difference ◽  
Resting Muscle ◽  
Muscle Glycogen Concentration ◽  
Glycogen Breakdown

The influence of differences in glycogen concentration on glycogen breakdown and on phosphorylase activity was investigated in perfused contracting rat skeletal muscle. The rats were preconditioned by a combination of swimming exercise and diet (carbohydrate-free or carbohydrate-rich) in order to obtain four sub-groups of rats with varying resting muscle glycogen concentrations (range 10-60 mumol/g wet wt.). Pre-contraction muscle glycogen concentration was closely positively correlated with glycogen breakdown over 15 min of intermittent short tetanic contractions (r = 0.75; P less than 0.001; n = 56) at the same tension development and oxygen uptake. Additional studies in supercompensated and glycogen-depleted hindquarters during electrical stimulation for 20 s or 2 min revealed that the difference in glycogenolytic rate was found at the beginning rather than at the end of the contraction period. Phosphorylase alpha activity was approximately twice as high (P less than 0.001) in supercompensated muscles as in glycogen-depleted muscles after 20 s as well as after 2 min of contractions. It is concluded that glycogen concentration is an important determinant of phosphorylase activity in contracting skeletal muscle, and probably via this mechanism a regulator of glycogenolytic rate during muscle contraction.

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