Summary
In order to achieve further clarification of the regulation of glycogenolysis in adipose
tissue, we studied the effect of glucose-6-phosphate on phosphorylase activation in
Sephadex G-25 filtrate of adipose tissue. The activity of phosphorylase kinase was
decreased by 50% and by 75% in the presence of 0.5 mM and 2 mM of glucose-6-phosphate,
respectively. This inhibition could be partially prevented by 0.5 mM AMP.
Furthermore, we investigated the influence of glucose-6-phosphate on the effect of
cyclic-AMP-dependent protein kinase on the activation of phosphorylase. The addition
of cyclic-AMP and cyclic-AMP-dependent protein kinase caused a decrease in the inhibition
of the phosphorylase activation by glucose-6-phosphate. Also, the glucose-6-phosphate
at physiological concentration, decreased adipose tissue cyclic-AMP-dependent protein
kinase activity.
Key-Words
Glycogenolysis
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Phosphorylase Kinase
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Glucose-6-Phosphate
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Adipose Tissue
