Conversion of glycogen to hexose monophosphate in muscle appears to be limited by the activity of phosphorylase (l-3). The enzyme exists in two forms, a and b. Increased phosphorylase activity can result from (a) conversion of phosphorylase b to a (l-5), and (6) regulation of phosphorylase b activity by changes in the intracellular levels of adenine nucleotides (6). In the isolated rat heart pe...

Physiological level of insulin showed more prominent inhibiting effect on the activation of hepatic glucose production and glycogenolysis promoted by cAMP than physiological levels of leptin.

The aim of this study was to determine whether the decreased muscle and blood lactate during exercise with hyperoxia (60% inspired O2) vs. room air is due to decreased muscle glycogenolysis, leading to decreased pyruvate and lactate production and efflux. We measured pyruvate oxidation via PDH, muscle pyruvate and lactate accumulation, and lactate and pyruvate efflux to estimate total pyruvate ...

This paper reviews the role played by glycogen breakdown (glycogenolysis) and glycogen re-synthesis in memory processing in two different chick brain regions, (1) the hippocampus and (2) the avian equivalent of the mammalian cortex, the intermediate medial mesopallium (IMM). Memory processing is regulated by the neuromodulators noradrenaline and serotonin soon after training glycogen breakdown ...

Alterations in myocardial glucose metabolism are a key determinant of ischemia-induced depression of left ventricular mechanical function. Since myocardial glycogen is an important source of endogenous glucose, we compared the effects of ischemia on glucose uptake and utilization in isolated working rat hearts in which glycogen content was either replete (G replete, 114 micromol/g dry wt) or pa...

Two distinct glycogen phosphorylase inhibitors, 5-chloro-1H-indole-2-carboxylic acid [1-(4-fluorobenzyl)-2-(4-hydroxy-piperidin-1-yl)-2-oxoethyl]amide (CP-320,626) and 1,4-dideoxy-1,4-D-arabinitol (DAB), were characterized in vitro with respect to the influence of glucose on their potencies. CP-320,626 has previously been shown to bind to a newly characterized indole site, whereas DAB seems to ...

Stress hyperglycemia following trauma has been shown to potentiate morbidity and mortality. Glucose control in obese patients can be challenging due to insulin resistance. Thus, understanding the mechanisms for glucose generation following hemorrhage may provide important insights into alternative options for glycemic control in obesity. Obesity is characterized by elevated glycogen and increas...

The effects of exogenous prostaglandin E(1) (PGE(1)) or prostaglandin E(2) (PGE(2)) were studied in the isolated perfused rat liver and in the intact canine liver in order to determine the possible physiological role of prostaglandins on hepatic carbohydrate and lipid metabolism. The data indicate that PGE(1) and PGE(2) did not stimulate cyclic AMP (cAMP) and cyclic GMP (cGMP) concentrations in...