Gemmill (1940, 1941)andGemmill&Hamann (1941), confirmed by Hechter, Levine & Soskin (1941) and by Stadie (1944), showed that surviving rat diaphragm can synthesize glycogen from added glucose. The rate of this synthesis may be increased by addition of insulin in vitro. Following these findings the in vitro synthesis of glycogen from glucose as well as glycogenolysis by muscle were further inves...

Epinephrine and amylin stimulate glycogenolysis, glycolysis, and Na+-K+-ATPase activity in skeletal muscle. However, it is not known whether these hormones stimulate glycolytic ATP production that is specifically coupled to ATP consumption by the Na+-K+pump. These studies correlated glycolysis with Na+-K+-ATPase activity in resting rat extensor digitorum longus and soleus muscles incubated at 3...

Prostaglandins, released from Kupffer cells, have been shown to mediate the increase in hepatic glycogenolysis by various stimuli such as zymosan, endotoxin, immune complexes, and anaphylotoxin C3a involving prostaglandin (PG) receptors coupled to phospholipase C via a G(0) protein. PGs also decreased glucagon-stimulated glycogenolysis in hepatocytes by a different signal chain involving PGE2 r...

Phenylephrine (1.5 X lo-‘ M) administered to perfused livers from fed rats gave rise to a rapid, parallel increase in oxygen uptake and glucose output. The time of onset for oxygen uptake was 9.9 f 0.4 s following phenylephrine administration, and immediately preceded glucose output which occurred at 11.6 k 0.5 s. Near-maximal effects were observed 50 s following aagonist treatment. Both respon...

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...

The effect of warm-up exercise on energy metabolism and muscle glycogenolysis during sprint exercise (Spr) was examined in six fit Standardbred horses exercised at 115% of maximal O(2) consumption (VO(2 max)) until fatigued, 5 min after each of three protocols: 1) no warm-up (NWU); 2) 10 min at 50% of VO(2 max) [low-intensity warm-up (LWU)]; and 3) 7 min at 50% VO(2 max) followed by 45-s interv...

BURTON, STANLEY D., CARL E. MONDON, AND TADASHI ISHIDA. Dissociation of potassium and glucose e$lux in isolated perfused rat I iver. Am. J. Physiol. 212(2) : 261-266. Ig67.-The dissociation of potassium and glucose movement during glucagon-induced glycogenolysis was studied in the isolated rat liver utilizing a small volume perfusion apparatus. When glucagon was added to a preparation assumed t...

Vasoactive intestinal peptide (VIP) and noradrenaline (NA) have been previously shown to promote glycogenolysis in mouse cerebral cortex (Magistretti, 1990). This action, which is fully expressed within a few minutes, is exerted on astrocytes (Sorg and Magistretti, 1991). In the present article, we report a second, temporally delayed, action of VIP or NA in primary cultures of mouse cerebral co...

BACKGROUND In healthy subjects after an overnight fast, glucose production is for approximately 50% derived from glycogenolysis. If the fast is prolonged, glucose production decreases due to a decline in glycogenolysis, while gluconeogenesis remains stable. In cerebral malaria, glucose production is completely derived from gluconeogenesis after an overnight fast. It is not known if glucose prod...