Glucose production, regulation

Draw the structure of cyclic adenosine monophosphate (cAMP), a messenger involved in the regulation of glucose production in the body. Cyclic AMP has a phosphate ring connecting the 3 and 5 hydroxyl groups on adenosine. 

Newsholme EA, Start C Regulation in Metabolism. Wiley, 1973. Nordlie RC, Foster JD, Lange AJ Regulation of glucose production by the liver. Annu Rev Nutr 1999 19 379. 

Figure 7.2 Glucose regulation by insulin. Increased concentrations of glucose and amino acids in the circulation, vagus nerve stimulation and circulating hormones e.g. GLP) stimulate insulin secretion by 3-cells of the pancreatic islets. Insulin suppresses glucose production by the liver and increases glucose uptake by skeletal muscle and fat, leading to decreased circulating glucose concentrations.

Nordlie, R.C., Foster, J.D., Lange, A.J. (1999) Regulation of glucose production by the liver. Annu. Rev. Nutr. 19, 379-406. Advanced review. 

The Hormone Epinephrine Stimulates Glucose Production in Both Liver Cells and Muscle Cells The Hormonal Regulation of the Flux between Fructose-6-phosphate and Fructose-1,6-bisphosphate Is Mediated by Fructose-2,6-bisphosphate... 

The majority of Type-II diabetics are obese (II b) and suffer predominantly from an impairment of insulin action due to heterogeneous mechanisms. Decreased insulin responsiveness of peripheral tissues may be due to (1) a post-receptor defect with secondary hyperinsulinaemia, (2) down-regulation of the number of insulin receptors, or (3) the glucotoxic effect of hyper-glycaemia caused by accelerated hepatic glucose production. An additional impairment of insulin secretion is present, however, only in non-obese Type-II-a diabetics. 

Insulin inhibits transcription of the enzyme phosphoenolpyruvate carboxykinase (PEPCK). PEPCK is a key enzyme in gluconeogenesis and transcription is the primary means of regulating it. By inhibiting PEPCK transcription, insulin can depress glucose production tremendously. (Conversely, the hormone glucagon, which increases blood glucose levels, stimulates PEPCK transcription.)... 

Gerich, 1, Raymond, M., Rizza, R., Verdonk, C. Miles, J. (1981) Hormonal and substrate determinants of hepatic glucose production in man. In The regulation of carbohydrate formation and utilization in mammals, (C. Veneziale), University Park Press, Baltimore, 419-45. 

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