Insulin glucagon

Storage and utilization of tissue glycogen, maintenance of blood glucose concentration, and other aspects of carbohydrate metabolism are meticulously regulated by hormones, including insulin, glucagon, epinephrine, and the glucocorticoids. 

The hormone pancreatic polypeptide (PP) is a 36 amino acid peptide, which is closely related to neuropeptide Y and peptide YY PP is mainly found in pancreatic cells distinct from those storing insulin, glucagon or somatostatin. It acts on receptors that belong to the family of neuropeptide Y receptors, particularly on the Y4 subtype. 

Phosphofructokinase-1 T T Insulin Glucagon (cAMP) AMP, fructose 6-phosphate, P, fructose 2,6-bisphos-phate Citrate (fatty acids, ketone bodies), ATP, glucagon (cAMP)... 

Phosphoenolpyruvate carboxykinase i t Glucocorticoids, glucagon, epinephrine (cAMP) Insulin Glucagon ... 

We ll distinguish five basic metabolic states. There are three major metabolic signals that we ll consider—insulin, glucagon, and epinephrine. 

True endocrine hormones, however, remain a fairly well defined group. Virtually all of the hormones used therapeutically (discussed below) fit into this grouping. Examples include insulin, glucagon, GH and the gonadotrophins. 

In the fed state when the insulin glucagon ratio is high, would you expect glycogen synthase, PK and PDH to be phosphorylated or de-phosphorylated Give reasons to support your answer. 

Improved stability with simultaneous preservation of activity has been demonstrated with analogues of glucagon-like peptide-1 and gastric inhibitory polypeptide, two hormones that stimulate the release of insulin. Glucagon-like peptide-1 (GLP-1) is a 30-residue gastrointestinal hormone, ami-dated at the C-terminus that has potential as a treatment for type-2 diabetes. However, GLP-1 is rapidly degraded by dipeptidyl-peptidase IV (EC... 

Examples Insulin Glucagon Catecholamines Examples Steroids Calcitriol Thyroxines Retinoic acid, . ... 

Specific hormones Insulin, glucagon, somatostatin, gastrin, pancreatic polypeptide, serotonin, vasoactive intestinal peptide, cholecystokinin... 

Glucagon, a peptide of 29 amino acids, is a product of the A cells of the pancreas. It is the antagonist of insulin and, like insulin, mainly influences carbohydrate and lipid metabolism. Its effects are each opposite to those of insulin. Glucagon mainly acts via the second messenger cAMP (see p. 384). 

This zinc-dependent enzyme [EC 3.4.24.56], a member of the peptidase family M16, catalyzes the degradation of insulin, glucagon, and other polypeptides. 

The decreased insulin/glucagon ratio activates degradation of glycogen, protein, and triacylglycerols. 

The decreased insulin/glucagon ratio leads to inhibition of glycogen synthesis and increased glycogenolysis to supply some of the body s glucose needs on an immediate basis. 

In addition to the effects of a low insulin/glucagon ratio, long-term changes in metabolism during starvation are induced by the corticosteroid, cortisol. 

Dysfunction of fat metabolism is caused by the low insulin/glucagon ratio, which stimulates fat mobilization by adipose tissue, flooding the liver with fatty acids and raising intracellular acetyl CoA levels. 

The signal is often modulated by integration with input from other signaling pathways (eg, the insulin/glucagon ratio is important for balancing carbohydrate metabolism in the liver). 

Figure 5.6. Metabolism of proteins by proteases found at the cell surface and internal cellular organelles. Intracellular uptake of proteins often involved receptor-mediated endocytosis initial surface binding can be specific for a hormone (e.g., insulin, glucagon).

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