History and Uses: Although calcium is the fifth most abundant element in the earth's crust, it is never found free in nature since it easily forms compounds by reacting with oxygen and water.Metallic calcium was first isolated by Sir Humphry Davy in 1808 through the electrolysis of a mixture of lime (CaO) and mercuric oxide (HgO).ther common compounds of calcium include: calcium sulfate (CaSO 4), also known as gypsum, which is used to make dry wall and plaster of Paris, calcium nitrate (Ca(NO 3) 2), a naturally occurring fertilizer and calcium phosphate (Ca 3 (PO 4) 2), the main material found in bones and teeth.
incretin: A gastrointestinal hormone causing an increase in the amount of insulin released from the beta cells of the islets of Langerhans after eating, even before blood glucose levels become elevated.
Are there other hormones and mediators beyond GIP and GLP-1 with incretin like activity? Several other peptide hormones, nutrients, bile acids, and lipid amides are also secreted following nutrient ingestion, bind to receptors on islet b-cells and stimulate glucose-dependent insulin secretion.he discovery of a second incretin hormone, glucagon-like peptide-1 (GLP-1), followed the cloning and sequencing of mammalian proglucagon genes and complementary DNAs (see Glucagon Gene) .