Discovery of incretin hormones and incretin effect was postulated in the early 20th century when Murce administered duodenal extract to diabetic patients and demonstrated a reduction in glycosuria. However, the specific substance responsible for the action of incretin remained elusive for a long time. With the discovery of insulin and later of its available assays, studies were carried out by measuring insulin levels in the blood after administering an intravenous load of glucose and comparing it with oral ingestion of same. Surprisingly insulin levels were higher after oral ingestion of glucose than after IV administration.
It became clear that a sequence of physiological response is activated following meal intake. The GI tract has a significant role in absorption, digestion, and assimilation of ingested nutrient with incretin, mainly GIP and GLP. Purification and characterization…
