Description
The incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagons-like peptide-1 (GLP-1), are a group of gastrointestinal hormones that cause an increase in the amount of insulin released from the beta cells ofthe islets of Langerhans after ingestion of food.
The intestinal peptide GIP was first isolated from porcine upper small intestine1). The sequences ofporcine, bovine and human GIP have been determined, each has 42 amino acids, and thesequences is highly conserved. The porcine and bovine peptides differ from the human at two and three site, respectively. Takeda et al. have isolated a human cDNA encoding the GIP precursor and confirming that GIP belongs to the vasoactive intestinal peptide (VIP)/Glucagon/secretin family.
GIP is a gastrointestinal peptide hormone that is released from duodenal endocrine K cells after absorption of glucose or fat. GIP is a potent releaser of insulin in experimental animals8) and in man 9,10) provided that the blood glucose is above basal level. Plasma level of GIP is elevated after an oral glucose load or a meal in normal man. This increase after a meal is below normal in newly diagnosed insulin dependent diabetics).
It is now being recognized that GIP receptor is also expressed in organs and cells such as duodenum, small intestine, pancreatic alpha-cell, adipocyte and osteoblast. These results demonstrate GIP may have a lot of physiological effect inaddition to their glucoregulatory effects. GIP is rapidly inactivated by the enzyme dipeptidyl peptidase- 4 (DPP- 4) to GIP with a blood half-life of only several minutes. DPP- 4 inhibitor can prolong the half-life of GIP, that expecting treatment of incretin effect.
The kit can be used for measurement of total GIP [both GIP (1-42) and GIP (3-42)] in human plasma with high sensitivity. It will be a specifically useful tool for incretin research.
This ELISA kit is used for quantitative determination of human total GIP in plasma and culture medium supernatant. The kit is characterized by its sensitive quantification and high specificity. In addition, it has no influence by other components in samples. GIP standard is highly purified synthetic product.
Specificity: This ELISA kit has high specificity to human GIP(1-42) and GIP(3-42), and shows no cross reactivity to Glucagon, GLP-1(7-37), GLP-1(7-36) NH2, GLP-1(9-36) NH2and human GLP-2.
Assay principle: This ELISA kit for determination of human total GIP is based on a sandwich enzyme immunoassay. To the wells of plate coated with highly purified mouse monoclonal antibody against human GIP, standards orsamples are added for the 1st step immunoreaction. After the 1st step incubation and plate washing, HRP labeled antibody solution against human GIP is added as the 2nd step to form antibody - antigen - labeled antibody complex on the surface ofthe wells. After the 2nd step incubation and rinsing out excess labeled antibody, Finally, HRP enzyme activity is determined by 3,3’,5,5’-Tetramethylbenzidine (TMB) and the concentration of human total GIP is calculated.
