Description
Introduction: Growth hormone is a protein hormone of about 190 amino acids that is synthesized and secreted by cells called somatotrophs in the anterior pituitary. It is a major participant in contro l of several complex physiologic processes, including growth and metabolism. Growth hormone is also of considerable interest as a drug used in both humans and animals. Growth is a very complex process, and requires the coordinated action of several hormones. The major role of growth hormone in stimulating body growth is to stimulate the liver and other tissues to secrete IGF-I. IGF-I stimulates proliferation of chondrocytes (cartilage cells), resulting in bone growth. Growth hormone does seem to have a direct effect on bone growth in stimulating differentiation of chondrocytes. IGF-I also appears to be the key player in muscle growth. It stimulates both the differentiation and proliferation of myoblasts. It also stimulates amino acid uptake and protein synthesis in muscle and other tissues. Growth hormone has important effects on protein, lipid and carbohydrate metabolism. In some cases, a direct effect of growth hormone has been clearly demonstrated, in others, IGF-I is thought to be the critical mediator, and some cases it appears that both direct and indirect effects are at play.
Principle of the Assay: This assay employs the competitive inhibition enzyme immunoassay technique. A antibody specific to GH has been pre-coated onto a microplate. Standards or samples are added to the appropriate microtiter plate wells with biotin-conjugated GH and incubated. A competitive inhibition reaction is launche d between GH (Standards or samples) and Biotin-conjugated GH with the pre-coated antibody specific for GH. The more amount of GH in samples, the less antibody bound by Biotin-conjugated GH. Then Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. The substrate solutions are added to the wells, respectively. And the color develops in opposite to the amount of GH in the sample. The color development is stopped and the intensity of the color is measured