Hormones & Steroids

Human growth hormone (hGH)

Human growth hormone (hGH), also known as somatotropin, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration and is essential for normal growth and development in children. In adults, growth hormone plays a role in regulating bone density, muscle mass, and glucose and lipid metabolism. It can also affect heart and kidney function. Growth hormone is produced by the pituitary gland and is normally released into the bloodstream in pulses throughout the day and night. As a result, obtaining a single measurement of GH in blood is difficult to interpret and not clinically useful. GH stimulation and suppression tests are therefore often used to diagnose GH abnormalities. Growth hormone deficiency (GHD) is a rare disorder characterized by the inadequate secretion of GH and it can result from congenital abnormalities or from damage to the pituitary gland caused by a head injury, brain tumor, or surgery or radiation treatment. Childhood-onset GHD results in growth retardation, short stature, and maturation delays. Adult-onset GHD is characterized by a number of variable symptoms including reduced energy levels, altered body composition, osteoporosis (reduced bone mineral density), reduced muscle strength, lipid abnormalities such as increased LDL cholesterol, insulin resistance, and impaired cardiac function. Excess GH is most often due to a GH-secreting pituitary tumor (usually benign) and can result in acromegaly (gigantism) in children. Among the most serious symptoms of acromegaly are type 2 diabetes, high blood pressure, increased risk of cardiovascular disease, and arthritis. To determine hGH levels, dynamic tests are required for proper diagnosis. These tests are meant to stimulate the pituitary (via insulin, arginine, clonidine and l-dopa) to secrete GH allowing for the testing of blood samples at timed intervals. hGH assays are based on the two-site sandwich enzyme immunoassay principles using monoclonal antibodies or a combination of monoclonal and polyclonal antibodies. One challenge faced with hGH assays is that the normal composition of hGH in blood is actually mixture of different isoforms, present at constant relative proportions. The primary isoform is a 22 kD molecule and a 20 kD molecule, as well as hetero- and homodimers and multimers. Assay results can vary considerably depending on reactivity with various isoforms.

Reagents for Immunoassay Development

MAb to hGH • Cross-reactive with Human Placental Lactogen (<0.02%) and Human Prolactin (<0.02%) • Capture Antibody MAb to hGH • Cross-reactive with Human Placental Lactogen (<0.02%) and Human Prolactin (<0.02%) • Detection Antibody hGH Native Antigen • Cross-reactivity: FSH (<0.01%), LH (<0.01%), TSH (<0.01%) and Prolactin (<0.01%) • >80% pure (SDS-PAGE) • Lyophilized from 50 mM Ammonium Bicarbonate

MAF06-154

MAF06-210

Suitable for use in ELISA

A75714H