Description
Introduction: Gonadotropin-releasing hormone (GnRH), also known as Luteinizing-hormone releasing hormone (LHRH) and luliberin, is a tropic peptide hormone responsible for the release of FSH and LH from the anterior pituitary. GnRH is synthesized and released from neurons within the hypothalamus. The gene, GNRH1, for the GNRH precursor is located on chromosome 8. In mammals, the linear decapeptide end product is synthesized from a 92 amino acid preprohormone in the preoptic anterior hypothalamus. GnRH is considered a neurohormone, a hormone produced in a specific neural cell and released at its neural terminal. A key area for production of GNRH is the preoptic area of the hypothalamus, that contains most of the GNRH-secreting neurons. GnRH neurons originate in the nose and migrate into the brain where they are scattered throughout the medial septum and hypothalamus and connected by very long >1 mm long dendrites. These bundle together so they receive shared synaptic input, a process that allows them to synchronize their GnRH release. GnRH is secreted in the hypophysial portal bloodstream at the median eminence. The portal blood carries the GnRH to the pituitary gland, which contains the gonadotrope cells, where GnRH activates its own receptor, gonadotropin-releasing hormone receptor (GNRHR), a seven transmembrane G-protein coupled receptor that stimulates the beta isoform of Phosphoinositide phospholipase C, which goes on to mobilize calcium and protein kinase C. This results in the activation of proteins involved in the synthesis and secretion of the gonadotropins, LH and FSH. GnRH is degraded by proteolysis within a few minutes.
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to GnRH. Standards or samples are then added to the appropriate microtiter plate wells with a Horseradish Peroxidase (HRP)-conjugated monoclonal antibody preparation specific for GnRH and incubated. Then substrate solution A and B are added to each well. Only those wells that contain GnRH, HRP-conjugated antibody will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450 nm +/- 2 nm. The concentration of GnRH in the samples is then determined by comparing the O.D. of the samples to the standard curve