Description
Introduction: Glial Cell Line-derived Neurotrophic Factor (GDNF) is a recently discoved neurotrophic factor that has been shown to promote the survival of various neuronal subpopulations in both the central as well as the peripheral nervous systems at different stages of their development. Neuronal subpopulations that have been shown to be affected by GDNF include motoneurons, midbrain dopaminergic neurons, Purkinje cells and sympathetic neurons. Native GDNF, a disulfide-linked homodimeric glycoprotein, is a novel member of the TGF-superfamily. In humans, GDNF is encoded by the GDNF gene. This gene encodes a highly conserved neurotrophic factor. The recombinant form of this protein was shown to promote the survival and differentiation of dopaminergic neurons in culture, and was able to prevent apoptosis of motor neurons induced by axotomy. The encoded protein is processed to a mature secreted form that exists as a homodimer. The mature form of the protein is a ligand for the product of the RET (rearranged during transfection) protooncogene. In addition to the transcript encoding GDNF, two additional alternative transcripts encoding distinct proteins, referred to as astrocyte-derived trophic factors, have also been described. Mutations in this gene may be associated with Hirschprung disease. The most prominent feature of GDNF is its ability to support the survival of dopaminergic and motorneurons. These neuronal populations die in the course of Parkinson's disease and amyotrophic lateral sclerosis (ALS) respectively. GDNF also regulates kidney development and spermatogenesis, and it affects alcohol consumption.
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to GDNF. Standards or samples are then added to the appropriate microtiter plate wells with a biotin conjugated antibody preparation specific for GDNF and Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. Then a TMB (3,3',5,5' tetramethyl-benzidine) substrate solution is added to each well. Only those wells that contain GDNF, biotin-conjugated antibody and enzyme-conjugated Avidin 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 GDNF in the samples is then determined by comparing the O.D. of the samples to the standard curve