TRH immunoreactivity in rat brain regions, spinal cord and pancreas: validation by high-pressure liquid chromatography and thin-layer chromatography.
Thyrotropin-releasing hormone (TRH) immunoreactivity in rat tissue was assayed using a new reversed-phase, ion-pair, high-pressure liquid chromatography (HPLC) method for separating TRH from its analogs. Virtually all of the TRH immunoreactivity in hypothalamus, brain stem, preoptic area, septum, striatum, frontal cortex, spinal cord and pancreas had chromatographic characteristics corresponding to those of synthetic TRH. When analyzed by two additional, previously described HPLC methods for neuropeptides, all TRH immunoreactivity in rat brain, spinal cord and pancreas also behaved identically to that of authentic TRH. Similarly, in two different thin-layer chromatography systems, all TRH immunoreactivity migrated with that of synthetic TRH. We conclude that TRH-immunoreactive material in rat brain, spinal cord and pancreas really is TRH. The perhaps surprising specificity of the TRH immunoassay may occur because antibodies directed against TRH (pyroglutamyl-histidyl-prolineamide) recognize two atypical amino acids in close proximity.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D001933:Brain Stem / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003342:Corpus Striatum / Q000378:metabolism; D005625:Frontal Lobe / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism; D010179:Pancreas / Q000378:metabolism*; D051381:Rats; D013116:Spinal Cord / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism*
D013973:Thyrotropin-Releasing Hormone