title: Chromatographic evidence for the existence of another species of luteinizing hormone-releasing factor (LRF).
abstract: Fractionation of ultrafiltrates of rat hypothalamic extracts has been performed on Sephadex LH-20 in dimethylformamide/water. The fractions were examined for their content of luteinizing hormone-releasing activity by bioassay in vitro utilizing LH radioimmunoassay, and also for their content of LRF decapeptide-like material by direct radioimmunoassay. Each method revealed the same pattern of activity. This consisted of a major peak whose elution position coincided with that of authentic decapeptide, and a minor region which closely preceded it, often taking the form of a shoulder on the leading edge of the main peak. The active component in the minor peak could be completely resolved by repeated filtration in the same system thus indicating that it represented another gonadotropin-releasing species rather than a chromatographic artefact although its biological and immunological activities indicate that its structure must resemble closely that of the decapeptide.
mesh_terms: D001681:Biological Assay; D002850:Chromatography, Gel; D007987:Gonadotropin-Releasing Hormone / Q000302:isolation & purification / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism*; D011863:Radioimmunoassay
chemical_list: D007987:Gonadotropin-Releasing Hormone