title: A specific radioimmunoassay for [Leu] and [Met]enkephalin applied to a HPLC separation of human CSF.
abstract: Highly specific antisera have been raised to [Leu]enkephalin and applied in a radioimmunoassay that is sufficiently sensitive and precise for the measurement of enkephalin pentapeptides in body fluids. Extraction of CSF by Sep-pak cartridges, followed by reverse-phase HPLC to separate [Leu] and [Met]enkephalin prior to assay, has assessed their concentrations as 59-170 pmol/l and 0.5-30 pmol/l, respectively, in three patients with chronic pain. The reproducibility of the HPLC separation step was checked by adding to the sample a synthetic analogue of very low cross-reactivity in UV detectable quantities. The assay procedure described is generally applicable to the assessment of [Leu] and [Met]enkephalin concentrations in CSF.
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003429:Cross Reactions; D004743:Enkephalin, Leucine / Q000134:cerebrospinal fluid*; D004744:Enkephalin, Methionine / Q000134:cerebrospinal fluid*; D006801:Humans; D007016:Hypophysectomy; D007106:Immune Sera; D009369:Neoplasms / Q000503:physiopathology; D010148:Intractable Pain / Q000134:cerebrospinal fluid; D011863:Radioimmunoassay / Q000379:methods
chemical_list: D007106:Immune Sera; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine