title: High-performance liquid chromatographic analysis with diode-array detection of bradykinin, neuropeptide K, and substance P in human plasma.
abstract: A method is described for the determination of bradykinin, neuropeptide K (NPK), and substance P in patients with atypical carcinoid syndrome. The developed method uses a combination of conventional and solid-phase extraction as well as high-performance liquid chromatographic techniques. A narrow-bore C18 column with ultraviolet detection is used (200 nm). The technique recovers bradykinin at a level of 98%, NPK at 96%, and substance P at 98% (when pure standards are dissolved) at concentration levels relevant to the atypical carcinoid syndrome. In biological samples, the recovery rate of bradykinin, NPK, and substance P drops to 88, 86, and 88% respectively. The overall analysis time is 150 min from receipt of samples. This method proves to be a valuable tool in the identification of neuropeptides and thus the diagnosis of atypical carcinoid syndrome, especially in puzzling cases with nonspecific symptoms.
authors.affiliation: Department of Chemistry and Physics, Technikon Pretoria, South Africa.
authors.forename: S M
authors.initials: SM
authors.lastname: Lehmann
authors.forename: W H
authors.initials: WH
authors.lastname: de Beer
mesh_terms: D001920:Bradykinin / Q000097:blood*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D009479:Neuropeptides / Q000097:blood*; D010949:Plasma / Q000737:chemistry*; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet; D013373:Substance P / Q000097:blood*; D015320:Tachykinins
chemical_list: D009479:Neuropeptides; D015320:Tachykinins; C045206:neuropeptide K; D013373:Substance P; D001920:Bradykinin