title: Development of an enzymatic assay for sphingomyelin with rapid and automatable performances: Analysis in healthy subjects and coronary heart disease patients.
abstract: BACKGROUND
  Sphingomyelin (SM) is an important choline group-containing phospholipid and is considered to be an independent risk factor for coronary heart disease.
  
  
  METHODS
  We have developed a specific enzymatic assay for SM measurement with rapid and automatable performances by using two-reagent system involving sphingomyelinase. We performed within-run and between-run precision, linearity test, detection limit, recovery test and interference to validate this assay. Then, we measured the serum SM concentration in 194 healthy subjects and 141 consecutive patients undergoing coronary angiography.
  
  
  RESULTS
  The within-run and between-run coefficients of variation for SM concentrations were 1.1-1.3% and 1.0-1.2%, respectively. Quantitative measurements to a lower limit of 30 μmol/L were shown to be possible. The recoveries of the exogenously added SM to the control samples were 98.7%-101.5%. No effect was observed after the addition of some interference materials. The mean ± SD of the serum SM concentration in the 194 healthy subjects was 553.3 ± 100.1 μmol/L. We found that the SM concentration was significantly higher among an acute coronary syndrome subjects than among the healthy subjects (P<0.01) and that the serum SM concentrations were significantly correlated with the serum magnesium concentration.
  
  
  CONCLUSIONS
  We have developed a rapid and automatable enzymatic assay for SM that enables the automatic measurement of choline-containing phospholipids. This assay may be useful for various types of biochemical and clinical research.
authors: Department of Clinical Laboratory, The University of Tokyo Hospital, Tokyo, Japan.
authors: Ryunosuke
authors: R
authors: Ohkawa
authors: Tatsuya
authors: T
authors: Kishimoto
authors: Makoto
authors: M
authors: Kurano
authors: Tomotaka
authors: T
authors: Dohi
authors: Katsumi
authors: K
authors: Miyauchi
authors: Hiroyuki
authors: H
authors: Daida
authors: Mika
authors: M
authors: Nagasaki
authors: Kansei
authors: K
authors: Uno
authors: Naoto
authors: N
authors: Hayashi
authors: Noboru
authors: N
authors: Sakai
authors: Naoto
authors: N
authors: Matsuyama
authors: Takahiro
authors: T
authors: Nojiri
authors: Kazuhiro
authors: K
authors: Nakamura
authors: Shigeo
authors: S
authors: Okubo
authors: Hiromitsu
authors: H
authors: Yokota
authors: Hitoshi
authors: H
authors: Ikeda
authors: Yutaka
authors: Y
authors: Yatomi
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000097:blood; D054058:Acute Coronary Syndrome / Q000097:blood*; D000704:Analysis of Variance; D060050:Angina, Stable / Q000097:blood*; D002138:Calibration; D016022:Case-Control Studies; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003324:Coronary Artery Disease / Q000097:blood*; D057075:Enzyme Assays / Q000592:standards*; D005260:Female; D006801:Humans; D057230:Limit of Detection; D008244:Lysophosphatidylcholines / Q000097:blood; D008274:Magnesium / Q000097:blood; D008297:Male; D012015:Reference Standards; D013109:Sphingomyelins / Q000097:blood*
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008244:Lysophosphatidylcholines; D013109:Sphingomyelins; C006065:We 201; D015060:1,2-Dipalmitoylphosphatidylcholine; D008274:Magnesium