title: Serotonin levels in platelet-poor plasma and whole blood from healthy subjects: relationship with lipid markers and coronary heart disease risk score.
abstract: OBJECTIVE
  The serotonin level in platelet-poor plasma (PPP) is an important clinical marker for monitoring platelet activation accompanying vascular endothelial injury. We previously developed an HPLC method that combines column-switching with a post-column reaction to measure serotonin in PPP. This study determined serotonin levels in healthy volunteers and evaluated the possible relationship of serotonin levels with lipid markers and Framingham 10-year risk scores (FRS) for coronary heart disease.
  
  
  METHODS
  Serotonin was isolated from samples using our HPLC method and converted into a fluorescent derivative with benzylamine for specific and sensitive detection. Lipid fractionation was also performed by HPLC. FRS was calculated using the following: age, sex, LDL cholesterol, HDL cholesterol, blood pressure, and smoking and diabetes status.
  
  
  RESULTS
  The PPP serotonin to whole blood serotonin ratio (PPP/WB) and the PPP serotonin level correlated significantly with HDL cholesterol levels: r= 0.187, p< 0.05 and r= 0.184, p< 0.05, respectively. The PPP/WB ratio also correlated significantly with FRS (r= 0.176, p< 0.05). The reference range (95% confidence interval) of PPP and WB serotonin levels in healthy subjects were 0.86-16.96 and 385-1319 nmol/L, respectively.
  
  
  CONCLUSIONS
  Significant positive correlations between the serotonin PPP/WB ratio and FRS suggest that the PPP/WB ratio can serve as a biomarker for estimating atherosclerotic cardiovascular risk.
authors.affiliation: Bioscience Division, TOSOH Corp., Kanagawa, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hirowatari
authors.forename: Katsuko
authors.initials: K
authors.lastname: Hara
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shimura
authors.forename: Hakuo
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood*; D001792:Blood Platelets / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003327:Coronary Disease / Q000097:blood*; D006801:Humans; D008055:Lipids / Q000097:blood*; D008875:Middle Aged; D012016:Reference Values; D012307:Risk Factors; D012701:Serotonin / Q000097:blood*
chemical_list: D015415:Biomarkers; D008055:Lipids; D012701:Serotonin