Serotonin levels in platelet-poor plasma and whole blood from healthy subjects: Relationship with lipid markers and coronary heart disease risk score

Aim: 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.