摘要目的 建立一种HPLC测定血清胆固醇酯n-3脂肪酸指数的方法.方法 血清标本来自于70名北京医院健康志愿者和36例冠心病患者,用NaOH乙醇溶液水解血清三酰甘油,乙酸终止水解反应,正己烷提取胆固醇和胆固醇酯,HPLC分离脂质,UV(205 nm)检测.20:5-CE和22:6-CE用液相色谱串联质谱鉴定,各胆固醇酯峰面积修正因子用测定相应组分胆固醇含量的方法确定,归一化法定量,计算n-3脂肪酸胆固醇酯的百分比(即胆固醇酯n-3指数).结果 色谱分析在6 min内完成;影响胆固醇酯n-3指数测定的三酰甘油用4 mol/L NaOH乙醇溶液水解30 s可被去除;测定血清胆固醇酯n-3指数的批内和总CV为0.66%和0.90%,106名试验对象血清胆固醇酯n-3指数略呈正偏态分布(偏度值=1.25,峰度值=1.70),全体中位数为0.98%(0.37%～2.40%).n-3指数对数基本呈正态分布,(x)±s为0.003 7%±0.15%.性别组n-3指数分布与全体类似,女性和男性中位数(范围)分别为1.08%(0.60%～2.40%)和0.95%(0.37%～2.11%),不同性别间差异具有统计学意义(t=-3.021,P=0.003).结论 成功建立了HPLC测定血清胆固醇酯n-3指数的方法,有望在营养监测和心血管病危险分析中发挥作用.

abstractsObjective To develop an HPLC method for the measurement of n-3 fatty acid index of serum cholesteryl esters.Methods Serum triglycerides were hydrolyzed with ethanolic sodium hydroxide and cholesteryl esters (CEs) were extracted with hexane.The extracted CEs were analyzed by reversed phase HPLC with a UV detection at 205 nm.Cholesteryl eicosapentaenoate and docosahexaenoate ( major n-3 fatty acid cholesteryl esters) were identified by liquid chromatography-tandem mass spectrometry and cholesterol in each CE fraction was measured.Peak areas of CEs were corrected for cholesterol and CE n-3 index was calculated using the corrected peak area and expressed as the percentage of n-3 fatty acid CEs in total CEs.Results The HPLC analysis can be finished in 6 minutes.Triglycerides which interfere with the determination of n-3 fatty acid index, were hydrolyzed with ethanolic sodium hydroxide (4 mol/L) in 30 seconds.The within-run and total CVs for CE n-3 index averaged 0.66% and 0.90%, respectively.CE n-3 indexes of 70 volunteers and 36 coronary heart disease patients apparently healthy subjects and patients with coronary heart disease in Beijing Hospital appeared to be positively skewed and leptokurtic distribution ( skewness = 1.25, kurtosis = 1.70 ).The median of n-3 indices were 0.98% ( 0.37% - 2.40% ).The logarithm of n-3 index appeared to be normal distribution and the average is 0.003 7% with standard deviations of 0.15.The distribution of n-3 indices of gender groups was similar with the total.The medians of females and males were 1.08% (0.60% -2.40%) and 0.95% (0.37% -2.11%) respectively, and the former were significantly higher than the latter( t = - 3.021, P = 0.003 ).Conclusion A new method for the measurement of n-3 index of serum cholesteryl esters by HPLC has been established.It is simple and precise and can be used in predicting cardiovascular diseases risks and monitoring dietary intake of n-3 fatty acids.