Application of high-performance liquid chromatography of plasma fatty acids as their phenacyl eaters to evaluate splanchnic and renal fatty acid balance in vivo

Plasma fatty acids from renal and hepatic veins, and arterialized hand vein obtained in 20 subjects before and after insulin infusion were separated b y reversed-phase high-performance liquid chromatography following phenacyl esterification. Separation and quantification over the range 1.0-100 nmol p er injection of nine fatty acids was achieved within 60 min using [H-2(31)] palmitic acid as internal standard. Analytical recoveries were greater than 90% and the intra- and inter-assay coefficients of variation were less tha n 2.5 and 4.0%, respectively. Following insulin infusion, net splanchnic up take of total fatty acids decreased from 3.0+/-0.3 to 1.0+/-0.1 mu mol/kg m in (p<0.01), whereas net renal balance remained neutral (-0.04+/-0.04 vs. - 0.06+/-0.03 mu mol/kg min, p=N.S.). Individual fatty acid balance varied fr om a low of 0.012+/-0.005 (myristic acid) to a high of 0.95+/-0.08 (oleic a cid) mu mol/kg min across the splanchnic tissues and from 0.005+/-0.002 (st earic acid) to 0.21+/-0.1 (oleic acid) mu mol/kg min across the kidney. The re is a substantial diversity in changes in plasma concentration and region al balance of individual fatty acid during short-term fasting and hyperinsu linemia. This method is simple, accurate, and can be applied to assess indi vidual fatty acid metabolism in vivo. (C) 1999 Elsevier Science B.V. All ri ghts reserved.