Determination of splanchnic secretion rate of plasma triglycerides and of total and splanchnic turnover of plasma free fatty acids in man.

Abstract

Abstract. A method has been developed whereby the splanchnic secretion rate of plasma triglycerides (TG) and the splanchnic uptake and mobilization of plasma free fatty acids (FFA) can be measured in man. The method includes constant intravenous infusion of albumin‐bound 3H‐labelled palmitate, and simultaneous sampling of blood from the hepatic vein and an artery.The methodological problems associated with the quantitative determination of the small hepatio venous‐arterial differences of labelled and unlabelled plasma TG and FFA have been studied. By performing ten estimates on each hepatic vein and arterial sample, analytical precision was increased sufficiently to detect significant hepatic venous‐arterial differences in TG concentration and radioactivity.The splanchnic secretion rates of labelled plasma TG were found to be constant 3 hours after beginning the continous infusion of the precursor 3H‐palmitate. The plasma TG turnover was calculated according to three different methods: the chemical, the isotope and the plasma TG clearance methods. The mean values and standard deviations of the three methods were 59 ± 105, 29 ± 12 and 37 ± 22 μmoles/min.The splanchnic uptake of plasma FFA was estimated to be between 225 and 269 μmoles/min and the splanchnic mobilization of plasma FFA was between 76 and 120 μmoles/min.