Studies on the Elimination of Exogenous Lipids from the Blood Stream The Kinetics of the Elimination of a Fat Emulsion Studied by a Constant Infusion Technique in Man

Hallberg, D. Studies on the elimination of exogenous lipids from the blood stream. The kinetics of the elimination of a fat emulsion studied by a constant infusion technique in man. Acta physiol. scand. 1965. 64 . 299–305. – The earlier described kinetic principle for the elimination of a fat emulsion (Intralipid®) from the circulation studied after single injections was confirmed in this study, using a constant infusion technique. A primer dose of the fat emulsion, followed by a constant infusion, was given. The plasma triglyceride (TG) level was followed. The emulsion TG fraction in plasma was separated from endogenous plasma TG with a polyvinylpyrrolidone density gradient. At low infusion rates there was a constant TG level in the top fraction of the gradient containing the emulsion TG, indicating a first order removal. At high infusion rates there was a linearly increasing TG concentration in the top fraction, indicating a zero order removal. The data confirm equivocally the kinetic principle described earlier which consists of a maximal elimination capacity (zero order kinetic) at high concentrations and an exponential elimination rate (first order kinetic) at low concentrations. During the elimination of the emulsion TG fraction from the circulation changes were noted in the concentrations of the other TG fractions in plasma. Some data on these changes are also presented.