Clinical tolerance and metabolism of a fat emulsion containing carnitine and gamma-linolenic acid.

The purpose of the present study was to study the metabolism and evaluate the tolerance of a new fat emulsion, which is rich in gamma-linolenic acid and has been supplemented with carnitine. 24 adult male volunteers participated in an open, randomised, crossover study where half of the subjects were given Intralipid 20% (IL) on day one followed by administration of the supplemented fat emulsion (FE) on day two, the other half being treated in the reverse order. Both fat emulsions were first administered as a bolus dose of 0.10 g triglycerides per kg BW (an intravenous fat tolerance test) followed 40 min later by a continuous intravenous infusion during 4 h at a rate of 0.21 g triglycerides per min. The plasma fractional elimination rate, k(2)-value, was lower for FE than for IL (4.6 +/- 1.8 vs 5.3 +/- 1.6% per min, P < 0.05, mean +/- SD). Infusion of FE, as distinct from IL administration, was accompanied by a marked increase in serum gamma-linolenic acid concentration (239 +/- 133 vs 0 +/- 11 mumol/l, P < 0.05). No differences between FE and IL were discernible regarding the serum concentrations of dihomo-gamma linolenic acid (C 20: 3omega6), arachidonic acid (C 20: 4omega6), adrenic acid (C 22: 4omega6) or docosapentanaenoic acid (C 22: 5omega6). Leucocyte chemotaxis and random migration increased, 0.5 +/- 0.3 arb. units (P < 0.01) and 0.2 +/- 0.2 arb. units (P < 0.05), during infusion of FE but no such effect was noted during IL administration. No effect of the fat emulsion composition and carnitine was detected on phagocytosis and oxidative metabolism of neutrophil leucocytes. In conclusion, the new fat emulsion containing a relatively high proportion of gammalinolenic acid and supplemented with carnitine was found to be well tolerated although it was eliminated from plasma at a 13% slower rate. The supplemented fat emulsion had a moderate stimulatory effect on leukocyte chemotaxis.