2002 年 14 巻 3 号 p. 183-190
Lipid peroxidation proceeds by a free radical chain reaction yielding lipid hydroperoxides (L-OOH) as the major initial reaction product. Moreover, the unsaturated fatty acids that constitute a large component of a lipid emulsion, such as IntralipidTM, are highly susceptible to peroxidation. To determine the degree of lipid peroxidation in artificial lipid emulsions, we measured the content of triacylglycerol hydroperoxides (TG-OOH) and phospholipid hydroperoxides (PL-OOH) in 10% IntralipidTM solution. The chemiluminescence-based high-performance liquid chromatography (HPLC) assay is the one of the most advanced methods for the direct detection of L-OOH at picomole levels. Using this method, TG-OOH and PL-OOH could be detected in IntralipidTM (166.7±83.9μmol/l and 3.5±2.9μmol/l, respectively) . The concentration of TG-OOH and PL-OOH in IntralipidTM was significantly increased (228.0±106.8μmol/l (p<0.01) and 30.4±14.3μmol/l (p<0.02), respectively), during a 24 h infusion under ambient light and room temperature (26°C) in NICU with a concomitant reduction of emulsion α-tocopherol to 97% (55.9±4.7 mmol/l, p<0.05) compared with baseline levels (57.3±4.3mM) . This observation suggests that endogenous α-tocopherol could not prevent the formation of L-OOH in IntralipidTM over a 24 h period. Thus, it is clear that lipid infusion has greater nutritional advantages for small, premature infants. Furthermore, we should consider that lipid emulsions are prone to peroxidation, and that this may be an important feature of oxidant-associated tissue damage.
