Effect of low and high amounts of a structured lipid containing fish oil on protein metabolism in enterally fed burned rats

To determine the optimal fat intake and source in nutritional support, we measured the protein-sparing effects of a structured lipid (SL) derived from 60% medium-chain triglyceride (MCT) and 40% fish oil and a 50:50 soybean to safflower oil emulsion (long-chain triglyceride, LCT). Male Sprague-Dawley rats received an enteral diet for 7 d with either all non-protein energy as dextrose (control diet) or 10% or 35% nonprotein energy as SL or LCT. The rats were burned on day 3. Indirect calorimetry and nitrogen balance were measured on day 2 (preburn) and days 4 and 6 (postburn). Respiratory quotient decreased postburn. There was a significant increase in total energy expenditure postburn, particularly with 35% LCT. Nitrogen balance was best without fat and 10% fat compared with 35% fat and with SL compared with LCT. These results confirm previous studies that fish oil-containing SLs possess protein-sparing effects in burn injury and that 10% SL seems optimal for nutritional support in burn injury.link_to_subscribed_fulltex

Long-term feeding with structured lipid composed of medium-chain and N-3 fatty acids ameliorates endotoxic shock in guinea pigs

The metabolic and physiologic responses to 7-hour endotoxin infusion (5.0 mg/kg h) were evaluated in guinea pigs following 6 weeks of dietary enrichment with diets containing either chemically structured lipid (SL) composed of medium-chain triglycerides (MCT) and long-chain triglycerides (LCT) in the form of N-3 polyunsaturated fatty acids (PUFAs), or safflower oil (SO), which is high in N-6 fatty acids. Plasma phospholipid fatty acid profiles, arterial blood pH, P(CO2), P(O2), HCO3, lactate, blood pressure, oxygen consumption, and energy expenditure were examined. Plasma phospholipid fatty acids profiles reflected dietary intake with SL-fed animals demonstrating a significantly higher N-3 to N-6 fatty acid ratio compared with SO-fed animals. SL-fed animals responded to endotoxemia with a mild metabolic acidosis with respiratory compensation, which was associated with moderate lactatemia (3 mmol/L). SO-fed animals developed a severe metabolic acidosis with acidemia and respiratory compensation, which was associated with hyperlactatemia (8 mmol/L,P < .05 v SL). No differences were observed in blood pressure, oxygen consumption, energy expenditure, or respiratory guotient during endotoxemia between dietary groups compared with controls. We conclude that diets enriched with structured lipid composed of medium-chain and N-3 fatty acids can attenuate the sequelae of endotoxemia.link_to_subscribed_fulltex