Effect of dietary n-3 fatty acids and γ-linolenic acid on protein metabolism in the thermally injured rat

In this study, it is determined what the effect of dietary n-3 fatty acids found in fish oil and γ-linolenic acid found in borage oil is on protein metabolism in burned rats given endotoxin versus feeding a more traditional corn oil-based diet. Animals were given a non- lethal, anesthetizing scald burn encompassing 30% of total body surface area and immediately injected IP with 1 mg/kg S. enteritidis endotoxin. Rats were then fed via gastrostomy isocaloric, isovolemic diets containing high amounts of either fish and borage oil or corn oil for 3 days. Tolerance to each diet formula was monitored throughout the 72 hour feeding period. On day three, whole-body leucine kinetics was measured, as well as fractional synthetic rates of protein in liver and rectus muscle. In burned rats given endotoxin, there was no significant (p ≤ 0.05) difference between diet groups in either leucine kinetics or fractional protein synthetic rates (FSR) in liver or rectus muscle. However, burned animals had significantly better gastrointestinal tolerance to the diet containing fish and borage oil than to the corn oil-based diet. This study shows that although there may be no difference in whole-body protein kinetics and fractional protein synthetic rates in liver and muscle between burned rats enterally fed fish and borage oil or corn oil-based diets for 3 days, these animals did tolerate the fish and borage oil formula much better than the corn oil diet, which may have important implications in improving the tolerance of critically injured patients to enteral feeding.