Abstract 552: Enhancement of Rat Lymphatic Lipid Transport by Glucose or Amino Acids Ingestion

Abstract

Objectives: Dietary lipid absorption usually occurs with absorption of other nutrients because lipid is contained in foods fed as a meal. The effect of simultaneously fed carbohydrate and protein on lipid absorption is not clear. In this study, lymphatic lipid transports in the rat intestine were observed during intraduodenal lipid feeding with or without simultaneous feeding of glucose or amino acids. Methods: Mesenteric lymph duct was cannulated in male SD rats and a feeding tube was inserted into the duodenum through the fundus of the stomach. Postoperatively, the rats were intraduodenally infused with saline. On the day after surgery, the saline infusion was replaced by a lipid infusion containing 40 μmol/h (35.4 mg/h) of triolein, 2.74 μmol/h (1.06 mg/h) of cholesterol, 7.8 μmol/h ( 6.08 mg/h) of egg lecithin with 300 mg/h of glucose (the Glucose group), with 150 mg/h of amino acids derived from medical amino acid injections (the Amino Acids group), or without any additive (the Control group). The lipid emulsion was infused at 3mL/h for 8 hours. Results: The amounts of triglyceride transported in lymph for 8 hours were 185 ± 12 (mean ± SE) mg in the Amino Acids group (n=4), 175 ± 3 mg in the Glucose group (n=5), and 147 ± 7 mg in the Control group (n=4), respectively, with a statistically significant difference (p < 0.05) among the groups. The amount of cholesterol transported in lymph for 8 hours were 7.30 ± 0.63 mg in the Amino Acids group, 6.82 ± 0.46 mg in the Glucose group, and 5.96 ± 0.17 mg in the Control group, respectively. The amount of phosphatidylcholine transported in lymph for 8 hours were 16.4 ± 1.0 mg in the Amino Acids group, 15.7 ± 0.4 mg in the Glucose group, and 12.4 ± 0.3 mg in the Control group, respectively, with a statistically significant difference (p < 0.01) among the groups. Conclusions: Simultaneous glucose or amino acids feeding enhanced lymphatic lipid transport in the rat intestine during lipid feeding.