Increased lymphatic lipid transport in genetically diabetic obese rats

Otsuka Long-Evans Tokushima fatty (OLETF) rats are a model for noninsulin-dependent diabetes mellitus (NIDDM), which is first manifested at 18 wk of age. We assessed age-related changes in lymphatic lipid transport in the intestine of OLETF rats and compared them with those of control Long-Evans Tokushima Otsuka (LETO) rats. Olive oil was infused into the rats with a mesenteric lymph fistula, which was created under ethrane anesthesia. A significant increase in lymphatic triglyceride (TG) transport in OLETF rats was observed at 18-19 wk compared with under 17 wk, but no age-related change was observed in LETO rats. Food restriction, exercise training, or troglitazone treatment in OLETF rats prevented the age-related increase in lipid transport. Biliary phosphatidylcholine concentration was higher in OLETF rats than in LETO rats, but no difference was seen in bile acid concentrations or the activity of microsomal TG transfer protein between the two strains. This study shows that increased lipid transport in the intestine may occur in NIDDM.