Short-term administration of conjugated linoleic acid reduces liver triglyceride concentration and phosphatidate phosphohydrolase activity in OLETF rats.
The present study explored the short-term effects of dietary conjugated-linoleic acid (CLA) on liver lipid metabolism in starved/refed Otsuka Long Evans Tokushima Fatty (OLETF) rats. Male OLETF rats (12 weeks old) were starved for 24 hours, then refed for 48 hours with either a CLA diet [7.5% CLA and 7.5% Safflower oil (SAF)] or a SAF control diet (15% SAF). The results demonstrated a 30% reduction of hepatic triglyceride (TG) concentration in the CLA group when compared to the control group. Liver cholesterol concentration was also 26% lower in the CLA fed rats. The activity of mitochondrial carnitine palmitoyltransferase, the rate-limiting enzyme of fatty acid oxidation, was moderately elevated by 1.2-fold in the livers of the CLA group when compared to the control. In contrast, phosphatidate phosphohydrolase, the rate-limiting enzyme for TG synthesis, was found to be 20% lower in the livers of the CLA-fed rats. Therefore, dietary CLA evidently lowers liver lipid concentrations through a reduced TG synthesis and enhanced fatty acid oxidation in starved/refed OLETF rats.
D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000628:therapy; D004041:Dietary Fats / Q000494:pharmacology*; D004195:Disease Models, Animal; D005502:Food; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D019787:Linoleic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008291:Malate Dehydrogenase / Q000378:metabolism; D008297:Male; D010711:Phosphatidate Phosphatase / Q000378:metabolism*; D051381:Rats; D020334:Rats, Inbred OLETF; D013217:Starvation; D014280:Triglycerides / Q000378:metabolism*
D004041:Dietary Fats; D014280:Triglycerides; D019787:Linoleic Acid; D008291:Malate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D002334:Carnitine O-Palmitoyltransferase; D010711:Phosphatidate Phosphatase