Reduced hepatocyte fatty acid oxidation in outbred rats prescreened for susceptibility to diet-induced obesity.
Rats vary in their propensity to become obese when eating a high-fat diet, but the factors that make some rats susceptible and others resistant to diet-induced obesity are unclear. Recent studies show that rats predisposed to diet-induced obesity have a preexisting deficit in fat oxidation and suggest that this impairment is due in part to reduced fatty acid oxidation in liver. To determine directly whether rats susceptible to diet-induced obesity are less able to oxidize fatty acids in liver, we measured palmitate oxidation in hepatocytes isolated from outbred Sprague-Dawley rats that were identified while still eating a low-fat diet as obesity-prone or obesity-resistant by using a new screening procedure based on the change in plasma triglyceride concentration produced by an intragastric load of a fat and carbohydrate mixture. The results showed that hepatocytes from rats thus identified as obesity-prone oxidized 44% less palmitate in vitro than did those from obesity-resistant rats. This difference in hepatocyte fatty acid oxidation is consistent with and may explain at least in part the reduced capacity of obesity-prone rats to oxidize fat.
Ji
H
H
Monell Chemical Senses Center, Philadelphia, PA 19104, USA.
Friedman
M I
MI
D000818:Animals; D002478:Cells, Cultured; D004032:Diet / Q000009:adverse effects; D020022:Genetic Predisposition to Disease; D022781:Hepatocytes / Q000378:metabolism*; D008297:Male; D009765:Obesity / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D010168:Palmitates / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014280:Triglycerides / Q000097:blood
D010168:Palmitates; D014280:Triglycerides