Influence of different dietary fats on triacylglycerol deposition in rat adipose tissue

It has been demonstrated that triacylglycerol (TAG) mobilization from adipo se tissue is selective and depends on fatty acid (FA) chain length, unsatur ation and positional isomerism. The present study was performed to determin e the influence of dietary fat on the composition of TAG stored in rat peri renal and subcutaneous adipose tissues. These results may provide informati on on the susceptibility of stored TAG to hydrolysis and further mobilizati on, and may help to establish an interrelationship between dietary composit ion and the FA efflux from adipose tissue. TAG molecular species and FA com position were determined by HPLC and GLC respectively. No significant diffe rences were found in either FA or TAG composition between perirenal and sub cutaneous adipose depots. The major FA in the dietary fats were present in the adipose tissues of the animals; in most cases, in similar proportions. However, differences were found between dietary and adipose tissue content of minor FA, which suggests that dietary FA composition is altered between ingestion and deposition in adipose tissue. The TAG molecular species of ra t adipose tissue were enriched with the FA characteristic of each dietary f at. Dietary sunflower oil was responsible for enrichment with the most pola r TAG. This finding may suggest easier mobilization of stored TAG. In concl usion, the process of fatty acid and TAG deposition in rat adipose tissue i s selective, and depends on the composition of the diet.