High‐fat diet alters serum fatty acid profiles in obesity prone rats: implications for in‐vitro studies

Abstract

High‐fat diet (HFD) feeding is commonly used in animal models to induce obesity and metabolic diseases. However, the effect of HFD on serum fatty acid profiles remains unclear. Changes in serum fatty acid profiles due to HFD may be a factor in lipotoxicity in various organs. Historically, in vitro studies have utilized individual non‐esterified fatty acids (NEFA) to study lipid exposure, potentially ignoring the importance of fatty acid combinations on cellular lipid metabolism.OBJECTIVETo create a physiological relevant fatty acid mixture to investigate lipid exposure in a cell culture system.METHODSObesity prone rats were fed a HFD (60% en fat) or a control diet (10% en fat) for 2 weeks; portal and systemic blood samples were collected. Triglycerides (TG) and NEFA were extracted and analyzed using gas chromatography.RESULTSBoth systemic and portal serum TG were ~40% lower in HFD. In the control, monounsaturated fatty acids (MUFAs) were the predominant fatty acids in serum TG, whereas polyunsaturated fatty acids (PUFAs) were the dominant fatty acids in the HFD group. Serum NEFA levels were not affected by diet.CONCLUSIONHFD alters serum fatty acid composition of TG from one where MUFAs predominant to PUFAs in rats. A more physiologically relevant fatty acid mixture to mimic HFD conditions for in vitro studies may include increased PUFAs relative to saturated fatty acids and MUFAs. Support: R01DK088940 (JPT)