1208-P: Caloric Restriction Modified Factors Regulating Lipid Storage and Apoptosis in Inguinal but Not Epididymal Adipose Tissue of 24-Month-Old Male Rats

Calorie restriction (CR) and the resultant weight-loss are known to improve metabolic health, but the effects of CR on factors regulating white adipose tissue (WAT) metabolic function and remodeling remain unclear. The purpose of this study was to examine the effects of 8 weeks of CR on markers of lipid storage/release, endoplasmic reticulum (ER) stress, and apoptosis in inguinal and epididymal WAT collected from aged rats. We harvested inguinal and epididymal adipose tissue from 24-month-old male Fischer-344 x Brown Norway rats that were either fed an ad libitum chow diet (AL, n=6) or subjected to CR (consuming 35% below AL intake) of the same diet (n=6) for 8 weeks. Using standard immunoblotting methods, inguinal WAT from CR had a greater abundance of phosphorylated hormone sensitive lipase (pHSL) than AL (11.1±6.6 vs. 4.5±3.3 arbitrary units (AU); P=0.05) indicative of elevated lipase activity in CR, and a lower protein abundance of the esterification marker, diacylglycerol acyltransferase (DGAT; 1.0±0.2 vs. 2.4±0.6 AU; P