High saturated fat diet alters skeletal muscle phospholipid composition and increases SERCA activity (895.2)

Abstract

Sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) is a transmembrane protein whose activity is, in part, dependent on its lipid environment. Past studies using synthetic membranes have demonstrated that 20‐22 carbon long monounsaturated fatty acids are associated with maximal SERCA activity. However, this association has not been examined in biological membranes. Thus, the objective of this study was to examine this association in a biological system and the response to high saturated fat (HSF) diet‐mediated membrane alterations in skeletal muscle. Female Wistar rats (28 days old) were fed control (CON; AIN93G, 7% soybean oil by weight) or HSF (AIN93G, 20% lard by weight) diet for 16 weeks. Mixed hind limb muscle phospholipids from rats fed a HSF diet had lower percent mole fraction of polyunsaturated fatty acids, unsaturation index (UI), and average chain length (ACL); and higher saturated fatty acids and SERCA activity compared to CON (p<0.05). Correlation analysis demonstrated ACL (R2= 0.83, p < 0.05) and UI (R2=0.53, p = 0.062) were negatively correlated with SERCA activity. These results suggest that SERCA activity may be influenced by phospholipid composition in biological membranes differently than in synthetic membranes. Future studies will examine the lipid annulus closely associated with SERCA.Grant Funding Source: Supported by Natural Sciences and Engineering Research Council (NSERC)