Molecular mechanisms of conjugated linoleic acid (CLA) on muscle metabolism in adult onset inactivity‐induced obese mice (1045.46)

Abstract

Conjugated linoleic acid (CLA) has been reported to increase voluntary activities in mice. Current study was conducted to investigate how CLA modulates activity levels by determining the molecular targets on skeletal muscle in nescient basic helix‐loop‐helix 2 knock‐out (N2KO) mice, a unique adult‐onset inactivity induced obesity model. 4‐week‐old female N2KO and wild‐type mice were fed either control or CLA containing diet (0.5%) for 10‐weeks. Non‐exercise physical activity (NEPA) was determined biweekly and markers for muscle metabolisms were determined from the gastrocnemius. CLA fed N2KO animals showed significant increase of NEPA (~40%) from 6 weeks compared to controls. The gastrocnemius weights were lower in N2KO animals compared to wild types, while CLA supplementation resulted in heavier the gastrocnemius over controls in N2KO animals. Protein expressions for peroxisome proliferator‐activated receptor‐δ (PPARδ) and peroxisome proliferator‐activated receptor gamma co‐activator 1α (PGC‐1α) in the gastrocnemius were increased in CLA fed N2KO animals compared to controls, 65% and 38% increase, respectively. CLA feeding increased pAMPK/AMPK ratio, 36% increase, compared to controls. These results suggest that CLA act as a potential exercise‐mimetic, resulting in increased voluntary activity and improving muscle metabolisms in both normal and obese animals.