Effects of specific conjugated linoleic acid (CLA) isomers on insulin resistance, and skeletal muscle AMP-activated protein kinase-alpha (AMPK-alpha) in fa/fa and lean Zucker rats

Conjugated linoleic acid (CLA) has been observed to reduce insulin resistance by improving glucose tolerance and reducing serum triglycerides and serum free fatty acids in certain animal models. Similarly, AMP-activated protein-kinase (AMPK) has been observed to mediate the action of antidiabetic drugs such as metformin and rosiglitazone by improving insulin resistance in animal models of Type 2 diabetes and obesity.; We hypothesized that CLA would improve insulin sensitivity in the fa/fa Zucker rat by increasing skeletal muscle AMPK-alpha protein levels and activation, and concomitantly reducing TNF-alpha protein levels in skeletal muscle. Thus, the main objective of this study was to investigate the effects of an 8 week dietary supplementation with cis9, trans11 (c9,t11) and trans10,cis12 (t10,c12) CLA isomers, individually and in combination, on glycemic control, hyperlipidemia, skeletal muscle AMPK-alpha protein levels and activation, and TNF-alpha protein levels in fa/fa and lean Zucker rats. (Abstract shortened by UMI.)...