Eeffects in Obese Hyperinsulinemic FA/FA Zucker Rats
The effects of dietary CLA on glucose tolerance and obesity were examined in the fa/fa Zucker rat, a model of obesity and insulin resistance. Weanling lean and fa/fa male Zucker rats were fed a 1.5% CLA mixture (lnCLA and faCLA groups) or control diet (lnCTL and faCTL groups) for 8 weeks. Despite similar body weight and fat pad weights, faCLA rats had lower serum leptin concentrations, reduced leptin mRNA levels in fat tissue and smaller adipocyte diameters than faCTL rats. Oral glucose tolerance was improved in faCLA rats based on lower serum glucose concentrations (12.8+1.2 vs 16.6+0.7 mM at 30 min, P<0.05) and insulin concentrations (P<0.05 at 0, 15, 30 and 60 min), and smaller area under the curve for glucose and insulin. Futhermore, the faCLA rats had smaller pancreatic b-cell diameters, and reduced fasting serum concentrations of insulin and C-peptide (34%-46% of faCLA rats, respectively). In summary, the dietary CLA mixture significantly improved oral glucose tolerance, attenuated hyperinsulinemia, and altered leptin metabolism in fa/fa Zucker rats wihtout affecting body weight or fat pad weight.
Funding from Dairy farmers of Canada and NSERC, CRDP