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PPAR Research
Volume 2013 (2013), Article ID 305347, 14 pages
http://dx.doi.org/10.1155/2013/305347
Research Article

The PPARα/γ Agonist, Tesaglitazar, Improves Insulin Mediated Switching of Tissue Glucose and Free Fatty Acid Utilization In Vivo in the Obese Zucker Rat

AstraZeneca R&D Mölndal, 431 83 Mölndal, Sweden

Received 1 July 2013; Revised 27 August 2013; Accepted 27 August 2013

Academic Editor: Brian Finck

Copyright © 2013 Kristina Wallenius et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Metabolic flexibility was assessed in male Zucker rats: lean controls, obese controls, and obese rats treated with the dual peroxisome proliferator activated receptor (PPAR) agonist, tesaglitazar, 3 μmol/kg/day for 3 weeks. Whole body glucose disposal rate ( ) and hepatic glucose output (HGO) were assessed under basal fasting and hyperinsulinemic isoglycemic clamp conditions using [3,3H]glucose. Indices of tissue specific glucose utilization ( ) were measured at basal, physiological, and supraphysiological levels of insulinemia using 2-deoxy-D-[2,6-3H]glucose. Finally, whole body and tissue specific FFA and glucose utilization and metabolic fate were evaluated under basal and hyperinsulinemic conditions using a combination of [U-13C]glucose, 2-deoxy-D-[U-14C]glucose, [U-14C]palmitate, and [9,10-3H]-(R)-bromopalmitate. Tesaglitazar improved whole body insulin action by greater suppression of HGO and stimulation of compared to obese controls. This involved increased insulin stimulation of in fat and skeletal muscle as well as increased glycogen synthesis. Tesaglitazar dramatically improved insulin mediated suppression of plasma FFA level, whole body turnover ( ), and muscle, liver, and fat utilization. At basal insulin levels, tesaglitazar failed to lower HGO or compared to obese controls. In conclusion, the results demonstrate that tesaglitazar has a remarkable ability to improve insulin mediated control of glucose and FFA fluxes in obese Zucker rats.