Tesaglitazar, a dual PPAR{alpha}/{gamma} agonist, ameliorates glucose and lipid intolerance in obese Zucker rats

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology integrative and comparative physiology, 2005-10, Vol.289 (4), p.R938-R946
• Main Authors: Oakes, Nicholas D, Thalen, Pia, Hultstrand, Therese, Jacinto, Severina, Camejo, German, Wallin, Boel, Ljung, Bengt
• Format: Article
• Language: English
• Subjects: Administration, Oral; Alkanesulfonates - administration & dosage; Animals; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Glucose - administration & dosage; Glucose - metabolism; Insulin Resistance; Lipid Metabolism; Lipids - administration & dosage; Liver - drug effects; Liver - metabolism; Metabolic Syndrome - drug therapy; Metabolic Syndrome - metabolism; Obesity - drug therapy; Obesity - metabolism; Phenylpropionates - administration & dosage; PPAR alpha - agonists; PPAR gamma - agonists; Rats; Rats, Zucker; Treatment Outcome; Triglycerides - metabolism
• ISSN: 0363-6119; 1522-1490
• DOI: 10.1152/ajpregu.00252.2005

AstraZeneca R&D, Research Area CV/GI, Mölndal, Sweden Submitted 12 April 2005 ; accepted in final form 8 June 2005 Insulin resistance, impaired glucose tolerance, high circulating levels of free fatty acids (FFA), and postprandial hyperlipidemia are associated with the metabolic syndrome, which has been linked to increased risk of cardiovascular disease. We studied the metabolic responses to an oral glucose/triglyceride (TG) (1.7/2.0 g/kg lean body mass) load in three groups of conscious 7-h fasted Zucker rats: lean healthy controls, obese insulin-resistant/dyslipidemic controls, and obese rats treated with the dual peroxisome proliferator-activated receptor / agonist, tesaglitazar, 3 µmol·kg –1 ·day –1 for 4 wk. Untreated obese Zucker rats displayed marked insulin resistance, as well as glucose and lipid intolerance in response to the glucose/TG load. The 2-h postload area under the curve values were greater for glucose (+19%), insulin (+849%), FFA (+53%), and TG (+413%) compared with untreated lean controls. Treatment with tesaglitazar lowered fasting plasma glucose, improved glucose tolerance, substantially reduced fasting and postload insulin levels, and markedly lowered fasting TG and improved lipid tolerance. Fasting FFA were not affected, but postprandial FFA suppression was restored to levels seen in lean controls. Mechanisms of tesaglitazar-induced lowering of plasma TG were studied separately using the Triton WR1339 method. In anesthetized, 5-h fasted, obese Zucker rats, tesaglitazar reduced hepatic TG secretion by 47%, increased plasma TG clearance by 490%, and reduced very low-density lipoprotein (VLDL) apolipoprotein CIII content by 86%, compared with obese controls. In conclusion, the glucose/lipid tolerance test in obese Zucker rats appears to be a useful model of the metabolic syndrome that can be used to evaluate therapeutic effects on impaired postprandial glucose and lipid metabolism. The present work demonstrates that tesaglitazar ameliorates these abnormalities and enhances insulin sensitivity in this animal model. in vivo; metabolism; liver; triglyceride Address for reprint requests and other correspondence: Nick Oakes, AstraZeneca R&D Mölndal, S-431 83 Mölndal, Sweden (e-mail: Nick.Oakes{at}astrazeneca.com )