PPARγ agonists diminish serum VEGF elevation in diet-induced insulin resistant SD rats and ZDF rats

Abstract

We investigated the effect of peroxisome proliferator-activated receptor gamma (PPARγ) agonists on serum vascular endothelial growth factor (VEGF) in diet-induced insulin resistant SD rats and ZDF rats. SD rats fed a high fat/sucrose diet showed increases in serum insulin and VEGF (both p < 0.01). Treatment with a PPARγ agonist GI262570 normalized the diet-elevated insulin and VEGF (both p < 0.01). There was a positive correlation between serum insulin and VEGF ( p < 0.05) in SD rats. ZDF rats had higher serum glucose, insulin, and VEGF than Zucker lean rats (all p < 0.01). Treatment of ZDF rats with PPARγ agonist pioglitazone decreased serum glucose and VEGF (both p < 0.01). There was a positive correlation between glucose and VEGF in ZDF rats ( p < 0.05). In 3T3-L1 adipocytes, GI262570 did not affect insulin-stimulated VEGF secretion. These studies demonstrated that hyperinsulinemia in SD rats and hyperglycemia in ZDF rats were associated with increased serum VEGF; PPARγ agonists normalized serum insulin, glucose, and VEGF, but did not affect VEGF secretion in vitro.