The effects of telmisartan on insulin-resistant properties and expression of adiponectin receptors (AdipoRs) were investigated. A diabetic rat model was established using a high-fat diet and streptozotocin (25 mg/kg) and primary rat coronary vascular smooth muscle cells (VSMCs) were used to elucidate the underlying mechanisms. The diabetic rats were insulin-resistant and exhibited weight gain, elevated blood pressures, and increased plasma triglyceride levels. These manifestations were ameliorated by elmisartan treatment. Four-week telmisartan therapy increased plasma adiponectin and decreased TNF-alpha expression in the coronary artery. Moreover, telmisartan significantly decreased AdipoR1 and AdipoR2 expression. Using high glucose-treated rat coronary VSMCs, telmisartan and PPAR-gamma agonist GW1929 prominently stimulated PPAR-gamma and decreased TNF-alpha expression. Interestingly, telmisartan or GW1929 also prevented hyperglycemia-induced downregulation of AdipoR1 and AdipoR2 expression. Additionally, GW9662 (PPAR-gamma antagonist) significantly decreased the effects of telmisartan on AdipoR1 and AdipoR2 expression. These results demonstrated that telmisartan effectively ameliorated coronary insulin resistance and inflammation in diabetic rats and upregulated AdipoR1/R2 expression via activation of PPAR-gamma in the coronary artery and VSMCs. (C) 2017 Published by Elsevier Masson SAS.