P-386 - Contribution of perivascular adipose tissue to vascular dysfunction in type 2 diabetes

Abstract

Perivascular adipose tissue (PVAT) surrounds most large blood vessels and plays an important role in vascular homeostasis. The present study was conducted to investigate the contribution of PVATto vascular dysfunction in a rat model of type 2 diabetes (GK) fed with a high-fat diet (HFD). Aortic vascular reactivity was performed in GK, GK fed with HFD and compared with Wistar rats in the absence (PVAT−) or in the presence (PVAT+) of thoracic PVAT. We also measured vascular oxidative stress Endothelium-dependent relaxation to acetylcholine, assessed by wire myography, was impaired in GK and GKHFD rats, not affected by NG-nitro-L-arginine methyl ester, inhibitor of endothelial nitric oxide (NO) synthase, and improved by the antioxidant tempol, suggesting reduced NO bioavailability and increased oxidative stress. Furthermore, vascular superoxide and peroxynitrite production was increased in the vascular wall of diabetic rats. The presence of PVAThad an anti-contractile effect in response to phenylephrine in Wistar rats. In GK rats, the anti-contractile effects of PVAT were lost. Our data suggest that this rat model of type 2 diabetes is associated with perivascular adipose dysfunction, oxidative stress and endothelial dysfunction.