Uncoupling of Endothelial Nitric Oxide Synthase in Perivascular Adipose Tissue of Diet-Induced Obese Mice

Arterioscler Thromb Vasc Biol. 2016 Jan;36(1):78-85. doi: 10.1161/ATVBAHA.115.306263. Epub 2015 Nov 19.


Objective: The present study was conducted to investigate the contribution of perivascular adipose tissue (PVAT) to vascular dysfunction in a mouse model of diet-induced obesity.

Approach and results: Obesity was induced in male C57BL/6J mice with a high-fat diet for 20 weeks, and vascular function was studied with myograph. In PVAT-free aortas isolated from obese mice, the endothelium-dependent, nitric oxide-mediated vasodilator response to acetylcholine remained normal. In contrast, a clear reduction in the vasodilator response to acetylcholine was observed in aortas from obese mice when PVAT was left in place. Adipocytes in PVAT were clearly positive in endothelial nitric oxide synthase (eNOS) staining, and PVAT nitric oxide production was significantly reduced in obese mice. High-fat diet had no effect on eNOS expression but led to eNOS uncoupling, evidenced by diminished superoxide production in PVAT after eNOS inhibition. As mechanisms for eNOS uncoupling, arginase induction and l-arginine deficiency were observed in PVAT. Obesity-induced vascular dysfunction could be reversed by ex vivo l-arginine treatment and arginase inhibition.

Conclusions: Diet-induced obesity leads to l-arginine deficiency and eNOS uncoupling in PVAT. The combination therapy with l-arginine and arginase inhibitors may represent a novel therapeutic strategy for obesity-induced vascular disease.

Keywords: eNOS uncoupling; nitric oxide; obesity; perivascular adipose tissue; vascular function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / enzymology
  • Adipokines / metabolism
  • Adipose Tissue / enzymology*
  • Adipose Tissue / physiopathology
  • Adiposity
  • Animals
  • Aorta, Thoracic / drug effects
  • Aorta, Thoracic / metabolism*
  • Aorta, Thoracic / physiopathology
  • Arginase / antagonists & inhibitors
  • Arginase / metabolism
  • Arginine / deficiency
  • Cytokines / metabolism
  • Diet, High-Fat
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Enzyme Inhibitors / pharmacology
  • Inflammation Mediators / metabolism
  • Male
  • Mice, Inbred C57BL
  • Nitric Oxide / metabolism*
  • Nitric Oxide Synthase Type III / antagonists & inhibitors
  • Nitric Oxide Synthase Type III / metabolism*
  • Obesity / enzymology*
  • Obesity / physiopathology
  • Paracrine Communication
  • Phosphorylation
  • Signal Transduction
  • Superoxides / metabolism
  • Vasodilation* / drug effects
  • Vasodilator Agents / pharmacology


  • Adipokines
  • Cytokines
  • Enzyme Inhibitors
  • Inflammation Mediators
  • Vasodilator Agents
  • Superoxides
  • Nitric Oxide
  • Arginine
  • Nitric Oxide Synthase Type III
  • Nos3 protein, mouse
  • Arginase