Hyperglycaemia-induced impairment of endothelium-dependent vasorelaxation in rat mesenteric arteries is mediated by intracellular methylglyoxal levels in a pathway dependent on oxidative stress

Diabetologia. 2010 May;53(5):989-1000. doi: 10.1007/s00125-010-1677-0. Epub 2010 Feb 26.


Aims/hypothesis: Impaired nitric oxide (NO)-dependent vasorelaxation plays a key role in the development of diabetic vascular complications. We investigated the effect of hyperglycaemia on impaired vasoreactivity and a putative role therein of the AGE precursor methylglyoxal.

Methods: The effects of high glucose and methylglyoxal on NO-dependent vasorelaxation in isolated rat mesenteric arteries from wild-type and transgenic glyoxalase (GLO)-I (also known as GLO1) rats, i.e. the enzyme detoxifying methylglyoxal, were recorded in a wire myograph. AGE formation of the major methylglyoxal-adduct 5-hydro-5-methylimidazolone (MG-H1) was detected with an antibody against MG-H1 and quantified with ultra-performance liquid chromatography (tandem) mass spectrometry. Reactive oxygen species formation was measured with a 5-(and-6)-chloromethyl-2'7'-dichlorodihydrofluorescein diacetate acetyl ester probe and by immunohistochemistry with an antibody against nitrotyrosine.

Results: High glucose and methylglyoxal exposure of mesenteric arteries significantly reduced the efficacy of NO-dependent vasorelaxation (p < 0.05). This impairment was not observed in mesenteric arteries of GLO-I transgenic rats indicating a specific intracellular methylglyoxal effect. The diabetes-induced impaired potency (pD(2)) in mesenteric arteries of wild-type rats was significantly improved by GLO-I overexpression (p < 0.05). Methylglyoxal-modified albumin did not affect NO-dependent vasorelaxation, while under the same conditions the receptor for AGE ligand S100b did (p < 0.05). Methylglyoxal treatment of arteries increased intracellular staining of MG-H1 in endothelial cells and adventitia by fivefold accompanied by an eightfold increase in the oxidative stress marker nitrotyrosine. Antioxidant pre-incubation prevented methylglyoxal-induced impairment of vasoreactivity.

Conclusions/interpretation: These data show that hyperglycaemia-induced impairment of endothelium-dependent vasorelaxation is mediated by increased intracellular methylglyoxal levels in a pathway dependent on oxidative stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Cell Count
  • Cell Line
  • Cells, Cultured
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / metabolism*
  • Endothelium, Vascular / physiopathology
  • Humans
  • Hyperglycemia / metabolism*
  • Hyperglycemia / physiopathology
  • Immunohistochemistry
  • Lactoylglutathione Lyase / genetics
  • Mesenteric Arteries / drug effects
  • Mesenteric Arteries / metabolism*
  • Mesenteric Arteries / physiopathology
  • Nitric Oxide / metabolism
  • Oxidative Stress / drug effects
  • Oxidative Stress / physiology*
  • Pyruvaldehyde / metabolism*
  • Pyruvaldehyde / pharmacology
  • Rats
  • Rats, Transgenic
  • Reactive Oxygen Species / metabolism
  • Vasodilation / drug effects*
  • Vasodilation / physiology


  • Reactive Oxygen Species
  • Nitric Oxide
  • Pyruvaldehyde
  • Lactoylglutathione Lyase