title: Vasorelaxing Effect of Resveratrol on Bovine Retinal Arteries.
abstract: OBJECTIVE
  Resveratrol is a red wine polyphenol that causes vasorelaxation, which could be of interest in the treatment or prevention of eye diseases with an impaired blood flow. In this study, the vasorelaxant capacity of resveratrol (cis and trans) on bovine retinal arteries, its vasorelaxing mechanism, and its influence on the relaxation induced by the retinal relaxing factor (RRF) were examined.
  
  
  METHODS
  Isolated bovine retinal arteries were mounted into wire myographs for isometric tension measurements. Concentration-response curves of cis- and trans-resveratrol and concentration-response curves of resveratrol in the absence or presence of the endothelium or different inhibitors were constructed. Relaxations elicited by the RRF with and without resveratrol incubation were also compared.
  
  
  RESULTS
  Both resveratrol isomers caused a similar strong concentration-dependent relaxation. Removal of the endothelium or blocking endothelium-dependent pathways did not change the relaxation. Also, K+ channel blockers did not reduce the relaxation, except the 120 mM K+ Krebs Ringer bicarbonate solution. Phorbol 12-myristate 13-acetate and phorbol 12,13-dibutyrate blocked the relaxation partially and so did the inhibition of heme oxygenase-1. Blocking adenylyl cyclase, AMP-activated protein kinase, estrogen receptors, sirtuin 1, or sarco/endoplasmic reticulum Ca2+ ATPase did not have an effect. The relaxation caused by the RRF was not altered by resveratrol incubation.
  
  
  CONCLUSIONS
  Cis- and trans-resveratrol relax bovine retinal arteries similarly and concentration dependently. The main relaxation mechanism remains unclear, but K+ channels, carbon monoxide, and the myosin phosphatase pathway may be involved. Resveratrol does not have an influence on the RRF.
authors.forename: Laura
authors.initials: L
authors.lastname: Vanden Daele
authors.forename: Charlotte
authors.initials: C
authors.lastname: Boydens
authors.forename: Bart
authors.initials: B
authors.lastname: Pauwels
authors.forename: Johan
authors.initials: J
authors.lastname: Van de Voorde
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000502:physiology; D007537:Isometric Contraction; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009213:Myography; D009569:Nitric Oxide / Q000502:physiology; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D015221:Potassium Channels / Q000502:physiology; D011493:Protein Kinase C / Q000502:physiology; D000077185:Resveratrol; D012161:Retinal Artery / Q000502:physiology*; D013267:Stilbenes / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014664:Vasodilation / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D015221:Potassium Channels; D013267:Stilbenes; D014665:Vasodilator Agents; D009569:Nitric Oxide; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D000077185:Resveratrol