title: The manifold actions of statins. Comment on "Effects of systemic administration of simvastatin on retinal circulation, by T. Nagaoka, A. Takahashi, E. Sato, et al. Arch Ophthalmol 124:665-70, 2006.
abstract: OBJECTIVE
  To investigate the effect of systemic administration of simvastatin on the retinal circulation.
  
  
  METHODS
  The effects of systemic administration of simvastatin on the retinal circulation after 90 minutes and after 7 days were studied in a placebo-controlled, double-masked, clinical trial among 12 healthy men. We used laser Doppler velocimetry to measure vessel diameter and blood velocity and calculated the blood flow in retinal arteries and veins. We also measured the intraocular pressure and the plasma nitrite/nitrate levels, the stable end products of nitric oxide metabolism.
  
  
  RESULTS
  There were no significant changes in any retinal circulatory parameters at 90 minutes after administration of simvastatin. Daily administration of simvastatin for 7 days significantly increased blood velocity and blood flow in retinal arteries and veins but did not significantly change vessel diameter. The intraocular pressure significantly decreased at 90 minutes and at 7 days after administration of simvastatin. Simvastatin also significantly increased the plasma nitrite/nitrate levels.
  
  
  CONCLUSIONS
  Simvastatin induced an increase in blood velocity and blood flow in retinal arteries and veins, increased the plasma nitrite/nitrate levels, and decreased the intraocular pressure, probably through the increase in nitric oxide.
authors.forename: Jorge G
authors.initials: JG
authors.lastname: Arroyo
mesh_terms: D000284:Administration, Oral; D001783:Blood Flow Velocity / Q000187:drug effects; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000008:administration & dosage*; D007429:Intraocular Pressure / Q000502:physiology; D017078:Laser-Doppler Flowmetry; D009566:Nitrates / Q000097:blood; D009573:Nitrites / Q000097:blood; D012039:Regional Blood Flow / Q000187:drug effects; D012171:Retinal Vessels / Q000502:physiology*; D019821:Simvastatin / Q000008:administration & dosage*
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D009566:Nitrates; D009573:Nitrites; D019821:Simvastatin