title: High-frequency ultrasonic waves cause endothelial dysfunction on canine epicardial coronary arteries.
abstract: OBJECTIVE
  Application of ultrasound energy by an endarterectomy probe can facilitate the removal of atheromatous plaque, but the effect of this procedure on surrounding vessel structure and function is still a matter of experimental investigations.
  
  
  METHODS
  To determine whether ultrasound energy impairs the production of nitric oxide or damages vascular smooth muscle function, isolated canine epicardial coronary artery segments were exposed to either high (25 W) or low (0-10 W) ultrasonic energy outputs, for 15 seconds, using an endarterectomy device prototype. After exposure, segments of epicardial coronary artery were studied in organ chambers. The following drugs were used: adenosine diphosphate (ADP), acetylcholine (Ach) and sodium fluoride (NaF) to study endothelium-dependent relaxation and sodium nitroprusside (SNP) and isoproterenol to evaluate endothelium-independent relaxation.
  
  
  RESULTS
  Application of high ultrasonic energy power impaired endothelium-dependent relaxation to ADP (10(-9)-10(-4) M), Ach (10(-9)-10(-4) M) and NaF (0.5-9.5 mM) in epicardial coronary arteries. However, low ultrasound energy output at the tip of the probe did not alter the endothelium-dependent relaxation (either maximal relaxation or EC50) to the same agonists. Vascular smooth muscle relaxation to isoproterenol (10(-9)-10(-5) M) or SNP (10(-9)-10(-6) M) was unaltered following exposure to either low or high ultrasonic energy outputs.
  
  
  CONCLUSIONS
  These experiments currently prove that ultrasonic energy changes endothelial function of epicardial coronary arteries at high power. However, ultrasound does not alter the ability of vascular smooth muscle of canine epicardial coronary arteries to relax.
authors.affiliation: Department of Cardiovascular Surgery, Faculty of Medicine, Adnan Menderes University, Turkey.
authors.forename: Berent
authors.initials: B
authors.lastname: Discigil
authors.forename: R Michael
authors.initials: RM
authors.lastname: King
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Pearson
authors.forename: Verena K
authors.initials: VK
authors.lastname: Capellini
authors.forename: Alfredo José
authors.initials: AJ
authors.lastname: Rodrigues
authors.forename: Hartzell V
authors.initials: HV
authors.lastname: Schaff
authors.forename: Paulo Roberto Barbosa
authors.initials: PR
authors.lastname: Evora
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D003331:Coronary Vessels / Q000293:injuries / Q000378:metabolism; D004285:Dogs; D004691:Endarterectomy / Q000379:methods; D004730:Endothelium, Vascular / Q000187:drug effects / Q000293:injuries* / Q000503:physiopathology; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D023421:Models, Animal; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000293:injuries* / Q000503:physiopathology; D009569:Nitric Oxide / Q000096:biosynthesis*; D009599:Nitroprusside / Q000494:pharmacology; D012969:Sodium Fluoride / Q000494:pharmacology; D014464:Ultrasonic Therapy / Q000009:adverse effects*; D018084:Ultrasonography, Interventional / Q000009:adverse effects* / Q000379:methods; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
chemical_list: D009599:Nitroprusside; D009569:Nitric Oxide; D000244:Adenosine Diphosphate; D012969:Sodium Fluoride; D007545:Isoproterenol; D000109:Acetylcholine