title: Bronchial arterial response to contrast medium.
abstract: OBJECTIVE
  Contrast agents have been shown to produce vasodilatory responses in several vascular beds. To our knowledge, however, their effect on the bronchial vasculature has not been examined. Clinically, contrast-induced bronchial vasodilation could potentially exacerbate life-threatening pulmonary hemorrhage during bronchial angiography for hemoptysis. In the current study, we systematically measured the bronchial vasodilatory response to diatrizoate meglumine 66% and diatrizoate sodium 10% (MD-76) and examined whether vasodilation would be mediated by nitric oxide (NO).
  
  
  METHODS
  We measured bronchial blood flow in seven anesthetized, ventilated, open-chested sheep using an ultrasonic flow probe placed around the bronchial artery. Bronchial blood flow was recorded before and after injection of 2 ml MD-76 into the bronchial artery. The protocol was repeated after 20 min infusion of N omega-nitro-L-arginine (L-NA; 10(-2) mol/l), an NO-synthase inhibitor, into the bronchial artery.
  
  
  RESULTS
  There was a 45 +/- 8 ml/min increase (p < .01) in bronchial blood flow after injection of MD-76, which was reduced to 20 +/- 6 ml/min (p < .01) after infusion of L-NA.
  
  
  CONCLUSIONS
  Bronchial arterial injection of MD-76 results in a consistent increase in bronchial blood flow that is mediated partly by NO.
authors.affiliation: University of British Columbia Pulmonary Research Laboratory, St. Paul's Hospital, Vancouver, British Columbia, Canada.
authors.forename: E M
authors.initials: EM
authors.lastname: Baile
authors.forename: J R
authors.initials: JR
authors.lastname: Mayo
authors.forename: F
authors.initials: F
authors.lastname: Sasaki
authors.forename: T R
authors.initials: TR
authors.lastname: Bai
authors.forename: P D
authors.initials: PD
authors.lastname: Paré
mesh_terms: D000818:Animals; D001981:Bronchial Arteries / Q000187:drug effects*; D003287:Contrast Media / Q000494:pharmacology*; D003973:Diatrizoate / Q000494:pharmacology*; D003974:Diatrizoate Meglumine / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019335:Nitroarginine / Q000494:pharmacology; D012039:Regional Blood Flow / Q000187:drug effects; D012756:Sheep; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D003287:Contrast Media; D004791:Enzyme Inhibitors; D014665:Vasodilator Agents; D003973:Diatrizoate; D019335:Nitroarginine; D009569:Nitric Oxide; D003974:Diatrizoate Meglumine; D019001:Nitric Oxide Synthase