title: Assessment of renal flow and flow reserve in humans.
abstract: OBJECTIVE
  The purpose of this work was to establish the normal range of maximal renal hyperemic response in humans and to identify the ideal renal vasodilatory stimuli.
  
  
  BACKGROUND
  Stenotic renovascular atherosclerosis is increasingly treated by percutaneous transluminal renal intervention but with an unpredictable outcome. This may be due to hemodynamically non-significant stenosis or the presence of irreversible damage to the glomerular circulation. We propose that the renovascular hyperemic response may help identify appropriate patients.
  
  
  METHODS
  In 28 normotensive patients, quantitative angiographic measurements of the renal artery were obtained, and renal artery pressure and flow velocity were continuously recorded after various hyperemic agents.
  
  
  RESULTS
  In a first group of 11 patients, a significant increase in renal artery average peak velocity (APV) was observed after intrarenal (IR) bolus injection of 600 microg isosorbide dinitrate (41 +/- 19%), 30 mg papaverine (50 +/- 34%), 50 microg dopamine (94 +/- 54%), 0.8 microg x kg(-1) fenoldopam (80 +/- 25%), and during IR infusion of 1 microg x kg(-1) x min(-1) fenoldopam (86 +/- 28%). A second group of 17 patients received intravenous infusion of dopamine (3, 5, 10, 20, 30, and 40 microg x kg(-1) x min(-1)). The 3 and 5 microg x kg(-1) x min(-1) of dopamine modestly reduced renal resistance index (RI) (-13 +/- 15% and -25 +/- 20%, respectively). At higher dosages, no further decline in RI was observed. No significant change in vessel diameter was observed before and after the administration of the pharmacological stimuli suggesting that changes in APV corresponded with changes in absolute renal blood flow.
  
  
  CONCLUSIONS
  The normal renal flow reserve averages approximately 2 in humans with normal renal function. An IR bolus injection of 50 microg x kg(-1) of dopamine is the most convenient means to elicit maximal renal hyperemia.
authors.affiliation: Cardiovascular Centre Aalst, OLV-Clinic, Aalst, Belgium.
authors.forename: Ganesh
authors.initials: G
authors.lastname: Manoharan
authors.forename: Nico H J
authors.initials: NH
authors.lastname: Pijls
authors.forename: Norbert
authors.initials: N
authors.lastname: Lameire
authors.forename: Katia
authors.initials: K
authors.lastname: Verhamme
authors.forename: Guy R
authors.initials: GR
authors.lastname: Heyndrickx
authors.forename: Emanuele
authors.initials: E
authors.lastname: Barbato
authors.forename: William
authors.initials: W
authors.lastname: Wijns
authors.forename: Juraj
authors.initials: J
authors.lastname: Madaric
authors.forename: Xanden
authors.initials: X
authors.lastname: Tielbeele
authors.forename: Jozef
authors.initials: J
authors.lastname: Bartunek
authors.forename: Bernard
authors.initials: B
authors.lastname: De Bruyne
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D004298:Dopamine / Q000494:pharmacology; D005260:Female; D018818:Fenoldopam / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006940:Hyperemia; D007548:Isosorbide Dinitrate / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D010208:Papaverine / Q000494:pharmacology; D012079:Renal Circulation / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014665:Vasodilator Agents; D010208:Papaverine; D007548:Isosorbide Dinitrate; D018818:Fenoldopam; D004298:Dopamine