title: Drugs interacting with organic anion transporter-1 affect uptake of Tc-99m-mercaptoacetyl-triglycine (MAG3) in the human kidney: therapeutic drug interaction in Tc-99m-MAG3 diagnosis of renal function and possible application of Tc-99m-MAG3 for drug development.
abstract: BACKGROUND
  Renal uptake of Tc-99m-MG3 involves organic anion transporter (OAT). Treatment with drugs showing OAT affinity might interfere with renal uptake of Tc-99m-MAG3, leading to misinterpretation in Tc-99m-MAG3. This study was conducted to discuss a possible drug interference with Tc-99m-MAG3 diagnosis on OAT sites.
  
  
  METHODS
  Renal uptake and plasma clearance of Tc-99m-MAG3 were analyzed in healthy volunteers under control and OAT1 and OAT3 related drug treatment conditions. An in vitro uptake study using OAT1 or OAT3 expressing cells was also conducted.
  
  
  RESULTS
  Both PAH and probenecid treatment induced delays in Tc-99m-MAG3 clearance from blood, and reductions in the renal uptake clearance. As a result, the normalized effective renal plasma flow estimated from Tc-99m-MAG3 clearance was significantly underestimated, whereas the glomerular filtration rate estimated from plasma creatinine levels was unchanged. The transport activity of Tc-99m-MAG3 was higher in OAT1-expressing cells than in OAT3-expressing cells.
  
  
  CONCLUSIONS
  Drugs with OAT1 affinity affect the renal uptake of Tc-99m-MAG3 and blood clearance. This might cause misinterpretation of functional diagnosis of the kidney using Tc-99m-MAG3.
authors.affiliation: Department of Urology, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Takahara
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Saga
authors.forename: Masayuki
authors.initials: M
authors.lastname: Inubushi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kusuhara
authors.forename: Chie
authors.initials: C
authors.lastname: Seki
authors.forename: Sumito
authors.initials: S
authors.lastname: Ito
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Oyama
authors.forename: Osamu
authors.initials: O
authors.lastname: Yokoyama
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Fujibayashi
mesh_terms: D000328:Adult; D001692:Biological Transport / Q000187:drug effects; D018592:Cross-Over Studies; D055808:Drug Discovery; D005919:Glomerular Filtration Rate / Q000187:drug effects; D064368:Healthy Volunteers; D006801:Humans; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D007677:Kidney Function Tests; D008297:Male; D027362:Organic Anion Transport Protein 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D029362:Organic Anion Transporters, Sodium-Independent / Q000037:antagonists & inhibitors / Q000378:metabolism; D011339:Probenecid / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D011485:Protein Binding; D017263:Technetium Tc 99m Mertiatide / Q000378:metabolism*; D055815:Young Adult; D010130:p-Aminohippuric Acid / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D027362:Organic Anion Transport Protein 1; D029362:Organic Anion Transporters, Sodium-Independent; C114338:organic anion transport protein 3; D017263:Technetium Tc 99m Mertiatide; D011339:Probenecid; D010130:p-Aminohippuric Acid