title: Interference by o-phenanthroline in the radioimmunoassay of angiotensin II in small volume blood samples.
abstract: OBJECTIVE
  To investigate the ratio of enzyme inhibitor volume to blood volume in angiotensin II (Ang II) blood collection tubes.
  
  
  METHODS
  Whole blood was mixed with known volumes of inhibitor prior to angiotensin II analysis.
  
  
  RESULTS
  Imunoreactive Ang II levels increased at low blood volume to high inhibitor volume ratios, due to interference by o-phenanthroline.
  
  
  CONCLUSIONS
  To prevent falsely elevated Ang II levels in low volume blood samples an appropriate volume of inhibitor solution must be used.
authors: Christchurch Cardioendocrine Research Group, Department of Medicine, Christchurch School of Medicine and Health Sciences, University of Otago, Dunedin, Otago, New Zealand.
authors: Joy E
authors: JE
authors: Braithwaite
authors: Tim G
authors: TG
authors: Yandle
authors: M Gary
authors: MG
authors: Nicholls
authors: Lynley K
authors: LK
authors: Lewis
mesh_terms: D000804:Angiotensin II / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects; D001810:Blood Volume / Q000187:drug effects; D002021:Buffers; D004359:Drug Therapy, Combination / Q000379:methods; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D015233:Models, Statistical; D010618:Phenanthrolines / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000494:pharmacology; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D002021:Buffers; D004791:Enzyme Inhibitors; D010618:Phenanthrolines; D011480:Protease Inhibitors; D000804:Angiotensin II; C025205:1,10-phenanthroline