title: Sodium cholate, a solubilizing agent for the necrosis avid radioiodinated hypericin in rabbits with acute myocardial infarction.
abstract: OBJECTIVE
  We determined whether sodium cholate (NaCh) could act as a solubilizing agent for the necrosis avid iodine-123-labeled hypericin ((123)I-Hyp) and investigated biodistribution and targetability of this formulation in rabbits with acute myocardial infarction (AMI).
  
  
  METHODS
  Solubility of radioiodinated hypericin/hypericin (Hyp) in NaCh solutions was evaluated by microscopy. Hyp with (123)I-sodium iodide was performed using hydrogen peroxide as oxidant in 0.06 M NaCh. Radiochemical yield determination and purification were conducted using high performance liquid chromatography. (123)I-Hyp was solubilized in 0.06 M NaCh containing 1.9 × 10(-4 )M Hyp. The formulation was macroscopically inspected and intravenously injected to five rabbits with AMI. At 24 h, biodistribution was evaluated by tissue gamma counting (TGC) and necrosis targetability was assessed by TGC, autoradiography, fluorescence examination and histology.
  
  
  RESULTS
  Microscopically NaCh at 0.06 M shows the best properties for solubilizing the radioiodinated Hyp/Hyp. (123)I-Hyp in 0.06 M NaCh was achieved in 85% with radiochemical purity of 99% after purification. NaCh-dissolved (123)I-Hyp/Hyp shows no particles. By TGC, animals exhibited higher (p = 0.003) radioactivity accumulation in AMI (0.8 ± 0.2% ID/g) than in normal myocardium (0.05 ± 0.02% ID/g), as confirmed by autoradiography, fluorescence measurement and histology. Among organs, the highest uptake of radioactivity was found in liver (15.7 ± 0.6% ID), large (9.7 ± 1.0% ID) and small (5.9 ± 0.6% ID) intestines.
  
  
  CONCLUSIONS
  Necrosis avidity of NaCh-dissolved (123)I-Hyp/Hyp and its hepatobiliary excretion were demonstrated. The suitability of NaCh as solubilizing agent of (123)I-Hyp for hotspot imaging of AMI was proved.
authors.affiliation: Department of Imaging and Pathology, Faculty of Medicine, Biomedical Sciences Group , KU Leuven, Leuven , Belgium .
authors.forename: Marlein Miranda
authors.initials: MM
authors.lastname: Cona
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Feng
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.forename: Alfons
authors.initials: A
authors.lastname: Verbruggen
authors.forename: Raymond
authors.initials: R
authors.lastname: Oyen
authors.forename: Yicheng
authors.initials: Y
authors.lastname: Ni
mesh_terms: D000818:Animals; D000873:Anthracenes; D001345:Autoradiography; D004195:Disease Models, Animal; D015902:Gamma Cameras; D006321:Heart / Q000000981:diagnostic imaging*; D007457:Iodine Radioisotopes; D008297:Male; D008856:Microscopy, Fluorescence; D015394:Molecular Structure; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000473:pathology*; D009206:Myocardium / Q000473:pathology*; D009336:Necrosis; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D011817:Rabbits; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000737:chemistry*; D020358:Sodium Cholate / Q000737:chemistry*; D012995:Solubility; D012996:Solutions; D014018:Tissue Distribution
chemical_list: D000873:Anthracenes; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D012996:Solutions; D010569:Perylene; C004965:hypericin; D020358:Sodium Cholate
keywords: 123I-Hyp/Hyp; formulation; myocardial infarct detection; solubility; surfactant solubilization