title: The effects of chemical and radioactive properties of Tl-201 on human erythrocyte glutathione reductase activity.
abstract: OBJECTIVE
  The aim of the study was to evaluate the inhibitory effects of thallium-201 ((201)Tl) solution on human erythrocyte glutathione reductase (GR) activity.
  
  
  METHODS
  Erythrocyte GR was initially purified by 2',5'-adenosine diphosphate Sepharose-4B affinity and Sephadex G-200 gel filtration chromatography. The purification was monitored by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which showed a single band for the final enzyme preparation. The in vitro and in vivo effects of the (201)Tl solution including Tl(+), Fe(+3) and Cu(+2) metals and the in vitro effects of the radiation effect of the (201)Tl solution and nonradioactive Tl(+), Fe(+3) and Cu(+2) metals on human erythrocyte GR enzyme were studied. Enzyme activity was determined with the Beutler method at 340 nm using a spectrophotometer. All purification procedures were carried out at (+)4 °C.
  
  
  RESULTS
  Glutathione reductase was purified 2033-fold at a yield of 28.17%. (201)Tl solution and radiation exposure had inhibitory effects on the enzyme activity. Besides, effects of nonradioactive Tl(+), Fe(+3) and Cu(+2) were studied on enzyme activity in vitro. Furthermore, seven human patients were also used for in vivo studies of (201)Tl solution.
  
  
  CONCLUSIONS
  It was detected in in vitro and in vivo studies that the human erythrocyte GR enzyme is inhibited due to the radiation effect of (201)Tl solution.
authors.affiliation: Department of Nuclear Medicine, Faculty of Medicine, Ataturk University, 25240 Erzurum, Turkey. alibabam2001@yahoo.com
authors.forename: Ali
authors.initials: A
authors.lastname: Sahin
authors.forename: Murat
authors.initials: M
authors.lastname: Senturk
authors.forename: Ebru
authors.initials: E
authors.lastname: Akkemik
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ciftci
mesh_terms: D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000187:drug effects / Q000201:enzymology* / Q000528:radiation effects; D005980:Glutathione Reductase / Q000037:antagonists & inhibitors*; D006801:Humans; D013053:Spectrophotometry; D013794:Thallium Radioisotopes / Q000494:pharmacology*
chemical_list: D013794:Thallium Radioisotopes; D005980:Glutathione Reductase