In vitro comparison of the antiproliferative effects of rhenium-186 and rhenium-188 on human aortic endothelial cells.
OBJECTIVE
Rhenium-186 ((186)Re) and rhenium-188 ((188)Re) are promising radionuclides for the inhibition of restenosis after percutaneous transluminal angioplasty or other vascular interventions. Until now the maximal dose tolerance of endothelial cells has not been clearly known.


METHODS
To characterize the effects of local irradiation treatment, human aortic endothelial cells (ECs) were incubated with different doses of (186)Re and (188)Re. Two days after plating, ECs received treatment for a period of 5 days. The total radiation doses applied were 1, 4, 8, 16, and 32 Gy. On days 1, 3, 5, 7, and 12 after initial rhenium incubation, cell growth, clonogenic activity, cell-cycle distribution, and cytoskeletal architecture were evaluated.


RESULTS
From the first day on, a dose-dependent growth inhibition was observed. Cumulative doses of ≥32 Gy caused a weak colony formation and significant alterations in the cytoskeletal architecture. An increased fraction of cells in G2/M phase was seen for cumulative radiation doses of ≥16 Gy. Interestingly, there were no significant differences between (186)Re and (188)Re.


CONCLUSIONS
Even for low dose rates of β particles a dose-dependent proliferation inhibition of ECs is seen. Doses beyond 32 Gy alter the cytoskeletal architecture with possibly endothelial dysfunction and late thrombosis.
Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Hoppe-Seyler-Str. 3 72076, Tuebingen, Germany. alexander.sauter@klinikum.uni-tuebingen.de
Alexander
A
Sauter
Daniel
D
Arthasana
Helmut
H
Dittmann
Maren
M
Pritzkow
Benjamin
B
Wiesinger
Joerg
J
Schmehl
Klaus
K
Brechtel
Rüdiger
R
Bantleon
Claus
C
Claussen
Rainer
R
Kehlbach
D017130:Angioplasty; D001011:Aorta / Q000166:cytology*; D002453:Cell Cycle / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects*; D003114:Colony-Forming Units Assay; D004307:Dose-Response Relationship, Radiation; D042783:Endothelial Cells; D066298:In Vitro Techniques; D020714:Maximum Tolerated Dose; D008856:Microscopy, Fluorescence; D011868:Radioisotopes / Q000494:pharmacology*; D012211:Rhenium / Q000494:pharmacology*
D011868:Radioisotopes; D012211:Rhenium