Dose-dependent effects of the combined beta/gamma emitter (186)rhenium on the growth of human vessel wall cells.

Purpose:The aim of this study was to evaluate the capability of human aorti c smooth muse e cells (HaSMC) and endothelial cells (EC) to recover after i ncubation with the combined beta/gamma emitter (186)rhenium. Materials and Methods: Two days after plating, HaSMC and EC were incubated for five days with Re-186 (total doses applied 4 Gy - 32 Gy). Cell counts were performed for a period of 30 days (haSMC) and 22 days (EC). To detect possible growth recovery, colony formation assays were plated for both cell types on day 5 , 10, and 20 land lay 30 for haSMC). Results: Both cell types presented a d ose-dependent growth inhibition which was maximum at a dose of 32 Gy, Human endothelial cells presented with total growth recovery at 4 and 8 Cy, and a partial growth recovery at 16 Gy. Smooth muscle cells only presented part ial growth recovery at 4 and 8 Cy. At 16 Gy and mo-re no recovery was detec ted. Conclusion: HaSMC as well as EC growth can be modulated effectively wi th Re-186 over a period of 30 days in vitro. Compared to smooth muscle cell s human endothelial cells seem to possess a higher potential to recover at doses of 8 to 16 Gy. Re-186 may be a valuable radionuclide to prevent reste nosis.