Endovascular brachytherapy with Liquid ~(188) Re affect cell proliferation, phenotype of smooth muscle cell and secretion of transforming growth factor

Objective To investigate the effect of endovascular brachytherapy with Rhenium-188-filled catheter balloon on cell proliferation,phenotype of smooth muscle cell and secretion of transforming growth factor; to explore the possible mechanism of this method employed in restenosis prevention. Methods After the right common carotid arteries were overstretched by 3.5×20 mm balloon,twenty New Zealand White rabbits were randomized into irradiation (n=10) and control group (n=10). Endovascular bachytherapy was performed wth a 188[KG*2/2]Re filled 3.0×20 mm balloon catheter delivering a dosage of 16 Gy (0.5 mm underneath the luminal surface) in the irradiation group, whereas isovolume normal-sodium-filled balloon catheter was used in the control group for an equal period. After thirty days, analysis of the carotial arteries was made by measns of histological and immunohistochemical staining. Results (1) The positive staining index of proliferation cellular nuclear antigen (PCNA) and transforming growth factor (TGF) of the irradiation group is significantly less than the control group (0.028±0.005 vs 0.054±0.011, 0.033±0.008 vs 0.063±0.014, respectively); (2) The positive staining of α-actin index in intima has no significant difference between the irradiatin group and the control group. Conclusion (1) The preventive effect on restenosis with endovascular brachytherapy is possibly achieved by suppression of cellular proliferation and transforming growth factor secretion. (2)The phenotype of smooth muscle cell is possibly unaffected by endovascular brachytherapy.