To establish the theoretical and practical base for implementing radioactive stents after PTCA in order to prevent restenosis

in virto observation was taken over the effects of 125I-seeds and 103Pd-implanted stents on the vascular smooth muscle cell (VSMC) proliferation. In virto VSMC model from guinea-pig aortic arteries was established using adherent cell culture methods. The effects of 125 I-seeds and 103 Pd-implanted stents on the VSMC proliferation

with or without fetal bovine serum (FCS)

were investigated through cell counting methods and H-TDR 3 implementation tests. It was shown that (1) 10% FCS significantly promoted the DNA syntheses of VSMC (P<0.05). (2) Both 125I-seeds and 103Pd-implanted stents inhibited the VSMC DNA syntheses in dose-dependent manner

regardless of 10% FCS inducement. At lower radioactive doses

neither 125I-seeds (18.5—74 kBq) nor 103Pd-implanted stents (1.48—2.96 MBq) exhibited distinctive effects on the VSMC DNA syntheses (P>0.05); and (3) 48 hour exposure from 125I-seeds at 128 kBq or 103 Pd-implanted stents at 7.4MBq did not result in VSMC morphological alteration

but 125I-seeds at 370 kBq caused cells’ morphological changes. Therefore both 125I-seeds and 103 Pd-implanted stents inhibit the in vitro VSMC DNA syntheses

and the inhibition effects are significantly related to their exposure duration and doses.