【Abstract】Objective To research relation of apoptosis muscular cell in 103Pd radioactive stent of dog biliary muscular formation and inhibition of biliary ductal stricture. Methods Twelve dogs were randomly divided into two groups, which were general stent group and 103Pd radioactive stent group. General stent and 103Pd radioactive stent were respectively put into extrahepatic biliary tract of two groups. After 30 days all dogs were killed, and biliary tract were taken out. Apoptotic cells were detected by immunohistochemical methodsand agar electrophoresis, and nucleus browyellow was positive cell. Dog biliary duct cross-sections were stained by hematoxylin-erosin; area and perimeter of lumen,thickness of inner membrane and stenosis degree in bile duct were analysed by image analysis software of computer.Results The apoptotic biliary duct smooth muscle cell ［(87.9±7.96)/cm2］ was more significantly increased in the 103Pd radioactive stent group than in the general stent group ［(5.6±0.51)/cm2］, P＜0.05; and comparing with the general stent group, the 103Pd radioactive stent significantly reduced biliary muscular formation thickness. Conclusion The result shows that 103Pd radioactive stent can inhibit proliferation of biliary ductal smooth muscle cell.
Objective To research the effect of γ-radiation released from 103Pd radioactive stent on the expression of Fas gene and its relation with apoptosis of bile duct cancer cells lines. Methods The cancer cells of bile duct were dissociated into suspension in culture flasks, and the number of cells was counted by hemacytometry. The suspension was then stored in 2 ml freezing tubes in the density of 1×105/ml. They were set in two stents: general stent （general stent group） and 103Pd radioactive stent (103Pd stent group). The expression of Fas gene and apoptosis of bile duct cancer cells in general stent group and 103Pd stent group were analysed with immunohistochemistry technique and TUNEL method, respectively. Results The expression level of Fas gene in 103Pd stent group was significantly higher than that in general stent group （P＜0.05）, and the number of apoptotic cancer cells in 103Pd stent group was also significantly more than that in general stent group （P＜0.01）. Conclusion There is a correlation between the expression of Fas gene and the apoptosis of bile duct cancer cells, which means that 103Pd radioactive stent may increase the expression of Fas gene and promote the apoptosis of cancer cells. It may be helpful for the further study of treatment for bile duct cancer using 103Pd radiative stent.