ABSTRACT
BACKGROUND: With the objective of developing a locally-produced radioactive stent, the present study used in vivo animal experiments to explore apoptosis of proliferative smooth muscle cells resulting from facilitation of the expression of genes caused by gamma-radiation in order to prevent bile duct restenosis. We therefore explored the effects and significance of gamma-radiation on the activity of caspase-3, Fas and Bcl-2 genes in apoptosis of proliferative smooth muscle cells in the bile duct walls of dogs. METHODS: Twelve dogs were randomly divided into 2 groups (6 in each group). A postinjury bile duct stenosis model was established and radioactive (103)Pd ((103)palladium) or ordinary bile duct stents were implanted into the bile ducts. HE staining, RT-PCR and immunohistochemistry were used to detect the proliferation and apoptosis of bile duct smooth muscle cells in proliferative endomembrane and the expression of related caspase-3, Bcl-2 and Fas genes. RESULTS: The expression of caspase-3 and Fas genes in the bile duct tissues of dogs with radioactive stents was higher than that of dogs with ordinary stents. There was significant apoptosis of proliferative smooth muscle cells in the bile ducts. The expression of the Bcl-2 gene in the bile duct tissues of dogs with radioactive stents was lower than that in those with ordinary stents. There was significant apoptosis of proliferative smooth muscle cells in the dogs with low Bcl-2 gene expression. CONCLUSIONS: Radiation increases the activity of caspase-3 and Fas genes and is associated with apoptosis. The radioactive (103)Pd stent may facilitate apoptosis of proliferative smooth muscle cells in the bile ducts of dogs by activating these genes. The Bcl-2 gene expression level is correlated with the occurrence of apoptosis and the radiosusceptibility of cells.
Subject(s)
Apoptosis/physiology , Bile Ducts/ultrastructure , Muscle, Smooth/ultrastructure , Palladium/pharmacology , RNA, Messenger/genetics , Animals , Bile Ducts/radiation effects , Bile Ducts/surgery , Caspase 3/genetics , Caspase 3/radiation effects , Cell Proliferation , Coated Materials, Biocompatible , Disease Models, Animal , Dogs , Female , Gene Expression/radiation effects , Genes, bcl-2/genetics , Genes, bcl-2/radiation effects , Immunohistochemistry , In Situ Nick-End Labeling , Isotopes , Male , Microscopy, Electron , Muscle, Smooth/radiation effects , Prosthesis Implantation/instrumentation , RNA, Messenger/radiation effects , Reverse Transcriptase Polymerase Chain Reaction , Stents , fas Receptor/genetics , fas Receptor/radiation effectsABSTRACT
BACKGROUND: This study was designed to assess the expression of smooth muscle actin (SMA) in the healing process after implanting a (103)Pd radioactive stent in the biliary duct, and to discuss the function and significance of this stent in preventing biliary stricture formation. METHODS: A model of biliary injury in dogs was made and then a (103)Pd radioactive stent was positioned in the biliary duct. The expression and distribution of SMA were assessed in the anastomotic tissue 30 days after implantation of the stent. RESULTS: SMA expression was less in the (103)Pd stent group than in the ordinary stent group. The (103)Pd stent inhibited scar contracture and anastomotic stenosis. CONCLUSION: The (103)Pd stent can reduce the expression of SMA in the healing process and inhibit scar contracture and anastomotic stenosis in the dog biliary duct.
Subject(s)
Actins/metabolism , Bile Ducts, Extrahepatic/surgery , Palladium , Radioisotopes , Stents , Animals , Bile Ducts, Extrahepatic/metabolism , Bile Ducts, Extrahepatic/pathology , Constriction, Pathologic/pathology , Constriction, Pathologic/prevention & control , Dogs , Male , Muscle, Smooth/metabolismABSTRACT
OBJECTIVE: To discuss the expression and significance of caspase-3 gene in the apoptotic muscle cells in gamma-radiation-induced muscle cell lines. METHODS: The caspase-3 mRNA in the control and gamma-radiation induced apoptotic muscle cells was analysed by RT-PCR. RESULTS: The expression of caspase-3 gene transcript was higher in 103Pd radioactive stent dog bile duct than in general stent dog bile duct, and apoptotic muscle cells were higher in 103Pd radioactive stent dog bile duct than in general stent dog bile duct. CONCLUSIONS: The high level expression of caspase-3 gene may help to understand the muscle cells sensitivity to gamma-radiation apoptosis. 103Pd radioactive stent may increase the expression of caspase-3 gene in dog bile duct and prevent the billiary narrow when dog bile duct was injured by balloon.
Subject(s)
Apoptosis/radiation effects , Bile Ducts/radiation effects , Caspases/radiation effects , Myocytes, Smooth Muscle/radiation effects , Palladium/administration & dosage , Radioisotopes/administration & dosage , Stents , Animals , Apoptosis Regulatory Proteins , Bile Ducts/enzymology , Caspase 3 , Caspases/genetics , Dogs , Myocytes, Smooth Muscle/cytology , RNA, Messenger/genetics , RNA, Messenger/radiation effects , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
OBJECTIVE: To observe the effect of radiation on the expression of smooth muscle actin (SMA) in the bile duct during the healing process and the inhibitory function of (103)palladium (Pd) radioactive stent on the stricture of bile duct after injury. METHODS: Twelve mongrel dogs were made models of bile duct injury: duodenotomy was performed, a balloon catheter was inserted into the general bile duct and saline with high pressure was perfused thereinto to cause laceration of the mucosa, and then the balloon catheter was withdrawn and ordinary alloy stent or (103)Pd radioactive stent was inserted into the general bile duct. Thirty days after the dogs were killed. Their bile ducts were taken out to undergo HE staining to observe the area of general bile duct, thickness of the tunica intima, area of residual bile duct cavity, stricture degree, and circumference of bile duct. The expression of SMA in the bile duct tissue was detected by immunoistochemistry. RESULTS: SMA was expressed in 5 of the 6 specimens of bile duct in the (103)Pd radioactive stent group and 2 of the 6 specimens of the ordinary stent group (P < 0.01). The maximum thickness of tunica intima of general bile duct was 0.78 mm +/- 0.12 mm in the (103)Pd radioactive stent group, significantly less than that of the ordinary stent group (1.86 mm +/- 0.14 mm, P < 0.01). The percentage of maximum stricture area of the (103)Pd radioactive stent group was 23% +/- 16%, significantly lower that that of the ordinary stent group (56% +/- 22%, P < 0.01). The circumference of bile duct cavity of the (103)Pd radioactive stent group was 9.7 mm +/- 1.6 mm, significantly longer that of the ordinary stent group (7.0 mm +/- 1.4 mm, P < 0.01). CONCLUSION: (103)Pd radioactive stent reduces the expression of SMA in the bile duct during the healing process, thus inhibiting the stricture of bile duct caused by scar contracture at the anastomotic stoma.
