The effect of intracholangeal radiation on the expression of BCL-2 in dogs and its relationship to apoptosis of smooth muscle cells / 中国普通外科杂志

ABSTRACT

Objective To study the effect of BCL-2 ?-radiation on BCL-2 gene in dogs, and its relationship and signifcane on apoptosis of proliferated smooth muscle cells of bile duct wall. Methods The ~(103)Pd (radioactivity) stent(experiment group) or ordinary stent(control group) was positioned into the target segment of bile duct. The injured bile duct segments were dissected free from the dogs, and BCL-2 gene in the (control) and r-radiation-induced apoptotic smooth mucle cells of bile duct wall was analysed by using (immuno-histochemical) technique. The number of apoptotic cells was counted, and size of lumen of bile duct in both groups was measured by a computerized imaging system.Results BCL-2 gene expression was weaker in the ~(103)Pd radioactive stent group than in the ordinary stent group. The group of dogs with low expression of BCL-2 genes showed marked apoptosis of proliferated smooth mucle cells of bile duct and there was no overt stenosis of extrahepatic bile ducts. The group that showed high expression of BCL-2 gene did not show marked apoptosisi of proliferated smooth muscle cells of bile duct, and there was marked stenosis of extrahepatic bile duct.Conclusions The expression level of BCL-2 in experimental dogs is related to the develoment of (cellular) apoptosis and to radiation sensitivity of the cells. ~(103)Pd radioactive stent can reduce the expression of BCL-2 gene, promote apoptosis of proliferated smooth muscle cells of bile duct, and suppress stricture (formation) of extrahepatic bile duct.