A Dynamic Study On Myoelectric Waves And Ultrastructure Of Oddi's Sphincter During Formation Of Primary Intrahepatic Stone In Rabbits

Background ObjectivePrimary intrahepatic stone (PIS) is a common ailment in our country, especially in southwest area.The pathopoiesis of PIS is of multiple factor,and researchers payed more and more attention that the dysfunction of Oddi's sphincter of ( SO ) contribute to lithogenesis. The contraction and relaxation of SO plays an important role in biliary molity,which regulates the direction and velocity of bile flow.It regulates the passage of bile pancreatic fluid into duodenum as a nonreturn valve. We can find in clinic that the function disorder of SO can produce an abnormal biliary kinesics---biliary dysmotility,and many biliary diseases may lead to it. We establish random and control study of PIS animal model, and do a dynamic study on myoelectric waves and ultrastructure of Oddi's sphincter during formation of primary intrahepatic stone in rabbits. To investigate the relationship between motor abnormality of SO and hepatolithiasis. Subsequently we observe the microstructure and ultrastructure of SO, to explore the pathogenesis of abnormal biliary kinesics, which helps we prevent the formation of PIS.MethodsEstablish rabbit model with hepatolithiasis ,adult rabbits were randomized into 2 groups,control group and experimental group ,including 2w group,4w group and 8w group. During the formation process of hepatolithiasis,bile character and ratio of stone formation were both observed,then we recorded the myoelectric waves of SO. Finally, The S0 segment was slided and observed by optics microscope and transmissional electron microscope.ResultsThe rate of true stone formation in group 8w(68.75% 11/16)was higher than in group 4w(12.50% 2/16 )and in group 2w(0.00% 0/16). Compared with the control group, there could be found significant decrease of both SO myoelectric peak amplitude and SO myoelectric frequency. Electron microscopy showed that SO cells in control group and 2w group no change, in 4w and 8w group underwent changes including fibrolysis of myofilament, increasing of collagen fibers ,fusion and thickening of microfilament,decreasing and array disorder of macula densa, swelling of chondrosome and endoplasmic reticulum, widen of perinuclear space and immigration and pyknosis of nucleus,formation of inclusion body in cytoplasm. (degeneration degree 8w>4w).Conclusions1.On the basis of PIS pathogenesis ,we establish high-performance rabbit model, which can be used to explore dynamic regularity and feature of PIS.2. The functiona1 abnorm ality of SO may contribute important effects on the formation of hepatolithiasis.3. SO fibrous degeneration maybe the pathogenesis .