[A study on the histologic basis of human bile duct peristalsis]

In 62 human cadavers, full length specimen of bile duct including right hepatic intersegmental duct (from fetus, infants, children and adult up to 74 yrs of age) was examined with light and electron microscopy. 1 for longitudinal maximum section, 61 for cross serial section of each of 6 selected tissue blocks stained with HE for general survey, Mallory, Van-Gieson stain and PAP anti-desmin for smooth muscle, Weigert stain for elastic fiber. No muscle bundles were found in the bile-duct. Some cases have scattered smooth muscle cells in the fibrous duct wall, with the frequency in pancreatic portion as 54/62, supraduodenal portion 33/62, common hepatic 15/62, right hepatic 2/61, and intrahepatic o/62, but never in full layers, circular or longitudinal, nor right joint of cell membrane existed. Total area of muscle cells measured in slide is less than 8% that of the fibrous wall. No myofibroblast was found. It is concluded that, there is no characteristic histologic structure of contractile potential and wave transmission. There is no other contractile element in intrahepatic duct capable of initiating propulsive movement. The so-called bile duct movement is most likely passive and should not be interpreted as peristalsis.