ULTRASTRUCTURAL-CHANGES OF FEMALE SYRIAN-HAMSTER CYSTIC DUCT EPITHELIUM AS A RESULT OF SEX STEROID TREATMENT

In view of the lack of sufficient data regarding the morphology of the cystic duct and the extensive focus on the gallbladder, a preliminary examination of the cystic duct response to female sex steroid treatme nt was conducted to follow up a detailed ultrastructural study of the gallbladder epithelial response to a similar treatment. As observed in the gallbladder epithelium, the cystic duct epithelial cells of nulli parous Syrian hamsters demonstrate morphologic changes in response to female sex steroid treatment. Control (C) cystic duct epithelial cells are covered by short microvilli and each cell appears to exhibit a si ngle vestigial cilium. Estrogen (E)- and estrogen+medroxyprogesterone (E+MP)- treatments induce differential duct cell morphologic changes. These changes are the result of steroid treatments in the significant decreasing sequence E>E+MP>C for nuclear volume, indentations and peri nuclear lysosomal/lipofuscin bodies. Moreover E+MP-treatment results i n larger cytoplasmic volume and more sloughing of apical cell excresce nces than following E treatment. It is suggested that, similar to that in the gallbladder, the action of progestin is paramount in favoring cytoplasmic morphological changes in the cystic duct which, along with the alteration of mucus, cell sloughing, decreased bile acids and mot ility could also participate in the gallstone nucleation process as th ey are brought into the gallbladder with the incoming bile flow.