Primary culture of human gallbladder epithelial cells.

Growth requirements of epithelial cells isolated from the human gallbladder were examined. The growth of gallbladder epithelial cells (GBEC) was stimulated by medium conditioned with gallbladder fibroblasts (CM-GBF) in a dose-dependent manner. The conditioned medium derived from human embryo lung fibroblasts also showed similar growth stimulating activity for GBEC, suggesting that fibroblasts secrete a factor or factors which induce GBEC growth in vitro. CM-GBF in the presence of 10% fetal bovine serum increased GBEC growth up to 10 times the growth in the absence of CM-GBF supplement. GBEC cultured with CM-GBF showed hexagonal shape under a phase-contrast microscope, and also expressed cytokeratin and mucopolysaccharide in the cytoplasm, both of which are specific for GBEC. Electron microscopy revealed desmosomes and tight junctions between the cells and microvilli on the apical plasma membrane, suggesting that they regained morphological polarity in the medium containing CM-GBF. These results shows that CM-GBF is essential for the growth and the differentiation of GBEC in culture.