A primary culture of guinea pig gallbladder epithelial cells that is responsive to secretagogues

We have developed a cell culture of guinea pig gallbladder epithelial cells with which to study ion transport. When grown on permeable supports, the c ultured epithelia developed a transepithelial resistance (R-t) of similar t o 500 Omega .cm(2). The epithelial cell origin of the cell culture was furt her confirmed by immunocytochemical localization of cytokeratin. Ionomycin and forskolin increased transepithelial voltage and short-circuit current ( I-sc) and decreased R-t. The response to ionomycin was transient, whereas t hat to forskolin was sustained. Both were attenuated by replacement of Cl- and/or HCO3-. Mucosal addition of the anion transport inhibitors DIDS or di phenylamine-2-carboxylic acid (DPC) blocked the response to ionomycin. The response to forskolin was blocked by DPC but not by DIDS. Ionomycin, but no t forskolin, increased intracellular Ca2+ concentration in fura 2-loaded ce lls. PGE(2), histamine, vasoactive intestinal polypeptide, and secretin eli cited a sustained increase in I-sc. Responses to ATP and CCK were transient . Thus cultured guinea pig gallbladder epithelia display the range of respo nses observed in the native tissue and are an appropriate model for studies of ion transport in gallbladder and intestinal epithelia.