Growth and function of isolated canine pancreatic ductal cells

These studies investigated the growth characteristics and functional proper ties of isolated canine pancreatic ductal epithelial cells. Cells were isol ated from the accessory pancreatic duct and cultured by using three conditi ons: on vitrogen-coated petri dishes with fibroblast conditioned medium (no npolarized); in vitrogen-coated Transwells above a fibroblast feeder layer (polarized); or as organotypic rafts above a fibroblast-embedded collagen l ayer (polarized). Growth characteristics, transepithelial resistances, and carbonic anhydrase and cyclic adenosine monophosphate (AMP) responses were evaluated. Under polarized conditions, the cells grew as monolayers with co lumnar epithelial characteristics. The monolayers developed high transepith elial resistance and became impervious to the passage of horseradish peroxi dase. Epithelial growth factor (EGF) (2 ng/ml) stimulated ductal cell growt h and accelerated the formation of a high-resistance monolayer. Forskolin ( 10 mu M) rapidly decreased transepithelial resistance. Carbonic anhydrase a ctivity, which was lower in nonpolarized compared with polarized conditions , was stimulated by carbachol (175 mu M). Secretin, however, did not stimul ate carbonic anhydrase activity in these cells. Although secretin stimulate d adenylyl cyclase activity in early-passage cells, this response was lost in later-passage cells. Both vasoactive intestinal polypeptide (VIP; 1 mu M ) and forskolin (10 mu M) consistently increased adenylyl cyclase activity. Isolated canine pancreatic ductal epithelial cells proliferate in vitro, d evelop high resistance epithelial monolayers, and respond to stimuli that a ctivate adenylyl cyclase. These cells should provide a useful model for reg ulatory studies of ductal cell functions.