Results

Normal pancreas tissue (N= 56) was obtained from organ donors; isolation of highly enriched exocrine fraction consistently yielded epithelial cultures. In vitro proliferation assays revealed a lag growth phase of 2 days followed by a proliferative phase until 8. Epithelial cells formed a polarized monolayer displaying apical microvilli, tight junctions, and desmosomes. Zymogen granules were not observed. A panel of mouse monoclonal antibodies detecting differentiation antigens of epithelial cells was used to determine the phenotype of the cultures: all cells expressed cytokeratin polypeptides of simple epithelial (CK 7, CK 8, CK 18, and CK 19), whereas polypeptides typical of stratified epithelial (CK 5, CK 10, CK 13, and CK 16) were not detected. Cultured cells expressed the MUC1 apomucin as well as mucin-associated carbohydrate epitopes. Expression of the cystic fibrosis transmembrane regulator was demonstrated at the RNA level. Secretin induced a very high stimulation of cAMP levels.

Conclusions

The ultrastructural characteristics, molecular markers, and hormone responsiveness of the cultures suggest a ductal cell phenotype. These cultures should be useful in the analysis of pancreas growth and differentiation.