Recently, there has been a great deal of interest in the role of cytokines in acute pancreatitis. Serum levels of IL-1, IL-6, and TNF-alpha have been demonstrated to be elevated in acute pancreatitis. We hypothesized that cytokines may be produced primarily by pancreatic parenchymal cells. Reasoning that ductal epithelium is the cell type most likely to be exposed to noxious stimuli in common causes of pancreatitis, such as ERCP and passage of a gallstone, we examined the response of well differentiated pancreatic ductal adenocarcinoma cell lines to stimuli known to stimulate cytokine production in other cells. CAPAN-1 and CAPAN-2 cells were incubated with endotoxin or TNF-alpha. The supernatant was assayed for production of IL-1, IL-6, and IL-8 by ELISA. The cells were assayed for activation of the transcription factor NF-kappaB by electrophoretic mobility shift assay. There was no detectable production of IL-1 by either cell line. CAPAN-1 cells had concentration-dependent production of IL-6 and IL-8 in response to both endotoxin and TNF-alpha. CAPAN-2 cells had concentration-dependent production of IL-6 and IL-8 in response to TNF-alpha. They had low level expression of IL-8 that was unaffected by any concentration of LPS, and no detectable production of IL-6 in response to LPS. These findings suggest that pancreatic duct cells may take an active part in the pathogenesis of acute pancreatitis through the production of cytokines.