INTERLEUKIN-6 REGULATION OF CCK GASTRIN RECEPTORS AND AMYLASE SECRETION IN A RAT PANCREATIC ACINAR CELL-LINE (AR4-2J)

In necrotizing pancreatitis a high interleukin-6 (IL-6) serum level has been proposed as a prognostic criterium. However, literature does not report any information about the role of IL-6 in the function of pancreatic acinar cells. Cholecystokinin, gastrin binding, amylase release and intracellular calcium measurement were performed on a rat pancreatoma cell line, AR4-2J, which has been recognized as a useful tool for studies on the long-term regulation of pancreatic acinar cells. The addition of IL-6 (400 pM) for 48hrs to the AR4-2J cells induced no change in the binding affinities but there was a 2 fold increase in the binding capacity of cholecystokinin (CCKA R) and gastrin (CCKB R) receptors. Although IL-6 treatment did not change directly the secretory capacity and did not activate the intracellular calcium mobilization of AR4-2J, it indirectly increased the sensitivity of the cells to the stimulation of amylase release and the intracellular calcium mobilization by cholecystokinin and gastrin. It is most likely this effect was due to the IL-6-induced increase in the numbers of CCKA R and CCKB R. Therefore this report suggests that the cytokine IL-6 acts on the CCK regulation of pancreatic enzyme secretion.