Effect of CCK-octapeptide and secretin on amylase secretion in isolated rat pancreatic acinar cells.

Isolated acinar cells from rat pancreas responded well to hormonal treatment. Both secretin (synthetic and highly purified from porcine origin) and CCK-octapeptide stimulated amylase secretion in these cells. The response in both cases was very rapid. A maximal output of enzyme was reached within 5-10 min after the addition of hormones. The concentration producing maximal output for synthetic secretin (Schwarz/Mann) was 5 x 10(-8) M, synthetic secretin (Squibb), 10(-5) M, for purified porcine secretin, 10(-5) M, and for CCK-octapeptide was 5 x 10(-10) M. Secretin (2-fold at optimal concentration) was found to be less efficient compared to CCK-octapeptide (5-fold at optimal concentration) in stimulating amylase release. A combination of secretin and CCK-octapeptide had a synergistic action in stimulating enzyme release by the acinar cells. In addition, pretreatment of acinar cells with secretin potentiated the secretory response of the treated cells to CCK-octapeptide. To a lesser extent pretreatment with CCK-octapeptide also increased the effect of secretin in stimulating enzyme secretion.