EFFECTS OF INTRAVENOUS INFUSIONS OF CHOLECYSTOKININ (CCK)-8 ON EXOCRINE AND ENDOCRINE PANCREATIC-SECRETION IN CONSCIOUS SHEEP

The effects of cholecystokinin (CCK)-8 on both exocrine and endocrine pancreatic functions were examined simultaneously in five conscious sh eep. Intravenous infusions of CCK-8 (0, 5, 10, 20, 30, 60, 120 and 240 pmol/kg/min for 40 min) induced dose-dependent increases in flow rate , and in protein and amylase outputs in pancreatic juice. The same CCK -8 infusions induced dose-dependent increases in plasma insulin, but n o change in plasma glucagon concentrations. The threshold dose (10-30 pmol/kg/min) of CCK-8 infusion for stimulating insulin secretion was s imilar to that for stimulating amylase output. In conclusion, using am ylase output as an indicator of physiological action, CCK is one of th e potential candidates as a physiological regulator of insulin, but no t glucagon secretion in sheep.