INHIBITORY EFFECT OF INTRADUODENAL ADMINISTRATION OF SOMATOSTATIN ANALOG SDZ-CO-611 ON RAT PANCREATIC EXOCRINE SECRETION

The inhibitory effect of the intraduodenal administration of a new som atostatin analogue, SDZ CO 611 (SDZ), on pancreatic secretion was eval uated in the rat. The exocrine pancreas was stimulated by either intra venous infusion of both secretin (0.06 CU/kg/h) and cholecystokinin oc tapeptide (CCK-8) (0.03 mug/kg/h) or intraduodenal infusion of oleic a cid (0.25 mmol/h) or casein (200 mg/h). Intraduodenal administration o f SDZ in three different doses, 0.5, 1.0, and 2.0 mg/kg/h, resulted in dose-related inhibition of pancreatic secretion, including juice volu me, bicarbonate, and amylase, stimulated by exogenous secretin and CCK . Intraduodenal oleic acid- and casein-induced increases in pancreatic secretion in terms of juice volume, bicarbonate, and amylase were als o significantly suppressed by intraduodenal administration of SDZ in a dose of 2.0 mg/kg/h. Moreover, SDZ (2.0 mg/kg/h) significantly inhibi ted basal pancreatic secretion. It is concluded that the intraduodenal administration of SDZ inhibits pancreatic secretion stimulated by exo genous secretin and CCK-8 in physiological doses and by intestinal nut rients in the rat.