EFFECT OF ACUTE HYPERGLYCEMIA ON BASAL AND FAT-INDUCED EXOCRINE PANCREATIC-SECRETION IN HUMANS

1, We have investigated the effect of acute hyperglycaemia on pancreat ico-biliary secretion in healthy subjects, Duodenal outputs of trypsin , lipase, amylase, bicarbonate and bilirubin were measured for 90 min under basal conditions and for 90 min in response to intrajejunal fat administration (1 g/h) on 2 separate days: during normoglycaemia (bloo d glucose 5 mmol/l) and during acute hyperglycaemia aimed at 15 mmol/l , Plasma cholecystokinin levels, as the major hormonal stimulus of pan creatic and biliary secretion, and plasma pancreatic polypeptide level s, as an indirect measure of vagal-cholinergic tone, were determined a t regular intervals, 2, In the basal period pancreatico-biliary secret ion was significantly (P<0.05) reduced during hyperglycaemia compared with normoglycaemia. During normoglycaemia and hyperglycaemia intrajej unal fat significantly (P<0.05) stimulated pancreaticobiliary secretio n, However, during hyperglycaemia, fat-stimulated 90 min pancreatico-b iliary secretion was significantly (P<0.05) reduced compared with norm oglycaemia: trypsin (23 +/- 7 units versus 66 +/- 20 units), lipase (3 6 +/- 8 k-units versus 74 +/- 18 k-units), amylase (8 +/- 2 k-units ve rsus 18 +/- 5 k-units) and bilirubin (32 +/- 8 mu mol versus 71 +/- 14 mu mol). Plasma cholecystokinin levels increased significantly (P<0.0 5) during fat administration and were not different between the two ex periments, Plasma pancreatic polypeptide levels were significantly (P< 0.05) reduced during hyperglycaemia both in the basal period and durin g intrajejunal fat administration, 3, It is concluded that basal and f at-stimulated pancreatico-biliary secretion are significantly reduced during acute hyperglycaemia. Acute hyperglycaemia does not affect intr ajejunal fat-stimulated cholecystokinin secretion, Acute hyperglycaemi a inhibits basal and stimulated pancreatic polypeptide secretion sugge sting vagal-cholinergic inhibition of pancreatico-biliary secretion du ring hyperglycaemia.