In order to observe the plasma gastrin, secretin and pancreatic polypeptide (PP) levels in an acid hypersecretion state, the pyloric antrum was transposed onto the transverse colon in 4 mongrel dogs with a Heidenhain pouch. The effects of meal and cimetidine on these gut hormones and acid secretion levels were observed for 6 hr after meals. After antrocolic transposition (ACT), hypersecretion of acid and high plasma gastrin levels were observed both in the fasting and stimulated states. Plasma secretin levels were elevated for 6 postprandial hr, but were reduced by cimetidine as a result of marked suppression of acid secretion. Plasma PP levels also increased for 6 postprandial hr, but its responses were not altered with or without simultaneous administration of cimetidine. These findings indicate that acid hypersecretion in basal and postprandial states after ACT may be attributed to hypergastrinemia and that endogenous acid is capable of releasing secretin but not effective on the release of PP. gastric acid ; intraduodenal pH ; gastrin ; secretin ; pancreatic polypeptide It is well known that plasma secretin (Koizumi et al. 1980) and PP (Kayasseh et al. 1978) concentration significantly increases as hydrochloric acid is infused into the duodenum. The effect of physiological stimulus such as meal and gastric acid on plasma secretin and PP release, however, has not been elucidated in detail.It is important to examine the effect of endogenously released gastric acid on plasma secretin and PP response for the elucidation of release mechanism and furthermore of a physiological role of these gut hormones in gastrointestinal

We studied the effects of atropine, both in the basal state and after stimulation by modified sham feeding (MSF), and the effect of MSF alone, on the plasma gastrin and pancreatic polypeptide (PP) responses in 8 healthy human subjects. Atropine 1 mg in the basal state had no effect on the plasma gastrin concentrations but led to significant decrease in plasma PP concentrations. Plasma gastrin response to MSF was negligible but increased by atropine. The plasma PP level was markedly increased by MSF, and was antagonized by atropine. This study shows that the release of plasma PP during basal state and after MSF is under the control of the vagalcholinergic mechanism, but plasma gastrin is controlled by a different mechanism.gastrin ; pancreatic polypeptide ; atropine ; sham feedingEffects of atropine on plasma gastrin in man in the basal level and in the vagally mediated stimulation have been reported by several authors but are still a subject of controversy. On the other hand, PP is a recently characterized 36 amino acid peptide, discovered by Kimmel et al. (1968) and by Lin and Chance (1974) independently.But the release mechanism involving cephalic phase of plasma PP has not been elucidated in detail as yet. The purpose of the present study was to evaluate the effect of vagal stimulation archieved by sham feeding and the effect of the cholinergic blockade, atropine, on the gastrin and PP response both in the basal state and after stimulation by sham feeding in man. MATERIALS AND METHODSEight healthy volunteers (mean age 21 years, range 20-23 years) free from gastrointestinal disease participated as subjects in this study. On separate test days, three series of tests (A, B, C) were performed in random order after overnight fast on each subject.A. Effect of atropine during the basal state. After a 120-min control period, 1 mg of atropine sulfate (Tanabe, Osaka) was injected intramuscularly. Blood samples were taken