title: Effect of atropine and somatostatin on bombesin-stimulated plasma gastrin, cholecystokinin and pancreatic polypeptide in man.
abstract: Infusion of the neuropeptide bombesin stimulates the secretion of several gastrointestinal hormones by an unknown mechanism. We have investigated the effects of atropine (15 ng/kg as bolus followed by 2.5 ng/kg X 30 min) and somatostatin (125 micrograms as i.v. bolus followed by 62.5 micrograms/30 min) on the stimulation of 3 hormones (gastrin, cholecystokinin and pancreatic polypeptide) by 60 pmol/kg X 20 min bombesin in 6 healthy volunteers. Plasma samples for measurement of hormones by sensitive and specific radioimmunoassays were obtained at -5, 0, 2.5, 5, 7.5, 10, 15, 20, 25 and 30 min. Bombesin induced significant increases in plasma gastrin (12 +/- 2 to 34 +/- 3 pM; P less than 0.0005), cholecystokinin (1.2 +/- 0.2 to 8.9 +/- 0.7 pM; P less than 0.0001) and pancreatic polypeptide (22 +/- 4 to 72 +/- 19 pM; P less than 0.05). There were great differences between the effects of atropine and somatostatin on the hormonal responses to bombesin. Atropine slightly increased the response of gastrin by 19% and that of cholecystokinin by 15%, but strongly inhibited the bombesin-stimulated pancreatic polypeptide secretion by 97%. On the other hand, somatostatin inhibited the bombesin-induced secretion of gastrin by 48%, cholecystokinin by 82% and pancreatic polypeptide by 107%. These results point to considerable qualitative and quantitative differences in the stimulatory mechanisms of bombesin on the hormones studied.
mesh_terms: D000293:Adolescent; D000328:Adult; D001285:Atropine / Q000494:pharmacology*; D001839:Bombesin / Q000097:blood / Q000494:pharmacology*; D002766:Cholecystokinin / Q000097:blood*; D005260:Female; D005755:Gastrins / Q000097:blood*; D006801:Humans; D008297:Male; D010191:Pancreatic Polypeptide / Q000097:blood*; D013004:Somatostatin / Q000494:pharmacology*
chemical_list: D005755:Gastrins; D013004:Somatostatin; D010191:Pancreatic Polypeptide; D001285:Atropine; D002766:Cholecystokinin; D001839:Bombesin