SecretinReceptors, Gastrointestinal HormonePancreatic JuiceCholecystokininPancreasReceptors, G-Protein-CoupledVasoactive Intestinal PeptideSecretory RateGastrointestinal HormonesHydrochloric AcidDuodenumReceptors, Vasoactive Intestinal PeptideBicarbonatesGastrinsAmylasesZollinger-Ellison SyndromePeptide PHICeruletideGastric Juice