6533b82efe1ef96bd1293c95
RESEARCH PRODUCT
Effect of vasoactive intestinal polypeptide on the release of serotonin from the in vitro vascularly perfused small intestine of guinea pig.
Heinz KilbingerKurt RackéH. Schwörersubject
Malemedicine.medical_specialtySerotoninMetaboliteVasoactive intestinal peptideGuinea PigsTetrodotoxinBiologyIn Vitro TechniquesGuinea pigchemistry.chemical_compoundInternal medicineIntestine SmallmedicineAnimalsPharmacologyMuscle SmoothGeneral MedicineHydroxyindoleacetic AcidSmall intestineEndocrinologymedicine.anatomical_structurenervous systemGastrointestinal hormonechemistryEnterochromaffin cellTetrodotoxinSerotoninhormones hormone substitutes and hormone antagonistsMuscle ContractionVasoactive Intestinal Peptidedescription
Isolated segments of the guinea pig small intestine were vascularly perfused and the release of endogenous serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) into the portal vein was measured. All test substances were intraarterially perfused. Vasoactive intestinal polypeptide (VIP, 1 pmol/l-100 nmol/l) inhibited the spontaneous release of 5-HT and 5-HIAA. The maximal inhibitory effect (about 60%) was seen at 100 pmol/l. The effect of VIP on the spontaneous release of 5-HT and 5-HIAA was not changed in the presence of 1 mumol/l tetrodotoxin (TTX). Raising intraluminal pressure by 500 Pa for 5 min increased the release of 5-HT and 5-HIAA by about 25%. Raising the intraluminal pressure in the presence of VIP reduced the release of 5-HT and 5-HIAA by about 75%. In the presence of TTX (1 mumol/l), raising intraluminal pressure also caused a decrease of the release of 5-HT and 5-HIAA which was unaffected by the additional presence of VIP. The fluid volume expelled during peristaltic activity was not affected by VIP, but reduced by about 90% in the presence of TTX. In conclusion the results demonstrate a direct inhibitory effect of VIP on the release of 5-HT from the enterochromaffin cells. In addition, VIP appears to interfere with the neuronally mediated stimulation of 5-HT release during peristaltic activity.
year | journal | country | edition | language |
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1989-05-01 | Naunyn-Schmiedeberg's archives of pharmacology |