Inhibition of gastric acid secretion in rat stomach by PACAP is mediated by secretin, somatostatin, and PGE2
| Autor: | Ta-Min Chang, D. Coy, P. Li, William Y. Chey |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Physiology Indomethacin In Vitro Techniques Biology Histamine Release Dinoprostone Secretin Gastric Acid Rats Sprague-Dawley Physiology (medical) Internal medicine medicine Animals Secretion Hepatology Portal Vein Immune Sera Stomach Neuropeptides Gastroenterology Rats Pituitary adenylate cyclase-activating peptide Endocrinology Somatostatin medicine.anatomical_structure Gastrointestinal hormone Gastric Mucosa Pituitary Adenylate Cyclase-Activating Polypeptide Gastric acid Pentagastrin Enteric nervous system hormones hormone substitutes and hormone antagonists |
| Zdroj: | American Journal of Physiology-Gastrointestinal and Liver Physiology. 278:G121-G127 |
| ISSN: | 1522-1547 0193-1857 |
| Popis: | Pituitary adenylate cyclase-activating polypeptide (PACAP), existing in two variants, PACAP-27 and PACAP-38, is found in the enteric nervous system and regulates function of the digestive system. However, the regulatory mechanism of PACAP on gastric acid secretion has not been well elucidated. We investigated the inhibitory action of PACAP-27 on acid secretion and its mechanism in isolated vascularly perfused rat stomach. PACAP-27 in four graded doses (5, 10, 20, and 50 μg/h) was vascularly infused to determine its effect on basal and pentagastrin (50 ng/h)-stimulated acid secretion. To study the inhibitory mechanism of PACAP-27 on acid secretion, a rabbit antisecretin serum, antisomatostatin serum, or indomethacin was administered. Concentrations of secretin, somatostatin, PGE2, and histamine in portal venous effluent were measured by RIA. PACAP-27 dose-dependently inhibited both basal and pentagastrin-stimulated acid secretion. PACAP-27 at 10 μg/h significantly increased concentrations of secretin, somatostatin, and PGE2in basal or pentagastrin-stimulated state. The inhibitory effect of PACAP-27 on pentagastrin-stimulated acid secretion was reversed 33% by an antisecretin serum, 80.0% by an antisomatostatin serum, and 46.1% by indomethacin. The antisecretin serum partially reduced PACAP-27-induced local release of somatostatin and PGE2. PACAP-27 at 10 μg/h elevated histamine level in portal venous effluent, which was further increased by antisomatostatin serum. However, antisomatostatin serum did not significantly increase acid secretion. It is concluded that PACAP-27 inhibits both basal and pentagastrin-stimulated gastric acid secretion. The effect of PACAP-27 is mediated by local release of secretin, somatostatin, and PGE2in isolated perfused rat stomach. The increase in somatostatin and PGE2levels in portal venous effluent is, in part, attributable to local action of the endogenous secretin. |
| Databáze: | OpenAIRE |
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