5-hydroxytryptamine strongly inhibits fluid secretion in guinea pig pancreatic duct cells

Citation
A. Suzuki et al., 5-hydroxytryptamine strongly inhibits fluid secretion in guinea pig pancreatic duct cells, J CLIN INV, 108(5), 2001, pp. 749-756
Citations number
36
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Medical Research General Topics
Journal title
JOURNAL OF CLINICAL INVESTIGATION
ISSN journal
0021-9738 → ACNP
Volume
108
Issue
5
Year of publication
2001
Pages
749 - 756
Database
ISI
SICI code
0021-9738(200109)108:5<749:5SIFSI>2.0.ZU;2-7
Abstract
We studied the distribution of 5-hydroxytryptamine- (5-HT-) containing cell s in the guinea pig pancreas and examined the effects of 5-HT on fluid secr etion by interlobular pancreatic ducts. The 5-HT-immunoreactive cells with morphological characteristics of enterochromaffin (EC) cells were scattered throughout the duct system and were enriched in islets of Langerhans. The fluid secretory rate in the isolated interlobular ducts was measured by vid eomicroscopy. Basolateral applications of 5-HT strongly but reversibly redu ced HCO3-dependent, as well as secretin- and acetylcholine- (ACh-) stimulat ed, fluid secretion.,whereas 5-HT applied into the lumen had no such effect s. Secretin-stimulated fluid secretion could be inhibited by a 5-HT3 recept or agonist, but not by agonists of the 5-HT1, 5-HT2, or 5-HT4 receptors. Un der the stimulation with secretin, 5-HT decreased the intracellular pH (pH( i)) and reduced the rate of pH(i) recovery after acid loading with NH4+, su ggesting that 5-HT inhibits the intracellular accumulation of HCO3-. The el evation of intraductal pressure in vivo reduced secretin-stimulated fluid s ecretion, an effect that could be attenuated by a 5-HT3 receptor antagonist . Thus, 5-HT3 acting through basolateral 5-HT3 receptors, strongly inhibits spontaneous, secretin-, and ACh-stimulated fluid secretion by guinea pig p ancreatic ducts. 5-HT released from pancreatic ductal EC cells on elevation of the intraductal pressure may regulate fluid secretion of neighboring du ct cells in a paracrine fashion.