The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 

Guanylin strongly stimulates rat duodenal HCO3- secretion: proposed mechanism and comparison with other secretagogues.

BACKGROUND & AIMS: Guanylin and heat-stable enterotoxin ( STa) stimulate intestinal Cl- secretion via activation of the cystic fibrosis transmembrane regulator (CFTR)-encoded Cl- channel. It was speculated that CFTR activation also regulates electrogenic duodenal HCO3- secretion. Therefore, the effect of guanylin/ STa and other secretagogues on rat duodenal HCO3- secretion was studied. METHODS: The HCO3- secretory rate of in vitro rat proximal duodenum was determined by pH stat titration and paracellular permeability by 3H-mannitol fluxes, bidirectional 36Cl- fluxes were measured, and the short-circuit current (Isc) was recorded. RESULTS: Luminal guanylin and STa concentration dependently stimulated the HCO3- secretory rate and Isc. Guanylin-stimulated HCO3- secretion was independent of luminal Cl-, inhibited by the Cl- channel blocker 5-nitro-2-(3-phenylpropylamino)-benzoate, and additive to the HCO3- secretory rate stimulated by glucagon and carbachol but not by the tested adenosine 3',5'-cyclic monophosphate (cAMP)-dependent agonists. The ratio of the HCO3- secretory rate/Isc stimulated by the tested guanosine 3',5'-cyclic monophosphate (cGMP)-dependent agonists was markedly higher than the cAMP-dependent agonists. Prostaglandin E2 and 8-bromo-cAMP but not STa/guanylin also transiently increased paracellular permeability. CONCLUSIONS: Guanylin and STa stimulate electrogenic HCO3- secretion in rat duodenum, most likely via CFTR Cl- channel activation, but the different relationship for HCO3- to Isc in cGMP-than in cAMP-stimulated anion secretion suggests a different cellular source and/or signaling pathways.[1]

References

  1. Guanylin strongly stimulates rat duodenal HCO3- secretion: proposed mechanism and comparison with other secretagogues. Guba, M., Kuhn, M., Forssmann, W.G., Classen, M., Gregor, M., Seidler, U. Gastroenterology (1996) [Pubmed]
 
WikiGenes - Universities