title: AlF4- and vanadate stimulate chloride secretion in rabbit colon by a Ca(2+)-dependent mechanism.
abstract: Stripped rabbit descending colon mucosae were studied in vitro in modified Ussing chambers to determine the effects of AlF4- and vanadate on Cl- transport. Serosal additions of AlF4- and vanadate increase short circuit current (Isc) and tissue conductance, while luminal addition of the agents is ineffective. Addition of aluminium potentiates the effect of NaF on Isc. AlF4- and vanadate increase serosal-to-mucosal flux of 36Cl without affecting mucosal-to-serosal flux. The effects of these agents on Isc are markedly inhibited by serosal addition of bumetanide and depend on the presence of Na+ in the serosal bathing solution. The effects of AlF4- and vanadate on Isc are dependent on the presence of Ca2+ in the bathing solution, and are completely inhibited by indomethacin, but the effect of forskolin is not affected by the removal of Ca2+ from the bathing solution and the addition of indomethacin. AlF4- and vanadate significantly increase the level of inositol phosphate metabolites. The results indicate that AlF4- and vanadate increase Cl- secretion in the rabbit colon via an increase in prostaglandin synthesis which is mediated by the increase of intracellular Ca2+ concentrations.
authors.affiliation: Department of Physiology, College of Medicine, Pusan National University, Korea.
authors.forename: J S
authors.initials: JS
authors.lastname: Jung
authors.forename: T H
authors.initials: TH
authors.lastname: Hwang
authors.forename: D K
authors.initials: DK
authors.lastname: Jung
authors.forename: Y K
authors.initials: YK
authors.lastname: Kim
authors.forename: S H
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000535:Aluminum / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism*; D005576:Colforsin / Q000494:pharmacology; D003106:Colon / Q000378:metabolism*; D005459:Fluorides / Q000494:pharmacology*; D011817:Rabbits; D014638:Vanadates / Q000494:pharmacology
chemical_list: D002712:Chlorides; D005576:Colforsin; D014638:Vanadates; D000535:Aluminum; D005459:Fluorides; D002118:Calcium