Ion transport across isolated antral mucosa of the rabbit.
Isotopic fluxes of Na, Cl, and K were measured across isolated antral mucosa under short-circuit conditions. HCO3 fluxes were also measured with either isotopic and/or pH-stat methods. Net secretion of all four ions was observed. HCO3 secretion is due to a transmural process requiring metabolic energy. Secretion of endogenous HCO3 was not observed, and the unidirectional mucosal-to-serosal flux of HCO3 was negligible. There appears to be a close relationship between HCO3 secretion and the unidirectional mucosal-to-serosal Cl flux, but not relationships were observed between the unidirectional serosal-to-mucosal flux or either unidirectional Na flux. The bulk of HCO3 secretion is independent of the unidirectional Cl fluxes, but there is a fraction of HCO3 transport that is dependent on unidirectional Cl transport. However, HCO3 transport is not measurably influenced by inhibition of net Cl (and Na) transport per se.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001639:Bicarbonates / Q000378:metabolism*; D001693:Biological Transport, Active / Q000187:drug effects; D002712:Chlorides / Q000378:metabolism*; D004976:Ethacrynic Acid / Q000494:pharmacology; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D011706:Pyloric Antrum / Q000187:drug effects / Q000378:metabolism*; D011817:Rabbits; D012964:Sodium / Q000378:metabolism*
D001639:Bicarbonates; D002712:Chlorides; D010042:Ouabain; D012964:Sodium; D004976:Ethacrynic Acid; D000109:Acetylcholine; D011188:Potassium; D009638:Norepinephrine