title: Effects of hydrochloric acid on duodenal and jejunal mucosal permeability in the rat.
abstract: The effects of various concentrations of hydrochloric acid (1, 5, 10, and 100 mM) on mucosal permeability and acid disappearance (H+-dis) in duodenum and jejunum were studied in anesthetized rats. Mucosal permeability was assessed by measuring blood-to-lumen clearance of 51Cr-labeled EDTA (ED-Cl). Luminal alkalinization (LA) and H+-dis were determined by backtitration. ED-Cl was stable during saline perfusion and was not affected by changes in intestinal blood flow. Basal ED-Cl was four times higher in duodenum than in jejunum. Mucosal permeability of both duodenum and jejunum was not altered by 1 mM HCl. However, 5 mM HCl induced a 3.3-fold increase (P less than 0.001) in ED-Cl in jejunum but was without effect in duodenum. A 15-fold increase in ED-Cl was obtained in jejunum and a doubling (P less than 0.001) in ED-Cl was observed in duodenum when HCl concentration was increased to 10 mM HCl. One hundred millimolar HCl induced large increases of ED-Cl in both segments. The twofold increase of ED-Cl in response to 10 mM HCl in duodenum was completely reversible, whereas ED-Cl in jejunum was three to four times higher (P less than 0.05) than preacid levels 60 min after cessation of acid perfusion. The net increase in jejunal ED-Cl obtained after acid exposure was closely correlated (r = 0.99) with the net increase in LA, indicating leakage of interstitial fluid into the luminal solution. LA (saline perfusion) and H+-dis (HCl perfusion) were significantly higher in duodenum than in jejunum.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Physiology and Medical Biophysics, Louisiana State University Medical Center, Shreveport 71130-3932.
authors.forename: O
authors.initials: O
authors.lastname: Nylander
authors.forename: P
authors.initials: P
authors.lastname: Kvietys
authors.forename: D N
authors.initials: DN
authors.lastname: Granger
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002860:Chromium Radioisotopes; D004386:Duodenum / Q000098:blood supply / Q000502:physiology*; D006851:Hydrochloric Acid / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000187:drug effects / Q000502:physiology*; D007583:Jejunum / Q000098:blood supply / Q000502:physiology*; D008297:Male; D009130:Muscle, Smooth / Q000098:blood supply / Q000502:physiology; D010539:Permeability; D011865:Radioisotope Dilution Technique; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012039:Regional Blood Flow / Q000187:drug effects; D014667:Vasopressins / Q000494:pharmacology
chemical_list: D002860:Chromium Radioisotopes; D014667:Vasopressins; D000241:Adenosine; D006851:Hydrochloric Acid