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Mechanisms of acid damage to oesophageal epithelium: role of the paracellular pathway
Author(s) -
ORLANDO R. C.
Publication year - 1990
Publication title -
journal of internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.625
H-Index - 160
eISSN - 1365-2796
pISSN - 0954-6820
DOI - 10.1111/j.1365-2796.1990.tb01472.x
Subject(s) - paracellular transport , transcellular , epithelium , extracellular , bicarbonate , microbiology and biotechnology , respiratory epithelium , biophysics , biochemistry , medicine , chemistry , biology , pathology , permeability (electromagnetism) , membrane
. The mechanisms of acid damage to oesophageal epithelium are incompletely understood. In particular, it is unclear whether luminal acid enters and damages the oesophageal epithelium by traversing the paracellular and/or transcellular route. The present paper describes studies of the role of serosal bicarbonate ions (HCO 3 − ) in oesophageal protection against acid damage, the results of which have direct implications regarding the route of H + entry. The results indicate that HCO 3 − protects by buffering H + within the intercellular compartment of the extracellular space, and that this protection can be mimicked almost completely by replacement of serosal HCO 3 − with HEPES (N‐2‐hydroxyethylpiperazine‐N′‐2‐ethane sulphonic acid), a buffer that cannot permeate cells. These findings support the hypothesis that luminal acid damages oesophageal epithelium primarily by H + diffusion through the paracellular pathway.