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Mobilization of the hormone‐sensitive calcium pool increases hepatocyte tight junctional permeability in the perfused rat liver
Author(s) -
Llopis Juan,
Kass George E.N.,
Duddy Steven K.,
Farell Geoffrey C.,
Gahm Annie,
Orrenius Sten
Publication year - 1991
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(91)80209-l
Subject(s) - horseradish peroxidase , paracellular transport , hepatocyte , chemistry , tight junction , permeability (electromagnetism) , endoplasmic reticulum , intracellular , microbiology and biotechnology , medicine , endocrinology , biochemistry , biology , enzyme , in vitro , membrane
Hepatocyte tight junctional permeability has been shown to be regulated by hormones that exert their effects via phospholipase C activation. However, the precise transduction pathway involved in this effect is not known. The present study has employed the selective inhibitor of microsomal Ca 2+ sequestration, 2,5‐di( tert ‐butyl)‐1,4‐benzohydroquinone (tBuBHQ), to examine the effect of the mobilization of the endoplasmic reticular Ca 2+ pool on tight junctional permeability in the perfused rat liver. Infusion of tBuBHQ followed by a bolus infusion of horseradish peroxidase (HRP) resulted in a significant increase in the first peak of biliary HRP, a measure of junctional permeability, whereas transcellular (vesicular) transport of HRP was not affected. Therefore, we conclude that the effect of hormones on tight junctional permeability is mediated, at least in part, by the mobilization of intracellular Ca 2+ .