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Effects of alterations in endothelial cell volume on transendothelial albumin permeability
Author(s) -
Shepard J. M.,
Goderie S. K.,
Brzyski N.,
Del Vecchio P. J.,
Malik A. B.,
Kimelberg H. K.
Publication year - 1987
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041330226
Subject(s) - tonicity , endothelium , permeability (electromagnetism) , albumin , endothelial stem cell , intracellular , mannitol , vascular permeability , microbiology and biotechnology , chemistry , biophysics , biology , biochemistry , endocrinology , in vitro , membrane
Abstract We examined the effects of alterations in endothelial cell volume on transendothelial albumin permeability. Studies were done using a confluent monolayer of bovine pulmonary artery endothelial cells grown on gelatinized microporous filters. When endothelial cells were exposed to media made hypertonic with 200 mM mannitol, the intracellular volume (measured with 14 C‐urea) decreased twofold and remained decreased over a 30‐minute time‐span, thus showing no significant regulatory volume increase (RVI) within this time period. When endothelial cells were exposed to hypotonic media, intracellular volume rapidly doubled within 2 minutes, and then decreased to baseline values within 10 minutes in spite of the sustained hypotonic environment, a process known as regulatory volume decrease (RVD). We also measured the transendothelial flux of 125 l‐albumin with the cells exposed to the same osmotic changes. We observed that only under hypertonic conditions was there a significant change in the 125 l‐albumin permeability. These results indicate that the pulmonary artery endothelial cells in culture alter their cell volume when exposed to variations in the osmotic environment, and also show RVD in response to hypotonic conditions but no RVI within 40 minutes after exposure to hypertonic conditions. The transendothelial albumin permeability did not change under hypotonic conditions but increased under hypertonic conditions. Thus, endothelial cells shrinkage may be an important mechanism of increased endothelial macromolecule permeability. These volume changes may occur in endothelial cells in situ and have a role in inducing alterations in the transendothelial permeability to proteins.