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Effect of Dexamethasone on Transport of α‐Aminoisobutyric Acid and Sucrose Across the Blood‐Brain Barrier
Author(s) -
Ziylan Y. Z.,
LeFauconnier J. M.,
Bernard G.,
Bourre J. M.
Publication year - 1988
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1988.tb01094.x
Subject(s) - aminoisobutyric acid , dexamethasone , blood–brain barrier , sucrose , chemistry , medicine , endocrinology , biophysics , biochemistry , amino acid , biology , central nervous system
The effect of glucocorticoids on the blood‐brain barrier (BBB) was studied in rats following a single injection or 3 days of dexamethasone administration. Tracers with a low permeability across the intact endothelium, [ 14 C]sucrose and α‐[ 3 H]aminoisobutyric acid ([ 3 H]AIB), were simultaneously injected intravenously in untreated rats or in rats treated with dexamethasone. Unidirectional blood‐to‐brain transfer constants ( K i ) in 14 regions of the rat brain were determined. In regions of control brain, average K i values for AIB and sucrose were ∼0.0020 and 0.00060 ml g −1 min −1 , respectively. The lowest transfer constants were found in caudate nucleus, hippocampus, white matter, and cerebellum. In dexamethasone‐treated animals, K i values for both sucrose and AIB markedly decreased by 30‐50% in almost all brain regions. These results indicate that a single injection or 3 days of treatment with dexamethasone causes an apparent reduction in the normal BBB permeability, and dexamethasone may greatly interfere with drug delivery into brain. These observations may have an importance for the administration of drugs in brain disease in the presence of steroids.