Premium
Transport of Prostaglandins and Other Eicosanoids by the Choroid Plexus: Its Characterization and Physiological Significance
Author(s) -
DiBenedetto F. E.,
Bito L. Z.
Publication year - 1986
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.1471-4159.1986.tb08490.x
Subject(s) - choroid plexus , ouabain , chemistry , medicine , endocrinology , biochemistry , biology , sodium , central nervous system , organic chemistry
Choroid plexi from the lateral ventricles of rabbits, cats, and dogfish ( Mustelus canis ) were used to characterize the prostaglandin (PG) uptake process and to establish its kinetic parameters and substrate specificity. The apparent K t for PGF 2α transport by the rabbit choroid plexus was 20 μ M ; the J max was 27 nmol g −1 mm −1 . The K i of inhibition of PGF 2α transport by PGE 2 was 20 μ M ; the J max of PGF 2α transport was unaltered by PGE 2 . A concentration of p ‐aminohippuric acid of up to 1 m M did not appreciably affect the K 1 or the J max of PGF 2α transport. The rate of PGF 2α accumulation by rabbit choroid plexus was reduced by incubation at 4°C, under anaerobic conditions, in the absence of sodium or in the presence of ouabain, probenecid, or bromcresol green. The choroid plexi of all three species also accumulated thromboxane B 2 , PGI 2 , and 6‐keto‐PGF 1α , suggesting that most, if not all, eicosanoids are substrates for this transport system. It is concluded that the choroid plexus transport system satisfies all the criteria of an active, energy‐dependent transport system and that this system functions effectively at concentrations of eicosanoids present in the ventricular system under normal or pathological conditions. Hence, this transport system must make an important contribution to the pharmacokinetics of eicosanoids within the brain.