ISSN:
1432-0878
Keywords:
Key words: Autoradiography
;
Glutamic acid transport
;
Blood-brain barrier
;
Dicarboxylic acid
;
Rat (Long Evans)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract. The permeability of the blood-brain barrier to glutamate was measured by quantitative autoradiography in brains of control rats (average plasma glutamate concentration of 95 μm) and rats infused with glutamate (average plasma glutamate concentration of 837 μm). Measurements of glutamate permeability were initiated by the injection of [14C]glutamate and stopped at 1 min to avoid the accumulation of [14C]glutamate metabolites. Glutamate entered the brain at a slow rate, with an average permeability-surface area product of 7 μl·min–·g–1, except in those areas known to have fenestrated capillaries. Glutamate accumulated in the choroid plexus of ventricles, but did not seem to enter the cerebrospinal fluid in detectable amounts regardless of the circulating concentration. Glutamate accumulated in circumventricular organs, such as the median eminence, where the radioactivity was localized without detectable spread. Infusion of glutamate to create high plasma concentrations did not result in greater spread of [14C]glutamate beyond the immediate vicinity of the circumventricular organs.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00583389
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