## Abstract The brain capillary endothelium is a formidable barrier to entry of foreign chemicals into the central nervous system (CNS). For the most part it poorly distinguishes between therapeutics and neurotoxins and thus the blood‐brain barrier both protects the brain from toxic chemicals and l
Regional transport of phenylalanine across the blood-brain barrier
✍ Scribed by Michael Pollay
- Publisher
- John Wiley and Sons
- Year
- 1976
- Tongue
- English
- Weight
- 476 KB
- Volume
- 2
- Category
- Article
- ISSN
- 0360-4012
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✦ Synopsis
Abstract
In adult rats, using the single‐pass brain uptake technique with a tritiated water standard, L‐phenylalanine was shown to enter brain across the blood‐brain barrier (BBB) by both a saturable and diffusionary process. A kinetic analysis of the data revealed Michaelis constant (K~a~) of 0.42 mM and V ~max~ of 35 nmoles g^−1^ min^−1^ The saturable component of L‐phenylalanine transport was adversely affected by dinitrophenol or low sodium concentration in the intracarotid injection solution. Intravascular ouabain did not affect transport and only partial inhibition was observed with 1.5 mM L‐leucine. It appears that there is no regional difference in the capacity of the BBB to more L‐phenylalanine from blood to brain. This process is directly or indirectly coupled to sodium movement and is partially dependent on cellular energy.
📜 SIMILAR VOLUMES
The influence of plasma zinc concentration on the rate of zinc transport into the brain was examined using an in vitro model of the blood-brain barrier. The model was constructed by culturing porcine brain capillary endothelial cells on porous membrane filters suspended between two chambers of fluid