Carrier-mediated transport of amino acids through the blood-retinal and the blood-brain barriers

1986 ◽  
Vol 224 (1) ◽  
pp. 21-25 ◽  
Author(s):  
P. Törnquist ◽  
A. Alm
Keyword(s):  
Amino Acids ◽  
Blood Brain ◽  
Carrier Mediated Transport ◽  
Brain Barriers

scholarly journals Transfer of rhodamine-123 into the brain and cerebrospinal fluid of fetal, neonatal and adult rats

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Liam M. Koehn ◽  
Katarzyna M. Dziegielewska ◽  
Mark D. Habgood ◽  
Yifan Huang ◽  
Norman R. Saunders
Keyword(s):  
Cerebrospinal Fluid ◽  
Fetal Brain ◽  
Maternal Blood ◽  
Adult Brain ◽  
Rhodamine 123 ◽  
Patient Specific ◽  
Adult Rats ◽  
Blood Brain ◽  
The Brain ◽  
Brain Barriers

Abstract Background Adenosine triphosphate binding cassette transporters such as P-glycoprotein (PGP) play an important role in drug pharmacokinetics by actively effluxing their substrates at barrier interfaces, including the blood-brain, blood-cerebrospinal fluid (CSF) and placental barriers. For a molecule to access the brain during fetal stages it must bypass efflux transporters at both the placental barrier and brain barriers themselves. Following birth, placental protection is no longer present and brain barriers remain the major line of defense. Understanding developmental differences that exist in the transfer of PGP substrates into the brain is important for ensuring that medication regimes are safe and appropriate for all patients. Methods In the present study PGP substrate rhodamine-123 (R123) was injected intraperitoneally into E19 dams, postnatal (P4, P14) and adult rats. Naturally fluorescent properties of R123 were utilized to measure its concentration in blood-plasma, CSF and brain by spectrofluorimetry (Clariostar). Statistical differences in R123 transfer (concentration ratios between tissue and plasma ratios) were determined using Kruskal-Wallis tests with Dunn’s corrections. Results Following maternal injection the transfer of R123 across the E19 placenta from maternal blood to fetal blood was around 20 %. Of the R123 that reached fetal circulation 43 % transferred into brain and 38 % into CSF. The transfer of R123 from blood to brain and CSF was lower in postnatal pups and decreased with age (brain: 43 % at P4, 22 % at P14 and 9 % in adults; CSF: 8 % at P4, 8 % at P14 and 1 % in adults). Transfer from maternal blood across placental and brain barriers into fetal brain was approximately 9 %, similar to the transfer across adult blood-brain barriers (also 9 %). Following birth when placental protection was no longer present, transfer of R123 from blood into the newborn brain was significantly higher than into adult brain (3 fold, p < 0.05). Conclusions Administration of a PGP substrate to infant rats resulted in a higher transfer into the brain than equivalent doses at later stages of life or equivalent maternal doses during gestation. Toxicological testing of PGP substrate drugs should consider the possibility of these patient specific differences in safety analysis.

Carrier‐Mediated Transport of Amino Acids Through Bulk Liquid Membranes

2004 ◽  
Vol 39 (16) ◽  
pp. 3821-3838 ◽  
Author(s):  
R. Bucci ◽  
S. Canepari ◽  
E. Cardarelli ◽  
A. M. Girelli ◽  
A. Pietrodangelo ◽  
...  
Keyword(s):  
Amino Acids ◽  
Bulk Liquid ◽  
Liquid Membranes ◽  
Carrier Mediated Transport

The Blood-Aqueous and Blood-Brain Barriers to Permeability

1988 ◽  
Vol 105 (4) ◽  
pp. 412-416 ◽  
Author(s):  
Gary D. Novack ◽  
Irving H. Leopold
Keyword(s):  
Blood Brain ◽  
Brain Barriers

GHB (γ-Hydroxybutyrate) Carrier-Mediated Transport across the Blood-Brain Barrier

2004 ◽  
Vol 311 (1) ◽  
pp. 92-98 ◽  
Author(s):  
Indranil Bhattacharya ◽  
Kathleen M. K. Boje
Keyword(s):  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Blood Brain ◽  
Carrier Mediated Transport

Blood-brain barrier permeability to dipeptides and their constituent amino acids

1983 ◽  
Vol 271 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Berislav V. Zlokovic ◽  
David J. Begley ◽  
Daniel G. Chain
Keyword(s):  
Amino Acids ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Barrier Permeability ◽  
Blood Brain Barrier Permeability ◽  
Blood Brain ◽  
Brain Barrier Permeability

The Blood-Brain Barrier, Amino Acids and Peptides

1989 ◽  
Author(s):  
M. B. Segal ◽  
B. V. Zlokovic
Keyword(s):  
Amino Acids ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Blood Brain

Der Liquor Cerebrospinalis im Kindersalter

PEDIATRICS ◽  
1960 ◽  
Vol 25 (6) ◽  
pp. 1024-1024
Author(s):  
HANS ZELLWEGER
Keyword(s):  
Amino Acids ◽  
Cerebrospinal Fluid ◽  
Liquor Cerebrospinalis ◽  
Blood Brain ◽  
Equal Consideration

In the first section of this book techniques and hazards of obtaining cerebrospinal fluid as well as the physiology of the production and absorption of cerebrospinal fluid, the significance of the barriers between blood, brain and cerebrospinal fluid are reviewed. Cytology and chemistry of the cerebrospinal fluid are extensively discussed. Non-routine methods like electrophoresis and chromatography of proteins respectively, and amino acids are given equal consideration.

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