A mathematical approach for assessing the transport of large neutral amino acids across the blood-brain barrier in man
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A mathematical approach for assessing the transport of large neutral amino acids across the blood-brain barrier in man. / Dahl, Rasmus Holmboe; Berg, Ronan M G.
In: Acta Neurobiologiae Experimentalis, Vol. 75, No. 4, 2015, p. 446-456.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - A mathematical approach for assessing the transport of large neutral amino acids across the blood-brain barrier in man
AU - Dahl, Rasmus Holmboe
AU - Berg, Ronan M G
PY - 2015
Y1 - 2015
N2 - Changes in the large neutral amino acid (LNAA) transport across the blood-brain barrier (BBB) is thought to contribute to brain dysfunction in a number of clinical conditions, including phenylketonuria, acute liver failure, and sepsis. Here, we present a novel approach for estimating BBB permeability and the LNAA concentrations in brain extracellular fluid, by demonstrating that they can be mathematically derived on the basis of kinetic constants of the BBB available from the literature, if cerebral blood flow and the arterial and jugular venous LNAA concentrations are known. While it is well known that the permeability surface area product of the BBB to a LNAA from blood to brain (PS1) can be calculated from the arterial LNAA concentrations and kinetic constants of the BBB, we demonstrate that the permeability surface area product from brain to blood (PS2) can be calculated by deriving the substrate activity of the saturable transporter from the kinetic constants and arterial and jugular venous LNAA concentrations, and that the concentration of the LNAA in brain extracellular fluid can then be determined. This approach is methodically simple, and may be useful for assessing the transcerebral exchange kinetics of LNAAs in future human-experimental and clinical studies.
AB - Changes in the large neutral amino acid (LNAA) transport across the blood-brain barrier (BBB) is thought to contribute to brain dysfunction in a number of clinical conditions, including phenylketonuria, acute liver failure, and sepsis. Here, we present a novel approach for estimating BBB permeability and the LNAA concentrations in brain extracellular fluid, by demonstrating that they can be mathematically derived on the basis of kinetic constants of the BBB available from the literature, if cerebral blood flow and the arterial and jugular venous LNAA concentrations are known. While it is well known that the permeability surface area product of the BBB to a LNAA from blood to brain (PS1) can be calculated from the arterial LNAA concentrations and kinetic constants of the BBB, we demonstrate that the permeability surface area product from brain to blood (PS2) can be calculated by deriving the substrate activity of the saturable transporter from the kinetic constants and arterial and jugular venous LNAA concentrations, and that the concentration of the LNAA in brain extracellular fluid can then be determined. This approach is methodically simple, and may be useful for assessing the transcerebral exchange kinetics of LNAAs in future human-experimental and clinical studies.
KW - Amino Acids, Neutral/metabolism
KW - Biological Transport
KW - Blood-Brain Barrier/metabolism
KW - Brain/metabolism
KW - Humans
KW - Kinetics
KW - Male
KW - Models, Theoretical
KW - Permeability
M3 - Journal article
C2 - 26994422
VL - 75
SP - 446
EP - 456
JO - Acta Neurobiologiae Experimentalis
JF - Acta Neurobiologiae Experimentalis
SN - 0065-1400
IS - 4
ER -
ID: 236992887