The characteristics of β-alanine transport at the blood-brain barrier were studied by using primary cultured bovine brain capillary endothelial cells. Kinetic analysis of the β-[3H]alanine transport indicated that the transporter for β-alanine functions with K(t) of 25.3 ± 2.5 μM and J(max) of 6.90 ± 0.48 nmol/30 min/mg of protein in the brain capillary endothelial cells. β-[3H]Alanine uptake is mediated by an active transporter, because metabolic inhibitors (2,4-dinitrophenol and NaN3) and low temperature reduced the uptake significantly. Furthermore, the uptake of β-[3H]alanine required Na+ and Cl- in the external medium. Stoichiometric analysis of the transport demonstrated that two sodium ions and one chloride ion are associated with one β-alanine molecule. The Na+ and Cl- dependent uptake of β-[3H]alanine was stimulated by a valinomycin-induced inside-negative K+-diffusion potential. β-Amino acids (β-alanine, taurine, and hypotaurine) inhibited strongly the uptake of β-[3H]alanine, whereas α- and γ-amino acids had little or no inhibitory effect. In ATP-depleted cells, the uptake of β[3H]alanine was stimulated by preloading of β-alanine or taurine but not L-leucine. These results show that β-alanine is taken up by brain capillary endothelial cells, via the secondary active transport mechanism that is common to β-amino acids.
|ジャーナル||Journal of Neurochemistry|
|出版ステータス||Published - 1996 7|
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience