Stereoselective blood-brain barrier transport of histidine in rats

Yamakami, Jun; Sakurai, Eiichi; Sakurada, Tomoya; Maeda, Kazumi; Hikichi, Noboru

doi:10.1016/s0006-8993(98)00958-5

Cited by 33 publications

(19 citation statements)

References 33 publications

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“…Two experimental conditions were established to reduce the entry of His into the root of B. juncea. First, l-His was replaced by d-His, the stereoisomer that is less efficiently taken into root cells, as previously reported for rat (Rattus norvegicus) brain microvascular endothelial cells (Yamakami et al, 1998). Second, a 10-fold excess was added of the amino acid l-Ala, which reduced His uptake, presumably by competitive inhibition (Fig.…”

Section: Discussionmentioning

confidence: 96%

The Role of Free Histidine in Xylem Loading of Nickel inAlyssum lesbiacum and Brassica juncea

2003

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Exposure of the hyperaccumulator Alyssum lesbiacum to nickel (Ni) is known to result in a dose-dependent increase in xylem sap concentrations of Ni and the chelator free histidine (His). Addition of equimolar concentrations of exogenousl-His to an Ni-amended hydroponic rooting medium enhances Ni flux into the xylem in the nonaccumulator Alyssum montanum, and, as reported here, in Brassica juncea L. cv Vitasso. In B. juncea, reducing the entry of l-His into the root by supplying d-His instead of l-His, or l-His in the presence of a 10-fold excess of l-alanine, did not affect root Ni uptake, but reduced Ni release into the xylem. Compared with B. juncea, root His concentrations were constitutively about 4.4-fold higher in A. lesbiacum, and did not increase within 9 h of exposure to Ni. Cycloheximide did not affect root His or Ni concentrations, but strongly decreased the release of His and Ni from the root into the xylem of A. lesbiacum, whereas xylem sap concentrations of Ca and Mg remained unaffected. Near-quantitative chelation of Ni with nitrilotriacetate in the rooting medium did not enhance Ni flux into the xylem of A. lesbiacum and B. juncea, suggesting the absence of a significant apoplastic pathway for Ni entry into the xylem. The data suggest that in B. juncea roots, Ni2+uptake is independent of simultaneous uptake of His. In both species, enhanced release of Ni into the xylem is associated with concurrent release of His from an increased root free His pool.

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Section: Discussionmentioning

confidence: 96%

The Role of Free Histidine in Xylem Loading of Nickel inAlyssum lesbiacum and Brassica juncea

2003

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“…The effect of cortical superfusion with histamine on BBB permeability was also studied in cat by measuring extravasation of the tracers Na + -fluorescein (MW 376) or fluorescein isothiocyanate (FITC) labeled dextran (MW 62,000 or 145,000), demonstrating that histamine induced an opening of BBB resulting in extravasation of small and large molecular weight tracers with threshold concentrations of 10 -9 , 10 -8 and 10 -6 M for Na + -fluorescein, FITC-dextran 62,000 and 145,000, respectively [8]. On the other hand, we have already clarified the transport characteristics of D-and L-histidine at BBB using cultured rat BMEC, suggesting that L-histidine uptake by rat BMEC is mediated by both System-N and -L transporters [9]. BBB amino acid transport plays a critical role in the overall regulation of several pathways of brain amino acid metabolism.…”

Section: Introductionmentioning

confidence: 80%

“…Hirata et al also demonstrated in the dissected inferior turbinate mucosa that expression of histamine Nmethyltransferase (HMT) mRNA was positively correlated to the expression of HDC mRNA in the normal subjects, but the correlation was not significant in patients with allergic rhinitis, suggesting that increased HDC mRNA expression and decreased HMT mRNA expression may play a role in the development of nasal symptoms in allergic rhinitis patients [22]. We previously reported that L-histidine was uptaken by rat BMEC via both amino acid transporter System-N and -L [9]. The endothelial cells of the brain microvasculature, generally considered to constitute the BBB, function as both a permeability barrier and a metabolic barrier to the passage of chemicals from the blood into the central nervous system [23].…”

Section: Discussionmentioning

confidence: 99%

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L-Histidine decarboxylase protein and activity in rat brain microvascular endothelial cells

Yamakami

Sakurai

Kuramasu

et al. 2000

Inflammation Research

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“…For in vitro studies, rat BMEC were isolated and cultured from rat brains as previously described [1], and subcultured cells were grown on collagen-coated culture flask and slide, and on transwell membrane. Then, L-histidine uptake rate, assay of L-histidine decarboxylase (HDC) activity, immunofluorescence analysis of HDC protein distribution, expression of HDC mRNA by RT-PCR and paracellular transport clearance of fluorescein were performed in rat BMECs [1,2,3]. Values cited in results section are mean AE SEM for n = 5 independent determinations.…”

Section: Methodsmentioning

confidence: 99%