Cerebral amino acid uptakein vivo in newborn mice

Seta, Kiichiro; Sershen, Henry; Lajtha, Ábel

doi:10.1016/0006-8993(72)90649-x

Cited by 56 publications

(10 citation statements)

References 21 publications

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“…Thus, an important homeostatic mechanism for maintaining low levels of amino acids in brain extracellular fluids does not develop until after weaning. This lack of an active efflux mechanism for amino acids at the immature BBB was predicted from the results of in vivo studies (Seta, Sershen & Lajtha, 1972).…”

Section: Discussionmentioning

confidence: 99%

Developmental changes in metabolism and transport properties of capillaries isolated from rat brain.

Betz¹,

Goldstein²

1981

The Journal of Physiology

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SUMMARY1. Capillaries were isolated from the brains oft-to 45-day-old rats in order to study the development of metabolic and transport aspects of the blood-brain barrier.2. The hydroxyproline content of capillary hydrolysates increased nearly threefold between 5 and 45 days of age. This finding is consistent with histological studies showing thickening of capillary basement membrane during development.3. The activities of L-DOPA decarboxylase and monoamine oxidase were greatest in capillaries from 10-day-old rat brain. Thus, the metabolic blood-brain barrier for amine precursors is present during early development.4. Capillaries from all ages were able to metabolize glucose, fi-hydroxybutyrate and palmitate. The rate of glucose oxidation more than doubled between 21 and 30 days of age but subsequently decreased. In contrast, f-hydroxybutyrate and palmitate oxidation increased throughout development. These data suggest a sparing effect by alternate fuels on glucose metabolism.5. Capillary glucose uptake was similar at 10 and 30 days of age and activity of the ouabain-sensitive K+ pump (measured using 86Rb+) was relatively constant at all ages. In contrast, Na+-dependent neutral amino acid transport was not present until after 21 days of age. Since this transport system may be responsible for the active efflux of neutral amino acids from brain to blood, it is likely that this process does not occur at the immature blood-brain barrier.6. We conclude that various aspects of brain capillary functions show distinct developmental patterns which may be related to changes in blood-brain barrier permeability during development.

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Section: Discussionmentioning

confidence: 99%

Developmental changes in metabolism and transport properties of capillaries isolated from rat brain.

Betz¹,

Goldstein²

1981

The Journal of Physiology

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“…Also. Scssa and Perez [19] and Seta et al [20] are pointing to the fact that several metabo lites including sucrose, inulin, amino acids and some drugs, in contradistinction to adult animals, easily penetrate the brain of the newborn, immature rat or other laboratory animals. Thus, usually in such a type of study, the definition of the BBB has to be clearly re lated to the particular tracer used as a marker of vascular permeability.…”

Section: Ap Activity and Maturation O F Bbbmentioning

confidence: 99%

Localization of Alkaline Phosphatase Activity in Endothelia of Developing and Mature Mouse Blood-Brain Barrier

1986

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The relationship between alkaline phosphatase (AP) activity and maturation of blood-brain barrier (BBB) in mouse brain was studied ultracytochemically. The permeability of micro-blood vessels (MBVs) to intravenously injected horseradish peroxidase was considered to be a criterion of BBB maturation, which occurs between the 12th and 24th day of mouse life. This process coincides with the appearance of cytochemically detectable AP activity in luminal plasma membrane (PM) of the endothelial cell (EC) of capillaries or in both luminal and abluminal PM in arterioles. No reaction appears in ECs of venules. These observations indicate that the development of BBB function is accompanied by the formation of enzymatic barrier in MBVs endothelia. AP constitutes one of the components of this barrier. Comparative study indicates that in various MBVs of non-BBB type, except in skeletal muscle, no AP activity is detected in similar incubation conditions.

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“…Available evidence indicates that blood-brain transport systems are functional in the newborn of several species 511 including the rabbit (Braun, Cornford & Oldendorf, 1980), rat (Sershen & Lajtha, 1976;Cremer, Braun & Oldendorf, 1976) and mouse (Seta, Sershen & Lajtha, 1972). Seta et al (1972) showed that a given increase of an amino acid (including isoleucine, valine, arginine, methionine and histidine) in the blood caused a greater corresponding increase in newborn than in adult brain amino acid concentration in the mouse. Lajtha (1976) andCremer et al (1976) both measured brain uptake indices (BCI) by the 'Oldendorf' method for various amino acids at different developmental stages in the rat.…”

Section: Brain Influx Of Amino Acidsmentioning

confidence: 99%

Transport of L‐phenylalanine and related amino acids at the ovine blood‐brain barrier.

Brenton

Gardiner

1988

The Journal of Physiology

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SUMMARY1. Unidirectional influx ofamino acids at the blood-brain barrier was studied in the lamb and sheep under barbiturate anaesthesia using the single-pass indicatordilution technique.2. In the lamb, influx of both L-phenylalanine (14+1 nmol g-1 min-1) and Lalanine (12 + 2 nmol g-1 min-') was greater than in the sheep: L-phenylalanine influx, 9 + 1 nmol g-' min-'; L-alanine influx, 5 +1 nmol g-' min-' (P < 0-01). This difference reflected higher blood concentrations of these amino acids in the younger animal.3. The kinetic parameters of transport for L-phenylalanine were determined in the lamb and sheep from measurements of influx over a range of blood concentrations. The concentration dependence of L-phenylalanine influx was best described by a model with a saturable and non-saturable component. Maximum influx (Jmax) was higher and apparent transport constant (km app) lower in the lamb. Values obtained (mean+S.E.M.) were : lamb, Jmax, 138+6 nmol g-1 min; km app, 0-85+0-10 mmol l-1; sheep, Jmax, 107 + 7 nmol g-1 min-'; km, app' 2-25 + 0-25 mmol 1-1. 5. Fractional extraction of phenylalanine and alanine was stereospecific with preference for the L-enantiomer. In the lamb, fractional extraction values (mean+s .E.M.) were: L-phenylalanine, 0-58+0-03; D-phenylalanine, 0-20+0-02; Lalanine, 0-16+0-03; D-alanine, 0-05+0002. Self-inhibition of extraction was evident for L-phenylalanine and L-alanine in both lamb and sheep.

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Cerebral amino acid uptakein vivo in newborn mice

Cited by 56 publications

References 21 publications

Developmental changes in metabolism and transport properties of capillaries isolated from rat brain.

Developmental changes in metabolism and transport properties of capillaries isolated from rat brain.

Localization of Alkaline Phosphatase Activity in Endothelia of Developing and Mature Mouse Blood-Brain Barrier

Transport of L‐phenylalanine and related amino acids at the ovine blood‐brain barrier.

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