COMPARATIVE-STUDY ON THE UPTAKE AND SUBSEQUENT DECARBOXYLATION OF MONO-AMINE PRECURSORS IN CEREBRAL MICROVESSELS
COMPARATIVE-STUDY ON THE UPTAKE AND SUBSEQUENT DECARBOXYLATION OF MONO-AMINE PRECURSORS IN CEREBRAL MICROVESSELS
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DOI：
10.1111/j.1748-1716.1979.tb06456.x
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发表时间：
1979-01-01
期刊：
影响因子：
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通讯作者：
OWMAN, C
中科院分区：
文献类型：
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作者：
HARDEBO, JE;FALCK, B;OWMAN, C
脑微血管（毛细血管和小静脉）的内皮细胞和周细胞具有酶屏障，阻碍循环氨基酸（如胺前体）进入大脑。在二羟基苯基丙氨酸（DOPA）、5-羟色氨酸（5-HTP）和二羟基苯基丝氨酸（DOPS）的孵育下，在包括人在内的多种动物（大鼠、小鼠、仓鼠、豚鼠、兔、猫、狗、猪、牛、狒猴）的脑切片和离体微血管中研究了这一机制的性质。在所有被研究的物种中都发现了导致脑微血管壁积聚的立体特异性、能量依赖性摄取；这个过程在胎儿时期就已经存在了。脱羧能力是血脑间期捕获机制的第二步，其物种差异很大。这种酶也存在于胎儿的大脑微血管中。抑制实验支持在微血管壁上存在单胺氧化酶，而不存在儿茶酚- o -甲基转移酶。
The endothelial cells and pericytes of brain microvessels (capillaries and small veins) are equipped with an enzymatic barrier, impeding the passage of circulating amino acids, such as amine precursors, into the brain. The properties of this mechanism were studied in brain slices and isolated microvessels from various species [rat, mouse, hamster guinea pig, rabbit, cat, dog, pig, cow, babboon] including man and also fetal material, following incubation in dihydroxyphenylalanine (DOPA), 5-hydroxytryptophan (5-HTP) and dihydroxyphenylserine (DOPS). A stereospecific, energy-dependent uptake leading to accumulation in the brain microvessel walls was found in all species studied; this process already existed prenatally. The capacity of decarboxylation, the 2nd step in the trapping mechanism at the blood-brain interphase, showed considerable species variation. The enzyme was present also in fetal brain microvessels. Inhibition experiments provided support for the presence of monoamine oxidase, but absence of catechol-O-methyl transferase, in the microvessel walls.