Moos T, Møllgård K
Department of Medical Anatomy A, University of Copenhagen, Panum Institute, Denmark.
Neuropathol Appl Neurobiol. 1993 Apr;19(2):120-7. doi: 10.1111/j.1365-2990.1993.tb00416.x.
The often quoted investigation by Behnsen [4] provides some evidence for an increased permeability of the neonatal mouse blood-brain barrier (BBB) to trypan blue compared to the adult. Trypan blue, which circulates in plasma mainly bound to albumin, is commonly used as a macromolecular tracer, although Behnsen probably injected dyes in amounts exceeding the dye-binding capacity of plasma proteins. The cerebrovascular permeability in neonatal and adult mice and rats was investigated using the visual tracers trypan blue and Evans blue and immunocytochemical staining for endogenous plasma proteins. By administering different concentrations of the dyes, the permeability of the BBB was assessed. The presence of the dyes in plasma as either dye-protein complexes or as free dye was measured by a plasma protein binding assay. When dyes occurred in plasma as macromolecular dye-protein complexes, dyes and plasma proteins were restricted to CNS regions normally devoid of a BBB in both neonates and adults. When unbound (free) dyes occurred in plasma, dyes were observed intraneuronally in regions without projections beyond the BBB in both neonates and adults corresponding to that observed by Behnsen; intraneuronal accumulation of plasma proteins also occurred in regions with projections confined to the BBB but only in neonates. It is concluded that the BBB to macromolecular tracers is fully developed at birth in mouse and rats. However, when free dye is present in plasma, there is a differential permeability to plasma proteins between neonates and adults.
贝恩森[4]经常被引用的研究提供了一些证据，表明与成年小鼠相比，新生小鼠血脑屏障（BBB）对台盼蓝的通透性增加。台盼蓝主要与白蛋白结合在血浆中循环，通常用作大分子示踪剂，尽管贝恩森注射的染料量可能超过了血浆蛋白的染料结合能力。使用视觉示踪剂台盼蓝和伊文思蓝以及对内源性血浆蛋白进行免疫细胞化学染色，研究了新生和成年小鼠及大鼠的脑血管通透性。通过给予不同浓度的染料，评估血脑屏障的通透性。通过血浆蛋白结合试验测量血浆中染料以染料 - 蛋白复合物形式或游离染料形式的存在情况。当染料以大分子染料 - 蛋白复合物形式出现在血浆中时，染料和血浆蛋白在新生和成年动物中都局限于通常没有血脑屏障的中枢神经系统区域。当血浆中出现未结合（游离）染料时，在新生和成年动物中，在没有超出血脑屏障投射的区域内神经元内观察到染料，这与贝恩森观察到的情况一致；血浆蛋白的神经元内积累也仅在新生动物中出现在局限于血脑屏障的投射区域。结论是，小鼠和大鼠出生时血脑屏障对大分子示踪剂已完全发育。然而，当血浆中存在游离染料时，新生和成年动物对血浆蛋白的通透性存在差异。
