Zlokovic B V, Skundric D S, Segal M B, Lipovac M N, Mackic J B, Davson H
Department of Medical Physiology, Faculty of Medicine, Belgrade, Yugoslavia.
Exp Neurol. 1990 Mar;107(3):263-70. doi: 10.1016/0014-4886(90)90144-h.
The existence of an immunological blood-brain barrier to homologous blood-borne immunoglobulin G (IgG) was investigated in the guinea pig using a vascular brain perfusion technique in situ. Cerebrovascular unidirectional transfer constants (Kin) for 125I-labeled IgG (2.5 micrograms/ml) estimated from the multiple-time brain uptake data, ranged from 0.53 to 0.58 ml min-1 g-1 X 10(3) in the parietal cortex, hippocampus, and caudate nucleus, the transfer rate being some 10 times higher than that for [3H]dextran (MW 70,000). In the presence of 4 mg/ml unlabeled IgG, unidirectional blood to brain transfer of 125I-IgG was markedly inhibited. Immunohistochemical analysis of the brain tissue after vascular perfusion with unlabeled IgG revealed a distribution of the blood-borne immunoglobulin in the endothelial cells of microvessels and in the surrounding perivascular tissue. It is concluded that there is a specific transfer mechanism for IgG at the blood-brain barrier in the guinea pig, which is saturated at physiological plasma levels of IgG.
采用原位血管脑灌注技术，在豚鼠中研究了针对同源血源性免疫球蛋白G（IgG）的免疫血脑屏障的存在情况。根据多次脑摄取数据估算，顶叶皮质、海马体和尾状核中125I标记的IgG（2.5微克/毫升）的脑血管单向转运常数（Kin）范围为0.53至0.58毫升·分钟-1·克-1×10（3），其转运速率比[3H]葡聚糖（分子量70,000）高约10倍。在存在4毫克/毫升未标记IgG的情况下，125I-IgG从血液到脑的单向转运受到显著抑制。用未标记IgG进行血管灌注后对脑组织进行免疫组织化学分析，结果显示血源性免疫球蛋白分布于微血管的内皮细胞和周围的血管周组织中。结论是，豚鼠血脑屏障处存在针对IgG的特异性转运机制，该机制在IgG的生理血浆水平时会饱和。
