Bundgaard M, Cserr H F
Brain Res. 1981 Feb 9;206(1):71-81. doi: 10.1016/0006-8993(81)90101-3.
The rate and extent of penetration of radiolabelled polyethylene glycols (900 and 4000 daltons) from plasma into brain was examined in the Atlantic hagfish (Myxine glutinosa), a primitive vertebrate, and, for comparison, in the rat. Tracer penetration into brain was limited to a similar extent in hagfish and in rats, indicating a basic similarity between the two species in the blood-brain barrier to polar non-electrolytes. The permeability of hagfish brain capillaries to the electron microscopic tracer microperoxidase (2000 Daltons) was also examined. Intravenously injected microperoxidase remained confined to the capillary lumen and was not found in the basal lamina or surrounding brain parenchyma. In contrast to an earlier study, these results indicate that the hagfish has a blood-brain barrier to hydrophilic molecules larger than 900 Daltons. It is concluded that a blood-brain barrier is a general characteristic of all vertebrates.
在原始脊椎动物大西洋盲鳗（Myxine glutinosa）以及作为对照的大鼠中，研究了放射性标记的聚乙二醇（900道尔顿和4000道尔顿）从血浆进入脑的速率和程度。在盲鳗和大鼠中，示踪剂进入脑的程度相似，这表明这两个物种在对极性非电解质的血脑屏障方面基本相似。还研究了盲鳗脑毛细血管对电子显微镜示踪剂微过氧化物酶（2000道尔顿）的通透性。静脉注射的微过氧化物酶仍局限于毛细血管腔内，未在基膜或周围脑实质中发现。与早期研究相反，这些结果表明盲鳗对大于900道尔顿的亲水分子具有血脑屏障。得出的结论是，血脑屏障是所有脊椎动物的一个普遍特征。
