Rapid distribution of intraventricularly administered sucrose into cerebrospinal fluid cisterns via subarachnoid velae in rat
Rapid distribution of intraventricularly administered sucrose into cerebrospinal fluid cisterns via subarachnoid velae in rat
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DOI：
10.1016/0306-4522(96)00281-3
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发表时间：
1996-12-01
期刊：
影响因子：
3.3
通讯作者：
Fenstermacher, JD
中科院分区：
文献类型：
--
作者：
GhersiEgea, JF;Finnegan, W;Fenstermacher, JD
[C-14]蔗糖是一种细胞外标志物，为30岁的S注入一侧脑室，用冷冻干燥脑切片放射自显影测定其在脑内的分布。在3.5分钟内[C-14]蔗糖出现在：(I)第三脑室，包括视神经、漏斗和哺乳动物的隐窝；(Ii)Sylvius的导水管；(Iii)中间膜，蛛网膜下腔的一部分，沿第三脑室的顶部运行，含有许多血管；(Iv)中脑和第四脑室；(V)上延髓膜，蛛网膜下腔的高度血管延伸，终止于中脑和第四脑室的壁。在5分钟内，中脑周围的脚间池、周围池和四叉脑池出现放射性。到10分钟时，大约11%的放射性已经通过先前未描述的包括中间膜和上髓膜的流动途径进入蛛网膜下腔。正如先前报道的那样，在脑室系统的许多地方，[C-14]蔗糖似乎通过简单的扩散从脑脊液进入邻近组织(Blasberg R.G.等人)。(1974)J.Pharmac。实验在那里。195，73-83；Levin V.A.等人。(1970)上午J.Physiol.219,1528-1533；Patlak C.和Fenstermacher J.D.(1975)AmJ.Physiol.229,877-884；Rosenberg G.A.和Kyner W.T.(1980)Brain Res.193，56-66；Rosenberg G.A.等人。(1986)上午J.Physiol.251、F485-F489)。然而，很少的蔗糖被：(I)脑室周围器官，如穹隆下器；(Ii)侧隐窝旁的延髓和小脑组织；以及(Iii)上、下丘和脑脚吸收。对于后两组结构，脑脊液的进入明显被厚的、多层的胶质细胞界限层所阻挡。虽然[C-14]蔗糖在1h后几乎不存在于蛛网膜下腔的其余部分，但它在软脑膜动脉和小动脉的血管周围空间和/或壁上停留了3h以上。脑脊液中存在某些运输蛋白、蛋白水解酶抑制剂、生长因子和其他神经生物活性物质，它们在脑和血管中的分布可能是重要的。目前的工作表明，在大鼠体内，脑脊液的流动及其成分的配置相当复杂，并且在不同地区有所不同。血流在整个脑室系统中很快，并流入各种蛛网膜下膜和脑池，但在大脑和小脑皮质上的血流出奇地缓慢和轻微。脑脊液到组织的物质流动在许多界面上是相对自由的，但在其他界面上却受到很大限制，后者表明在这些地方可能仍然存在“脑脊液-脑屏障”的旧概念。最后，放射性标记的蔗糖在软脑膜动脉和小动脉的管壁和血管周围空间中的停留时间比在其他蛛网膜下组织中的时间更长；因此，脑脊液系统的一项功能，即“第三循环”，可能是向这些软脑膜血管输送因子和药剂。版权所有(C)1996 IBRO。爱思唯尔科学有限公司出版。
The intracranial distribution of [C-14]sucrose, an extracellular marker infused for 30 s into one lateral ventricle, was determined by autoradiography of frozen-dried brain sections. Within 3.5 min [C-14]sucrose appeared in: (i) the third ventricle, including optic, infundibular and mammillary recesses; (ii) the aqueduct of Sylvius; (iii) the velum interpositum, a part of the subarachnoid space that runs along the roof of the third ventricle and contains many blood vessels; (iv) the mesencephalic and fourth ventricles; and (v) the superior medullary velum, a highly vascular extension of the subarachnoid space that terminates at the walls of the mesencephalic and fourth ventricles. Within 5 min, radioactivity was present in the interpeduncular, ambient and quadrigeminal cisterns, which encircle the midbrain. By 10 min, approximately 11% of the radioactivity had passed into the subarachnoid space via a previously undescribed flow pathway that included the velum interpositum and superior medullary velum. At many places along the ventricular system, [C-14]sucrose appeared to move from cerebrospinal fluid into the adjacent tissue by simple diffusion, as reported previously (Blasberg R. G. et al. (1974) J. Pharmac. exp. Ther. 195, 73-83; Levin V. A. et al. (1970) Am. J. Physiol. 219, 1528-1533; Patlak C. and Fenstermacher J. D. (1975) Am. J. Physiol. 229, 877-884; Rosenberg G. A. and Kyner W. T. (1980) Brain Res. 193, 56-66; Rosenberg G. A. et al. (1986) Am. J. Physiol. 251, F485-F489). Little sucrose was, however, taken up by: (i) circumventricular organs such as the subfornical organ; (ii) medullary and cerebellar tissue next to the lateral recesses; and (iii) the superior and inferior colliculi and cerebral peduncles. For the latter two groups of structures, entry from cerebrospinal fluid was apparently blocked by a thick, multilayered glia limitans. Although [C-14]sucrose was virtually absent from the rest of the subarachnoid system after 1 h, it remained in the perivascular spaces and/or walls of pial arteries and arterioles for more than 3 h.Certain transport proteins, protease inhibitors, growth factors and other neurobiologically active materials are present in cerebrospinal fluid, and their distribution to the brain and its blood vessels may be important. The present work shows, in the rat, that the flow of cerebrospinal fluid and the disposition of its constituents is fairly complex and differs among regions. Flow was rapid throughout the ventricular system and into various subarachnoid velae and cisterns, but was surprisingly slow and slight over the cerebral and cerebellar cortices. The cerebrospinal fluid-to-tissue flux of material was relatively free at many interfaces, but was greatly restricted at others, the latter indicating that the old concept of a ''cerebrospinal fluid-brain barrier'' may hold at such places. Finally, radiolabeled sucrose was retained longer within the walls and perivascular spaces of pial arteries and arterioles than in other subarachnoid tissues; one function of the cerebrospinal fluid system or ''third circulation'' may thus be delivering factors and agents to these pial blood vessels. Copyright (C) 1996 IBRO. Published by Elsevier Science Ltd.