已观察到药物和其他物质进入脑组织和脑脊液(CSF)的速率有很大的差别,因此认为存在血脑屏障。实际上药物渗入的差别有数种因素参与。其中主要的成分为颅内毛细血管的内皮细胞,因邻近的细胞紧密连接成为一道渗透屏障,除最小的分子能渗入脑组织和CSF外,其余均受限。透过这一内皮细胞的 It has been observed that the rate of entry of drugs and other substances into brain tissue and cerebrospinal fluid (CSF) varies widely and is therefore believed to be a blood-brain barrier. In fact there are several factors involved in the difference in drug penetration. The main component is the endothelial cells of the intracranial capillaries, which are confined by the close proximity of neighboring cells to form an osmotic barrier, with the exception of the smallest molecules that can penetrate into the brain and CSF. Through this endothelial cell