Bresler V M, Nikiforov A A, Simanovskiĭ L N
Fiziol Zh SSSR Im I M Sechenova. 1976 Jan;62(1):73-9.
With the aid of luminescent microscopy and microfluorimetry in vitro, the transport of labelled fluorescine into the structures of the brain lateral ventricles' chorioid plexus was studied in rabbits. An against-gradient pumping of fluorescine into the cytoplasm of the neuroepithelium cells and into the lumen of adjucent capillaries was shown to occur in the chorioid plexus. Such accumulation of fluorescine proceeds in the active transport way with participation of a carrier. The active transport system is congenial to fluorescine - Km = 4-10(-5) M, which renders even small amounts of this substance to be quickly removed from the milieu. The fluorescine-transporting system fulfills transition of other organic acids as well. The system of organic acids active transport is, apparently, localized in the apical and basal membranes of the neuroepithelial cells surrounding the plexus' filia which makes the concentration of transported acid in the neuroepithelial cells higher than in milieu, and in the capillaries' lumen higher than in the cytoplasm. An enzyme system adenylcyclasa-phosphodiesterase was found in the chorioid plexus' neuroepithelium. The system participates in regulation of velocity of the organic acids transport by means of changing the intracellular concentration 3',5'-AMP.
借助体外发光显微镜和微量荧光测定法，在兔身上研究了标记荧光素向脑侧脑室脉络丛结构的转运。结果显示，脉络丛中存在荧光素逆浓度梯度泵入神经上皮细胞胞质以及相邻毛细血管管腔的现象。荧光素的这种积累以主动运输方式进行，有载体参与。主动运输系统与荧光素相适配——米氏常数(Km = 4×10^{-5}) M，这使得即使少量该物质也能迅速从周围环境中清除。荧光素转运系统也能转运其他有机酸。有机酸主动运输系统显然定位于围绕脉络丛细丝的神经上皮细胞的顶端和基底膜，这使得被转运酸在神经上皮细胞中的浓度高于周围环境，在毛细血管管腔中的浓度高于胞质。在脉络丛神经上皮中发现了腺苷酸环化酶 - 磷酸二酯酶酶系统。该系统通过改变细胞内(3',5'-AMP)浓度参与调节有机酸的运输速度。
