抄録
Ultracytochemical localization of Ca++-adenosinetriphosphatase (ATPase) activity was investigated in the choroid plexus of the rat fourth ventricle. A newly devised lead citrate method (Ando et al., 1981) was employed for the detection of this enzyme. Electron dense reaction products for Ca++-ATPase activity were shown on the external surfaces of apical plasma membranes, including those of the microvilli and cilia, and on the external surfaces of basal plasma membranes, especially those of the basal infoldings. The gap junctions also showed reaction products on the cytoplasmic side of the plasma membranes. Among the intracellular organelles, activity was seen exclusively on the cristae of mitochondria. From these findings, it can be suggested that Ca++-ATPase participates in Ca++ transport and in the regulation of cerebrospinal fluid secretion in association with intracellular Ca++ and Na+, K+-ATPase.
