Enzyme Histochemistry of Ventricular Choroid Plexus (Part II)

—The Localization of Carbonic Anhydrase Activity—

Abstract

Localization of carbonic anhydrase (CAHase) activity was studied electron microscopically on rat choroid plexus epithelial cells.
The ultracytochemical localization of CAHase activity was found in the microvilli and in the basal infoldings of the choroidal epithelial cells using Yokota's technique (1969). The carbonic anhydrase helps the formation of H⁺ and HCO₃^- from CO₂. Intracellular H⁺ exchanges with extracellular sodium ion through the basal infoldings. The HCO₃^- moves into the cerebrospinal fluid through the plasmalemma of the microvilli.