Accumulation of ascorbate in rat cerebellum.

Ultrafiltration and gel chromatography on Sephadex G-75 have revealed no evidence of ascorbate-binding to protein components of the soluble fraction derived from a tissue homogenate of rat cerebellum. Furthermore, partition studies have failed to detect any binding of ascorbic acid to structural components of rat cerebellum, as the ascorbate content of cerebellar tissue exhibited linear dependence upon the concentration of free vitamin in the surrounding medium (0.1 M phosphate, pH 6.5). The accumulation of ascorbic acid in rat cerebellum is discussed, therefore, in terms of an elevated intracellular concentration maintained by active transport of the vitamin across cerebellar tissue membranes.