The enzyme cytochemistry of the intracellular organelles in the rat choroid plexus epithelial cell.

Electron microscopic cytochemical studies on the rat choroid plexus epithelium have revealed enzymatic sites for the activities of acid phosphatase, glucose-6-phosphatase and thiamine pyrophosphatase on different organelles. Only the activity of acid phosphatase has been previously described. Acid phosphatase, glucose-6-phosphatase and thiamine pyrophosphatase were respectively situated mainly in the lysosomes, in the endoplasmic reticulum an nuclear envelope, and in the Golgi complex. These three enzymes can thus be considered as marker enzymes for their respective organelles in the choroid plexus epithelial cells as well as in other tissue cells. The possible function of these enzymes in the choroid plexus epithelial cells is also briefly discussed.