Adenosine Triphosphatase Distribution in the Organ of Corti: Histochemical Study by Light and Electron Microscopy

Abstract

Adenosine triphosphatase (ATP-ase) provides energy for active transport across cell membranes by its hydrolysis of Adenosinetriphosphate to Adenosinediphosphate. ATP-ase generally is found where active transport of water and electrolytes occurs. We used a histochemical method to study the location of this enzyme within the organ of Corti. We found that the outer surface of most cells in Corti's organ show enzyme activity. No ATP-ase was found along the side of hair cells where they are in contact with “cortilymph” or between adjacent nerve endings. Supporting cells have the enzyme on their entire surface. The enzyme was found in the basement membrane of the spiral vessel. Tunnel-crossing nerve fibers exhibited enzyme activity on their outer membrane. The enzyme was located on the endolymphatic layer of Reissner's membrane cells, but not on the perilymphatic layer.