Distribution and properties of ATPase activities in the cochlea of the chicken

Abstract

• 1.

  1. The properties and distribution of an ouabain sensitive Na⁺-K⁺-ATPase system in the cochlear structures of the chicken were investigated with ultramicrochemical techniques.

• 2.

  2. The properties of this enzyme system are in good agreement with those found in other tissues including the stria vascularis.

• 3.

  3. The enzyme system was present in very high activity and appeared to be predominantly located in the tegmentum vasculosum.

• 4.

  4. The agreement between the activities and properties of the Na⁺-K⁺-ATPase system in the tegmentum vasculosum of the chicken cochlea and the stria vascularis of the mammalian cochlea suggests that the tegmentum vasculosum may play the same essential role in the maintenance of the cochlear cation gradients and the cochlear potentials as the stria vascularis.