Distribution of lens sodium-potassium-adenosine triphosphatase.

These findings suggest that plasma membrane adenosine triphosphatase enzyme responsible for sodium-potassium transport is expressed in newly formed lens fibers and the transport molecules are retained as the fibers age and are compressed toward the center of the lens. However, with fiber aging there is a loss of functional ability of the Na-K-ATPase to hydrolyze adenosine triphosphate.