Acetylcholinesterase in the Rabbit Cornea

Abstract

There is strong evidence that the acetylcholine system is responsible for the electric currents which propagate impulses in conducting tissues.^1,2 In the eye, high concentrations of acetylcholine have been reported in the corneal epithelium;³ cholinesterase has been demonstrated in various other ocular tissues chemically⁴ and histochemically;^5,6 and high choline acetylase activity has been found in the corneal epithelium.⁷ The present study is concerned with determining the concentration and localization of cholinesterase in the cornea. Methods and Materials Hestrin's colorimetric technique for determining acetylcholine⁸ was used for measurement of cholinesterase activity chemically, and Koelle's method for localization of the cholinesterase in the tissues.^5,6,9-11 Normal New Zealand albino rabbits were used throughout. A. Chemical Determination of Cholinesterase Activity. —Rabbits were anesthetized with pentobarbital (Nembutal) immediately prior to having the epithelium scraped off their corneas. The fresh epithelium was placed in a small ground glass tissue