Choline acetyltransferase in ocular tissues of rabbits, cats, cattle, and man

The variation of choline acetyltransferase activity in ocular tissues of four mammalian species, rabbits, cats, cattle, and man, was determined. Enzyme activity of irides and ciliary bodies, i.e., parasympathetically innervated structures, tended to be similar in all four species. Two exceptions were bovine irides and human ciliary bodies; these two tissues had higher enzyme activities. Choline acetyltransferase activity was present in the corneal epithelium of rabbit, bovine, and human eyes, but little or none could be detected in that of cats. Feline retina and pigment epithelium-choroid also contained far less choline acetyltransferase activity than the same tissues in the other three species.