IN 1943 Nachmansohn and Machado1 discovered a new enzyme, choline acetylase, which in cell-free solution, under strict anaerobic conditions and in the presence of adenosine triphosphate, synthesizes acetylcholine in vitro. The presence of the enzyme was demonstrated in2 nerve-containing and muscle-containing tissues of a wide variety of animals, viz., in those tissues that also contain an appreciable amount of cholinesterase. Since the acetylase forms and the esterase splits acetylchline, such a finding should not be surprising. To demonstrate the presence of choline acetylase in ocular tissues, the following experiment was undertaken.
Preparation of the Ensyme.
—The acetone-dried powder method as described by Nachmansohn and John2c was employed, since it yields higher values than the fresh tissue homogenates. The animals were killed, the eyes enucleated and the tissues dissected and placed immediately into solid carbon dioxide, such a step being necessary because choline acetylase, being a very
deROETTH A. CHOLINE ACETYLASE ACTIVITY IN OCULAR TISSUES. Arch Ophthalmol. 1950;43(5):849-852. doi:10.1001/archopht.1950.00910010864008