Choline esterase in the amphibian sphincter pupillae

✍ Scribed by Armstrong, Philip B.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1942
• Tongue: English
• Weight: 375 KB
• Volume: 20
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030200105

✦ Synopsis

It has been established that there is present in the eye choline estcrase in concentrations adequate to destroy acetylcholine liberated by the short ciliary nerves (Engelhart, '31). These nerves were stimulated reflexly by exposure of the eye to light or directly by strong stimulation of the oculomotor nerve. The presence of acetylcholine in the anterior chamber of the eye could be demonstrated after stimulation only if the acetylcholine was protected from choline esterase by previously instilling eserine in the conjunctival sac. Shen and Cannon ('36) showed that eserine potentiates the effect of acetylcholine instilled in the eye and also that the denervated sphincter is much more sensitive t o instilled acetylcholine than is the normal. These findings were confirmed by Keil and Root ( '41).

Although the experiments cited above clearly demonstrate the presence of choline esterase in the eye, they do not differentiate between esterase in the eye tissues generally and that present at the nerve endings in the sphincter pupillae itself. I n the experiments described in this paper such a differentiation is attempted.