Abstract
Summary
Hemicholinium No. 3 (HC-3) was administered acutely to cats, either as a 1% solution topically to the eyes or an i.v. injection of 1 mg/kg, and tissue levels of acetylcholine (ACh) were determined. The effects of nerve stimulation on ACh levels were also studied in these tissues, which included auricles, intestines and gastrocnemius muscles. Levels of ACh were significantly greater in control resting irises and ciliary bodies than in those treated with HC-3. The content of the auricles were also greater in the controls but only if nerve stimulation had been previously applied. Otherwise there were no differences between tissues from HC-3 treated and control animals. Another group of cats received a more chronic treatment with HC-3, 1 mg/kg repeated i.m. every 6 hours for a 24-hour period. Analysis of the same tissues for resting ACh content revealed no differences between treated and control animals. The results were discussed with regard to HC-3 exerting a possible anti-release mechanism. The possibility was also considered that much of the ACh might be of extraneural origin and not affected by HC-3.
Get full access to this article
View all access options for this article.