Acetylcholine Synthesis from Recaptured Choline by a Sympathetic Ganglion,
MCGILL UNIV MONTREAL (QUEBEC) DEPT OF PHARMACOLOGY AND THERAPEUTICS
Pagination or Media Count:
Although choline produced by ACh hydrolysis can be re-used for ACh synthesis, it is clear from experiments that exogenous choline can compete with endogenously produced choline for use in ACh synthesis, and this is consistent with the technique used to label the ganglions ACh store. The present experiments suggest that ganglia, stimulated at 5 Hz and perfused with a physiological concentration of choline, recapture about 50-60 of the choline made available from ACh hydrolysis. Thus endogenously produced choline is at least as important as is circulating choline for maintaining ACh synthesis. The release of AChimpulse at 20 Hz is the same as at 5 Hz and therefore the concentration of choline from hydrolysed ACh should be the same at either frequency. The present experiments also demonstrated that choline recapture is more efficient when exogenous choline is absent than when exogenous choline is present.
- Anatomy and Physiology