Ciliary muscle muscarinic binding sites, choline acetyltransferase, and acetylcholinesterase in aging rhesus monkeys.

Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activity, and the affinity and number of muscarinic binding sites (as reflected by specific 3H-quinuclidinyl benzilate binding) were determined in the ciliary muscle of rhesus monkeys ranging in age from 1-34 years. No age dependence was evident for any of these parameters. Within the limits of their specificity and precision, the data indicate that biochemical alterations in ciliary neuromuscular mechanisms do not account for the age-related loss of ciliary muscle configurational responses to topical pilocarpine and electrical stimulation of the Edinger-Westphal nucleus in the rhesus monkey.