Correlation of muscarinic receptor density and acetylcholinesterase activity in repeated DFP-treated rats after the termination of DFP administration.

Following chronic exposure to DFP, both AChE activity and muscarinic receptor density were markedly depressed in the rat striatum. The rate of recovery of AChE activity was 5.2% per day within 7 days, while the density of muscarinic receptor recovered at the rate of 1.94% per day. The correlation between 2 parameters was very high (R = 0.99). Thus, it is suggested that the muscarinic receptor density was intimately related to AChE activity.