Effect of Glycyl-L-glutamine on the Rate of Regeneration of Acetylcholinesterase in the Rat Gastrocnemius Muscle after Diisopropyl Phosphorofluoridate Administration

Rats were given glycyl-L-glutamine (Gly-Gln) by intraaortic infusion with Alzet osmotic pumps during the 48-hr period following the intraaortic administration of diisopropyl phosphorofluoridate (DFP) (10 μ mol/kg). The infusion of 1.2 μ mol of Gly-Gln per 24 hr resulted in a significant increase in the acetylcholinesterase (AcChoEase; acetylcholine acetylhydrolase, EC 3.1.1.7) activity of the gastrocnemius muscles over that of rats that received DFP only. At a total dose of 3.6 μ mol per 24 hr, a diminished result was obtained; at 0.36 μ mol per 24 hr, no effect was detectable. These findings, together with earlier ones, suggest that the neurotrophic effect of Gly-Gln or a similar endogenous factor on AcChoEase synthesis is a general phenomenon at sites of cholinergic transmission.