Steady State and Regenerating Levels of Acetylcholinesterase in the Superior Cervical Ganglion of the Rat Following Selective Inactivation of Propionylcholinesterase1

The effects of selective inactivation of propionylcholinesterase (PrChE) by tetramonoisopropylpyrophosphortetramide (iso‐OMPA) on the steady state and regenerating levels of acetylcholinesterase (AChE) were investigated on the superior cervical ganglion (SCG) of the rat. Over the dosage range of 1.5‐40.0 μmol iso‐OMPA/kg intraperitoneally, which produced nearly total inactivation of ganglionic PrChE and 0‐35% inactivation of AChE, there was no subsequent increase in AChE activity above the control level. Single or repeated injections of iso‐OMPA at total doses of 5.0‐40.0 μmol/kg intraperitoneally caused no reduction in the rate of regeneration of ganglionic AChE during the 24 h following its inactivation by sarin, 2.0 μmol/kg intravenously. Both sets of findings differ from those obtained previously in a similar study of ganglionic AChE and butyrylcholinesterase (BuChE) in the cat. Possible reasons for this distinct species difference are discussed.