title: Intra- versus extracellular recovery of 16S acetylcholinesterase following organophosphate inactivation in the rat.
abstract: Acetylcholinesterase (AChE) inhibitor treatments were used to study the temporal course of intra- versus extracellular 16S AChE recovery in endplate regions of adult rat anterior gracilis muscles previously exposed to a brief, in situ application of diisopropylfluorophosphate (DFP). Following such enzymatic inactivation (95-100%), extracellular 16S AChE recovery began significantly later than that of intracellular (onset at approximately 36 and 12 h, respectively) but, once begun, progressed at approximately the same rate (1.32%/h). The recovery of AChE molecular form activities subsequent to identical DFP-inactivation was blocked to a large extent (65-85%) by in vivo treatment with cycloheximide, a protein synthesis inhibitor. These results support the hypothesis that extracellular 16S AChE at mammalian skeletal muscle motor endplates is primarily derived from complete, previously assembled 16S molecules originating in myofibers.
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D066298:In Vitro Techniques; D007531:Isoflurophate / Q000494:pharmacology*; D008297:Male; D009045:Motor Endplate / Q000201:enzymology*; D009469:Neuromuscular Junction / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D007531:Isoflurophate; D003513:Cycloheximide; D000110:Acetylcholinesterase