Motor nerve terminal response to edrophonium in delayed DFP neuropathy.
A localized peripheral neuropathy was induced in cats with di-isopropyl fluorophosphate (DFP). Soleus nerve-muscle preparations, and the motor nerve terminals in particular, were evaluated for responsiveness to edrophonium (200 mug/kg i.v.). Potentiation of contractile strength was absent 24 hr after DFP, and showed a trend toward recovery 7-14 days post-DFP; it then fell to about 25% of normal 3 weeks following DFP administration. During the ensuing 5 weeks this aspect of edrophonium responsiveness was largely regained. The underlying post-drug repetition which gives rise to the potentiated responses was not demonstrable in either the nerve or muscle 3 weeks after DFP, but was again observed 8 weeks after poisoning. These findings suggest a delayed peripheral neuropathy indicative of a trophic deprivation and further illustrate a motor nerve terminal deficit as the initial function alteration in DFP neuropathy.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002415:Cats; D004357:Drug Synergism; D004491:Edrophonium / Q000494:pharmacology*; D005260:Female; D007531:Isoflurophate / Q000494:pharmacology*; D008297:Male; D009046:Motor Neurons / Q000187:drug effects*; D009119:Muscle Contraction / Q000187:drug effects; D009411:Nerve Endings / Q000187:drug effects*; D009422:Nervous System Diseases / Q000139:chemically induced*; D012584:Sciatic Nerve / Q000187:drug effects; D013997:Time Factors
D007531:Isoflurophate; D004491:Edrophonium