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Inhibition of sympathetic sprouting in CCD rats by lacosamide
Author(s) -
Wang Y.,
Huo F.
Publication year - 2018
Publication title -
european journal of pain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.305
H-Index - 109
eISSN - 1532-2149
pISSN - 1090-3801
DOI - 10.1002/ejp.1246
Subject(s) - sprouting , lacosamide , neuropathic pain , medicine , nerve injury , anesthesia , pharmacology , neuroscience , epilepsy , biology , botany , psychiatry
Background Early hyperexcitability activity of injured nerve/neuron is critical for developing sympathetic nerve sprouting within dorsal root ganglia ( DRG ) since lacosamide ( LCM ), an anticonvulsant, inhibits Na + channel. The present study tried to test the potential effect of LCM on inhibiting sympathetic sprouting in vivo . Methods Lacosamide (50 mg/kg) was daily injected intraperitoneally into rats subjected to chronic compression DRG ( CCD ), an animal model of neuropathic pain that exhibits sympathetic nerve sprouting, for the 1st 7 days after injury. Mechanical sensitivity was tested from day 3 to day 18 after injury, and then DRG s were removed off. Immunohistochemical staining for tyrosine hydroxylase ( TH ) was examined to observe sympathetic sprouting, and patch‐clamp recording was performed to test the excitability and Na + current of DRG neurons. Results Early systemic LCM treatment significantly reduced TH immunoreactivity density in injured DRG , lowered the excitability level of injured DRG neurons and increased paw withdrawal threshold. These effects on reducing sympathetic sprouting, inhibiting excitability and suppressing pain behaviour were observed 10 days after the end of early LCM injection. In vitro 100 μmol/L LCM instantly reduced the excitability of CCD neurons via inhibiting Na + current and reducing the amplitude of AP . Conclusions All the findings suggest, for the first time, that early administration of LCM inhibited sympathetic sprouting and then alleviated neuropathic pain. Significance Early LCM administration inhibited sympathetic sprouting within DRG in CCD rats via reducing hyperexcitability of neurons. Early LCM administration suppressed neuropathic pain in CCD rats.