The antinociceptive effect of intrathecal administration of fluorocitrate in a rat model of inflammatory pain / 中国药理学通报

ABSTRACT

Aim To investigate the effect of intrathecal injection of fluorocitrate(Fc)on mechanical and thermal hyperalgesia induced by complete Freund's adjuvant(CFA)injection in rats.Methods The mechanical withdrawal threshold(MWT)and thermal withdrawal latency(TWL)were measured before and after CFA or Fc treatment.The changes of glial fibrillary acidic protein(GFAP)and OX-42(a microglial marker)expression in the spinal cord dorsal horn were evaluated by immunohistochemistry analysis.Results Rats with CFA-induced arthritis showed mechanical allodynia and thermal hyperalgesia,which was correlated with the increased GFAP and OX-42 expression in the spinal cord dorsal horn.Intrathecal injection of Fc markedly suppressed CFA-induced thermal hyperalgesia and mechanical allodynia.Fc significantly attenuated the activation of GFAP and OX-42 in the spinal cord dorsal horn.Conclusions The glia activation in spinal cord is closely related to the progress of CFA-induced peripheral hyperalgesia.Fc may exert antihyperalgesic effect by inhibiting the activation of astrocyte and microglia.