The carbenoxolone reduces nociceptive behavior and exprission of Fos-like immunoreactive neurons in Sp5C of rats after subcutameous formalin injection

Objective: To investigate the effect of carbenoxolone (CBX), a gap junction blocker, was injected into the cerebellomedullary cistern, to nociceptive behavior and the plastic response of neurons and astrocytes in spinal trigeminal nucleus caudalis (Sp5C) induced by subcutaneous formalin injection into the unilateral upper lip. Methods: Twenty rats were randomly classified as normal rats, physiological saline injection (NS), formalin injection, CBX plus formalin injection, Sham CBX plus formalin injection groups. The cumulative time spent in scratching the injected area with the ipsilateral fore- or hindpaw was accounted 45 min after formalin injection. By means of anti-Fos protein and anti-glial fibrillary acidic protein (GFAP) immunohistochemical staining investigated the changes of reactive neurons and astrocytes in Sp5C of different group. Results: The extent, degree, cumulative time of scratching, as well as Fos-Li neurons and GFAP-Li astrocytes in Sp5C of NS group were much less than formalin or Sham CBX plus Formalin group. The results from CBX plus Formalin group were intervenient between NS group and Sham CBX plus Formalin group. Conclusion: The results suggested that gap junction might be a station participating in pain modulation of the central nervous system.

Duke Scholars

Author Li Lan Molecular Genetics and Microbiology