Changes in trafficking of GluR1-containing AMPA receptor and GluR2-containing AMPA receptor from cytoplasm to cell membrane in spinal dorsal horn in a rat model of incisional pain / 中华麻醉学杂志

ABSTRACT

Objective To investigate the changes in trafficking of GluRl-containing AMPA (GluR1-AMPA) receptor and GluR2-AMPA receptor from cytoplasm to cell membrane in the spinal cord dorsal horn in a rat model of incisional pain.Methods Thirty-two adult male SD rats aged 6-8 weeks weighing 280-300 g were randomly divided into 2 groupscontrol group (group C,n =8) and incisional pain group (group Ⅰ,n =24).An 1 cm long incision was made in the plautar surface of right hindpaw according to Brennan et al.in group Ⅰ.Cumulative pain score (CPS) and paw-withdrawal threshold to yon Frey stimuli (PWT) were measured at 3 h and day 1 and 3 afar incision ( T1,2,3 ).The animals were sacrificed after pain behavior assessment.Their lumbar segments of the spinal cord (L3-6) were removed.The expression of GluR1 and GluR2 in cell membrane and cytoplasm in spinal cord dorsal horn was determined by Western blot analysis.The co-expression of Stargazing with GluR1 and GluR2 in the spinal cord dorsal horn was examined by co-immuno-precipitation.Results The CPS was increased and PWT decreased; the GluR1 expression in cytoplasm was decreased while the expression of GluR1 in cell membrane and the co-expression of Stargazing with GluR1 were up-regulated in group Ⅰ as compared with group C.There was no significant change in the expression of GluR2 in cytoplasm and cell membrane and the co-expression of Stargazing with GluR2 in group Ⅰ as compared with group C.Conclusion GluR1-AMPA receptor transfers from cytoplasm to cell membrane but GluR2-AMPA receptor does not in rats with incisional pain.