RESUMEN
Objective:To explore the annexin A2 (ANXA2) expression and distribution in dorsal root ganglion (DRG) after chronic compression of DRG (CCD) in rat models.Methods:One hundred and two adult male Wistar rats were randomly divided into control group ( n=24), CCD model group A (7 d after modeling, n=30), CCD model group B (14 d after modeling, n=24), and CCD model group D (28 d after modeling, n=24). Rats in the later 3 groups were established CCD models with the help of "U" rod screw. Mechanical withdrawal threshold (MWT) and thermal radiation paw withdrawal latency (TWL) were measured by mechanical pain stimulator and thermal pain stimulator. The ANXA2 protein expression in the DRG was detected by Western blotting and immunofluorescent staining. The distributions of ANXA2 and class III β-tubulin (TUBB3) positive cells in DRG were detected by immunofluorescence double staining. Results:As compared with those in the control group, MWT and TWL in the CCD model group A and CCD model group B were significantly decreased ( P<0.05). Western blotting showed that ANXA2 protein expression in the DRG of CCD model group A was statistically increased as compared with that in the control group ( P<0.05). Immunofluorescent staining showed that the immunoreactivity of ANXA2 in DRG of CCD model group A was enhanced as compared with that in control group. Immunofluorescence double staining showed that ANXA2 was mainly expressed in the cell membrane of neurons in the DRG of CCD model group A. Conclusion:The mechanical and thermal pain thresholds are decreased, while the ANXA2 protein expression at the pressure side of DRG is up-regulated and the immunoreactivity is increased in CCD models; ANXA2 may be involved in the occurrence and development of pathological neuralgia after CCD.