Gonadectomy affects brain derived neurotrophic factor in rats after chronic constriction nerve injury.

AIM To assess the effect of gonadectomy on brain derived neurotrophic factor (BDNF) expression in neuropathic pain. METHODS Using chronic constriction injury (CCI) model, we detected BDNF mRNA in dorsal root ganglion and protein content in spinal cord by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay respectively. The time point we chose was post CCI operation d 0, 3, 7, 14, and 21. RESULTS After CCI surgery, BDNF mRNA in ipsilateral DRGs was upregulated and reached its maximum on post operation d 7. BDNF protein level in ipsilateral spinal cord was also increased and reached its maximum on post operation d 14. The magnitude of this increase in gonadectomy (GDX) rats was significantly smaller than the GDX-sham rats at each time point. CONCLUSION Gonadectomy reduced the BDNF increment after CCI surgery. Estrogen may affect nociceptive processing by its effect on BDNF.