Neurotrophic factors influence upregulation of constitutive isoform of heme oxygenase and cellular stress response in the spinal cord following trauma - An experimental study using immunohistochemistry in the rat

The influence of brain derived neurotrophic factor (BDNF) or insulin like g rowth factor-1 (IGF-1) on spinal cord trauma induced carbon monoxide (CO) p roduction and cellular stress response was examined using immunostaining of the constitutive isoform of the hemeoxygenase (HO-2) enzyme and the heat s hock protein (HSP 72 kD) expression in a rat model. Subjection of rats to a 5 h spinal trauma inflicted by an incision into the right dorsal horn at T 10-11 segment markedly upregulated the HO-2 and HSP expression in the adjac ent spinal cord segments (T9 and T12). Pretreatment with BDNF or IGF-1 sign ificantly attenuated the trauma induced HSP expression. The upregulation of HO-2 was also considerably reduced. These results show that BDNF and IGF-1 attenuate cellular stress response and production of CO following spinal c ord injury which seems to be the key factors in neurotrophins induced neuro protection.