Effects of electro-acupuncture on IGF-I expression in spared dorsal root ganglia and associated spinal dorsal horn in cats subjected to adjacent dorsal root ganglionectomies.

The effects of electro-acupuncture (EA) on insulin-like growth factor-I (IGF-I) expression in the spared dorsal root ganglia (DRG) and associated spinal dorsal horns were explored in cats subjected to unilateral removal of L(1)-L(5) and L(7)-S(2) DRG, sparing the L(6) DRG. Immunohistochemistry revealed the presence of IGF-I immunoreactive products in the L(6) DRG neurons and some neurons and glial cells in the spinal cord. Western blot demonstrated that the level of IGF-I was significantly up-regulated both in the spared DRG and the dorsal horns of L(3) and L(6) cord segments at both 7 and 14 days post operation following EA. The present findings demonstrated the association between neuroplasticity and IGF-I expression, suggesting the possible role of IGF-I in EA promoted spinal cord plasticity.