VEGF Upregulation The Expression Of TRPV1Mediated By PI3K/Akt Pathway Contributes To The Neuropathic Pain Of CCI Rats

ObjectAs a key factor in the process of angiogenesis, VEGF is also play an important role in the nerve systerm. In order to investigate the mechanism of VEGF involving in the neuropathic pain, we applicated VEGF antibody and LY294002on CCI rats respectively, and observed the effects of both two substance on the pain thresholds and the expression of p-Akt and TRPV1in the spinal cord.MethodsThirty-six rats were divided into six groups randomly. The rats in sham group received exposure of left sciatic nerve without ligation,The rats in CCI group received an operation of ligation of left sciatic nerve. The rats in VEGF antibody group received intrathecal of VEGF antibody and CCI. The rats in LY294002group received intrathecal of LY294002and CCI. The rats in NS group received intrathecal of saline and CCI. The rats in DMSO group received intrathecal of DMSO and CCI.Result1. There is no distinction in basic PWMT or PWTL between each group of rats before surgery (P>0.05); also no significant difference in the pain thresholds of the sham group rats each time point in the perioperative period (P>0.05). Compared with the sham group rats, the PWMT and PWTL of the rats in CCI group significantly reduced(P<0.05). There is significant difference in the PWMT and PWTL of rats between VEGF antibody group and the CCI group(P<0.05), and the same situation occurred in LY294002group.2. TRPV1and p-AKT immunoreactivities in the superficial lamella spinal cord horn were detected by immunohistochemistry on day8after surgery each group. The staining of p-AKT of CCI group was all higher than that in sham group, VEGF antibody group and LY294002group, which is the same as TRPV1.3. Western Blot studies showed that the expression of p-AKT and TRPV1in spinal cord were more abundant in CCI group comparison with that in sham group, VEGF antibody group and LY294002group respectively. There are no significant difference in the expressions values of p-AKT and TRPV1between DMSO group and NS group.ConclusionThe results show that VEGF may participate in the pathogenesis of neuropathic pain in CCI rats, and PI3K/Akt signaling pathway contributes to neuropathic pain too. It was conclued that VEGF may upregulate the expression of TRPV1mediated by PI3K/Akt signaling pathway in spinal cord neurons, and involve in the pathogenesis of neuropathic pain.