Dissertation > Excellent graduate degree dissertation topics show

The Expressions of VEGF in the Spinal Cords of Rats with Neuropathic Pain and the Facilitating Effects on Noxious Stimuli

Author: WangJiaZhen
Tutor: GaoJianXin
School: Shandong University
Course: Physiology
Keywords: Paw withdrawal response latency Intrathecal injection Vascular endothelial growth factor Neuropathic pain VEGFR2/Flk-1 receptor
CLC: R363
Type: Master's thesis
Year: 2009
Downloads: 54
Quote: 0
Read: Download Dissertation

Abstract

Purpose 1. Observed chronic sciatic nerve ligation injury model (chronic constriction of sciatic nerve, CCI) on the hot plate of nociceptive stimulation and mechanical pressure stimulation flinching reaction; 2. Investigate VEGF and its Flk-1 receptor in rat neuropathy The role in neuropathic pain. Learn the time-dependent changes in the expression of VEGF protein in CCI rat spinal cord. Method 1. Establish CCI rat model. Rat biceps femoris was separated according Benntt and Xie model created in 1988, i.e., under sterile conditions, exposure of the left sciatic nerve trunk 8-10mm, then with 4-0 chromic catgut interval 1.0-1.5mm loose ligation of the sciatic nerve ligation of a total of four times, ligation rat calf muscles mild fibrillation and does not affect the blood supply of the epineurium for the degree of intensity to cause. The ligation nerve after careful hemostasis and sutured. The sham group exposed sciatic nerve in the same manner, but not ligation of the sciatic nerve. 2 behavioral tests. 7th day after surgery, a hot plate with the smart meter (RB-200, is maintained at a temperature of 52 ℃) and the electronic the tenderness meter (YT-100) measured the rat hind paw plantar paw of the thermal and mechanical stimuli response latency (HWLs) rated the rat chronic neuropathic pain model success. Will the behavior test HWLs determine the successful model rats included in the experiment. Experiment, to test prior to administration rats with bilateral HWLs3 times, whichever is the average value as the control that is administered before the previous value, and then were tested 5,10,15,20,30,45,60 min after administration of HWLs . After administration different time HWLs translation into a percentage change, namely: (after administration of value - before administration value) / pre-dose value × 100%. 3. Staining and image processing software using immunohistochemical methods to detect the sham group and the CCI group after surgery 1d, 3d, 5d, 7d, 14d and 28d six time segments L4-5 spinal cord tissue VEGF protein expression in rats. Results of a normal control group of normal rats with CCI rats HWLs rat left and right sides after the claw foot the HWL mean hot plate stimulus were 4.52 ± 0.19 and 4.54 ± 0.18; mechanical pressure stimulation the HWL mean value of 5.12 ± 0.39 and 5.16 ± 0.40, respectively. Compare the rats left and right sides of the hind paw plantar stimulation on the hot plate and mechanical pressure stimulation HWLs, were statistically significant difference. CCI the rats group of left, right claw foot hot plate stimulus HWL mean were 2.86 ± 0.12 and 3.63 ± 0.16, the HWL mean mechanical pressure stimulation was 2.65 ± 0.83 and 3.78 ± 0.24, respectively. Compared with the normal control group, the the CCI rat group left, the right hind paw on the the hot plate stimulation and mechanical pressure stimulation HWLs difference has very significant statistical significance (P lt; 0.01). The experimental results suggest that the increased sensitivity of the CCI rats group response to noxious stimuli. 2. Intrathecal injection of VEGF shorten the CCI rats bilateral the claw foot nociceptive stimulation HWLs35 only CCI rats were randomly divided into four groups: a control group and three groups for the VEGF group. The control group (n = 9): intrathecal injection of 10μl saline; the VEGF group is further divided into: the experimental group A (n = 8): intrathecal injection of 0.1 nmolVEGF; experimental group B (n = 9): intrathecal injection of 0.2 nmol VEGF; experimental group C (n = 9): intrathecal injection of 0.4 nmol VEGF. (1) shorten the intrathecal injection of VEGF CCI rats claw foot mechanical pressure stimulation the HWL control rats left and right rear claw mechanical pressure stimulation of HWL respectively: the F _{left / left < / sub> = 0.57, F _{right / right} = 0.56. Experimental group the intrathecal injection 0.1nmol VEGF rat left and right hind paw mechanical pressure stimulation HWL: F _{left / left} = 0.52 and F _{right / right = 0.30, compared with the control group, no significant difference (P gt; 0.05). Intrathecal injection of 0.2 noml VEGF rat left, right claw foot mechanical pressure stimulation HWL respectively: F _{left / left} = 15.40 and F _{right / right = 15.01; the intrathecal injection 0.4 nmolVEGF rat left, right claw foot mechanical pressure stimulus reaction HWL: F _{left / left} = 19.03 and F _{right / right} = 18.60. Compared with the control group, respectively, claw-foot mechanical pressure to stimulate the HWL after intrathecal injection of VEGF (0.2 and 0.4 nmol) rats was significantly shorter, were statistically significant differences (P lt; 0.01). Claw foot mechanical pressure stimulation suggest that VEGF can improve on both sides of the CCI rats at the spinal level sensitivity. HWL control rats left hind paws on the hot plate (2) intrathecal injection of VEGF shorten CCI rats with bilateral stimulation, claw foot on the right side of the hot plate stimulation HWL respectively: F _{left / left} = 0.61 and F _{right / right} = 0.63. Rats intrathecal injection 0.1nmol VEGF, left, right claw foot hot plate stimulation HWL respectively: F _{left / left} = 46.82 and F _{right / right = 41.22; a the intrathecal injection 0.2nmol VEGF rats left, the right hind paw plantar stimulation HWL hot plate were: F _{left / left} = 98.43 and F _{right / right} = 92.32; intrathecal injection 0.4nmol VEGF rat left after the right side of the claw-foot hot plate stimulation HWL respectively: F _{left / left} = 125.22 and F < sub> right / right} = 118.56. Compared with the control group, intrathecal injection of 0.1 nmol 0.2nmol, 0.4nmol VEGF rats left and right sides of the hind paw plantar stimulation HWL hot plate statistically very significant difference (P lt; 0.01) . Intrathecal injection SU1498 reversible VEGF the rats HWLs the role of CCI rats intrathecal injection of 0.4 nmol of VEGF 10min, intrathecal injection of 0.4 nmol SU1498 rats left and right sides of the hind paw plantar hot plate stimulus reaction HWL F _{left / left} = 124.35 and F _{right / right} = 120.42 reduced to F _{left / left} = 45.68 and F < sub> right / right} = 43.83, statistically significant difference (P lt; 0.01); the CCI rats intrathecal injection of 0.4 nmol VEGF 10min, intrathecal injection of 0.4 nmol SU1498, rats the left and right sides of the hind paw plantar stimulate the HWL to mechanical pressure by F _{left / left} = 20.35 and F _{right / right} = 19.87 reduced to F _{left / left} = 7.62 and F _{right / right} = 6.85, a statistically significant difference (P lt; 0.01). Above visible VEGF facilitated rat claw foot nociceptive stimulation results may be SU1498 blocked, suggesting that the facilitatory effect of VEGFR2 mediated by VEGF induced rat claw foot nociceptive stimulation. 4.CCI rat L4-5 spinal cord VEGF protein expression changes sham surgery group blood vessels in the spinal cord, nerve cells, glial cells VEGF expression rarely; after CCI 1d, 3d, 5d, 7d, 14d and 28d spinal cord organization of neurons within the nucleus and the cytoplasm showed strong expression of VEGF protein, the first 3d expression reached the peak of 0.60 ± 0.89 20.80 ± 6.06, with the control group, there is a significant difference; CCI after 14d, 28d of VEGF appears only in the cytoplasm, its positive neurons was 7.80 ± 2.17 and 2.60 ± 1.82 Ge than CCI decreased, but still higher than the control group significantly increased at 7d. L4-5 spinal cord glial cells began to appear after CCI 3d expression of VEGF-positive glial cells 13.25 ± 3.16; 14d reached the peak, 35.83 ± 6.11; 28d when positive nerve the number of glial cells than before to reduce, for 21.50 ± 4.93; the CCI group VEGF positive cells than in the control group, a significant difference (P lt; 0.01). This experiment, changes in the expression of VEGF in vascular endothelial cells in the spinal cord after CCI # 1d L4-5 spinal cord vascular endothelial cell VEGF expression was strongly positive in the subsequent section 3d, 5d, 7d, 14d still expressed 28d no expression. The results of this experimental study of VEGF protein in neurons of CCI rats at different time periods, glial cells and vascular endothelial cells highly expressed, may be involved in spinal cord nociceptive sensory information or modulation process, its role in the molecular mechanisms need to be in-depth research. The experimental results show that, the exogenous VEGF facilitation at the spinal level chronic neuropathic pain in rats claw response to noxious stimuli, Flk-1 receptor-mediated process of the reaction. The experiment is to understand the molecular mechanisms of neuropathic pain added new content. The the the conclusion 1.CCI rats of noxious heat or mechanical pressure stimulation HWLs was significantly lower than the normal control rats. The 2.CCI rats, intrathecal injection of VEGF group was significantly shorter stimulation HWLs of noxious heat or mechanical pressure on the intrathecal injection of saline group, its shortened VEGF dose-effect relationship. SU1498 can block of 3.VEGFR2/Flk-1 blockers intrathecal injection of VEGF-induced CCI rats of noxious heat or mechanical pressure stimulus HWLs shortened. 4.CCI rat L4-5 spinal cord vascular endothelial cells, nerve cells, glial cells showed a time-dependent changes in the expression of VEGF protein.}}

The Expressions of VEGF in the Spinal Cords of Rats with Neuropathic Pain and the Facilitating Effects on Noxious Stimuli

Abstract

Related Dissertations