The Role Of The Primary Sensory Presynaptic GABR-AR In The Neuropathic Pain

Objective: This research is by the establishment of the rat's chronic sciatic nerve crush model (chronic constriction injury of the sciatic nerve model, CCI), it is using molecular biology techniques to study the expression changes of theγ-aminobutyric acid (gamma-aminobutyric acid, GABA) receptors in the neuropathic pain of the rat dorsal root ganglia (dorsal root ganglion, DRG), and to discussion its possible mechanism, in order to reveal the further mechanism of neuropathic pain,which is provide a theoretical basis for the experiments.Methods:1) CCI model,30 male Wistar rats, those were randomly divided into three groups: control group (n=10),sham-operation group (n=10) and CCI group (n=10) were weighted and anesthesia under 1% pentobarbital sodium of intraperitoneal injection. Sham-operation group is only exposed to sciatic nerve without any treatment, CCI group was sciatic nerve ligation 4-0 chromic catgut, and the hot plate test was given to measure paw withdrawal thermal latency(PTWL) at 0d before operation and at 1d,3d,5d,7d,9d,11d and 14d after operation;2)Take three groups of rats from L4-6 of DRG neurons in the molecular biology section.To detect three cases GABR-AR gene and protein expression changes through the control group CCI group and shem-operation DRG by technology of RT-PCR and Western-blot, which is analyze the role of the primary sensory presynaptic GABR-AR in the Neuropathic Pain from gene level and protein level.Results: 1) The rats with the heat stimulus flinching reflex latency (PWTL) in the CCI group was significantly shorter than control group (P<0.05) after operation and lasted through the whole experiment. 2) The level of mRNA of GABA-ARα2 receptorα2 andγ2 receptor CCI group, sham-operation group and by the method of RT-PCR, the result is: CCI operation group, of which the expression was decreased, while sham-operation group was higher than the control group, the difference was statistically significant (P<0.05).3) Detected protein levels from the GABA-AR receptorα2 andγ2 receptor CCI group, sham-operation and control group by Western-blot. By quantitative gel electrophoresis image analysis system scan showed the expression of CCI group is decreased, sham-operation group is increased slightly, these results were consistent with the RT-PCR.Conclusions:when the neuropathic pain was occurring, GABA-AR gene and operation exprassion was decreased,GABA in primary afferent terminals presynaptic inhibition have been reduced, and the injury of information transmission is alienated.