The Role Of SRF-IEG Pathway On The Visceral Hypersensitivity Induced By Restraint Stress

Part â…  Changs in the expression of SRF-IEG on DRG of the rat model with visceral hypersensitivity induced by acute restraint stressBackground and Objective:To explore the role of SRF-IEG on the formation of visceral hypersensitivity induced by acute restraint stress.Methods:12SD rats were randomly divided into acute restraint stress group(model group) and control group. Visceral hypersensitivity was gained by acute restraint stress for2h. The colorectal distension(CRD) with different pressure were performed and abdominal withdrawal reflex(AWR) scores were assessed during CRD. And when the AWR score was three, the minimum pressure of CRD was recorded as the threshold of pain. The visceral sensitivity was determined by AWR scores and threshold of pain. The expression of serum response factor(SRF) and immediate early gene(IEG, including arc and c-fos) were measured by immunohistochemistry, real time RT-PCR and Western blot.Results:The AWR scores in model group(at20and40mmHg) were significantly more than that in control group and the basal level.(P<0.05). The threshold of pain in model group is significantly lower than that in control group. The expression of mRNA of SRF, ARC and c-fos were higher in model group(P<0.05). The expression of protein of SRF and c-fos were higher in model growp(P<0.05).Conclusion:The SRF-IEG signal pathway probably plays an important role in the formation of visceral hypersensitivity induced by acute restraint stress. Part â…¡ The role of SRF-IEG on the rat model with visceral hypersensitivity induced by chronic restraint stressBackground and Objective:To explore the role and mechanism of SRF-IEG on the formation of visceral hypersensitivity induced by chronic restraint stress.Methods:18SD rats were randomly divided into3groups(6per group):chronic restraint stress group(model group1), sham restraint stress group(control group) and chronic restraint stress group without CRD(model group2). The colorectal distension(CRD) was performed in model group1and control group. When the AWR score was three, the minimum pressure of CRD was recorded as the threshold of pain. The visceral hypersensitivity was determined by the threshold of pain. The expression of serum response factor(SRF), immediate early gene(IEG, including arc and c-fos) and synaptic plasticity-associated proteins(synaptophysin, PSD-95, NMDAR1and p-CaMKâ…¡) were measured by Western blot.Results:(1)The threshold of pain in model group1is significantly lower than that in control group(P<0.05).(2)The protein expressions of SRF, Arc and c-fos were higher in model group1and model group2than those in control group (P<0.05). No significant difference was found between model group1and model group2.(3) The protein expressions of synaptophysin, PSD-95, NMDAR1and p-CaMKâ…¡ were higher in model group1and model group2than those in control group (P<0.05). No significant difference was found between model group1and model group2.Conclusion:The SRF-IEG signal pathway probably plays an important role in the formation of visceral hypersensitivity induced by chronic restraint stress.