新生期芬太尼镇痛下调幼鼠脊髓Fos蛋白表达

Neonatal Fentanyl analgesia decrease spinal Fos expression in young rats

目的:通过观察幼鼠腰骶段脊髓背角Fos蛋白表达,探讨新生期芬太尼镇痛抑制幼鼠慢性内脏痛觉高敏感性形成的作用机制。方法:32只SD新生大鼠按2×2析因设计分成4组,每组8只,A1B1组:新生期反复结直肠刺激(colorectal irritation,CI),建立幼鼠内脏痛觉高敏感模型,CI前腹腔注射芬太尼;A1B2组:新生期反复CI,CI前腹腔注射生理盐水;A2B1组:新生期未接受CI,腹腔注射芬太尼;A2B2组:新生期未接受CI,腹腔注射生理盐水。常规饲养到幼鼠期(6周龄),留取L6-S2脊髓,应用免疫组织化学染色及计算机图像分析系统进行脊髓Fos阳性细胞数(FLI细胞数)和积分光密度值半定量分析。结果:新生期CI前腹腔注射芬太尼镇痛,可使幼鼠腰骶段脊髓背角FLI细胞数和FLI细胞积分光密度值显著减低;幼鼠腰骶段脊髓背角Fos蛋白表达受到新生期CI和新生期应用芬太尼两因素的影响,两者存在交互作用,差别具有统计学意义。结论:新生期CI前腹腔注射芬太尼,能够导致幼鼠脊髓神经元Fos蛋白高表达下降,抑制幼鼠慢性内脏痛觉高敏感形成。

AIM： To investigate the mecha nism of blocking visceral hyperalgesia by Fenta- nyl analgesia in neonatal period through observe- ing the Fos expression of lumbosacral spinal dor- sal horn in visceral hyperalgesia rats. METH- ODS： Coloreetal irritation （CI） stimulation in neonatal period was used to establish the model of visceral hypersensitivity in young rats. 32 neo- natal rats were divided into four groups by 2 × 2 factorial design with each 8. Group A1B1 was imposed on CI at neonatal period and imposed on fentanyl intraperitoneal injection before CI stim- ulation; Group A1B2 was imposed on CI at neo- natal period and administration saline before CI; Group A2B1 was not imposed on CI at neonatal period and imposed on fentanyl intraperitoneal injection; Group A2B2 was not imposed on CI at neonatal period and not traperitoneal injection. breeding till the young imposed on fentanyl in- Then, conventionally period （6-week age）,rats were sampled the spinal cord from L6 to S2, the semi-quantity analysis of staining density and the cell numbers of Fos-like immunoreactivity （FLI） of spinal cord were made through immu- nohisrochemical coloration and computer image analyzing system. RESULTS：The number of FLI and integral opticaldensity of FLI significantly decreased in lumbosacral spinal dorsal horn by neonatal Fentanyl analgesia. The spinal Fos ex- pression in young rats were affected both by CI at neonatal period and neonatal fentanyl analge- sia. Futhermore, there were interaction effects between the two factors. CONCLUSION： Neo- natal fentanyl analgesia before CI can decrease spinal Fos expression and visceral hypersensitivi- ty in young rats.