结肠扩张刺激对肠易激综合征大鼠DCN核团及骶髓后角中P2X4及P2X7受体表达的影响

Effects of the stimulation of colorectal distention on expression of P2X4 and P2X7 receptors in dorsal commissural nucleus and dorsal horn of sacral segment of spinal cord in rats with irritable bowel syndrome

目的观察肠易激综合征(irritable bowel syndrome,IBS)致内脏高敏感化大鼠在结肠扩张刺激时大鼠腹直肌肌电变化,并观察骶髓后联合核(dorsal commissural nucleus,DCN)和脊髓后角中P2X4和P2X7受体表达的变化情况,为探讨IBS内脏敏化的神经机制提供理论依据。方法以旋毛虫感染大鼠建立IBS大鼠模型,并以正常大鼠作为对照,实验共分4组:正常大鼠无刺激组,正常大鼠结肠扩张刺激组,IBS大鼠无刺激组,IBS大鼠结肠扩张刺激组。采用免疫组织荧光化学方法,将P2X4和P2X7受体分别标记,观察其在骶髓后角及DCN核团上的表达变化,并同步测定大鼠腹直肌肌电变化。结果 IBS结肠刺激组大鼠腹直肌肌电变化、大鼠骶髓后角及DCN核团中的P2X4和P2X7受体表达较正常大鼠对照组及IBS未刺激组均显著增强。结论 P2X4和P2X7受体可能是IBS致内脏敏感性增高的重要因素。

Objective To explore the expression of P2X4 and P2X7 receptors in dorsal commissural nucleus（DCN） and dorsal horn of sacral segment of spinal cord in rats with irritable bowel syndrome（IBS） induced by the stimulation of colorectal distention,and to provide a theoretical evidence in prevention and treatment of IBS. Methods The rats were gavaged with the Trichinella spiralis to establish the irritable bowel syndrome model,and then divided into 2 groups：IBS without colon distension group and IBS with colon distension group.The normal rats were chosen as controls,and were also divided into 2 groups according to receiving colon distension or not.The expression of P2X4 and P2X7 receptors was detected in neurons of DCN and dorsal horn of the sacral segment of spinal cord in all rats using the immunofluorescent staining method,and the myoelectric changes of the rectus abdominis were recorded at the same time. Results The electro-activity of the rectus abdominis and the expression of P2X4 and P2X7 receptors were significantly enhanced in IBS rats with colon distension than those in the normal rats and IBS rats without colon distension. Conclusion P2X4 and P2X7 receptors may be the important factors to induce the increase of visceral sensitivity.