急性坏死性胰腺炎大鼠背根神经节中P2X3的表达

Expression of P2X3 receptor in dorsal root ganglion in rats with acute necrotizing pancreatitis

目的观察ANP大鼠痛觉敏感性的变化及脊髓背根神经节（DRG）中P2X3表达的差异。方法牛磺胆酸钠胰腺被膜下均匀注射法制备SD大鼠ANP模型，被膜下注射等量生理盐水为假手术组，不做手术为对照组。V-fray法观察大鼠术前、术后痛阈改变，采用免疫组织化学方法检测制模后1、3、7、14d DRG的P2X3表达。结果ANP大鼠的缩腹频率在制模后7d达到高峰，为65．67％，明显高于对照组（10．02％）及假手术组（0）（P〈0．01）；假手术组与对照组间也有统计学差异（P〈0．05）。ANP大鼠制模后1d，DRG即出现P2X3阳性细胞，细胞数从术前的8．7±2．4增加到32．3±8．2，制模后3d高达64．1±8．5，较假手术组的最高数21．5±4．0和对照组的高值9．5±1．9均相差显著（P〈0．01）；制模后3、7、14d假手术组P2X3阳性细胞数也显著高于对照组（P〈0．01或〈0．05）。结论ANP大鼠DRG的P2X3高表达与内脏痛觉过敏的发生相关。

Objective To investigate the expression of P2X3 receptor in dorsal root ganglion and detect the changes in the perception of pain in rats with acute necrotizing pancreatitis （ANP）. Methods The ANP model in SD rats was induced by the injection of cholaic acid. The sham group was induced by the injection of same volume of normal saline solution. The control group did not receive any treatment. Immunohistochemistry was taken to show the expression of P2X3 receptor in dorsal root ganglion 1, 3, 7, 14 d after operation on ANP rats. Meanwhile, V-fray method was deployed to exam the changes of pain threshold at corresponding time points. Results The abdomen contraction frequency （65.67%） in ANP rats reached the peak at the 7th day after operation, which was significantly higher than that of sham operation group and control group （P 〈0.01 ）, and there was significant difference between the sham operation group and the control group （ P 〈 0.05）. The number of P2X3 positive cell population in dorsal root ganglion was significantly increased from 8.7 ± 2.4 to 32.3 ± 8.2 one day after surgery in ANP rats, at the 3rd day the number of P2X3 positive cell population was 64.1±8.5, which was significantly higher than that of sham operation group （21.5±4.0） and control group （9.5 ± 1.9） （ P 〈 0.01 ）. The number of P2X3 positive cell populations in sham operation group at 3rd, 7th, 14th were significantly higher than that of control group （ P 〈 0. 01 or P 〈 0. 05 ）. Conclusions The high expression of P2X3 in dorsal root ganglion may he related to the occurrence of visceral pain in ANP rats.