Ucn3及其受体CRFR2在肠易激综合征大鼠模型肠神经系统中的表达

Expression of Urocotin3 and CRFR2 in the enteric nervous system of rats with irritable bowel syndrome

目的:探讨尿皮质素3(Urocotin3,Ucn3)及其受体促肾上腺皮质释放因子受体2(corticotrophin releasing factor receptor2,CRFR2)在肠易激综合征中的表达.方法:将36只180-220g的Wistar大鼠随机分为对照组(N)、急性应激组(A,急性束缚1h)、慢性应激组(C,28d不可预知轻度应激)、急慢性联合应激组(AC,在慢性应激基础上给予急性束缚)4组建模.采用排便粒数、敞箱行为评分和蔗糖水偏嗜度评价动物模型.建成后留取大鼠结肠组织,采用Real-timePCR方法检测各组大鼠结肠中Ucn3及其受体CRFR2表达水平的变化.结果:Ucn3在各组大鼠结肠中的表达:N组1.108±0.293,A组3.594±1.839,C组1.852±0.674,AC组3.989±1.591,各应激组Ucn3的表达均高于对照组(P<0.05),各应激组间A组vsC组(P<0.017),C组vsAC组(P<0.002),表达有统计学差异.CRFR2在各组大鼠结肠中的表达:N组1.042±0.217,A组2.119±0.468,C组1.568±0.507,AC组2.392±0.840,各应激组CRFR2的表达均高于对照组(P<0.05).各应激组之间没有统计学差异.结论:慢性应激、慢急性联合应激建立肠易激综合征大鼠模型重复性好.Ucn3及其受体CRFR2在肠易激综合征中表达升高,且Ucn3在急性应激后升高比慢性应激后更明显.

AIM： To examine the expression of Urocotin3 （Ucn3） and its receptor corticotrophin-releasing factor receptor 2 （CRFR2） in the colon of rats with irritable bowel syndrome （IBS）. METHODS： Thirty-six Wistar rats were randomly divided into four groups： normal control group （N）, acute stress group （A）, chronic stress group （C）, and acute-chronic stress group （AC）. The animal models were assessed by counting fecal pellets, open-field behavior scoring and fluid consumption testing. On day 28 after induction of IBS, the animals were killed to take colon tissue for detecting the expression of Ucn3 and CRFR2 by real-time PCR and for dissecting the myenteric plexus and submucosal plexus for immunoflurescence. RESULTS： Both Ucn3 and CRFR2 were ex- pressed in the myenteric and submucosal plexus in the colon of rats with IBS. The expression level of Ucn3 was higher in each stress group than in the control group （N： 1.108 ± 0.293; A： 3.594 ± 1.839; C： 1.852 ± 0.674; AC： 3.989 ± 1.591; all P 0.05）. The expression of Ucn3 in the acute stress and acute-chronic groups was higher than that in the chronic stress group （P 0.017, 0.002）. CRFR2 expression was also increased in all the three stress groups compared to the control group （A： 2.119 ± 0.468; C： 1.568 ± 0.507; AC： 2.392 ± 0.840; all P 0.05）. CRFR2 expression showed no significant differences among the three stress groups. CONCLUSION： The expression of both Ucn3 and CRFR2 increases in the colon of IBS rats, and they may play an important role in the enteric neural system in rats with IBS.