健脾化湿颗粒对D-IBS大鼠脑中酪氨酸羟化酶、单胺氧化酶及5-羟色胺转运体表达的影响

目的:从脑中酪氨酸羟化酶,单胺氧化酶及5-羟色胺(5-HT)转运体角度探讨健脾化湿颗粒改善腹泻型肠易激综合征(D-IBS)的作用机制。方法:SD大鼠随机分为正常组、模型组、健脾化湿颗粒低、中、高剂量组(6.25,12.5,25 g·kg-1)、阳性药组(匹维溴铵,0.03 g·kg-1),共6组,每组10只,除正常组外,其余各组大鼠均采用灌服番泻叶联合束缚应激的方法复制D-IBS大鼠模型,观察不同时间各组大鼠糖水偏爱度的的变化,应用健脾化湿颗粒进行干预14 d。应用免疫组化法和蛋白免疫印迹法(Western blot)检测脑中酪氨酸羟化酶、单胺氧化酶及5-HT转运体的表达。结果:与正常组比较,模型组大鼠糖水偏爱度显著下降(P0.01),脑中酪氨酸羟化酶表达显著升高,单胺氧化酶及5-HT转运体表达显著下降(P0.01)。模型组比较,中、高剂量组及匹维溴铵组大鼠糖水偏爱度显著升高(P0.05,P0.01);除阳性组大鼠单胺氧化酶相对表达量外,各治疗组大鼠脑中酪氨酸羟化酶阳性表达及表达量均显著降低,单胺氧化酶和5-HT转运体阳性表达及表达量均显著升高(P0.05,P0.01)。与匹维溴铵组比较,中、高剂量组大鼠糖水偏爱度均显著升高(P0.05,P0.01);中、高剂量组大鼠脑中酪氨酸羟化酶阳性表达及相对表达量显著降低(P0.05,P0.01);中、高剂量组大鼠脑中单胺氧化酶及高剂量组大鼠脑中5-HT转运体阳性表达显著升高(P0.05,P0.01);低、中、高剂量组大鼠脑中单胺氧化酶及5-HT转运体相对表达量显著升高(P0.05,P0.01)。结论:健脾化湿颗粒降低D-IBS模型大鼠脑内5-HT含量与其下调脑中酪氨酸羟化酶表达,上调单胺氧化酶和5-HT转运体表达密切相关,这可能是其治疗D-IBS的作用机制之一。

Effect of Jianpi Huashi Granule on Tyrosine Hydroxylase, Monoamine Oxidase and Serotonin Transporter Expression in Brain of Rats with Diarrhea-predominant Irritable Bowel Syndrome

Objective: To investigate the effect of Jianpi Huashi granule on tyrosine hydroxylase, Monoamine oxidase and serotonin transporter expression in brain of rats with diarrhea-predominant irritable bowel syndrome (D-IBS), and explore its mechanism. Method: SD rats were randomly divided into normal group, model group, Jianpi Huashi granule low, middle and high dose groups (6.25, 12.5, 25 g·kg^-1), and positive drug group (pinaverium bromide, 0.03 g·kg^-1), n=10 in each group. Except the rats in normal group, all the other rats received intragastric administration of Sennae combined with restraint stress to establish D-IBS models. The changes of sucrose preference in different groups were observed at different time points, and Jianpi Huashi granule was used for 14 days. Then immunohistochemical method and Western blot were used to detect the expression levels of tyrosine hydroxylase, monoamine oxidase and serotonin transporter in brain. Result: In the D-IBS model group, the sucrose preference was decreased significantly, the expression of tyrosine hydroxylase in brain was significantly increased, and the expression levels of monoamine oxidase and serotonin transporter in brain were decreased significantly as compared with the normal control group (P<0.01). After treatment, the sucrose preference was significantly increased in medium-and high-dose Jianpi Huashi granule groups and positive drug group (P<0.05, P<0.01) ; except the relative expression of monoamine oxidase in positive drug group, the expression levels of tyrosine hydroxylase in all other treatment groups were decreased significantly and the expression levels of monoamine oxidase and serotonin transporter were increased significantly as compared with the model group (P<0.05, P<0.01). As compared with the positive drug group, the sucrose preference was increased significantly (P<0.05, P<0.01); the expression of tyrosine hydroxylase was decreased significantly (P<0.05, P<0.01); the expression of monoamine oxidase in middle and high-dose Jianpi Huashi granule groups and the positive expression of serotonin transporter in high-dose Jianpi Huashi granule group were increased significantly (P<0.05, P<0.01); the expression levels of monoamine oxidase and serotonin transporter were increased significantly in low, middle and high dose Jianpi Huashi granule groups (P<0.05, P<0.01). Conclusion: Jianpi Huashi granule reduced the content of serotonin transporter in brain of rats with D-IBS, which was closely related to down-regulating the expression of tyrosine hydroxylase and up-regulating monoamine oxidase and serotonin transporter in brain. This may be one of the therapeutic mechanisms of Jianpi Huashi granule for D-IBS.