基于DA受体cAMP-PKA信号通路探讨加味当归芍药散治疗HPRL大鼠的机制

Mechanism of Modified Danggui Shaoyao Powder in treating hyperprolactinemia rats based on dopamine receptorcAMP-PKA signaling pathway

目的研究加味当归芍药散治疗高泌乳素血症(HPRL)大鼠的机制。方法 96只雌性SD大鼠采用随机数字表分为空白组,模型组,阳性组,高、中、低浓度组,每组16只,经背部皮下注射甲氧氯普胺液,制造HPRL模型,5天后造模成功,定时定量给药30天后立即处死取材,采用免疫组化法检测下丘脑多巴胺D1受体(DRD1)、D2受体(DRD2)、蛋白激酶A(PKA)的表达,酶联反应法(Elisa)检测各组大鼠血泌乳素(PRL)、多巴胺(DA)、环磷酸腺苷(cAMP),实时荧光定量PCR检测各组HPRL模型大鼠下丘脑多巴胺D1受体mRNA (DRD1 mRNA)、多巴胺D2受体mRNA(DRD2 mRNA)。结果与模型组相比,中高浓度组PRL水平降低[(260.12±4.814)、(241.98±8.351)比(332.18±9.472)](P<0.05),cAMP水平显著性降低[(1.05±0.427)、(0.89±0.745)比(1.37±0.002)](P<0.01),DA表达数量升高[(41.53±6.19)、(50.69±3.28)比(14.87±5.12)](P<0.05),三组不同浓度中药组与模型组比较,PKA活性明显降低,且低浓度组略高于高浓度组[(0.30±0.024)、(0.23±0.061)、(0.20±0.034)比(0.51±0.037),(0.30±0.024)比(0.20±0.034)](P<0.05);DRD1 mRNA表达各浓度组无差异、DRD2 mRNA表达增高且高浓度组表达量明显高于低浓度组[(0.20±0.322)比(0.11±0.700),P<0.05];与模型组比,DRD1有增高趋势,DRD2除了低浓度组数量略增高[(0.34±0.040)比(0.41±0.019),P<0.05],其余均明显增高(P<0.01)。结论加味当归芍药散可能作用于DRD2通过cAMPP-PKA信号通路发挥治疗高泌乳素血症模型大鼠的作用。

Objective To reveal the mechanism of Modified Danggui Shaoyao Powder in treating hyperprolactinemia(HPRL) rats.Methods Ninety-six female SD rats were randomly divided into 6 groupsby random number table method: blank group,model group,positive group,high,medium and low concentration groups,each had 16 individuals.HPRL model was prepared by subcutaneous injection of metoclopramide in the back of the rat.After 5 days,the HPRL model was successfully established.The rats were killed immediately after being dosed for 30 days.Expression of dopamine D1 receptor(DRD1),D2 receptor(DRD2) and protein kinase A(PKA) in hypothalamus was detected by immunohistochemistry,prolactin(PRL),dopamine receptor(DA) and cyclic adenosinemono phosphate(cAMP) were tested by ELISA,mRNA levels of DRD1 and DRD2 were assessed by real-time fluorescence quantitative PCR.Results Compared to the model rat,PRL of high and medium concentration groups reducedsignificantly[(260.12±4.814) and (241.98±8.351) vs (332.18±9.472),P<0.05,respectively],cAMP decreased significantly [(1.05±0.427) and (0.89±0.745) vs (1.37±0.002),P<0.01,respectively],and dopamine receptor(DA) increased significantly[(41.53±6.19) and (50.69±3.28) vs (14.87±5.12),P<0.05,respectively].PKA activity reduced significantly for high,medium and low concentration groups [(0.30±0.024),(0.23±0.061),and (0.20±0.034) vs (0.51±0.037),P<0.05,respectively],and those of the low concentration group was slightly higher than the high concentration group(P<0.05);There was no difference in expression of DRD1 mRNA,while DRD2 mRNA level increased especially in the high concentration group compared with low concentration group[(0.20±0.322) vs (0.11±0.700),P<0.05];Compared to the model rats,DRD1 increased,DRD2 expression increased slightly in the low concentration group [(0.34±0.040) vs (0.41±0.019),P<0.05],and those in the others showed significantly(P<0.01).Conclusion Modified Danggui Shaoyao Powder could effect on DRD2 via cAMPP-PKA signaling pathway in treating HPRL rats.