疏肝和胃汤对抑郁模型大鼠血清、下丘脑中Orexin-A、CCK水平及下丘脑室旁核中OX1-R、CCK-AR表达的影响

Effects of Shugan Hewei decoction on orexin-A,CCK levels in hypothalamic and expression of OX1-R,CCK-AR in paraventricular nucleus of depression model rats

目的:观察疏肝和胃汤对抑郁模型大鼠行为学、胃排空和血清、下丘脑中食欲素-A(orexin-A)、胆囊收缩素(cholecystokinin,CCK)水平及下丘脑室旁核(paraventricular nucleus,PVN)中食欲素1型受体(orexin receptor type 1,OX1-R)和胆囊收缩素A型受体(cholecystokinin receptor type A,CCK-AR)表达的影响,探讨疏肝和胃汤改善抑郁模型大鼠胃排空延迟的作用机制。方法:将115只SD大鼠随机分为空白组19只,造模组96只。以慢性不可预知性应激制作抑郁模型,造模5周后,筛选出行为学表现及体质量相近的85只大鼠,分为模型组、疏肝和胃汤低剂量组、中剂量组、高剂量组、氟西汀组。空白组与模型组给予生理盐水;疏肝和胃汤低、中、高剂量组分别按3.67,7.34,14.68 g·(kg·d)-1给药;氟西汀组按1.58 mg·(kg·d)-1给药,连续给药7 d,每天2次。采用糖水消耗实验和新奇摄食抑制实验评价大鼠行为学;比色法检测大鼠甲基橙胃残留率,计算胃排空率;ELISA法检测血清、下丘脑中orexin-A和CCK的含量;RT-PCR法检测下丘脑prepro-orexin、CCK、OX1-R及CCK-AR mRNA的表达;免疫荧光法检测下丘脑室旁核中OX1-R与CCK-AR的表达。结果:抑郁模型大鼠糖水偏好率下降(P<0.05),进食潜伏期延长(P<0.01),胃排空率降低(P<0.05,或P<0.01),与模型组比较,疏肝和胃汤可改善糖水偏好率(P<0.05,或P<0.01),缩短进食潜伏期(P<0.05),升高胃排空率(P<0.05);抑郁模型大鼠血清、下丘脑中orexin-A含量下降,CCK含量升高(P<0.01),疏肝和胃汤升高orexin-A含量,降低CCK含量(P<0.05,或P<0.01);抑郁模型大鼠下丘脑中prepro-orexin、OX1-R mRNA表达下降,CCK、CCK-AR mRNA表达升高(P<0.01);疏肝和胃汤升高Prepro-Orexin、OX1-R mRNA的表达,降低CCK、CCK-AR mRNA的表达(P<0.01或P<0.05);抑郁模型大鼠下丘脑室旁核中OX1-R表达下降,CCK-AR表达升高(P<0.05,或P<0.01),疏肝和胃汤升高OX1-R的表达,降低CCK-AR表达(P<0.01或P<0.05)。结论:抑郁模型大鼠的胃排空延迟可能与orexin、CCK及其受体的异常改变有关;疏肝和胃汤可能通过调节orexin、CCK及其受体,从而改善抑郁模型大鼠胃排空延迟。

OBJECTIVE To study the mechanism of Shugan Hewei decoction in improving gastric emptying in depression model rats by observing the effects of Shugan Hewei decoction on the behavior,gastric emptying,orexin-A levels in serum,paraventricular nucleus and gastric tissue,and expression of orexin receptor type 1(OX1-R)in serum,paraventricular nucleus and gastric tissue of depression model rats.METHODS 115 SD rats were randomly divided into blank control group(19 rats in the group)and model group(96 rats in the group).Depression models were established by chronic unpredictable stress.After 5 weeks of modeling,85 rats with similar behavioral performance and weight were selected and divided into model group,Shugan Hewei decoction low-dose group,medium-dose group,high-dose group and fluoxetine group.Blank control group and model group were given saline;Shugan Hewei decoction low,medium and high dose groups were administered at 3.67,7.34,14.68 g·(kg·d)-1 respectively:Fluoxetine group was administered at 1.58 mg·(kg·d)-1 for 7 consecutive days,twice a day.The behavior of rats was evaluated by sugar water consumption test and novel feeding inhibition test;the residual rate of methyl orange stomach in rats was detected by colorimetry to calculate the gastric emptying rate;the contents of orexin-A and CCK in serum and hypothalamus were detected by ELISA;the expressions of prepro-orexin,CCK,OX1-R and CCK-AR mRNA in hypothalamus were detected by RT-PCR;and the expressions of OX1-R and CCK-AR in hypothalamic paraventricular nucleus were detected by immunofluorescence..RESULTS The sugar water preference rate decreased(P<0.05),the eating latency prolonged(P<0.01),and the gastric emptying rate decreased(P<0.05,or P<0.01) in the depression model rats.Compared with the model group,Shugan Hewei decoction could improve the sugar water preference rate(P<0.05,or P<0.01),shorten the eating latency(P<0.05),and increase the gastric emptying rate(P<0.05);the orexin-A content decreased and the CCK content increased(P<0.01) in the serum and hypothalamus of the depression model rats,and Shugan Hewei decoction increased the orexin-A content and decreased the CCK content(P<0.05,or P<0.01);the prepro-orexin and OX1-R mRNA expression decreased and the CCK and CCK-AR mRNA expression increased(P<0.01) in the hypothalamus of the depression model rats;It decreased the expression of CCK and CCK-AR mRNA(P<0.01 or P<0.05);OX1-R expression decreased and CCK-AR expression increased in the paraventricular nucleus of the hypothalamus of depression model rats(P<0.05,or P<0.01),and Shugan Hewei decoction increased the expression of OX1-R and decreased CCK-AR expression(P<0.01 or P<0.05).CONCLUSION Delayed gastric emptying in depression model rats may be related to abnormal changes in orexin,CCK and their receptors:Shugan Hewei decoction may improve delayed gastric emptying in depression model rats by regulating Orexin,CCK and its receptors.