P物质对哮喘大鼠神经内分泌功能的调节

目的探讨哮喘大鼠脑内P物质在哮喘发作中的作用。方法以大鼠腹腔注射含百日咳和氢氧化铝的卵蛋白溶液制备哮喘动物模型,免疫组织化学方法(SABC)检测哮喘大鼠脑内c-fos蛋白,放射免疫法检测下丘脑室旁核(para-ventricular nucleus,PVN)内P物质(substance P,SP)的含量及正中隆起(ME)中促肾上腺皮质激素释放激素(cortico-tropin-releasing hormone,CRH)和外周血中促肾上腺皮质激素(adrenocorticotropic hormone,ACTH)、皮质酮(corticoster-one,CORT)含量,PVN内分别微量注射外源性SP、SP受体拮抗剂S0145,观察其对哮喘大鼠肺功能与下丘脑-垂体-肾上腺皮质功能轴(hypothalamus-pituitary-adrenal axis,HPA轴)活动的影响。结果哮喘大鼠发作时PVN内SP含量升高;正中隆起CRH与外周血中ACTH、CORT含量均降低(P<0.05),呼/吸时程比和气道阻力增加,膈肌放电积分、肺顺应性减小(P<0.01)。PVN内微量注射SP后哮喘大鼠的肺通气功能进一步下降,CORT、ACTH、CRH含量进一步降低(P<0.01)。SP受体阻断剂S0145则可逆转哮喘发生时大鼠肺功能与HPA轴的改变。结论哮喘大鼠下丘脑室旁核内SP可影响HPA轴的功能,参与哮喘发作。     

苏郁胶囊对双侧嗅球损伤抑郁模型大鼠行为学及下丘脑-垂体-肾上腺轴的影响

目的：探讨苏郁胶囊对双侧嗅球损伤抑郁模型大鼠行为学及下丘脑-垂体-肾上腺（HPA）轴的影响。方法：48只雄性大鼠随机分为假手术组、模型组、苏郁胶囊高、中、低剂量组（22．8、11．4、5．7g／kg）及氯米帕明组（0．02g／kg）。应用双侧嗅球损伤复制大鼠抑郁模型,敞箱法及跳台法测定大鼠的行为学指标;放射免疫方法测定大鼠血浆促肾上腺皮质素释放激素（CRH）、促肾上腺皮质激素（ACTH）及皮质醇（CORT）的水平。结果：苏郁胶囊可不同程度降低双侧嗅球损伤大鼠敞箱实验的水平运动次数与垂直运动次数;增加双侧嗅球损伤大鼠跳台实验的潜伏期及减少错误次数;同时降低双例嗅球损伤大鼠血浆CRH、ACTH和CORT含量。结论：苏郁胶囊能逆转双侧嗅球损伤抑郁模型大鼠的行为异常,其可能与苏郁胶囊有效地拮抗HPA轴功能亢进相关。     

应激启动下丘脑-垂体-肾上腺轴信号转导机制的实验研究

目的以束缚应激大鼠作为应激研究模型,探讨应激后下丘脑内信号转导分子的变化。方法用Western印迹杂交法研究了应激大鼠下丘脑内c-fos的蛋白表达和p38MAPK的磷酸化情况。结果Western印迹杂交结果显示束缚应激后鼠下丘脑内磷酸化的p38MAPK明显增加,与对照组相比具有非常显著性差异(P<0.01),应激解除后1、3h磷酸化的p38MAPK仍然保持较高的水平(P<0.05),但是应激解除后3h较应激刚结束时下丘脑内磷酸化p38MAPK的水平明显回落(P<0.05);应激后下丘脑内c-fos蛋白表达同样明显增加,与对照组相比具有显著性差异(P<0.01)。应激解除后0、1、3h,c-fos蛋白的表达仍然保持较高的水平(P<0.05)。结论应激发生后,其下丘脑内p38MAPK磷酸化的时相、c-fos蛋白表达时相以及血浆内皮质酮浓度时相具有类似之处,p38MAPK磷酸化、c-fos蛋白很可能是HPA轴活动的上游分子信号。     

地塞米松对卵蛋白所致哮喘大鼠下丘脑-垂体-肾上腺皮质轴及骨代谢的影响

目的：观察地塞米松对卵蛋白（Ovalbumin,OVA）所致哮喘大鼠的不同阶段（撤停前、撤停中、撤停后）下丘脑-垂体-肾上腺皮质轴（HPA轴）及骨代谢的影响。方法：90只大鼠随机分为正常对照组、哮喘模型组和地塞米松干预组,每组30只。每组根据处死时间的不同（实验第49、77、91天）随机各分为3个亚组,每组10只。以卵蛋白注射致敏结合卵蛋白雾化激发的方法建立大鼠哮喘模型。实验第35天开始,地塞米松干预组大鼠腹腔注射地塞米松0.5mg/kg,至实验第48天（撤停前阶段）;第49天开始按照每周0.1mg/kg的剂量递减地塞米松用量,至实验第76天（撤停中阶段）;第77天停用地塞米松,观察至实验第90天（撤停后阶段）。哮喘模型组及地塞米松干预组同时每周2次给予1%OVA生理盐水溶液雾化吸入。检测不同阶段各组大鼠脾脏及肾上腺指数、血清皮质酮（CORT）、血浆促肾上腺皮质激素（ACTH）、下丘脑促肾上腺皮质激素释放激素（CRH）及血浆骨钙素（BGP）含量。结果：（1）第49天,正常对照组、哮喘模型组、地塞米松干预组大鼠脾脏指数分别为1.504±0.213、1.548±0.208、1.254±0.239,肾上腺指数分别为0.132±0.039、0.108±0.027、0.065±0.017,CORT含量分别为（2301±628）、（1658±486）和（235±160）ng/L,ACTH含量分别为（62.7±17.4）、（32.7±17.2）和（19.7±8.8）ng/L,CRH含量分别为（5.77±2.01）、（4.20±1.87）和（3.40±1.28）ng/（mg.prot）,BGP含量分别为（5.22±2.14）、（3.64±1.40）和（0.65±0.62）μg/L。哮喘模型组ACTH及CRH含量均明显低于正常对照组（P（0.01,P（0.05）;地塞米松干预组CRH含量明显低于正常对照组,其他各项指标明显低于正常对照组和哮喘模型组（均P〈0.01）。（2）第77天,正常对照组、哮喘模型组、地塞米松干预组大鼠脾脏指数分别为1.515±0.169、1.567±0.180）、1.287±0.380,肾上腺指数分别为0.112±0.058、0.100±0.027、0.069±0.022,CORT含量分别为（2433±379）、（1905±410）和（355±239）ng/L,ACTH含量分别为（65.3±31.0）、（38.4±11.7）和（39.6±14.9）ng/L,CRH含量分别为（5.05±1.62）、（4.15±1.39）和（3.04±1.37）ng/（mg.prot）,BGP含量分别为（2.63±0.96）、（2.50±1.20）和（0.79±0.53）μg/L。哮喘模型组CORT含量明显低于正常对照组（P〈0.01）;地塞米松干预组除ACTH外其他各项指标均明显低于正常对照组和哮喘模型组（P〈0.05或0.01）。（3）第91天,正常对照组、哮喘模型组、地塞米松干预组大鼠脾脏指数分别为1.463±0.190、1.786±0.316、2.278±0.412,肾上腺指数分别为0.112±0.021、0.110±0.020、0.093±0.017,CORT含量分别为（2627±509）、（2318±364）和（2212±400）ng/L,ACTH含量分别为（63.0±33.5）、（48.8±19.9）和（30.7±19.1）ng/L,CRH含量分别为（5.39±1.40）、（3.80±0.94）和（3.67±1.09）ng/（mg.prot）,BGP含量分别为（4.58±2.19）、（3.21±1.34）和（1.93±0.91）μg/L。哮喘模型组脾脏指数明显高于正常对照组（P〈0.01）,CRH含量明显低于正常对照组（P〈0.01）;地塞米松干预组脾脏指数明显高于正常对照组和哮喘模型组（P〈0.01）,肾上腺指数、ACTH、BGP含量明显低于正常对照组和哮喘模型组（P〈0.05,P〈0.01）,CORT和CRH含量明显低于正常对照组（P〈0.05,P〈0.01）。结论：地塞米松干预对哮喘模型大鼠HPA轴具有很强的抑制作用,干预的不同阶段对HPA轴相关指标的抑制作用不同,并均抑制骨代谢。     

龟鹿二仙胶对创伤后应激障碍大鼠行为学和HPA轴功能的影响

目的观察创伤后应激障碍(PTSD)大鼠下丘脑-垂体-肾上腺(HPA)轴功能和行为学的变化及龟鹿二仙胶对其的影响。方法采用单一延长应激(SPS)的方法建立大鼠PTSD模型,采用旷场实验、高架十字迷宫实验,检测大鼠自主活动及焦虑水平;应用地塞米松抑制实验,检测大鼠HPA轴快速负反馈功能;采用ELISA法检测血浆皮质酮(CORT)水平和促肾上腺皮质激素(ACTH)含量。结果PTSD模型大鼠d 8开始出现HPA轴快速负反馈功能增强,并持续到d 22。模型组大鼠d 8焦虑水平升高,持续到d29。此外,d 29还出现自主活动下降和血浆CORT水平升高。龟鹿二仙胶连续给药14 d后能明显抑制HPA轴负反馈功能的增强;连续给药21 d后能明显提高大鼠的自主活动能力,降低其焦虑水平和血浆CORT水平。结论龟鹿二仙胶能够改善PTSD大鼠的行为学异常,其作用机制可能与调节HPA轴的功能紊乱有关。     

四君子汤合痛泻要方治疗肝郁脾虚型肠易激综合征的临床用药不良反应

目的:探讨四君子汤合痛泻要方治疗肝郁脾虚型肠易激综合征的临床用药不良反应.方法:选取60只刚出生的BALA/C实验大鼠,随机分为观察组(30只)与对照组(30只).对照组大鼠予以10mg/mL色甘酸二钠灌胃,给药剂量为1mL/100g.观察组大鼠予以四君子汤合痛泻要方灌胃,给药剂量为1mL/100g.两组大鼠皆连续用药...     

痛泻要方对腹泻型肠易激综合征大鼠胃肠激素的影响

目的：观察痛泻要方（TXYF）对腹泻型肠易激综合征（D-IBS）大鼠模型组织和血浆中胰高血糖样素肽（GLP-1）、生长抑素（SS）、P物质（SP）含量的影响,探讨其调节相关胃肠激素水平的作用机制。方法：采用灌胃番泻叶及束缚应激建立D-IBS大鼠模型,实验设空白对照组、模型组、匹维溴铵组、TXYF高剂量组、TXYF中剂量组、TXYF低剂量组。经灌胃给药或给生理盐水后,检测粪便干湿重,组织和血浆中GLP-1、SS、SP含量。结果：TXYF各治疗组除TXYF低剂量组外,大鼠粪便含水量均明显减少;组织和血液中GLP-1、SS、SP水平明显下降。结论：痛泻要方能抑制D-IBS大鼠GLP-1、SS、SP的分泌,TXYF高剂量组效果优于匹维溴铵组,且GLP-1与SS、SP关系密切,可能在D-IBS的治疗中起着中心环节的作用。     

加味痛泻要方联合匹维溴铵治疗肝郁脾虚腹泻型肠易激综合征64例

目的：观察加味痛泻要方联合匹维溴铵治疗肝郁脾虚腹泻型肠易激综合征（D-IBS）的临床疗效。方法：将128例肝郁脾虚DIBS患者随机分为对照组（n=64）和观察组（n=64）,对照组采用匹维溴铵为主治疗,观察组加用加味痛泻要方颗粒,疗程为12w,停药后1w、4w对照分析两组症状总积分。结果：停药1w后两组的症状总积分均明显低于治疗前（P〈0.05）,但差异无统计学意义（P〉0.05）。停药4w后两组的症状总积分均不同程度升高,但观察组仍明显低于治疗前和对照组（P〈0.05）,而对照组与治疗前比较差异无统计学意义（P〉0.05）。结论：加味痛泻药方联合匹维溴铵治疗肝郁脾虚D-IBS的临床远期疗效较好,值得临床推广。     

熄风静宁颗粒对多发性抽动症大鼠HPA轴及纹状体单胺类神经递质的影响

目的 探讨熄风静宁颗粒（XFJNG）对多发性抽动症（TS）模型大鼠HPA轴及纹状体单胺类神经递质的影响。方法 采用连续7 d ip亚氨基二丙腈（IDPN,150 mg/kg）建立TS大鼠模型,造模成功后将大鼠随机分为模型组、氟哌啶醇（0.5 mg/kg）组、XFJNG（6 mg/kg,临床等效剂量）组,同时设立对照组,每组10只,连续给药4周。于给药第0、1、2、3、4周进行刻板运动评分;末次给药后24 h杀鼠取材,试剂盒法检测各组大鼠纹状体内多巴胺（DA）、去甲肾上腺素（NE）、5-羟色胺（5-HT）含量,下丘脑及血清促肾上腺皮质素释放激素（CRH）含量,血清促肾上腺皮质激素（ACTH）、皮质醇（CORT）含量;取肾上腺组织,进行HE染色,光学显微镜下观察大鼠肾上腺组织形态。结果 与模型组比较,给药4周后,氟哌啶醇和XFJNG组大鼠刻板运动评分均显著降低,纹状体DA、NE、5-HT的水平均显著升高,血清及下丘脑CRH水平均显著降低,血清ACTH及CORT水平均显著降低,差异均具有统计学意义（P<0.05）。与对照组比较,模型组大鼠肾上腺细胞体积较小,染色深,细胞质占比较大,空泡明显减少;氟哌啶醇、XFJNG组大鼠肾上腺细胞质染色相对模型组较浅,空泡数量增多。结论 熄风静宁颗粒可能通过抑制大鼠纹状体DA系统失衡及HPA轴功能亢进来改善大鼠TS症状。     

白芍总苷联合甘草酸对腹泻型肠易激综合征脑-肠组织炎性反应的作用研究

目的：研究白芍总苷联合甘草酸对腹泻型肠易激综合征大鼠脑-肠轴炎症因子表达的干预作用。方法：采用高脂饮食、冰水浴刺激等方法建立腹泻型肠易激综合征大鼠模型,分别设定单用的白芍总苷组和甘草酸组,以及两药合用组,考察各组模型大鼠机械痛阈和肠推进变化,然后观察各组模型大鼠前额叶皮层和空肠组织炎性病理学变化,以及白介素6（interleukin-6,IL-6）、肿瘤坏死因子（tumor necrosis factor alpha,TNF-α）、P物质（substance P,SP）和五羟色胺（5-hydroxytryptamine,5-HT）水平。结果：甘草酸与白芍总苷均能显著增加模型大鼠机械痛阈值,白芍总苷可同时减缓肠推进速率,合用后可显著减少模型皮层和小肠组织IL-6、TNF-α的表达,减轻脑-肠组织的炎性反应。结论：白芍总苷和甘草酸对腹泻型肠易激综合征大鼠的及脑肠组织炎性因子均有不同程度的干预作用,合用效果显著增加,其作用机制可能与两药连用后显著降低脑内和肠道炎性因子IL-6、TNF-α水平有关。     

Effects of Liuwei Dihuang decoction and its compatible prescriptions on the function of hypothalamus-pituitary-adrenal axis in senescence-accelerated mouse

OBJECTIVE To investigate age-related functional change of hypothalamus-pituitary-adrenal(HPA)axis in senescence accelerated mouse(SAM)and the effects of Liuwei Dihuang decoction(LW)and its San-bu(three tonics)and San-xie(three eliminators)components on the function of HPA axis.METHODS Male SAM-resistance/1(SAMR1)and SAM-prone/8(SAMP8)at the ages of 6and 12 months old were used.SAMP8 were orally administered with LW,three tonics and three eliminators at the doses of 10,6.4and 3.6g·kg-1·d-1,respectively,for consecutive 60 d.Serum level of CORT was assayed with ELISA method.The levels of hypothalamic CRH and pituitary ACTH was determined with radioimmunoassay.RESULTS The levels of hypothalamic CRH,pituitary ACTH and serous CORT were much higher in 6 and 12 months old SAMP8 than those in age-matched SAMR1,which suggested the abnormal function of HPA axis in SAMP8.Oral administration of LW and three tonics significantly decreased the level of hypothalamic CRH of 6 and 12 months old SAMP8,and reduced the levels of pituitary ACTH and serous CORT of 6 month old SAMP8.Three eliminators significantly decreased the level of hypothalamic CRH of 6 months old SAMP8.The results indicated that oral administration of LW,three tonics and three eliminators improved the function of HPA axis of SAMP8.CONCLUSION The results showed the hyperactivity of HPA axis of SAMP8,and LW improved the hyperactivity of 6 month old SAMP8.Three tonics and three eliminators had similar effects as LW,which had better effect after compatibility.     

Novel in vitro perfusion system for the determination of hypothalamic-pituitary-adrenal axis responses

Introduction: The hypothalamic-pituitary-adrenal (HPA) axis is a three-gland component of the endocrine system and a key modulator of the stress response. We have developed a novel in vitro perfusion system to enable the study of pharmacological and hormonal challenges to tissue components of the HPA axis. In vivo studies have shown functional sex differences (sexual diergism) in HPA responses to cholinergic drugs, and in the present in vitro study, we examine these differences at several levels of the HPA axis. Methods: Hypothalami, pituitaries, and adrenal glands were collected from male and female rats (n=3 per sex). One-half hypothalamus, one-half pituitary, and one adrenal gland were placed individually into three Erlenmeyer flasks connected by tubing. Flasks were perfused with medium (pH 7.4) at 37 degrees C. Sampling ports between the flasks were used to collect buffer for determination of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and corticosterone (CORT) release from the hypothalamus, pituitary, and adrenal flasks, respectively, over an extended baseline period, to determine stability of the system, and after nicotine administration. Results: The perfusion system produced steady CRH, ACTH, and CORT baselines, the ACTH and CORT values being comparable to in vivo basal ACTH and CORT values in jugular-vein-cannulated rats. In vitro CRH, ACTH, and CORT responses to nicotine were significantly increased at 10 min and returned to baseline by 30 min, the CRH and ACTH responses from female tissues being greater than responses from male tissues. These sex differences were similar to those following nicotine administration in vivo. Discussion: The ability of this novel, dynamic in vitro system to replicate in vivo HPA axis responses supports its potential as a new method for pharmacological and toxicological studies.     

Effects of perinatal oxycodone exposure on the response to CRH in late adolescent rats

We hypothesized that prenatal oxycodone exposure suppresses the Hypothalamic–Pituitary–Adrenal (HPA) response to stress in late adolescence. Dark Agouti rats were given either intravenous oxycodone or vehicle (controls, CON) daily from gestation day 8 until postnatal day (PD) 5. At PD 45, the male and female offspring received intravenously either ovine corticotropin releasing hormone (CRH) or saline. Plasma adrenocorticotropic hormone (ACTH) and corticosterone (CORT) levels were determined before, and 15, 30, and 60 min after injection. Prenatal oxycodone had no effect on baseline ACTH values; CRH elicited a greater ACTH response than saline. In males, prenatal oxycodone delayed and enhanced the peak ACTH response to CRH, but had no effect in females. The CORT response to CRH was not different between oxycodone and CON; however mean CORT levels in females were significantly higher than those in males at baseline and after stimulation. These results demonstrate that prenatal oxycodone increases pituitary response to CRH in late adolescent male rats, but not in females. The absence of an enhanced adrenal response in oxycodone-exposed males suggests either desensitization or maximal adrenal response to a high CRH dose. The mechanisms of postnatal sex-specific HPA dysregulation following prenatal oxycodone remain to be elucidated.     

HPA轴紊乱致海马损伤与乳腺癌并发抑郁症相关性研究

目的 探讨HPA轴紊乱致海马损伤与乳腺癌并发抑郁症（BCRD）的相关性。方法 将BALB/c雌性小鼠分为4组：对照组、乳腺癌组（腋下1次性接种0.1 mL的10⁷/mL 4T1炎性乳腺癌细胞）、抑郁症组（背部sc皮质酮混悬液30 mg/kg,每天1次,连续21 d）和BCRD（先进行乳腺癌造模后进行抑郁症造模）组,每组10只。每周1次糖水偏好测试;连续注射皮质酮21 d后,进行旷场、悬尾行为学实验;杀鼠取材,HE染色观察各组大鼠海马、肾上腺和肿瘤的病理改变;Elisa法检测血浆促肾上腺皮质激素释放激素（CRH）、促肾上腺皮质激素（ACTH）、皮质酮含量。结果 与对照组比较,BCRD组小鼠糖水消耗明显降低（P<0.01）,第3周与乳腺癌组比较显著下降（P<0.05）。与对照组、抑郁症组、乳腺癌组比较,BCRD组小鼠旷场实验中水平运动与垂直运动显著减少（P<0.05）,悬尾实验中不动时间显著上升（P<0.01）。HE染色结果显示,与对照组比较,BCRD组小鼠海马、肾上腺出现明显病理改变,乳腺肿瘤细胞异常增生。与对照组比较,BCRD组血浆HPA轴相关指标皮质酮、ACTH和CRH含量显著升高（P<0.01、0.05）;与抑郁症组比较,BCRD组皮质酮、ACTH和CRH明显升高（P<0.05、0.01）;与乳腺癌组比较,BCRD组皮质酮、ACTH明显升高（P<0.05）。结论 BCRD小鼠存在快感缺乏、自主行为下降和绝望行为,并且海马和肾上腺存在明显损伤,HPA轴紊乱。     

右美托咪定对体外循环后围术期神经认知障碍老龄大鼠海马HPA轴和BDNF-ERK-CREB信号通路的影响

目的 评价右美托咪定对体外循环后围术期神经认知障碍老龄大鼠HPA轴和海马BDNF-ERK-CREB信号通路的影响.方法 选择老龄健康雄性Sprangue Dwaley大鼠120只,18～20月龄,体重400～550 g.采用随机数字表法将其分为4组(n=30):对照组(C组)、体外循环组(T组)、体外循环+右美托咪定组...     

疏肝健脾活血方对肝郁脾虚证FD大鼠血浆脑肠肽的影响

目的：观察疏肝健脾活血方对肝郁脾虚证FD大鼠血浆脑肠肽的影响。方法：70只SPF级雌性SD大鼠按体质量随机抽取10只作为正常组,其余60只采用“慢性束缚+过度疲劳+饮食失节”复合因素法造模21d,造模成功后,按体质量随机分为模型组、疏肝健脾活血方高剂量组、中剂量组、低剂量组、柴芍六君子汤组、多潘立酮组。分组后,大鼠灌胃给予相应药物干预14d,正常组和模型组大鼠灌胃给予相应体积纯净水。采用ELISA法检测大鼠血浆脑肠肽。结果：与模型组比较,疏肝健脾活血方各组大鼠血浆Ghrelin、MTL含量显著增加(P<0.05), CCK、CGRP含量显著降低(P<0.01),高剂量组大鼠血浆GAS含量显著增加(P<0.05),其余各组大鼠血浆GAS含量有增加的趋势,但差异无统计学意义(P>0.05);疏肝健脾活血方高剂量组、中剂量组大鼠血浆VIP含量显著降低(P<0.05)。结论：疏肝健脾活血方具有调节肝郁脾虚证FD大鼠Ghrelin、MTL 、CCK、 VIP、GAS、CGRP的作用。     

Lysophosphatidic acid-induced IL-8 secretion involves MSK1 and MSK2 mediated activation of CREB1 in human fibroblast-like synoviocytes

Lysophosphatidic acid (LPA) is a pleiotropic lipid mediator that promotes motility, survival, and the synthesis of chemokines/cytokines such as interleukin-8 (IL-8) and interleukin-6 by human fibroblast-like synoviocytes from patients with rheumatoid arthritis (RAFLS). In those cells LPA was reported to induce IL-8 secretion through activation of various signaling pathways including p38 mitogen-activated protein kinase (p38 MAPK), p42/44 MAPK, and Rho kinase. In addition to those pathways we report that mitogen- and stress-activated protein kinases (MSKs) known to be activated downstream of the ERK1/2 and p38 MAPK cascades and CREB are phosphorylated in response to LPA. The silencing of MSKs with small-interfering RNAs and the pharmacological inhibitor of MSKs SB747651A shows a role for both MSK1 and MSK2 in LPA-mediated phosphorylation of CREB at Ser-133 and secretion of IL-8 and MCP-1. Whereas CREB inhibitors have off target effects and increased LPA-mediated IL-8 secretion, the silencing of CREB1 with short hairpin RNA significantly reduced LPA-induced chemokine production in RAFLS. Taken together the data clearly suggest that MSK1 and MSK2 are the major CREB kinases in RAFLS stimulated with LPA and that phosphorylation of CREB1 at Ser-133 downstream of MSKs plays a significant role in chemokine production.     

Attenuation of hypothalamic-pituitary-adrenocortical hyperactivity in depressed patients by mirtazapine

Rationale. It has been suggested that hypothalamic-pituitary-adrenocortical (HPA) system dysregulation plays an important role in the pathophysiology of depression and that normalization of HPA axis hyperactivity precedes successful treatment with antidepressants. Mirtazapine acts as an antagonist at presynaptic α₂-receptors and at postsynaptic 5-hydroxytryptamine (5-HT)₂, 5-HT₃ and histamine H₁ receptors. It has been shown acutely to inhibit cortisol secretion in healthy subjects. Objective. In this study, we investigated whether mirtazapine may downtune HPA axis hyperactivity in depressed patients and whether this is related to treatment outcome. Methods. Forty patients suffering from a major depressive episode (DSM-IV criteria) were treated with mirtazapine for 5 weeks. The combined dexamethasone suppression/CRH stimulation test (DEX/CRH test) was performed before and after 1 week of mirtazapine treatment (45 mg daily). Results. Mirtazapine effectively reduced the overshoot of cortisol and ACTH during the DEX/CRH test both in treatment responders and non-responders within 1 week. Conclusions. Apparently, mirtazapine rapidly attenuates HPA axis hyperactivity in depressed patients via direct pharmacoendocrinological effects. However, this amelioration of HPA system dysregulation is not necessarily related to clinical improvement. Electronic Publication