人参皂甙对手术应激大鼠下丘脑—垂体—肾上腺轴？…

目的和方法 为探讨手术应激大鼠下丘脑－垂体－肾上腺轴（ＨＰＡＡ）和脾脏中肾上腺皮质激素释放素（ＣＲＦ）和促肾上腺皮质激素（ＡＣＴＨ）阳性细胞数及人参皂甙的调节作用。采用了免疫酶组化和免疫荧光检测方法。结果 应激后１５～３０ｍｉｎ，下丘脑，垂体中ＣＲＦ和ＡＣＴＨ阳性细胞数较正常对照组减少，ＣＲＦ阳性细胞在６０ｍｉｎ后逐渐增多，６ｈ时达正常水平，ＡＣＴＨ阳性细胞于３ｈ开始增多，１２ｈ时至正常水平，而肾     

人参皂甙对应激模型大鼠下丘脑－垂体－肾上腺轴和脾靶器官中神经肽Y阳性细胞数的影响

用手术截肢（ａｍｐｕｔａｔｉｏｎ）造成大鼠应激模型，观察下丘脑－垂体－肾上腺轴（ＨＰＡＡ）和脾脏中神经肽Ｙ（ＮＰＹ）阳性细胞数及人参皂甙的调节作用。免疫酶组织化学和免疫荧光检测结果显示：模型大鼠ＨＰＡＡ中ＮＰＹ阳性细胞与正常比较在应激初期（３０ｍｉｎ内）明显减少，随后开始增多，３～６ｈ达高峰，再逐渐至正常水平。脾组织中ＮＰＹ阳性细胞在应激后６０ｍｉｎ多于正常对照，１２ｈ达高峰，２４ｈ接近正常。用人参皂甙（ＧＳ）处理的动物可调节应激初期所致ＨＰＡＡ中ＮＰＹ阳性细胞数减少，使其增多，却使脾脏中ＮＰＹ细胞下降。     

人参皂甙对应激模型大鼠下丘脑—垂体—肾上腺轴和…

用手术截肢（ａｍｐｕｔａｔｉｏｎ）造成大鼠应激模型，观察下丘脑－垂体－肾上腺轴（ＨＰＡＡ）和脾脏中神经肽Ｙ（ＮＰＹ）阳性细胞数及人参皂甙的调节作用。免疫酶组织化学和免疫荧光检测结果显示：模型大鼠ＨＰＡＡ中ＮＰＹ阳性细胞与正常比较在应激初期（３０ｍｉｎ内）明显减少，随后开始增多，３－６ｈ达高峰，再逐渐至正常水平。脾组织中ＮＰＹ阳性细胞在应激后６０ｍｉｎ多于正常对照，１２ｈ达高峰，２４ｈ接近正常。用人     

缺血性脑损伤大鼠对应激反应性的实验研究

目的探讨缺血性脑损伤大鼠对轻度束缚应激的反应性。方法通过阻断大脑中动脉（MCAO）建立缺血性脑损伤大鼠模型，术后第5周开始行2周束缚应激，应激结束后处死大鼠，脑组织HE染色明确缺血灶，免疫组化法检测大鼠脑内Fos和促肾上腺皮质激素释放因子（CRF）蛋白表达水平。结果单纯MCAO组（M）和MCAO＋应激组（MR）大鼠可见明确缺血灶，损伤侧大脑半球萎缩和脑室扩大，光镜观察缺血区大量核固缩，坏死灶周边神经胶质细胞增生；MR组大鼠下丘脑室旁核、杏仁核中央亚核及终纹床核Fos和CRF阳性神经元明显多于其他组，差异有统计学意义（P〈0．05）。结论缺血性脑损伤后大鼠脑内Fos和CRF蛋白表达对应激的反应性增强，CRF通过前反馈机制持续激活下丘脑-垂体-肾上腺轴并导致抑郁可能是脑卒中后抑郁发生的主要机制之一。     

重楼皂甙翻转急性吗啡耐受关节炎大鼠下丘脑内ACTH水平的下降

采用大鼠温水甩尾实验、痛行为评分法和β-内啡肽、促肾上腺皮质激素的放射免疫分析，观察重楼免疫对完全福氏佐剂所致的关节炎大鼠急性吗啡镇痛耐受的作用及其机制。实验发现，完全福氏佐剂所致的关节炎大鼠在每2h间断皮下注射吗啡，共注射6次后出现吗啡镇痛耐受，此时大鼠海马内ACTH和β-内啡肽、下丘脑内β-内啡肽水平明显下降，大鼠灌服重楼皂甙（60mg/kg)后，急性吗啡镇痛耐受关节炎大鼠的痛行为学评分显著下降，而温水甩尾潜伏期明显升高，同时伴随下丘脑和海马内ACTH、下丘脑内β-内啡肽水平的明显升高，其中重楼皂甙的下丘脑内ACTH的作用和急性吗啡耐受关节炎大鼠的痛行为学变化显著相关。提示通过翻转佐剂性关节炎大鼠因急性吗啡镇痛耐受而引起的下丘脑内ACTH水平的下降，重楼皂甙可阻断急性吗啡镇痛耐受的形成。     

创伤后应激障碍与抑郁症患者对小剂量地塞米松抑制试验的反应

目的 通过小剂量的地塞米松抑制试验来比较抑郁症与创伤后应激障碍（PTSD）患者的垂体-肾上腺轴功能.方法 采用酶联免疫吸附法（ELISA）测定30例抑郁症和PTSD 患者的血浆中皮质醇、促肾上腺皮质激素基线水平,并行小剂量地塞米松（0.35 mg）抑制试验后再测定两组血浆的皮质醇、促肾上腺皮质激素水平.结果 抑郁症和PTSD 患者的的血浆皮质醇、促肾上腺皮质激素（ACTH）基线水平的差异无统计学意义（P＞0.05）;PTSD 患者对小剂量地塞米松抑制试验与抑郁症组比较,表现为皮质醇和ACTH的降低,即呈现超敏反应（P〈0.05）.结论 PTSD 患者对小剂量地塞米松抑制试验呈现超敏现象,这恰恰为该类PTSD 患者存在持久亢进的垂体-肾上腺轴功能的假说提供了证据.     

人参皂甙RD预处理对谷氨酸所致PC12细胞损伤的保护作用

目的探讨人参皂甙RD预处理对谷氨酸所致PC12细胞损伤的影响。方法将PC12细胞分为对照组、谷氨酸损伤组和人参皂甙RD预处理组。对照组细胞正常培养;谷氨酸损伤组细胞置于含10 mmon/L谷氨酸的DMEM培养基中培养24 h;人参皂甙RD预处理组细胞经50μmol/L人参皂甙RD预处理30 min后,再加谷氨酸继续培养24 h。采用噻唑蓝比色法检测细胞活力;按试剂盒检测培养液乳酸脱氢酶（LDH）释放量;流式细胞仪检测胞内活性氧（ROS）水平;按试剂盒检测细胞内超氧化物歧化酶（SOD）含量。结果人参皂甙RD预处理最佳浓度为50μmol/L。与谷氨酸损伤组相比,人参皂甙RD预处理PC12细胞活力明显增高（P〈0.05）,培养液LDH释放量明显降低（P〈0.05）,胞内ROS含量明显降低（P〈0.05）,胞内SOD含量明显增高（P〈0.05）。结论人参皂甙RD预处理可减轻谷氨酸引起的PC12细胞损伤。     

乙酰胆碱受体抗体抑制烟碱对大鼠下丘脑-垂体-肾上腺轴作用的研究

目的研究乙酰胆碱受体抗体(nAchRab)IgG在烟碱模拟应激状态下对下丘脑-垂体-肾上腺 (HPA)轴各层面活动的影响,探讨重症肌无力(MG)和MG危象发生机制与HPA内分泌轴变化的关系。方法将 nAchRab IgG或正常人IgG注入大鼠侧脑室,继后经烟碱刺激;应用原位杂交、放射免疫和化学发光免疫法观察:实验组和对照组鼠下丘脑、海马和颞叶促肾上腺皮质释放激素(CRH)mRNA表达和血浆促肾上腺皮质激素(ACTH) 及皮质酮(CORT)浓度。结果在基础状态,nAchRab抑制下丘脑CRHmRNA表达,对海马、颞叶CRHmRNA表达无抑制,对血浆ACTH及CORT水平无影响;nAchRab抑制烟碱所诱导的下丘脑、海马及颞叶CRHmRNA表达,血浆 ACTH及CORT水平下降。结论 nAchRab能与下丘脑、海马及颞叶的乙酰胆碱受体(nAchR)结合,基础状态仅抑制下丘脑CRHmRNA表达;在烟碱诱导的状态下则整个HPA功能受抑制,结果模拟了应激状态MG发病和MG危象时的状况,提示MG发病和MG危象发生可能与HPA功能低下有关。     

整合素信号通路可能参与大鼠束缚应激后的恢复过程

目的筛选与束缚应激大鼠应激反应恢复速度相关的基因,探讨应激反应个体恢复的分子机制。方法观察大鼠2小时束缚应激后血浆促肾上腺皮质激素（adrenocorticotropic-hormone,ACTH）及皮质酮的变化规律,根据应激结束后1小时的血浆ACTH及皮质酮下降程度将大鼠分为快速恢复组与慢速恢复组。采用微阵列技术检测快速恢复组与慢速恢复组下丘脑组织基因表达的差异,用实时逆转录-聚合酶链反应验证部分基因的表达差异。结果基因芯片分析结果显示：大部分基因在两组间并无差异表达,在11个差异表达的基因中,快速恢复组中参与整合素信号通路的踝蛋白（talin）、整合素α6和丝/苏氨酸蛋白磷酸酶PP1β催化亚基（serine/threonine pro-tein phosphatase PP1-beta catalytic subunit,PP1B）基因有1.5倍上调,而结合粘附分子1（junctional adhesion mol-ecule 1, F11r）基因有 1.5 倍下调。实时逆转录 - 聚合酶链反应结果与芯片分析结果一致。结论本研究构建了束缚应激大鼠恢复过程的下丘脑基因表达谱,结果提示整合素信号通路可能参与应激的恢复过程。     

病理为垂体促肾上腺皮质激素细胞增生的库欣病

目的 回顾性分析手术后病理证实为垂体促肾上腺皮质激素(ACTH)细胞增生的22例库欣病患者的临床资料。方法 男性3例，女性19例，平均年龄28．7岁，平均病程2年。22例临床均表现为典型的库欣综合征，均有血浆皮质醇和尿24h游离皮质醇(UFC)水平增高，血浆ACTH水平增高5例，小剂量地塞米松抑制试验不能抑制、大剂量地塞米松抑制试验能抑制17例。12例行蝶鞍CT冠状扫描和矢状重建，7例正常，5例有异常发现；15例行蝶鞍MRI，3例正常，12例有异常发现。22例均行经口鼻蝶窦显微外科垂体探查术?结果术后病理均为垂体ACTH细胞增生。随访6个月至15年，治愈13例，缓解3例，进步2例，无效4例，3例复发。结论 垂体ACTH细胞增生可引起库欣病，对这些患者，可考虑手术探查，行垂体部分、大部分或次全切除，多数可获得较好的疗效。     

Dissociation of ACTH-Secretory Mechanisms in Rat Pituitary Cells: Evidence that Basal and Vasopressin-Stimulated Secretion Act via a Mechanism Distinct from that of Corticotrophin-Releasing Factor

To study the relationship between basal, corticotrophin-releasing factor- (CRF) and vasopressin-stimulated adrenocorticotrophic hormone (ACTH) secretion by rat anterior pituitary cells, dissociated anterior pituitary cells were seeded into tissue culture dishes and treated overnight with a cytotoxic conjugate specific for CRF-target cells. Immediately after extensive washing, or 1, 3, 6, 9 or 12 days later, cellular ACTH content, basal secretion and secretion in response to CRF or vasopressin were measured. ACTH content and basal secretion rate increased over time in both cytotoxic conjugate-pretreated and vehicle-pretreated cell populations. Compared with vehicle-pretreated cells, basal ACTH secretion was higher in cytotoxic conjugate-pretreated populations by Day 3 and reached an apparent maximum by Day 6. In such cells, net ACTH secretion post-vasopressin decreased as basal secretion increased; by Day 6 no vasopressin-stimulated secretion was seen. In cytotoxic conjugate-pretreated cells, the response to CRF was initially completely eliminated; however, as ACTH content and secretion increased with time, a small recovery of the response to CRF was observed on Days 3 and 6. In vehicle-pretreated cells, ACTH secretion in response to vasopressin increased in parallel with basal secretion. The response to CRF increased progressively over Days 1 to 6 as well; this response was more closely related to the increases observed in ACTH content. The shift in responsiveness of the cytotoxic conjugate-pretreated cells over time, from vasopressin-responsive to CRF-responsive, further demonstrates the dissociation of the mechanisms of the ACTH secretory responses to CRF and vasopressin. In addition, the increase in unstimulated secretion at the expense of the response to vasopressin in cytotoxic conjugate-treated cells is consistent with a common pathway for vasopressin-stimulated and basal release of ACTH.     

The role of corticotropin-releasing factor and vasopressin in hypoglycemia-induced proopiomelanocortin gene expression in the rat anterior pituitary gland.

In this study, we examined the effect of passive immunization of endogenous corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) on hypoglycemia-induced adrenocorticotropic hormone (ACTH) secretion and determined proopiomelanocortin messenger RNA (POMC mRNA) levels in the anterior pituitary as well as hypothalamic CRF mRNA levels in pentobarbital anesthetized rats. The response of plasma ACTH to hypoglycemia was partially inhibited by the administration of CRF-antiserum (CRF-As) or AVP-antiserum (AVP-As) alone, but was found to be completely abolished by the administration of CRF-As + AVP-As as compared to the response in normal rabbit serum-treated rats. The hypoglycemia-induced POMC mRNA level in the anterior pituitary was completely inhibited by the administration of CRF-As alone and CRF-As + AVP-As, but was not inhibited by AVP-As alone as compared to the response in normal rabbit serum-treated rats. The administration of CRF-As and/or AVP-As did not affect hypoglycemia-induced CRF mRNA levels in the hypothalamus. These results indicate that the synergistic effect of CRF and AVP is important for hypoglycemia-induced ACTH secretion, but CRF is essential and indispensable for hypoglycemia-induced POMC gene expression in the anterior pituitary (AP).     

Time course study on the effect of reserpine on hypothalamic immunoreactive CRF levels in rats

A time course study on the changes of rat hypothalamic corticotropin-releasing factor (CRF) levels and ACTH levels in plasma, pituitary and hypothalamus after an acute treatment with reserpine was examined using a rat CRF RIA. The massive and prolonged depletion of hypothalamic norepinephrine and dopamine levels provoked by a single injection of reserpine (2 and 8 mg/kg, i.p.) caused a transient decrease of hypothalamic CRF levels and ACTH levels in the anterior pituitary glands, and an increase in plasma ACTH levels. There was a strong correlation between the depletion of hypothalamic CRF and norepinephrine levels. These results suggest that: acute depletion of hypothalamic norepinephrine levels cause the initial release of CRF that stimulates pituitary ACTH secretion, and the depletion of CRF and ACTH stores at the early stage; and noradrenergic pathways may be involved in the inhibitory mechanism of CRF release.     

Hypothalamus, anterior pituitary and adrenal gland involvement in the activation of adrenocorticotropin and corticosterone secretion by gastrin-releasing peptide

This study was designed to investigate the contribution of the hypothalamus, anterior pituitary and adrenal gland in the increase of adrenocorticotropin (ACTH) and corticosterone secretion induced by gastrin-releasing peptide (GRP) on in vitro isolated hypothalamus, pituitary and adrenal gland. Furthermore, we have examined in dispersed anterior pituitary cells whether the ACTH release induced by GRP is a Ca2+-dependent process. Moderate concentrations of GRP (1 and 10 nM) were able to increase the release of corticotropin-releasing factor (CRF)-like material in the medium of isolated hypothalami, whereas higher concentrations (100 and 1000 nM) were needed to elevate ACTH and corticosterone secretion in pituitary and adrenal quarters, respectively. The competitive and specific GRP receptor antagonist (Leu13-psi-CH2NH-Leu14) bombesin (10, 100 and 1000 nM) was without effect on basal secretion of CRF-like material, ACTH and corticosterone in isolated hypothalami, pituitary and adrenal quarters respectively. However, this antagonist (100 nM) completely blocked the stimulatory effects of GRP (100 nM) on bioactive CRF, ACTH and corticosterone release. In addition, in dispersed anterior pituitary cells which medium contained Ca2+ (1.5 mM), GRP stimulated the secretion of ACTH, but was without effect when the concentration of Ca2+ in the medium was lower (200 nM). These results suggest that: (1) the hypothalamus, anterior pituitary and adrenal gland seem to contribute to the elevation of ACTH and corticosterone secretion induced by GRP by a mechanism mediated through GRP receptors and (2) the stimulation of ACTH by GRP in the anterior pituitary appears to be dependent upon the presence of physiological concentrations of extracellular Ca2+.     

Activation of the hypothalamic-pituitary axis in adrenalectomised rats: potentiation by chronic stress

The influence of chronic stress on the status of the hypothalamo-pituitary-adrenal (HPA) axis of sham-operated and adrenalectomised rats was assessed. Animals underwent bilateral adrenalectomy (ADX) and 3 days later they were either left undisturbed or subjected daily to immobilization for 2 h each morning for 14 days (chronic IMO). In situ hybridization histochemistry revealed that ADX increased corticotropin-releasing factor (CRF) mRNA levels in the paraventricular nucleus of the hypothalamus (PVN) and proopiomelanocortin (POMC) mRNA levels in the anterior pituitary, in both control and chronically stressed rats as measured on the day following the last exposure to stress. Chronic IMO increased CRF mRNA levels in the PVN and POMC mRNA levels in the anterior pituitary of sham-operated rats, as measured on the day following the last exposure to stress. Chronic IMO potentiated the increase in CRF mRNA in the PVN following ADX and resulted in further increases in CRF mRNA above levels seen in adrenal-intact animals. Finally, chronic stress, while not altering basal ACTH levels of ADX rats, reduced the ACTH response of these animals to a novel stressor (tail-shock for 30 min). These results suggest that chronic stress exerts a stimulatory influence at the hypothalamic level that is partially restrained by daily stress-induced glucocorticoid release. Despite the potentiation by chronic stress of CRF mRNA content in the PVN of ADX rats, a blunted circulating ACTH response to an acute short-term stressor was apparent in ADX-chronically stressed rats, suggesting that chronic stress might also alter POMC processing and/or ACTH secretory patterns in the anterior pituitary in ADX animals.     

Decreased corticotropin-releasing factor receptor expression and adrenocorticotropic hormone responsiveness in anterior pituitary cells of Wistar-Kyoto rats

The Wistar-Kyoto (WKY) rat shows signs of persistent activation of the hypothalamic-pituitary-adrenal axis, but the cause and site of this activation is not yet known. Chronically activated corticotrophs generally show blunted adrenocorticotropic hormone (ACTH) response to corticotropin releasing factor (CRF); therefore, the anterior pituitary responsiveness to ACTH secretagogues, CRF and vasopressin, was compared in male WKY and Wistar rats. Anterior pituitary CRF binding and CRF receptor mRNA expression was significantly decreased in WKY rats. ACTH response to CRF or vasopressin was markedly impaired, and vasopressin failed to potentiate the CRF-stimulated ACTH release in cultured WKY anterior pituitary cells. In contrast, CRF and vasopressin alone and in combination stimulated large, concentration-dependent increases in ACTH release in Wistar anterior pituitary cells. By contrast to the decreased ACTH secretory responses, steady-state anterior pituitary pro-opiomelanocortin mRNA levels were approximately 12-fold greater in WKY rats compared to Wistar rats, and they further increased in response to CRF stimulation. These findings suggest that, although the WKY rat corticotroph is under a chronic state of activation or disinhibition, the in vitro secretory responses to classic ACTH secretagogues are impaired.     

去卵巢大鼠下丘脑-垂体-卵巢轴的功能代偿机制研究

目的：在细胞和分子水平上，探讨机体因各种原因导致卵巢功能低下时，下丘脑-垂体-卵巢轴(HPOA)功能的自然代偿机制。方法：观察大鼠切除卵巢后1～6个月，下丘脑促性腺激素释放激素(Gonadotmpin releasing hormone，GnRH)及其mRNA表达的改变以及阴道脱落细胞形态和外周血雌二醇(E2)水平的变化。结果：去卵巢后5～6个月时，大鼠阴道涂片出现成熟脱落细胞；4个月时血E2水平明显升高，6个月时几乎稳定在正常水平的一半以上；随去卵巢时间延长，大鼠下丘脑GnRH神经元数目较去卵巢1个月时逐渐增多，至6个月时，升高有显著差异，但仍低于正常组数目；去卵巢1个月大鼠下丘脑组织GnRHmRNA表达明显减少，去卵巢后5个月明显升高，与正常组相比没有显著差异；GnRH棘型神经元的比例在去卵巢4个月时即升高到正常水平。结论：大鼠卵巢功能低下时，机体体内可能存在一种自然代偿作用，使异常的HPOA功能趋于正常化。     

Abnormal ACTH and cortisol responses to ovine corticotropin releasing factor in patients with primary affective disorder

To further explore hypothalamic pituitary adrenal regulation in patients with affective illness, we administered 1 microgram/kg of synthetic ovine corticotropin releasing factor at 2000h to 26 drug-free patients with this disorder and to 15 healthy controls. Compared to controls, depressed patients (N = 12) showed a significant elevation in baseline cortisol and significant reductions in the net ACTH and cortisol responses to corticotropin releasing factor. These findings were normal in manic (N = 6) and improved (N = 8) subjects. An additional finding was that baseline cortisol and net ACTH and cortisol responses to CRF were negatively correlated in the entire group of patients and controls as well as in the patients alone. These data indicate that the reduced ACTH and cortisol responses to CRF in depression reflect normal functioning of the pituitary corticotroph cell (i.e., that the negative feedback effect of cortisol on ACTH secretion in depression is physiologically intact, effectively serving as a brake on the ACTH response to exogenous CRF. Thus, the hypercortisolism of depression may be due to a hypothalamic defect, possibly involving hypersecretion of endogenous CRF. This possibility may be of particular interest in light of clinical observations that depression can often be precipitated by stress and by data in experimental animals that CRF may influence several processes known to be altered in the overall symptom complex of depression.     

严重创伤早期大鼠下丘脑HSP70与iNOS表达分布及意义

目的研究严重创伤早期大鼠下丘脑热休克蛋白70(HSP70)与诱导型一氧化氮合酶(iNOS)转录表达变化分布和意义。方法采用BIM-Ⅲ型生物撞击机致大鼠胸部严重撞击伤,并造成单侧股骨骨折,运用S-ABC免疫组化、原位杂交技术测定下丘脑HSP70与iNOS及其mRNA的转录表达水平。结果正常对照组HSP70低水平表达,在伤后1h即开始明显增高(P<0.05),6h达到峰值为正常的18倍,12h后开始下降,24h时主要集中在室旁核内;iNOS无基础表达,在伤后1h开始出现,随HSP70同步增高,8h达到高峰,较1h时增加13倍。两者相关系数r=0.97601。结论严重创伤后早期下丘脑内HSP70和iNOS过度表达,在严重创伤应激时下丘脑的损伤与抗损伤机制中起重要作用。