刺激大鼠伏隔核对脑内脑啡肽含量的影响

应用放射免疫测定法,在电刺激大鼠伏隔核(Nucleus accumbens)后,下丘脑、纹状体、丘脑、海马、脑干和皮层亮氨酸-脑啡肽(Leu-enk)和甲硫氨酸-脑啡肽(Met-enk)含量的变化。实验结果:(1)动物经麻醉和手木后,Leu-enk的含量,除纹状体和丘脑变化不明显外,其他脑区均明显降低;Met-euk的含量,除下丘脑的变化显著外,其他脑区变化均不明显。(2)在乌拉坦麻醉及手术的基础上,电刺激伏隔核后,除丘脑和纹状体外,其他脑区Leu-enk均明显升高,而Mek-enk,除纹状体的升高具有显著性外,其他脑区均无明显变化。提示伏隔核的兴奋可明显影响其他脑区脑啡肽的含量。     

Effects of phentolamine and propranolol on the changes of pain threshold and contents of MEK and LEK in rat brain after EA

The contents of Met-enkephalin (MEK) and Leu-enkephalin (LEK) in striatum and MEK in hypothalamus of rat increased markedly after electroacupuncture analgesia (EAA). Intraperitoneal injection of phentolamine, a blocker of alpha receptor, potentiated the EAA and abolished the effects of EA increasing MEK and LEK contents; while injection of propranolol, a blocker of beta receptor, partially inhibited the EAA, as well as abolished the effects of EA increasing MEK and LEK concentrations in the striatum and the hypothalamus, and also elevated the MEK and LEK contents in hippocampus and MEK level in cortex. The results indicate that EA regulates metabolism of MEK and LEK, as well as EAA partially via alpha and beta receptors.     

Effect of electroacupuncture on brain enkephalins content at different times in rats

The basic level of methionin-enkephalin (MEK) in rat medulla oblongata plus pons was the highest at 05:00 o'clock and the lowest at 23:00. In both hypothalamus and striatum at 05:00 it was higher than at 11:00, 17:00 and 23:00. In both hippocampus and midbrain at 05:00 and 23:00 it was higher than those at 11:00 and 17:00. In the cortex it was higher at 05:00 than at 11:00 and 17:00. The basic level of leucine enkephalin (LEK) in the medulla oblongata plus pons was the highest at 11:00 and the lowest at 17:00 and 23:00. Electroacupuncture (EA) at 05:00 increased the MEK content in the medulla oblongata plus pons and the LEK level in the hypothalamus. It decreased the MEK content in the hypothalamus and the LEK level in the cortex; EA at 11:00 produced decreases of MEK concentrations in the medulla oblongata plus pons and the midbrain and increases of MEK content in the cortex, hypothalamus and striatum. At 17:00 it increased the MEK level in the hypothalamus and the LEK content in the hippocampus. At 23:00 it reduced the levels of MEK and LEK in the hippocampus. The results suggest that there are very marked circadian rhythms in the MEK basic levels of the six discrete brain regions observed and the LEK of the medulla oblongata plus pons; EA at different times produces different effects on brain MEK and LEK levels.     

噪声对大鼠不同脑区脑啡肽含量的影响

以放射免疫法测定了在噪声(115dB·3小时)刺激后,大鼠不同脑区脑啡肽含量的变化。结果表明:丘脑、下丘脑及中脑的甲-脑啡肽含量明显下降;皮层的亮-脑啡肽含量明显下降,而丘脑、下丘脑的亮-脑啡肽含量明显上升。噪声刺激后大鼠不同脑区甲-脑啡肽和亮-脑啡肽含量的变化表明内源性吗啡样物质可能与噪声对生物体的致害作用有关。     

大鼠失血性休克时中枢两种脑啡肽含量变化及其发病学意义

本文用放射免疫测定法观察大鼠失血性休克时中枢甲硫氨酸脑啡肽(MEK)和亮氨酸脑啡肽(LEK)含量的变化,并观察侧脑室注入纳洛酮和脑啡肽抗血清对休克的影响。结果表明延髓MEK和垂体LEK在休克60分钟即明显降低,210和360分钟时进一步下降;纳洛酮预处理可部分防止休克早期的心率减慢,并可在恒定贮血瓶压力下增加相同时间内的失血量;LEK抗血清(滴度1:20000)可部分防止休克早期心率减慢,而对失血量无影响,MEK抗血清(滴度1:5000)对失血性休克未见明显影响。     

MPTP对小鼠纹状体脑啡肽含量的影响

本文报道在小鼠给予较大剂量1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)后,纹状体甲硫氨酸脑啡肽(methionine-enkephalin,MEK)和亮氨酸脑啡肽(leucine-enkephalin,LEK)含量显著减少。与对照组相比平均MEK减少75%,LEK减少66%,这一结果表明较大剂量的MPTP能影响肽类神经元。在小鼠给予MPTP可能为研究肽与帕金森病提供一种较为有用的动物模型和实验方法。     

慢性疼痛病人血浆亮-脑啡肽及血浆皮质醇含量与中医虚证辨证

对48倒肩周炎及慢性腰腿痛病人进行中医虚证辨证分组,同时用放射免疫法测定其血浆亮-脑啡肽(LEK)与血浆皮质醇含量,观察针刺前后其含量的变化;用划表法评定针刺临床疗效,并分析上述指标与虚证类型的关系。结果表明阳虚组血浆LEK和血浆皮质醇含量均明显低于非阳虚组;阳虚组针刺后血浆LEK含量明显升高,非阳虚组反而降低,而血浆皮质醇含量在针刺前后均无明显变化;阳虚组针刺的临床疗效优于非阳虚组。     

创伤性脑损伤患者血浆β内啡肽、亮氨酸脑啡肽、甲硫氨酸脑啡肽水平的研究

[摘要]　目的 探讨内源性阿片肽在创伤性脑损伤发病机制中的作用。方法 采用放射免疫分析法(RIA)测定了30例全麻颅脑手术患者和30例全麻非颅脑手术患者术前、术后及30例正常人血浆β-内啡肽(β-Endorhin,β-EP),亮氨酸脑啡肽（leuthine enkephalin,LNK）,甲硫氨酸脑啡肽（mehionine enkephalin,MEK）的含量。结果 ①60例手术患者术后血浆β-EP含量显著升高(P<0.01),两组比较差异无统计学意义(p>0.05);②颅脑手术患者术后血浆LNK含量显著高(p<0.01),与非颅脑手术者比较差异有统计学意义(p<0.01);③不同部位颅脑手术血浆LNK含量比较差异无统计学意义(p>0.05);④60例手术患者术后血浆MEK含量不升高,两组比较差异无统计学意义(p>0.05);结论 内源性阿片肽在创伤性脑损伤的病理生理过程中发挥作用不同。β-内啡肽在机体应急状态普遍升高, 血浆中LNK的含量是创伤性脑损伤的特异性指标,LNK含量与脑损伤部位无关,MEK的含量变化与创伤性脑损伤无相关性。     

性激素对中枢甲硫氨酸脑啡肽含量的影响

用放免法测定大白鼠脑之纹状体、海马、下丘脑、垂体前叶与后叶中甲硫氨酸脑啡肽(metenkephalin,MEK)的含量,显示去势雌鼠纹状体、海马、下丘脑、垂体前叶MEK明显下降,去势雄鼠下丘脑、垂体前叶也明显下降,注射已烯雌酚,黄体酮及睾丸酮的雌鼠,下丘脑MEK明显降低而垂体后叶明显升高,注射睾丸酮的雄鼠,垂体前叶与后叶MEK下降,雄鼠注射已烯雌酚,未见有显著改变,提示性腺与性激素对中枢MEK含量有影响。     

神经免疫肽对人多形核白细胞吞噬功能的影响

用改良的NBT还原法观察了亮氨酸脑啡肽(LEK).甲硫酸脑啡肽(MEK)和P物质(SP)对正常人周缘血多形核白细胞(PMN)细胞吞噬杀伤作用的影响。结果表明:低浓度(10~(-10)mol/L)的三种神经免疫肽可使PMN的NBT阳性率分别提高到57.9%、49.8%和73.6%;而对照的阳性率为11.2%。表明三种神经免疫肽均能不同程度地增强正常人PMN的吞噬杀伤能力。不同神经免疫肽增强效应的差异可能是由于PMN的兴奋性和抑制性受体同时被激活后不同的净结果所致。     

EFFECTS OF GONADAL HORMONES ON MET-ENKEPHALIN IN BRAIN

The relationship between gonadal hormones and Met-enkephalin ( MEK ) in the brain was investigated to explore the role of gonadal hormones in regulating the contents of MEK, Experiments were performed on rats of both sexes. The animals were divided into     

电针对大鼠关节炎及脑内甲啡肽含量的影响

实验用Wistar大鼠40只,分对照、关节炎、电针、纳洛酮阻断四组。以减毒结核菌在后足踝、蹠关节形成实验性关节炎,作为慢性疼痛模型。测定蹠围、炎症局部皮温和痛反应阈。电针两侧环跳穴,引针20分。每日一次、五日为一疗程、间隙三天,共做三个疗程。甲啡肽(MEK)含量以放射免疫法测定。结果发现,电针对大鼠实验性关节炎无明显长时间的止痛作用,对炎症也无影响。正常大鼠下丘脑,垂体MEK含量分别为250.43±40.40pg/mg与297.81±39.00pg/mg。关节炎组分别为160.54±32.25与228.85±31.18pg/mg,明显低于正常(P<0.01)。电针组MEK含量分别为251.00±38.46与286.36±41.92pg/mg。可见,电针能使关节炎大鼠大丘脑和垂体的MEK含量提高(P<0.01)。     

Plasma leucine enkephalin and beta-endorphin levels in patients with essential hypertension and the effects of captopril

To further study the relationship between endogenous opioid peptides and essential hypertension, we measured the concentrations of plasma leucine-enkephalin (LEK) and beta-endorphin (beta-EP) in 50 patients with essential hypertension by radioimmunoassay and investigated the effects of captopril on them. It was shown that the concentrations of plasma LEK and beta-EP in patients with essential hypertension were lower than those in normotensive subjects. No effects of age and sex were found on the concentrations of plasma LEK and beta-EP, and there was no difference in plasma LEK and beta-EP levels between patients with Stage I essential hypertension and those with Stage II essential hypertension. After a single dose of captopril, blood pressure and plasma angiotensin II decreased, plasma renin activity increased; and plasma LEK and beta-EP levels increased. Plasma LEK and beta-EP levels in patients with essential hypertension increased after one month of captopril treatment. In conclusion, the lower plasma LEK and beta-EP levels in patients with essential hypertension indicate that LEK and beta-EP may play a role in the pathogenesis of essential hypertension, and the depressor effects of captopril may act through LEK and beta-EP, besides blocking formation of angiotension II.     

Effects of atropine on the changes of pain threshold and contents of leucine-enkephalin and catecholamines of the brain in rats induced by EA.

After rats received electroacupuncture (EA), leucine-enkephalin (LEK) content in striatum and dopamine (DA) concentration in both brain stem and diencephalon markedly increased, and noradrenaline (NA) level in telencephalon definitely decreased with an obvious elevation of pain threshold. However, a previous intraperitoneal injection of atropine, a blocker of muscarinic receptor, not only partially blocked the analgesic effect of EA, but also changed the effects of EA on LEK, NA and DA contents of the brain. The results indicate that cholinergic system plays an important role in electroacupuncture analgesia (EAA), which may be fulfilled partially through the central LEK and catecholamine (CA) systems.     

条件性味觉厌恶学习对大鼠丘脑脑区亮脑啡肽表达的影响

目的观察条件性味觉厌恶学习（CTA）对亮脑啡肽（LEK）表达的影响。方法采用免疫细胞化学方法,观察LEK阳性神经元在大鼠脑内的分布情况,并比较建立CTA前后丘脑5个核团内内源性LEK的表达水平。结果CTA组大鼠丘脑外侧背核、丘脑内侧背核外侧部及丘脑腹后内侧核内LEK阳性神经元数目显著少于对照组,差异有统计学意义（P〈0.05）。结论获得CTA的大鼠脑内的LEK表达水平均降低,提示脑内一些核团的LEK表达在CTA过程中发挥作用。     

MEK AND p38 MAPK-DEPENDANT PATHWAYS ARE INVOLOVED IN THE POSITIVE EFFECT OF INTERLEUKIN-6 ON HUMAN GROWTH HORMONE GENE EXPRESSION IN RAT MtT/S SOMATOTROPH CELLS

Objective To investigate the effect of interleukin-6（IL-6） on the human growth hormone （hGH） gene expression in a rat somatotropic pituitary cell line MtT/S. Methods The plasmids containing various lengths of hGH gene 5＇-promoter fragments were constructed. Stably transfected MtT/S cells were created by cotransfecting the above plasmids and pcDNA3.1 （＋） with DMRIE-C transfection reagent. After the administration of these cells with IL-6 and/or various inhibitors of signaling transduction path-ways, the luciferase activities in MtT/S cells lysis were assayed to demonstrate the effects of IL-6 on hGH gene promoter activity and possibly involved mechanism. Results The 10^3U/mL IL-6 stimulated GH secretion and synthesis, and promoted the 5＇-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.69 times above the control. Among inhibitors of signaling transduction pathways, mitogen-activated protein kinase kinase （MAPKK/MEK） inhibitor PD98059 （40μmol/L） and p38 mitogen-activated protein kinase （MAPK） inhibitor SB203580 （5μmol/L） completely blocked the stimulatory effect of IL-6. Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells. Neither over-expression of Pit-1 nor inhibition of Pit-1 expression affected IL-6 induction of hGH promoter activity. A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-6. The results showed that the stimulatory effect of IL-6 was abolished following deletion of the - 196 to - 132 bp fragment. Conclusions IL-6 promotes GH secretion and synthesis by rat MtT/S somatotroph cells. The stimulatory effect of IL-6 on hGH gene promoter appears to require the activation of MEK and p38 MAPK, and a fragment of promoter se- quence that spans the - 196 to - 132 bp of the gene, but may be unlinked with Pit-1 protein.     

EFFECT OF INTERLEUKIN-1β ON GROWTH HORMONE GENE EXPRESSION AND ITS POSSIBLE MOLECULAR MECHANISM IN RAT MtT/S SOMATOTROPH CELLS

Objective To elucidate the effect of interleukin-1β （IL- 1β） on human growth hormone （hGH） gene expression in a rat somatotropic pituitary cell line MtT/S.
Methods Stably transfected MtT/S cells were firstly established by transfecting 484-Lucl plasmid which contained hGH gene promoter --484 to ＋30 bp and luciferase reporter gene. The effect of IL-1β on hGH gene expression was determined by assaying the luciferase activities. RT-PCR method was also used to determine whether IL-1 recepor mRNA was expressed in MtT/S cells.
Results The 10^3 U/mL IL-1β stimulated secretion and synthesis of GH, and promoted the 5＇-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.38 times above the control. Among inhibitors of signaling transduction pathways, mitogen-activated protein kinase kinase （MAPKK/MEK） inhibitor PD98059 （40 μmol/L） and p38 mitogen-activated protein kinase （MAPK） inhibitor SB203580 （5 μmol/L） completely blocked the stimulatory effect of IL-1μ, and phosphatidylinositol-3-kinase （PI3-K） inhibitor LY294002 partly abolished the effect of IL-1μ. Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells. Neither over-expression of Pit- 1 nor inhibition of Pit- 1 expression affected induction of hGH promoter activity by IL-1μ. A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-1β, and results showed that the stimulatory effect of IL-1β was abolished following deletion of the --196 to -- 132 bp fragment.
Conclusions IL-1β promotes GH secretion and synthesis in rat MtT/S somatotroph cells. The stimulatory effect of IL-1β on hGH gene promoter appears to require the activation of MEK, p38 MAPK, PI3-K, and a fragment of promoter sequence that spans the -196 to -132 bp of the gene, but it may be unlinked with Pit-1 protein.     

阻断MEK／ERK上调内质网应激条件下CHOP和p53表达

目的：研究MEK／ERK信号途径在肝癌细胞SMMC-7721抵抗内质网应激诱导凋亡中的分子机制。方法：采用MEK特异抑制剂PD98059阻断内质网应激介导的MEK／ERK活化,并利用流式细胞和Western blot技术分析阻断MEK／ERK对内质网应激诱导的细胞凋亡及其关键调控分子GRP78、CHOP和p53表达的影响。结果：阻断MEK／ERK信号途径后,SMMC-7721细胞对内质网应激诱导凋亡的敏感性明显增强,CHOP和p53的蛋白水平显著上调。结论：内质网应激介导的MEK／ERK活化能够通过下调CHOP和p53表达抵抗细胞凋亡。     

BDNF对脑缺血大鼠肺组织MEK表达的调节

目的 研究脑源性神经营养因子（BDNF）干扰对脑缺血大鼠肺组织丝裂原细胞外激酶（MEK）表达的影响。 方法 成年SD大鼠分为假手术组、脑缺血肺损伤组及BDNF抗体封闭组（脑缺血术后立即给予BDNF抗体干预,腹腔注射,1 mL/100 g体质量,1次/d,共3 d）,每组13只。术后3 d取大鼠肺组织,5只大鼠用于免疫组化以观察MEK在肺组织的定位分布,并测定MEK蛋白的光密度值变化。8只大鼠用RT-PCR检测肺组织MEK mRNA含量变化。 结果 免疫组化染色结果显示,肺组织气管上皮和毛细血管内皮有MEK表达,脑缺血后肺组织上皮细胞和血管内皮细胞MEK光密度值明显增加（P<0.05）,而BDNF抗体处理导致MEK光密度值减少（P<0.05）。 RT-PCR结果显示,脑缺血肺组织MKE mRNA表达上调,与假手术组比较差异有统计学意义（P<0.05）;BDNF抗体处理导致MEK mRNA表达上调,与脑缺血肺损伤组比较差异有统计学意义（P<0.05）。 结论 BDNF抗体干预有效减少脑缺血肺组织MEK表达,提示BDNF可能通过调节MEK影响脑缺血肺水肿。     

MEK/ERK通路蛋白在肾癌骨转移患者的表达

目的：探讨MEK/ERK通路蛋白在肾癌骨转移患者原发灶及转移灶表达的差异及其意义,并探索这种差异的发生机制。方法： 选择北京大学人民医院2009年1月至2010年1月 7例肾癌骨转移患者的原发灶及转移灶组织标本,应用免疫组织化学法分析VEGFR-2、MEK、ERK蛋白在原发灶与转移灶表达的差异,VEGFR-2、MEK、ERK的Ⅰ抗工作浓度（体积比）分别为1 ∶200、1 ∶25、1 ∶250,应用PCR技术检测PDGFRA基因20号外显子,K-ras基因2号外显子,Braf基因15号外显子和MEK1基因2号外显子的相关突变。结果：免疫组织化学结果判读：细胞阳性率≤ 5% 为1分, 6% ~50% 为2分, 51% ~ 100% 为3分; 染色强度: 不着色为1分, 淡黄色细颗粒状为2分, 黄色颗粒状为3分, 棕黄色粗颗粒状为4分,将两个得分数相乘得到其表达强度。本组7例肾癌骨转移患者VEGFR-2在原发灶(2.86±2.27)和骨转移灶（2.67±1.85）表达差异无统计学意义（P=0.901）,而MEK（1.33±0.51 vs. 6.10±4.10,P=0.015）和ERK（4.43±2.84 vs.9.10±2.24, P=0.021）表达差异有统计学意义;在原发灶及转移灶标本中并未检测到相关的基因突变。结论：MEK/ERK通路蛋白在肾癌骨转移患者原发灶和转移灶表达的差异可能与其转移过程有关,也可能是影响靶向治疗效果的原因之一。