替罗非班通过上调miR-22保护ox-LDL诱导的脐静脉内皮细胞损伤

目的探讨替罗非班对氧化型低密度脂蛋白(ox-LDL)诱导的脐静脉内皮细胞(EA.hy926)损伤的影响和可能机制。方法采用低、中、高剂量的替罗非班作用于ox-LDL诱导的EA.hy926细胞,采用细胞计数法(CCK-8)、流式细胞术分别检测细胞活力和凋亡。实时荧光定量PCR(qRT-PCR)检测miR-22表达水平。酶联免疫吸附法(ELISA)检测细胞培养上清液中肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)水平。转染miR-22模拟物上调EA.hy926细胞中miR-22表达水平,采用上述方法检测上调miR-22对ox-LDL诱导的EA.hy926细胞损伤的影响。结果替罗非班作用于ox-LDL诱导的EA.hy926细胞后,细胞存活率显著升高,凋亡率显著降低,细胞培养上清液中TNF-α和IL-6含量显著降低,miR-22表达显著升高(P0.05)。上调miR-22表达后,ox-LDL诱导的EA.hy926细胞培养上清液中TNF-α和IL-6含量显著降低,细胞存活率显著升高,凋亡率显著降低(P0.05)。结论替罗非班能够减轻ox-LDL诱导的脐静脉内皮细胞凋亡和炎症反应,其机制可能与上调miR-22表达有关。     

棕榈酸对EA.hy926细胞胆固醇代谢相关基因表达的影响及机制

目的研究棕榈酸(PA)对内皮细胞株EA.hy926胆固醇代谢的影响,检测胆固醇流出、胆固醇胞内转化、脂蛋白摄入以及信号通路相关基因表达的变化。方法体外培养内皮细胞株EA.hy926,分为白蛋白(ALB)对照组和PA处理组。采用实时荧光定量PCR法检测ATP结合盒转运体A1(ABCA1)、ABCG1、27-羟化酶、清道夫受体A1(SR-A1)、SR-B1、CD36、凝集素样氧化低密度脂蛋白受体1(LOX-1)、肝X受体α(LXRα)、过氧化物酶体增殖物激活受体γ(PPARγ)的表达变化。结果和ALB对照组相比,10、20、30μmol/L PA处理组ABCG1 mRNA水平显著下降(P0.01),20、30μmol/L PA处理组CD36、LOX-1 mRNA水平显著升高(P0.05)。与ALB对照组相比,10、20、30μmol/L PA处理组LXRαmRNA水平显著下降(P0.001、P0.05、P0.001),10μmol/L PA处理组PPARγmRNA水平显著下降(P0.05)。而10、20、30μmol/L PA处理EA.hy926细胞未显著影响ABCA1、SR-A1、SR-B1、27-羟化酶的表达。结论 PA能够改变内皮细胞EA.hy926细胞胆固醇流出和脂蛋白摄入相关基因的表达,其机制与LXRα和PPARγ信号途径有关。     

替米沙坦通过激活PPARγ而下调NF-κB通路抑制脂多糖诱导的单核细胞THP-1炎症反应

目的探讨替米沙坦（Telm）对脂多糖（LPS）诱导的人THP-1巨噬细胞炎症因子释放的影响及机制。方法体外培养人THP-1单核细胞随机分为对照组、脂多糖组和替米沙坦组（LPS+Telm）。替米沙坦组细胞予替米沙坦（10μmol/L）预孵育2h后与脂多糖组均加入脂多糖刺激24h。应用Westernblot检测各组细胞过氧化体增殖物激活型受体γ（PPARγ）、磷酸化过氧化体增殖物激活型受体γ（p-PPARγ）、IκBα、磷酸化IκBα（p-IκBα）、核因子κB（NF-κB）、磷酸化核因子κB（p-NF-κB）的蛋白表达,ELISA法检测各组细胞培养上清中单核细胞趋化蛋白1（MCP-1）、肿瘤坏死因子α（TNF-α）和白细胞介素6（IL-6）的表达水平,应用实时定量PCR（RT-PCR）检测各组细胞MCP-1、TNF-α和IL-6的mRNA表达水平。结果Westernblot检测发现,与对照组相比,脂多糖组p-PPARγ、p-NF-κB和p-IκBα蛋白表达水平明显升高（P<0.05）,IκBα表达明显下降（P<0.05）,PPARγ和NF-κB表达水平无显著差异（P>0.05）;RT-PCR和ELISA检测发现,与对照组相比,脂多糖组MCP-1、TNF-α和IL-6蛋白水平和mRNA表达水平均明显增高（P<0.05）。与脂多糖组相比,替米沙坦组p-NF-κB和p-IκBα蛋白水平表达明显下降,MCP-1、TNF-α及IL-6分泌水平和mRNA水平也均明显降低,p-PPARγ和IκBα蛋白表达水平明显增加（P<0.05）,但是NF-κB和PPARγ表达水平依然无显著差异（P>0.05）。结论替米沙坦预处理可通过激活PPARγ而下调NF-κB活化从而抑制脂多糖诱导单核细胞THP-1产生炎症反应。     

美托洛尔对扩张型心肌病患者外周血单个核细胞炎性细胞因子表达和核转录因子κB/p65活化的影响

目的:观察美托洛尔对扩张型心肌病(DCM)心力衰竭患者外周血单个核细胞(PBMCs)炎性细胞因子表达和核转录因子κB/p65(NF-κB/p65)活化的影响。方法:选取心功能Ⅱ、Ⅲ、Ⅳ级DCM心力衰竭患者35例,清晨采外周静脉血并分离出PBMCs,加入细胞因子刺激剂脂多糖(LPS)和不同浓度(0、2.5、5及10μmol/L)的美托洛尔,经体外培养24h,离心后提取上清液并采用放射免疫法检测细胞因子白细胞介素-1β(IL-1β)、IL-6和肿瘤坏死因子-α(TNF-α)水平,并将细胞悬液固定后采用免疫组织化学染色法,进行NF-κB染色,测定NF-κB阳性细胞率,分析二者相关性。结果:不同剂量美托洛尔对DCM患者IL-1β、IL-6、TNF-α和NF-κB/p65的水平均有抑制作用(均P0.01);2.5、5及10μmol/L的美托洛尔组IL-1β、IL-6、TNF-α和NF-κB/p65的水平均明显低于0μmol/L组(均P0.05);10μmol/L美托洛尔组IL-1β、IL-6、TNF-α和NF-κB/p65的水平均明显低于2.5、5μmol/L组(均P0.05),而2.5、5μmol/L组IL-1β、IL-6、TNF-α和NF-κB/p65的水平差异无统计学意义(均P0.05);在不同浓度美托洛尔组NF-κB/p65水平和IL-1β、IL-6、TNF-α水平均有明显正相关性(相关系数r值分别为0.592、0.528、0.486,P0.01和P0.05)。结论:在DCM心力衰竭患者中,美托洛尔可呈剂量依赖性抑制LPS诱导的PBMCs炎性细胞因子表达增加,可能是通过下调NF-κB/p65活化水平来实现的。这可能是其改善DCM心力衰竭患者心功能的作用机制之一。     

黄芪多糖对LPS损伤小肠上皮细胞的保护作用

目的:探讨黄芪多糖(APS)在内毒素-脂多糖(LPS)损伤小肠上皮细胞(IEC-6)中的作用机制及对细胞因子和核因子-κB(NF-κB)表达的影响.方法:以小肠上皮细胞株IEC-6为研究对象, 将培养的细胞分为6组: 对照组、LPS组、LPS APS 50 mg/L组、LPS APS 100 mg/L组、LPS APS 200 mg/L组和LPS APS 500 mg/L组. 采用RT-PCR法检测细胞因子TNF-α和IL-8 mRNA的表达, 采用凝胶电泳迁移率法分析NF-κB蛋白活性.结果: LPS损伤IEC-6细胞后, TNF-α, IL-8 mRNA水平和NF-κB蛋白定量表达均升高, 均显著高于对照组(TNF-a: 1.26±0.06 vs 0.65±0.05, IL-8 mRNA: 1.19±0.05 vs 0.57±0.06, NF-kB: 2.76±0.07 vs 0.07±0.03, P均<0.01). 而黄芪多糖呈浓度和时间依赖性地抑制LPS诱导IEC-6细胞分泌的TNF-α, IL-8等细胞因子的mRNA的表达水平(P<0.01), 并能降低NF-κB的表达活性(P<0.01).结论:APS具有抑制LPS刺激IEC-6细胞产生的TNF-α, IL-8炎性因子的作用, 并能降低NF-κB的表达活性, 其对LPS所致的肠道损伤具有保护作用.     

脂多糖诱导巨噬细胞中核受体协同抑制因子启动子甲基化对炎症因子的调控作用

目的探讨核受体协同抑制因子(NCOR)在脂多糖(LPS)诱导巨噬细胞炎症反应中的作用及其调控机制。方法 1μg/ml的LPS分别处理小鼠巨噬细胞RAW264.7 24 h和48 h,应用Western blot和Real time-PCR检测NCOR的表达水平以及肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)mRNA水平,荧光素酶报告基因检测核因子-κB(NF-κB)的启动子活性。LPS处理细胞48 h后,应用MSP检测NCOR启动子是否发生甲基化以及Western blot检测DNMT3b的表达变化。Real time-PCR检测5'-aza和LPS联合处理细胞后NCOR mRNA的表达水平;转染DNMT3b siRNA后,分别应用Western blot和Real time-PCR检测DNMT3b的表达水平,以及DNMT3b siRNA和LPS联合作用下NCOR、TNF-α、IL-6的表达水平和NF-κB的启动子活性。结果 LPS干预细胞24、48 h后,NCOR蛋白和mRNA表达显著下调(P0.05),而TNF-α、IL-6 mRNA表达水平、DNMT3b蛋白的表达水平以及NF-κB的启动子活性显著上升(P0.05)。MSP检测说明LPS可介导NCOR的启动子甲基化。用5'-aza和LPS联合处理细胞后NCOR mRNA水平较LPS组有显著上升(P0.05)。采用DNMT3b siRNA可显著下调DNMT3b蛋白和mRNA水平,并可部分逆转LPS介导的抑制NCOR表达的效应,抑制TNF-α、IL-6的表达水平和NF-κB的启动子活性(P0.05)。结论 NCOR启动子的甲基化是LPS介导巨噬细胞炎症反应发生、发展的关键步骤,其可作为治疗ALI/ARDS的潜在靶点。     

原花青素B2对LPS诱导的心肌细胞损伤的保护作用及机制

目的 探讨原花青素B₂(PCB₂)对LPS诱导的心肌细胞损伤的保护作用及机制。方法 正常培养心肌细胞H9c2,用LPS诱导H9c2细胞建立细胞损伤模型,分别用6.25、12.5、25.0 μmol/L的PCB₂处理模型细胞,25.0 μmol/L的PCB₂处理模型细胞后加入核因子κB(NF-κB)信号通路抑制剂PDTC处理。采用MTT法检测细胞存活率;流式细胞术检测细胞凋亡率;酶联免疫吸附法(ELISA)检测细胞肿瘤坏死因子α(TNF-α)、白细胞介素1β(IL-1β)和白细胞介素6(IL-6)的水平;丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)试剂盒分别检测MDA含量和SOD、GSH-Px活性;Westem blot检测细胞中NF-κB、IκB-α蛋白表达。结果 LPS组细胞存活率较对照组显著降低(P＜0.05),而PCB₂显著升高细胞存活率(P＜0.05)。LPS组细胞凋亡率较对照组显著升高(P＜0.05),而PCB₂显著降低LPS处理的细胞凋亡率(P＜0.05)。LPS组细胞TNF-α、IL-1β、IL-6水平较对照组显著升高(P＜0.05),而PCB₂显著降低LPS处理细胞TNF-α、IL-1β、IL-6水平(P＜0.05)。与对照组比较,LPS组细胞MDA含量显著升高,SOD、GSH-Px活性显著降低(P＜0.05);PCB₂显著降低LPS处理的细胞MDA含量,显著升高SOD、GSH-Px活性(P＜0.05)。与对照组比较,LPS组细胞NF-κB蛋白表达显著升高,IκB-α蛋白表达显著降低(P＜0.05);与LPS组比较,PCB₂显著降低细胞NF-κB蛋白表达,显著升高IκB-α蛋白表达(P＜0.05)。与LPS+PCB₂组相比,LPS+PCB₂₊PDTC能显著降低细胞凋亡率和TNF-α、IL-1β、IL-6、MDA含量,显著升高SOD、GSH-Px活性。结论 PCB₂降低LPS诱导的心肌细胞凋亡率、炎症水平和氧化应激,提高细胞存活率,这可能与抑制NF-κB信号通路的活化有关。     

涤痰汤对动脉粥样硬化兔炎性因子的影响

目的观察涤痰汤对动脉粥样硬化兔炎性因子核因子-κB(NF-κB)、E-选择素(E-selectin)、肿瘤坏死因子-α(TNF-α)以及白细胞介素-6(IL-6)的影响,探讨涤痰汤防治动脉粥样硬化的作用机制。方法应用高脂饲料制备动脉粥样硬化兔模型,随机分为6组,分别加入涤痰汤以及阿托伐他汀钙干预,用酶联免疫方法(ELISA)检测血清TNF-α和IL-6的含量;用荧光定量PCR检测TNF-α和IL-6mRNA表达;用Western blot检测NF-κB和E-selectin蛋白的表达。结果与动脉粥样硬化模型组比较,涤痰汤能显著降低动脉粥样硬化兔血清TNF-α和IL-6的水平,降低主动脉TNF-α和IL-6mRNA的表达,降低NF-κB和E-selectin蛋白的表达。结论涤痰汤能降低NF-κB、E-selectin、TNF-α以及IL-6等炎性因子的表达,这可能是涤痰汤防治动脉粥样硬化的作用机制之一。     

化瘀祛痰方药及其拆方对内皮细胞TLR4/NF-κB炎症信号通路干预的研究

目的探讨化瘀祛痰方药及其拆方含药血清对脂多糖(LPS)诱导人脐静脉内皮细胞EA.hy926 TLR4/NF-κB信号通路活化的干预作用。方法 40只SD大鼠随机分为5组,即空白对照组、全方组、补气组、化瘀组、祛痰组,各组大鼠分别以生理盐水和相应中药煎剂连续灌胃9 d,末次灌胃给药2 h后,腹主动脉采血,离心后分离血清。体外培养EA.hy926细胞,随机分为7组,即①正常对照组、②LPS刺激组、③全方组、④补气组、⑤化瘀组、⑥祛痰组、⑦空白血清对照组。其中②组加入终浓度为10μg/ml的LPS,③～⑦组用各组含药血清(浓度为10%)预处理24 h后加入终浓度为10μg/ml的LPS,各组细胞培养24 h后进行各项指标测定。采用实时定量反转录-聚合酶链反应(Real-time PCR)定量分析TLR4、NF-κB和TNF-αmRNA表达;ELISA法检测TNF-α含量;Western印迹检测TLR4、NF-κB蛋白表达。结果与正常对照组相比,LPS刺激后TLR4、NF-κB和TNF-α表达显著增加(P<0.01),全方组TLR4、NF-κB和TNF-α的表达与刺激组相比显著减少(P<0.01);拆方各组中,化瘀组TLR4、NF-κB和TNF-α水平均显著减少(P<0.01),而补气组和祛痰组TLR4、NF-κB和TNF-α水平降低不明显。结论化瘀祛痰方药及化瘀拆方可显著抑制内皮细胞TLR4/NF-κB炎症信号通路的活化,这可能是其抗AS的作用机制之一。     

养心氏片对动脉粥样硬化模型小鼠的作用机制研究

目的探讨养心氏片治疗动脉粥样硬化(AS)的可能作用机制。方法以高脂饲料喂养雄性载脂蛋白E基因敲除(ApoE~(-/-))小鼠12周,复制AS模型。将AS小鼠随机分成模型组,养心氏片高剂量组、中剂量组、低剂量组及阳性对照组,每组8只。另设雄性C57BL/6J小鼠8只作为正常对照组。养心氏片高剂量组、中剂量组、低剂量组及阳性对照组给药量分别相当于70 kg成人临床剂量的2倍、1倍、0.5倍及1倍。养心氏片高剂量组、中剂量组、低剂量组给予养心氏片,剂量分别为1.40 g/(kg·d)、0.70 g/(kg·d)、0.35 g/(kg·d)灌胃,阳性对照组给予阿托伐他汀剂量为2.57 mg/(kg·d)灌胃,共给药12周。采用苏木素-伊红(HE)染色法观察小鼠升主动脉病理学变化,Image J软件测定小鼠升主动脉斑块校正后斑块面积。采用实时定量PCR(qPCR)法检测各组小鼠主动脉组织核转录因子-κB(NF-κB)、单核细胞趋化蛋白-1(MCP-1)、血管内皮细胞黏附分子-1(VCAM-1)、白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)mRNA的表达。结果与模型组比较,养心氏片高剂量组、中剂量组、低剂量组及阳性对照组升主动脉斑块校正后斑块面积呈现不同程度的降低(P0.05),以养心氏片高剂量组小鼠升主动脉斑块校正后斑块面积最低,而养心氏片高剂量组小鼠升主动脉斑块校正后斑块面积与阳性对照组相比差异无统计学意义(P0.05)。与正常对照组比较,模型组小鼠主动脉组织NF-κB、MCP-1、VCAM-1、IL-6、TNF-αmRNA的表达水平明显升高(P0.05),各药物干预组小鼠主动脉组织NF-κB、MCP-1、VCAM-1、IL-6、TNF-αmRNA表达水平较模型组均显著降低(P0.05),与养心氏片高剂量组相比,养心氏片中剂量组及低剂量组小鼠主动脉NF-κB、MCP-1、VCAM-1、IL-6、TNF-αmRNA表达升高(P0.05),而养心氏片高剂量组小鼠主动脉NF-κB、MCP-1、VCAM-1、IL-6、TNF-αmRNA表达与阳性对照组相比差异无统计学意义(P0.05)。结论养心氏片可抗动脉粥样硬化,并具有剂量依赖性,养心氏片给药组以养心氏片高剂量组抗AS效果最佳,其机制可能与降低AS小鼠升主动脉斑块校正后斑块面积及下调主动脉NF-κB信号通路相关因子mRNA表达有关。     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.