miR-206-3p通过LXRα调控糖尿病心肌病心肌细胞凋亡的研究

目的:探究微RNA(miR)-206-3p是否通过调控肝X受体α基因(LXRα)发挥高糖情况下的促心肌细胞凋亡作用。方法:根据不同培养基培养以及是否加LXRα激动剂GW3965将H9C2心肌细胞分为:低糖对照组(5.5mmol/L低糖完全培养基培养)、HM组(加甘露醇的33mmol/L高渗低糖完全培养基培养)、HG组(33mmol/L高糖完全培养基培养)、HG+GW3965-1μM组(HG组加1μmol/L GW3965激动剂)。构建miR-206-3p激活及抑制模型后,根据处理方案分为:低糖对照组(转染miR-inhibitor NC质粒+5.5mmol/L低糖培养基)、HG组(转染miR-inhibitor NC质粒+33mmol/L高糖培养基)、HG+inhibitor组(转染miR-206-3p inhibitor质粒+33mmol/L高糖培养基)。比较各组间心肌细胞凋亡情况、miR-206-3p和LXRα蛋白质相对表达水平,验证miR-206-3p对LXRα的靶向关系。结果:HG组心肌细胞miR-206-3p表达量显著高于低糖对照组[(6.775±0.615)比(0.976±0.781),P=0.001],HG+miR-206-3p inhibitor组凋亡细胞水平显著低于HG组[(0.059±0.001)比(0.123±0.074),P=0.001];双荧光素酶活性实验证实miR-206-3p同LXRα相结合。激活LXRα可减少高糖导致的心肌细胞凋亡。结论:高糖情况下miR-206-3p表达显著升高并通过靶向下调LXRα促进了高糖介导的心肌细胞凋亡。     

PAI-1引起2型糖尿病合并NAFLD小鼠肝脏炎性反应和纤维化的机制研究

目的探讨纤溶酶原激活物抑制剂-1(PAI-1)对2型糖尿病(T2DM)合并非酒精性脂肪性肝病(NAFLD)小鼠肝脏脂质沉积,炎性反应,纤维化等的影响。方法以C57BL/KSJ-Lepdb雄性小鼠作为T2DM合并NAFLD组(db/db组),同周龄C57BKS db/m雄性小鼠作为对照组(db/m组)。采用苏木素-伊红染色,油红О染色等方法检测小鼠肝组织切片脂质沉积;采用ELISA检测肝组织甘油三酯含量。以小鼠正常肝细胞NCTC1469作为研究对象,分为5组:对照组给予25 mmol/L葡萄糖(NG组)高渗对照组给予25 mmol/L葡萄糖+25 mmol/L甘露醇(HMA组)、高糖高脂组给予50mmol/L葡萄糖+0.75 mmol/L棕榈酸(HG+PA组)、高糖高脂+RNA干扰对照组(HG+PA+Si-NC组)用NC siRNA瞬时转染细胞并给予高糖高脂干预,高糖高脂+PAI-1沉默组(HG+PA+Si-PAI-1组)用PAI-1的siRNA瞬时转染细胞并给予高糖高脂干预。采用实时定量PCR和Western印迹方法检测炎性因子单核细胞趋化蛋白-1(MCP-1)、白细胞介素-1β(IL-1β),肝纤维化相关指标转化生长因子-B(TGF-3),α-平滑肌肌动蛋白(α-SMA)、Ⅰ型胶原蛋白(Col I)以及PAI-1的表达情况。结果与db/m组相比,db/db组小鼠肝组织中出现明显脂质聚集和纤维组织增生,甘油三酯含量增加,且MCP-1,IL-1β、TGF-β,a-SMA,ColⅠ和PAI-1的mRNA和蛋白水平均明显上调(均P<0.05)。与NC组细胞相比,HG+PA组MCP-1、IL-1β、TGF-β、α-SMA、Col Ⅰ、PAI-1表达量均明显上调(均P<0.05);与HG+PA组相比,HG+PA+si-PAI-1组PAI-1、MCP-1、IL-β、TGF-β、α-SMA和ColⅠ等表达量均明显下调(均P<0.05)。结论T2DM合并NAFLD小鼠模型肝组织中PAl-1表达明显增加,抑制PAI-1表达可明显改善肝组织炎性反应和纤维化水平。     

褪黑素通过激活Akt信号通路缓解高糖诱发的原代心肌细胞损伤

目的 明确高糖对心肌细胞损伤的影响;揭示褪黑素（Mel）在高糖诱发乳鼠原代心室肌细胞损伤中的作用及机制。 方法 体外培养乳鼠原代心室肌细胞,分为4组:正常葡萄糖浓度组(NG)、高糖组(HG,HG=25 mmo/L)、高糖+褪黑素组（HG+Mel,HG=25 mmo/L;Mel=30 μmo/L）、高糖+褪黑素+ PI3K/Akt抑制剂组（HG+Mel,HG=25 mmo/L;Mel=30 μmo/L;LY294002=50 μmo/L）组,采用Western Blotting、RT-PCR和免疫荧光技术检测心肌细胞凋亡相关蛋白以及PI3K/p-Akt等指标,评价褪黑素对高糖诱发心肌细胞凋亡的作用及机制。 结果 与NG组比较,HG组心肌细胞Cl -Caspase3、Caspase9的mRNA及蛋白表达明显升高,伴有p-Akt的mRNA及蛋白表达降低和PI3K蛋白表达降低;与HG组相比,HG+Mel组心肌细胞Cl-Caspase3、Caspase9的mRNA及蛋白表达下调伴有p-Akt的mRNA及蛋白表达回升和PI3K蛋白表达升高;与HG+Mel组相比,HG+Mel+LY294002组心肌细胞的Cl-Caspase3、Caspase9的mRNA及蛋白表达上升伴有p-Akt蛋白表达水平显著降低和PI3K蛋白表达降低。免疫荧光的结果与Western Blotting、RT-PCR的结果趋势一致。 结论 褪黑素通过激活PI3K/Akt信号通路缓解高糖诱导的原代心肌细胞损伤。     

Syk对高糖诱导的H9c2心肌细胞凋亡的影响及其机制研究

目的 探讨脾酪氨酸激酶(Syk)对高糖诱导的H9c2心肌细胞凋亡的影响及其机制.方法 将体外培养的H9c2心肌细胞分为5组:对照组(5.5 mmol/L葡萄糖,NG组)、高糖组(33 mmol/L葡萄糖,HG组)、Syk抑制剂对照组(5.5 mmol/L葡萄糖+1μmol/L BAY,NG+ BAY组)、Syk抑制剂高糖组(33 mmol/L葡萄糖+1μmol/L BAY,HG+ BAY组)、甘露醇高渗透压对照组(5.5 mmol/L葡萄糖+27.5 mmol/L甘露醇,OC组).采用Western印迹方法检测磷酸化Syk(p-Syk)、cleaved-caspase-1及Bax、Bcl-2的蛋白水平;逆转录PCR检测caspase-1、Bax、Bcl-2 mRNA的表达;流式细胞仪检测H9c2心肌细胞凋亡率;MTT比色法检测细胞活力.结果 与NG组相比,HG组H9c2心肌细胞活力下降(F=37.3,P<0.05)、凋亡率增加(F=46.5,P<0.05),OC组、NG+ BAY组细胞凋亡率与细胞活力差异均无统计学意义(P均>0.05);且HG组p-Syk、cleaved-caspase-1及Bax表达增加,Bcl-2表达降低(F=8.4、80.5、7.6、37.4,P均<0.05),caspase-1及Bax mRNA表达升高,Bcl-2 mRNA表达降低(F=130.7、17.8、7.18,P均<0.05);与HG组相比,HG+ BAY组细胞活力升高(F=37.3,P <0.05)、细胞凋亡率降低(F=46.5,P<0.05),且cleaved-caspase-1及Bax表达降低,Bcl-2表达水平升高(F =80.5、7.6、37.4,P均<0.05),caspase-1及Bax mRNA表达降低,Bcl-2 mRNA表达升高(F=130.7、17.8、7.18,P均<0.05).结论 在高糖条件下,Syk可诱导心肌细胞凋亡,其作用是通过调控Bax、Bcl-2的表达.     

环状RNA ITCH对高糖诱导的心脏成纤维细胞活化的影响与机制研究

目的 探讨环状RNA ITCH(Circ-ITCH)对高糖诱导的心脏成纤维细胞(CF)活化的影响及其机制。方法 体外培养人CF(HCF),按照处理方法的不同分为对照组、高糖组、过表达载体阴性对照(OV-NC)组、Circ-ITCH过表达载体(OV-Circ-ITCH)组；模拟物阴性对照[微小RNA(miR)-NC]组、miR-212-3p模拟物(miR-212-3p mimics)组、抑制物阴性对照(inhibitor-NC)组、miR-212-3p抑制物(miR-212-3p inhibitor)组；Circ-ITCH过表达载体+模拟物阴性对照(OV-Circ-ITCH+miR-NC)组、Circ-ITCH过表达载体+miR-212-3p模拟物(OV-Circ-ITCH+miR-212-3p mimics)组、Circ-ITCH过表达载体+小分子干扰RNA阴性对照(OV-Circ-ITCH+si-NC)组和Circ-ITCH过表达载体+Samd同源物7小分子干扰RNA(OV-Circ-ITCH+si-Smad7)组，除对照组外，其余各组转染12 h后采用30 mmol/L D-葡萄糖...     

吡格列酮对高糖诱导的小鼠主动脉平滑肌细胞晚期糖基化终末产物受体表达的影响及机制

目的探讨吡格列酮(PIO)对高糖诱导的小鼠主动脉血管平滑肌细胞(VSMCs)晚期糖基化终末产物受体(RAGE)表达的影响及其作用机制。方法原代培养小鼠主动脉VSMCs分为5组:(1)5. 5 mmol/L葡萄糖(正常浓度葡萄糖组,NG);(2)25 mmol/L葡萄糖(高浓度葡萄糖组,HG);(3)25 mmol/L葡萄糖+10μmol/L PIO(HG+PIO);(4)25 mmol/L葡萄糖+10μmol/L PIO+10μmol/L GW9662 (HG+PIO+GW9662);(5) 25 mmol/L葡萄糖+10μmol/L GW9662 (HG+GW9662)。应用RT-PCR及Western blot检测VSMCs中RAGE及过氧化物酶体增殖物激活受体γ(PPAR-γ)的表达。结果高糖增加VSMCs中RAGE的mRNA(P=0. 001)和蛋白(P=0. 002)表达;PPAR-γ激动剂PIO可抑制高糖增加VSMCs中RAGE的mRNA(P=0. 014)和蛋白(P=0. 006)表达的作用;加用PPAR-γ抑制剂GW9662后可明显减弱PIO对RAGE的mRNA(P=0. 001)和蛋白(P=0. 004)表达的抑制作用。结论 PIO可通过激活PPAR-γ,抑制高糖诱导的小鼠主动脉平滑肌细胞RAGE的表达。     

胰升糖素样肽1通过miR-137途径减轻高糖诱导的胎盘滋养细胞HTR8/SVneo炎症及凋亡

目的研究胰升糖素样肽1(GLP-1)减轻高糖诱导的胎盘滋养细胞HTR8/SVneo炎症及凋亡的作用及分子机制。方法收集妊娠期糖尿病(GDM)产妇及健康产妇的胎盘,检测miR-137及白细胞介素6(IL-6)的表达;培养胎盘滋养细胞HTR8/SVneo,分为低糖(5 mmol/L)处理的LG组、高糖(25 mmol/L)处理的HG组、高糖联合GLP-1处理的GLP-1组、转染miR-137模拟物后高糖联合GLP-1处理的miR-137+GLP-1组、转染miR-137模拟物的miR-137模拟物组、转染阴性对照(NC)模拟物的NC模拟物组、转染miR-137抑制物的miR-137抑制物组、转染NC抑制物的NC抑制物组。测定细胞凋亡率、miR-137及IL-6的表达量。结果 HG组的细胞凋亡率及miR-137、IL-6的表达水平均明显高于LG组,GLP-1组的细胞凋亡率及miR-137、IL-6的表达水平均明显低于HG组,miR-137+GLP-1组的细胞凋亡率及miR-137、IL-6的表达水平均明显高于GLP-1组;miR-137模拟物组细胞的凋亡率及IL-6的表达水平均明显高于NC模拟物组,miR-137抑制物组细胞的凋亡率及IL-6的表达水平均明显低于NC抑制物组。结论 GLP-1通过抑制miR-137/IL-6途径减轻高糖诱导的胎盘滋养细胞HTR8/SVneo炎症及凋亡。     

长链非编码RNA MIAT在2型糖尿病合并冠心病患者血清中的水平及对高糖诱导的心肌细胞损伤的影响

[目的]探讨长链非编码RNA心肌梗死相关转录本(lncRNA MIAT)在2型糖尿病(T2DM)合并冠心病(CHD)患者中的血清水平及其对高糖(HG)诱导的心肌细胞损伤的影响。[方法]选取2021年6月—12月于唐山市人民医院就诊的100例单纯T2DM患者作为T2DM组,100例单纯冠心病(CHD)患者作为CHD组,100例T2DM合并CHD患者作为T2DM+CHD组,另外选取100例健康人群作为对照组。采用实时荧光定量PCR(RT-qPCR)检测血液MIAT、microRNA-150-5p(miR-150-5p)的水平。体外培养人心肌细胞系AC16细胞,分为NG组(5.5 mmol/L正常葡萄糖)、HG组(30 mmol/L高葡萄糖)、HG+MIAT敲低阴性对照(HG+si-NC)组、HG+MIAT敲低(HG+si-MIAT)组、HG+si-MIAT+miR-150-5p抑制剂阴性对照(HG+si-MIAT+anti-NC)组、HG+si-MIAT+miR-150-5p抑制剂(HG+si-MIAT+anti-miR-150-5p)组,RT-qPCR检测细胞中MIAT和miR-150-...     

LncRNA BDNF-AS靶向miR-335-5p调控高糖诱导的小鼠足细胞损伤的分子机制

目的探讨脑源性神经营养因子反义因子(BDNF-AS)对高糖(HG)诱导的小鼠足细胞损伤的影响及其分子机制。方法用终浓度为30 mmol/L的D-葡萄糖溶液刺激细胞MPC5作为HG组,同时以终浓度为5 mmol/L的D-葡萄糖溶液处理细胞作为正常对照(NG)组。将si-NC、si-BDNF-AS、miR-NC、miR-335-5p分别转染至MPC5细胞中再用HG处理,记为HG+si-NC组、HG+si-BDNF-AS组、HG+miR-NC组、HG+miR-335-5p组。将pcDNA、pcDNA-BDNF-AS、si-NC、si-BDNF-AS转染至MPC5细胞中,记为pcDNA组、pcDNA-BDNF-AS组、si-NC组和si-BDNF-AS组。将si-BDNF-AS与anti-miR-NC、annti-miR-335-5p分别共同转染至MPC5细胞中再用HG处理,记为HG+si-BDNF-AS+anti-miR-NC组、HG+si-BDNF-AS+antimiR-335-5p组。实时荧光定量聚合酶链反应(qRT-PCR)检测miR-335-5p和BDNF-AS的表达水平;Western印迹检测podocin、nephrin、B细胞淋巴瘤(Bcl)-2、Bcl-2相关X蛋白(Bax)、酶切含半胱氨酸的天冬氨酸蛋白水解酶(caspase)-3蛋白表达;流式细胞术检测细胞凋亡;荧光素酶实验检测LncRNABDNF-AS和miR-335-5p的靶向关系。结果HG作用的小鼠足细胞中LncRNA BDNF-AS表达水平显著升高,miR-335-5p表达水平显著降低,podocin、nephrin蛋白表达水平显著降低,细胞凋亡率显著升高,Bcl-2蛋白表达水平显著降低,Bax、酶切caspase3蛋白表达水平显著升高(均P<0.05);干扰LncRNA BDNF-AS表达和miR-335-5p过表达小鼠足细胞中podocin、nephrin蛋白表达水平显著升高,细胞凋亡率显著降低,Bcl-2蛋白表达水平显著升高,Bax、酶切caspase3蛋白表达水平显著降低(均P<0.05)。LncRNA BDNF-AS靶向调控miR-335-5p的表达,抑制miR-335-5p表达逆转了干扰LncRNA BDNF-AS表达对HG诱导的小鼠足细胞损伤的保护作用。结论HG作用的小鼠足细胞中LncRNA BDNF-AS低表达,过表达LncRNA BDNF-AS可抑制细胞凋亡,保护HG诱导的小鼠足细胞损伤,其机制可能与miR-335-5p的表达相关。     

体外高糖环境对H9c2心肌细胞中STIM1、Orai1及TRPC1的影响

目的构建体外高糖诱导的心肌损伤模型,观察体外高糖环境对H9c2心肌细胞的增殖以及基质作用分子1(STIM1)、Orai1和瞬时受体电位通道1(TRPC1)表达的影响。方法体外培养鼠胚H9c2心肌细胞,随机分为4组,正常对照组(5.5 mmol/L葡萄糖)、高渗组(27.5 mmol/L甘露醇+5.5 mmol/L葡萄糖)、高糖组(33mmol/L葡萄糖),药物组(2μmol/L SKF96365+33 mmol/L葡萄糖)。培养72 h。采用CCK8技术检测细胞增殖率;采用RT-PCR以及Western blotting技术测定4组STIM1、Orai1及TRPC1的mRNA和蛋白表达水平的变化。结果正常对照组和高渗组STIM1、Orai1及TRPC1的mRNA及蛋白相对表达量差异无统计学意义(P均0.05);高糖组STIM1、Orai1及TRPC1的mRNA及蛋白相对表达量较正常对照组增加(P均0.05);药物组的表达量较正常对照组高(P均0.05),较高糖组下降(P均0.05)。结论体外高糖在一定程度上抑制心肌细胞增殖,促进STIM1、Orai1及TRPC1蛋白的表达,这可能是体外高糖环境下H9c2心肌细胞损伤的机制之一。     

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.     

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.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Variabilité des concentrations plasmatiques de l’angiotensinogène et risque d’hypertension artérielle chez le rat transgénique

Aim

Genetic polymorphisms of the human angiotensinogen gene are frequent and may induce up to 30% increase of plasma angiotensinogen concentrations with a blood pressure increase of up to 5 mmHg. Their role for the pathogenesis of human arterial hypertension remains unclear. High plasma angiotensinogen levels could increase the sensitivity to other blood pressure stressors.

Methods

Male transgenic rats with a 9-fold increase of plasma angiotensinogen concentrations and male non-transgenic rats aged 10 weeks were treated or not with NG-Nitro-L-arginine-methyl ester for 3 weeks in their drinking water (n = 3/group). Systolic blood pressure and body weight were measured at baseline and at the end of the study when left ventricular weight and ventricular expression of angiotensin I-converting enzyme and procollagen Iα1 were determined (polymerase chain reaction).

Results

At baseline, transgenic rats had +18 mmHg higher bood pressure and –8% lower body weight compared to non-transgenic rats (P < 0.05) without significant changes for the vehicle groups throughout the study (P > 0.05). NG-Nitro-L-arginine-methyl ester increased blood pressure, left ventricular weight and left ventricular weight indexed for body weight by +41%, +17.6% and +18.6% (P < 0.05) in transgenic and +25%, +5.3% and +6.7% (P > 0.05) in non-transgenic rats compared to untreated animals, respectively. Cardiac gene expression showed no differences between groups (P > 0.05).

Conclusion

Increased plasma angiotensinogen levels may sensitize to additional blood pressure stressors. Our preliminary results point towards an independent role of angiotensinogen in the pathogenesis of human hypertension and associated end-organ damage.     

Morphological and immunocytochemical heterogeneity of cultured pinealocytes from one-week-and two-month-old rats: Planimetric and densitometric investigations

Abstract: In vitro preparations of rat pinealocytes are widely used for biochemical analyses of signal transduction processes. This paper deals with morphological and immunocytochemical features of such preparations. Special attention was paid to the problems of whether pinealocytes represent a heterogeneous cell population and how such heterogeneity may develop during ontogeny. The investigations were performed with cells which were obtained from the pineal organ of one-week-and two-month-old rats, attached to synthetic peptide-coated coverslips or tissue culture chamber slides, and maintained under in vitro conditions overnight. The attached cells were then fixed with paraformaldehyde. These preparations yielded monolayers of spherical cells of different sizes; most cells were isolated, but some of them were aggregated and formed small clusters. On the average, the cells from the one-week-old animals were smaller than the cells from the two-month-old animals. Immunocytochemical demonstration of S-antigen, a pinealocyte-specific marker, showed that the majority of the cells from two-month-old animals were intensely or moderately labelled. Pinealocytes from one-week-old animals were less S-antigen immunoreactive. Only very few cells (less than 1% displayed glial fibrillary acidic protein (GFAP)-immunoreactivity. Planimetric investigations of the cell size and semiquantitative densitometric investigations of the intensity of the S-antigen immunoreaction revealed that (i) pinealocytes kept in vitro form a heterogeneous cell population, and that (ii) this heterogeneity increases during postnatal development from one-week-old to two-month-old animals. Two groups of pinealocytes can be distinguished based on their developmental fate: pinealocytes of one group grow dramatically, but show only a moderate increase in S-antigen immunoreactivity, and pinealocytes of the other group retain their size, but display a distinct increment in S-antigen immunoreacti vitv.     

MUTATION FREQUENCY IN NURSES AND PHARMACISTS WORKING WITH CYTOTOXIC DRUGS

Individuals occupationally exposed to cytotoxic drugs may be at risk owing to the effects of these agents on DNA. As an index of DNA damage, in vivo mutations were measured in lymphocytes from 24 oncology nurses or pharmacists and 24 matched controls. Mutation frequency was significantly increased in exposed individuals and appeared to be related to duration of exposure. However, the overall magnitude of the increase was small and its biological significance remains to be determined.