PPARγ配体罗格列酮防治实验性心力衰竭大鼠左室重构改善心功能的分子机制研究

目的研究PPARγ配体罗格列酮对心力衰竭大鼠左室重构和心功能及心肌MMPs表达的影响,并探讨其分子机制。方法60只雄性Wistar大鼠分三组:①心力衰竭模型组(CHF,n=25),阿霉素2.5mg/kg,尾静脉注射,每周一次,连续10周;②心力衰竭模型+罗格列酮治疗组(ROS,n=25),ROS3mg/kg,每天1次,灌胃治疗;③正常对照组(CON,n=10)。12周时进行相关指标的检测。结果ROS组较CHF组死亡率降低(20%vs40%,P<0.01)。与CON组相比,CHF组大鼠左室内径扩大,心功能明显下降;ROS组左室内径增加程度降低,心功能指标改善。苦味酸天狼星红染色显示CHF组胶原容积分数(CVF)明显增高(P<0.01);而ROS组纤维化明显减轻,CVF降低(P<0.01)。CHF组左室心肌MMP-2、MMP-9及MT1-MMP表达较CON组明显升高(P<0.01),MMPs明胶酶活性显著增加(P<0.01),ROS组明显抑制MMP-2、MMP-9及MT1-MMP的表达(P<0.01),降低MMPs明胶酶活性(P<0.01),而TIMP-1的表达在三组间差异均无统计学意义(P>0.05)。NF-B活性在CHF组升高(P<0.01),而ROS干预明显降低NF-B活性(P<0.01)。结论PPARγ配体罗格列酮通过拮抗NF-B从转录水平抑制MMPs的表达及活性,进而阻止或延缓心力衰竭左室重构的进展。     

基质金属蛋白酶在阿霉素心肌病左室重构中的表达与意义

目的:研究基质金属蛋白酶(MMPs)及金属蛋白酶组织抑制因子(TIMPs)在阿霉素心肌病(ADR DCM)大鼠左室心肌中的表达与意义。方法:雄性Wistar大鼠分两组:正常对照组(n=10)和ADR DCM组(n =25)。ADR DCM模型建立方法:阿霉素2.5mg/kg,尾静脉注射,每周1次,连续10周。12周时进行超声检测 评价其心功能,硫代巴比妥酸法检测丙二醛(MDA)含量,逆转录 聚合酶链反应、Western印迹分析检测MMP 2、 MMP 9及TIMP 1的表达。结果:ADR DCM组大鼠死亡率40%,左室舒张末期内径及收缩末期内径增加,左室 短轴缩短率明显下降,MDA含量增加(P<0.01)。ADR DCM组大鼠左室心肌MMP 2、MMP 9mRNA及蛋白 水平表达较正常对照组明显升高(P<0.01),而TIMP 1的表达在两组间均无统计学意义(P>0.05)。结论: ADR DCM左室心肌MMPs表达上调,MMPs可能参与ADR DCM左室重构和心力衰竭的发生发展。     

实验性心力衰竭大鼠模型的建立及评价

目的建立实验性心力衰竭大鼠模型,并对其进行评价。方法35只雄性Wistar大鼠随机分两组:正常对照组(CON组,n=10)和心力衰竭模型组(CHF组,n=25),CHF组采用阿霉素2.5 mg/kg尾静脉注射,每周一次,连续10 w,建立CHF大鼠模型。12 w时采用超声和血流动力学检测评价其心功能,放免法检测血浆肿瘤坏死因子-α、血管紧张素Ⅱ及醛固酮水平,氯胺T法检测羟脯氨酸及胶原含量,苦味酸天狼星红染色进行左室胶原特异染色及定量分析,计算胶原容积分数(CVF),并进行HE染色,观察其组织学变化。结果CHF组大鼠死亡率为40%(10/25),CON组无死亡。与CON组相比,CHF组大鼠左室舒张末期内径(LVEDD)及收缩末期内径(LVESD)增加,心功能明显下降,表现为左室短轴缩短率(FS)、二尖瓣环收缩期长轴方向峰值运动速度(Vs)、左室内压最大上升速率( dp/dtmax)、左室内压最大下降速率(-dp/dtmax)明显降低,左室舒张末期压(LVEDP)升高(P<0.01);CHF组血浆肿瘤坏死因子-α、血管紧张素Ⅱ及醛固酮水平升高(P<0.01),心肌羟脯氨酸及胶原含量较CON组增加(P<0.01);苦味酸天狼星红染色显示CHF组左室胶原明显增加,胶原容积分数(CVF)明显增高(P<0.01);病理学结果证实符合心肌病样改变。结论阿霉素多次小剂量静脉注射能导致大鼠发生心脏间质纤维化及心脏舒缩功能降低,可成功建立实验性心力衰竭大鼠模型。     

基质金属蛋白酶在心肌肥厚大鼠中的作用及强力霉素的干预效果

目的:观察心肌肥厚大鼠模型中基质金属蛋白酶(MMP)-2,MMP-9及其抑制剂(TIMP-1)的表达及强力霉素干预后对其影响。方法:24只大鼠随机分为对照组(A组,只给予0.9%氯化钠溶液腹腔注射);造模组(B组)和药物干预组(C组)均用去甲肾上腺素1.06mg/kg腹腔注射,bid,注射15d,建立大鼠心肌肥厚模型,C组造模同时给予强力霉素10mg/kg腹腔注射,qd,给药15d。全部动物于给药后16d处死测定全心质量指数、左室质量指数、心肌胶原含量、心肌组织MMP-2,MMP-9,TIMP-1、心肌胶原容积分数(CVF)。结果:与A组比较,B组全心质量指数、左室质量指数、MMP-2、MMP-9阳性表达率、心肌胶原含量及CVF均明显增加(P<0.05),TIMP-1阳性表达率明显降低(P<0.05)。与B组比较,C组全心质量指数、左室质量指数、MMP-2、MMP-9阳性表达率、心肌胶原含量及CVF均明显降低(P<0.05),TIMP-1阳性表达率增加(P<0.05)。结论:去甲肾上腺素诱导的心肌肥厚大鼠MMPs/TIMPs系统平衡破坏,使基质胶原降解与合成平衡破坏,从而导致心室重构。强力霉素可通过抑制MMP来逆转心室重构。     

葛根素对心肌纤维化模型大鼠左室心肌组织中转化生长因子β_1和结缔组织生长因子表达的影响

目的:研究葛根素对心肌纤维化模型大鼠左室心肌组织中转化生长因子β1(TGF-β1)和结缔组织生长因子(CTGF)表达的影响。方法:采用异丙肾上腺素(5mg·kg-1.d-1×10d)皮下注射诱导大鼠心肌纤维化,给予葛根素(100mg·kg-1.d-1)干预,实验共8周。32只雄性SD大鼠随机分成4组:模型组,空白对照组,葛根素早期干预组,葛根素后期干预组;每组于实验末,计算左室质量指数,取左室心肌组织进行VG染色、免疫组化染色,分别测算胶原容积积分(CVF)、CTGF蛋白和TGF-β1蛋白含量,取左室游离壁心肌组织检测羟脯氨酸浓度和运用RT-PCR半定量分析CTGFmRNA和TGF-β1mRNA水平。结果:葛根素减少模型组大鼠左室质量指数、左室心肌组织CVF及羟脯氨酸浓度(P0.01),模型组大鼠左室心肌组织CTGF和TGF-β1的过度表达(P0.05)。相关分析显示4组大鼠的左室心肌组织CTGF蛋白含量与左室心肌组织CVF和羟脯氨酸浓度呈正相关(P0.05)。结论:葛根素减少心肌纤维化大鼠的左室心肌间质胶原沉积,减轻和延缓大鼠心肌纤维化,这种作用机制可能是通过抑制左室心肌组织中CTGF、TGF-β1的过度表达来实现。     

心肌胶原变化与左心室功能关系的实验研究

目的 :探讨肥大心肌胶原变化与左心室功能的关系。方法 :采用大鼠腹主动脉缩窄模型 ,术后 10周检测左心室功能 ,并用生化测定、病理检查结合计算机分析等方法检测左室心肌胶原形态、胶原容积分数 （CVF）、血管周围胶原面积 （PVCA）、胶原浓度 （CC）、 , 型胶原比值 （ / ）。结果 :手术组左室压力下降最大速率 （- dp/ dtmax）绝对值显著低于假手术组 （P<0 .0 1） ,左室心肌 CVF,PVCA,CC, / 均显著高于假手术组 （P<0 .0 5 ） ,心肌胶原异常沉积。 - dp/ dtmax分别与 CC和 / 呈显著负相关 （r1 =- 0 .890 4,r2 =- 0 .8135 ,P<0 .0 5 ）。 Irbesartan治疗后 ,CVF,PVCA,CC, / 可显著降低 （P<0 .0 5 ） ,异常沉积的胶原消失 ,左室 - dp/ dtmax显著增高 （P<0 .0 1）。结论 :压力超负荷左室重构早期舒张功能的降低主要与心肌胶原增生和胶原类型比值的改变密切相关     

心肌组织基质金属蛋白酶-1,2,9及其抑制物-1,2基因表达变化在心肌肥厚患者心肌纤维化中的意义

目的:探讨人心室肥厚时心肌组织基质金属蛋白酶(MMP)-1,2,9及其抑制物(TIMP)-1,2基因表达的改变及与心肌纤维化的关系。方法:应用病理检查、逆转录—聚合酶链式反应、放射免疫和蛋白印迹杂交等方法,检测心肌肥厚患者(心肌肥厚组)和正常人(对照组)心肌间质胶原容积分数和心肌血管周围胶原面积、心肌组织Ⅰ型和Ⅲ型胶原信使核糖核酸(mRNA)表达、心脏局部血管紧张素Ⅱ(AngⅡ)水平和心肌MMP-1,2,9及TIMP-1,2蛋白表达。结果:心肌间质胶原容积分数和心肌血管周围胶原面积比心肌肥厚组比对照组均明显增高(P均<0．01)。心肌肥厚组心肌组织Ⅰ型胶原及Ⅲ型胶原mRNA表达相对含量也均明显高于对照组(P均<0．01)。心肌肥厚组心肌组织匀浆液血管紧张素Ⅱ水平为(179．3±36．1)pg／mg心肌组织,对照组为(103．2±13．6)pg/mg心肌组织,与对照组比较,心肌肥厚组心肌组织血管紧张素Ⅱ水平明显增高(P<0．01)。心肌肥厚组心肌组织MMP-1,2,9蛋白表达比对照组明显增多(P均<0．01),TIMP-1,2蛋白表达也比对照组明显增加(P均<0．05)。结论:心肌肥厚时心肌胶原的代谢受到MMPs／TIMPs的调节。MMP-1,2,9和TIMP-1,2蛋白表达均增加,使MMPs的活性受到抑制,胶原合成增加的速度大于胶原降解的速度,导致心肌纤维化。     

氟伐他汀对心肌梗死大鼠左室重塑和功能的影响

目的探讨羟甲基戊二酰辅酶A(HMGCoA)还原酶抑制剂氟伐他汀对急性心肌梗死(AMI)大鼠左室结构和功能的影响。方法雌性SD大鼠AMI后6h随机分为AMI组和氟伐他汀组;另设假手术组。三组大鼠直接灌胃给药或自来水8周后行高频多普勒超声、血流动力学、心脏重塑指标及左心室心肌α、β肌球蛋白重链(α、βMHC)mRNA表达的测定。结果与假手术组相比,AMI组左室舒张末期内径(LVEDD)、左室舒张末期容积(LVEDV)、E峰、E峰减速度、E/A、左室舒张末压(LVEDP)、左、右心室心肌肥厚指数、非梗死区胶原容积分数(CVF)和βMHCmRNA均明显增加(P<0.01),左室短轴缩短率(FS)、射血分数(EF)和αMHCmRNA显著降低(P<0.01)。与AMI组相比,氟伐他汀组的LVEDD、LVEDV、E峰、E峰减速度、E/A、LVEDP、左、右心室心肌肥厚指数、CVF和βMHCmRNA均显著降低或减少(P<0.01),FS、EF和αMHCmRNA显著升高(P<0.01)。结论氟伐他汀能抑制大鼠AMI后左室重塑,改善血流动力学异常和左室功能。     

Tribble 3在糖尿病心肌病心肌间质重构时的表达和缬沙坦干预的影响

目的探讨Tribble3(TRB3)基因在大鼠Ⅱ型糖尿病心肌病心肌间质重构中的可能作用及缬沙坦干预的影响。方法32只Wistar大鼠以高脂高热量饮食诱导加小剂量链脲佐菌素注射建立Ⅱ型糖尿病心肌病动物模型,随机分为糖尿病心肌病组和缬沙坦治疗组(缬沙坦30mg·kg-1·d-1灌胃),以8只正常大鼠作对照。采用Masson染色测定心肌胶原含量,实时定量逆转录-聚合酶链反应检测心肌TRB3mRNA表达。结果与对照组比较,糖尿病心肌病组左室心肌组织胶原含量显著高(11·01±3·05比16·92±3·18,P<0·01),与糖尿病心肌病组相比,缬沙坦组心肌胶原含量明显低(16·92±3·18比13·23±3·14,P<0·05),心肌组织胶原含量与空腹血糖呈明显正相关(r=0·746,P<0·01);与对照组相比,糖尿病心肌病组大鼠心肌TRB3mRNA表达水平明显高(0·0198±0·0082比0·1108±0·0933,P<0·05);与糖尿病心肌病组比较,缬沙坦组TRB3mRNA表达水平明显低(0·1108±0·0933比0·0367±0·0234,P<0·05);与对照组比较,缬沙坦组TRB3mRNA表达水平差异无统计学意义(P>0·05);糖尿病心肌病组大鼠心肌TRB3mRNA表达与血糖正相关(r=0·69,P<0·05),与心肌组织胶原含量正相关(r=0·67,P<0·05)。结论首次证实TRB3基因在大鼠心肌中表达,发现了TRB3基因可能参与了糖尿病心肌病心肌间质重构,缬沙坦干预减轻糖尿病心肌病心肌间质重构,改善左室舒张和收缩功能,下调TRB基因的表达。     

结缔组织生长因子在心力衰竭大鼠心肌中的表达及氟伐他汀的调节作用

目的观察结缔组织生长因子(CTGF)在心肌梗死后心力衰竭(心衰)大鼠心肌中的表达及氟伐他汀对其调节作用。方法制备大鼠心肌梗死模型术后6 h分为心肌梗死组24只、梗死后氟伐他汀治疗组18只、假手术组10只。给药8周后行超声、血流动力学、左、右心室相对重量(LVRW和RVRW)、左室非梗死区胶原容积分数(CVF)和CTGF mRNA及蛋白免疫印迹测定。结果与假手术组比较,心肌梗死组左室舒张末期内径(LVEDD)和容积(LVEDV)、E峰、E峰减速度、E/A、舒张末期压(LVEDP)、LVRW、RVRW、CVF、CTGF mRNA表达(分别为1．35±0．26和0．87±0．18)及蛋白质的产生(分别为1．21±0．23和0．49±0．15)增加(P＜0．01),左室短轴缩短率(FS)和射血分数(EF)降低(P＜0．01)。与心肌梗死组比较,氟伐他汀组的LVEDD、LVEDV、E峰、E峰减速度、E/A、LVEDP、LVRW、RVRW、CVF、CTGF mRNA表达(1．10±0．22)及蛋白质产生(0．73±0．24)降低(P＜0．05或0．01),FS和EF升高(P＜0．01)。结论CTGF参与了心肌梗死后心肌纤维化和心衰的进展,氟伐他汀抑制心肌梗死后心肌纤维化和心衰进展的机制部分与其下调CTGF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.     

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.     

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.     

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.     

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.     

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.