表没食子儿茶素没食子酸酯改善高脂饮食大鼠体重及相关代谢研究

目的:观察不同剂量表没食子儿茶素没食子酸酯(EGCG)对高脂饮食大鼠体重、糖脂代谢及肝脏氧化应激状态的影响,为深入研究EGCG防治肥胖的机制探索最佳干预剂量。方法:40只雄性SD大鼠随机分为正常对照组、高脂饮食组、EGCG低剂量组[100 mg/(kg·d)]、EGCG中剂量组[200 mg/(kg·d)]、EGCG高剂量组[400 mg/(kg·d)],每组8只。正常对照组喂饲基础饲料,高脂饮食组喂饲高脂饲料,EGCG各组喂饲高脂饲料的同时给予各剂量EGCG灌胃。喂养8周末处死大鼠。测定体重、内脏脂肪重量、肝脏重量、血清空腹血糖(FBG)、三酰甘油(TG)、总胆固醇(TC)、肝脏总超氧化物歧化酶(T-SOD)活性、谷胱甘肽过氧化物酶(GPx)活性、丙二醛(MDA)含量。结果:高脂饮食组实验末体重、肝脏重量、血清FBG均显著高于正常对照组(P<0.05)。与高脂饮食组相比,EGCG各剂量组能有效降低高脂饮食大鼠体重、肝脏重量、血清FBG和TG水平(均P0.05)。与高脂饮食组相比,低剂量EGCG可升高肝脏GPx活力(P<0.05)。中剂量EGCG可降低肝脏MDA含量(P0.05)。结论:中剂量EGCG对控制高脂饮食大鼠体重、改善糖脂代谢及肝脏氧化应激状态更为适宜,而高剂量EGCG可能反而会促进机体氧化应激水平。     

北五味子多糖对高脂血症大鼠肝损伤的影响

目的探讨北五味子多糖(SCP)对高脂饮食诱导肝损伤大鼠肝功能的保护作用。方法采用高脂饲料喂养16 w诱发高脂血症大鼠模型,随机分为模型组及SCP治疗组,另设正常对照组以及正常+SCP组。SCP(50 mg/kg)灌胃给药12 w,检测各组动物血清中总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、谷丙转氨酶(ALT)、谷草转氨酶(AST)水平,肝组织中TG和TC水平;苏木素-伊红(HE)染色观察药物对肝组织病理学改变的影响。结果与正常对照组比较,模型组大鼠血清中TC、TG、LDL-C、ALT及AST水平显著增高(P<0.01),肝组织中TG和TC水平显著增高(P<0.01)。与模型组比较,SCP显著降低了大鼠血清TC、TG、LDL-C水平(P<0.05或P<0.01)、ALT、AST水平(P<0.01),降低肝组织中TG和TC水平(P<0.01),而对正常大鼠血脂、肝脂质和肝功能没有明显影响。HE染色显示模型组大鼠肝小叶结构紊乱,出现明显的肝细胞脂肪变性;SCP组肝小叶结构基本正常,肝脏脂肪变性明显减轻。结论 SCP可改善高脂血症大鼠脂质代谢紊乱,改善肝功能,减轻肝损伤。     

脂肪肝1号方治疗非酒精性脂肪性肝炎的实验研究

目的:研究脂肪肝1号方治疗非酒精性脂肪性肝炎(NASH)的作用。方法:将48只SPF级SD雄性大鼠随机分为正常组,模型组,脂肪肝1号方高、中、低剂量组和易善复组,每组8只。采用高脂饲料喂养造模,共8周,药物灌胃与造模同时进行。脂肪肝1号方高、中、低剂量组大鼠分别以生药含量为10.8g/(kg·d)~(-1)、5.4g/(kg·d)~(-1)、2.7g/(kg·d)~(-1)脂肪肝1号方中药煎剂灌胃;易善复组以0.123g/(kg·d)~(-1)易善复混悬液灌胃。分别于第0周、第2周、第4周、第6周、第8周末称量大鼠体质量,第8周末处死大鼠,检测大鼠血清肝酶(ALT、AST)、血脂(TG、TC)水平;肝组织石蜡切片行HE染色、冰冻切片行油红O染色,观察肝脏病理学特征,并进行NAS评分。结果:①大鼠体质量变化:第0、2周,各组大鼠体质量差异未见统计学意义(P0.05);第4周末,脂肪肝1号方高剂量组大鼠体质量与模型组相比显著降低(P0.01);第6周末,脂肪肝1号方高、中剂量组和易善复组大鼠体质量与模型组相比均显著降低(P0.05或0.01),且脂肪肝1号方高剂量组大鼠体质量显著低于中剂量组和易善复组;第8周末,脂肪肝1号方高、中、低剂量组和易善复组大鼠体质量与模型组相比均显著降低(P0.05或0.01),且脂肪肝1号方高剂量组大鼠体质量显著低于中、低剂量组和易善复组(P0.01)。②肝酶和血脂的变化:与模型组相比,脂肪肝1号方高、中剂量组和易善复组大鼠血清肝酶、血脂水平均显著下降(P0.05或0.01),且脂肪肝1号方高剂量组大鼠肝酶水平显著低于中剂量组、低剂量组、易善复组3组大鼠(P0.01),但脂肪肝1号方高、中剂量组及易善复组大鼠血脂水平未见明显差异(P0.05)。③肝脏病理变化:与模型组相比,肝脂肪性病变、小叶内炎症、气球样变、肝组织脂滴沉积状况在脂肪肝1号方高、中剂量组和易善复组中均得到明显改善,且NAS评分具有显著性差异(P0.01)。结论:脂肪肝1号方可有效减轻高脂饲料所致的NASH大鼠体质量,降低大鼠肝酶、血脂水平,改善肝组织脂肪性病变。     

祛湿化瘀方防治实验性脂肪肝的药效学研究

目的:探讨中药祛湿化瘀方防治脂肪肝的作用.方法:采用Wistar 雄性大鼠,以四氯化碳(CCl4)皮下注射复合高脂低蛋白饮食制备大鼠脂肪肝模型.在造模2周后,将造模大鼠随机分为模型组、祛湿化瘀方高剂量组、中剂量组和低剂量组,灌胃用药2周.观察大鼠体重、肝指数、血清丙氨酸转氨酶(ALT)、门冬氨酸转氨酶(AST)、谷氨酰转肽酶(GGT)活性、肝组织甘油三酯(TG)、游离脂肪酸(FFA)含量以及肝组织病理变化(HE染色).结果:模型组肝组织出现明显大泡样脂肪变性;肝组织TG、FFA含量以及血清ALT、AST、GGT活性显著升高.祛湿化瘀方各剂量组的病理改变较模型组显著减轻;肝组织 TG、FFA含量和血清ALT、AST、GGT活性显著低于模型组.其中高剂量组降低ALT的作用显著强于中、低剂量组.结论:祛湿化瘀方防治实验性脂肪肝疗效显著.     

超微脂康饮对非酒精性脂肪性肝病大鼠模型的疗效

目的观察超微脂康饮对实验性非酒精性脂肪肝(NAFLD)大鼠模型的疗效。方法 SD大鼠高脂饮食饲养6周后诱导非酒精性脂肪肝大鼠模型,肝脏病理切片证实造模成功;造模大鼠50只随机分为5组,超微脂康饮(低、中、高剂量)组给予相应剂量的超微脂康饮灌胃,壳脂胶囊组给予壳脂胶囊混悬液,模型组及空白组灌服蒸馏水,除空白组外,其余组仍予高脂饮食。6周后分别检测各组的肝功能、血脂、肝脂及肝脏组织学改变。各组之间比较采用单因素方差分析。结果超微脂康饮各组血清ALT、AST、肝组织脂质(TC、TG)等方面均优于模型组,差异均有统计学意义(P值均0.05),超微脂康饮中,低剂量组血清TG、TC显著优于模型组,差异均有统计学意义(P值均0.05);超微脂康饮各组血清ALT、AST、肝组织TC与壳脂胶囊组比差差异无统计学意义(P值均0.05)。模型组及超微脂康饮各组均存在不同程度的肝脏炎症活动度,但与模型组比较,超微脂康饮各组、壳脂胶囊组大鼠的肝脏炎症活动度均有不同程度的改善(P值均0.05),而壳脂胶囊组较超微脂康饮各组改善稍明显(P值均0.05)。结论超微脂康饮能改善NAFLD大鼠肝功能、降低血脂、抑制肝脏炎症,整体疗效与壳脂胶囊相当,对非酒精性脂肪肝具有一定疗效。     

普罗布考和阿托伐他汀联合用药对高脂饮食自发性高血压大鼠肝脏的影响

目的 对普罗布考和阿托伐他汀联合用药对肝脏的安全性进行评价.方法 将92只雄性自发性高血压大鼠随机分为5组,对照组:普通饲料+生理盐水;高脂组:高脂饲料+生理盐水;普罗布考组:高脂饲料+普罗布考150 mg/(kg·d);阿托伐他汀组:高脂饲料+阿托伐他汀10 mg/(kg·d);联合用药组:高脂饲料+阿托伐他汀10 mg/(kg·d)+普罗布考150 mg/(kg·d),实验8周后处死.实验结束时抽血测血脂、高敏C-反应蛋白和肝功能,留肝脏标本行病理切片观察其脂肪变性及炎症程度.结果 ①高脂饮食各组总胆固醇和低密度脂蛋白胆固醇均高于对照组(P<0.01),而二药合用组较普罗布考组、阿托伐他汀组明显降低(P<0.05);②高脂组血清高敏C-反应蛋白、丙氨酸氨基转移酶和天门冬氨酸氨基转移酶水平较对照组明显升高(P<0.01),二药合用组明显低于高脂组和阿托伐他汀组(P<0.01);③高脂饮食各组均发生肝脏脂肪变性,高脂组最重,二药合用组较普罗布考组和阿托伐他汀组明显减轻(P<0.05);④肝脏炎性活动度评分二药合用组明显低于高脂组、阿托伐他汀组(P<0.01).结论 ①高脂饮食可引起血脂、炎症因子的紊乱,并可导致肝功能的损害和肝细胞脂肪变性及坏死;②普罗布考联合阿托伐他汀可减轻血脂和炎症因子的紊乱以及肝脏的脂肪变性和坏死程度,较二者单独用药效果更好;③二者联合用药可明显减轻高脂饮食引起的肝功能损害,且可减轻阿托伐他汀的肝毒性.     

罗格列酮对高脂饮食诱导非酒精性脂肪肝大鼠胰岛素抵抗及脂联素的影响

目的:探讨罗格列酮对高脂饮食所致的非酒精性脂肪肝大鼠模型胰岛素抵抗及脂联素的影响.方法:30只大鼠随机分为3组,即模型组(高脂饮食 蒸馏水ig),空白对照组(正常饲料 蒸馏水ig)和罗格列酮组[高脂饮食 罗格列酮3 mg/(kg·d)ig].观察各组血脂、肝功、胰岛素抵抗指数(HOMA-IR)的变化和各组肝组织HE染色与脂肪特异性的苏丹Ⅲ染色的变化.采用实时荧光定量聚合酶链式反应(PCR)和免疫印迹(western blot)检测各组肝组织的脂联素水平.结果:模型组与空白对照组相比,甘油三酯(TG)(1.51±0.37 mmol/L vs 0.98±0.51 mmol/L,P<0.01),总胆固醇(TC)(2.74±0.65 mmol/L vs 1.71±0.37 mmol/L,P<0.05),ALT(450.20±244.12 U/L vs 264.56±48.44 U/L,P<0.011,AST(460.30±310.13 U/L vs 196.11±52.23 U/L,P<0.01)和HOMA-IR(3.46±1.16 vs 1.07±0.26,P<0.01)均显著升高.罗格列酮治疗可使TG(1.27±0.50 mmol/L),ALT(360.26±244.37 U/L,AST(300.20±233.13 U/L)以及HOMR- IR(1.44±0.37)得到明显改善(均P<0.05).从组织病理学亦可得到证实.肝组织实时荧光定量PCR及免疫印迹显示罗格列酮组的Adiponectin mRNA(552.40±268.13 vs 215.95±135.87,P<0.05)和蛋白表达均较模型组升高.结论:高脂饮食可诱导大鼠NAFLD和IR发生,并使肝功,血脂异常升高.罗格列酮可以改善高脂饮食大鼠的脂肪肝及IR情况,可能与Adiponectin缓解IR和NAFLD改善有关.     

虎杖降脂颗粒对高脂血症大鼠降脂作用的研究

目的研究虎杖降脂颗粒对饮食性大鼠高脂血症的治疗作用。方法采用高脂性饮食诱导大鼠高脂血症,给予口服不同剂量的虎杖降脂颗粒,观察药物对模型动物血脂水平、体质量变化和肝脏脏器指数,肝脏脂质TC、TG,血清AST、ALT、肌酐和尿素氮以及肝脏组织形态的影响。结果虎杖降脂颗粒各剂量组大鼠肝指数及肝组织脂质TC和TG均明显下降(P0.05或P0.01);血清中TC、LDL-C、HDL-C含量不同程度地降低(P0.05或P0.01),但对TG作用不明显;血清AST、ALT有不同程度的降低(P0.05或P0.01),但对血清肌酐和尿素氮无明显作用。肝组织病理学结果表明,虎杖降脂颗粒各剂量组能不同程度地降低模型大鼠的肝脏脂肪变性程度。结论虎杖降脂颗粒可有效调节高脂乳剂所致高脂血症大鼠血脂和肝脂水平,对高脂血症具有较好的调脂作用。     

清肝化瘀颗粒对二乙基亚硝胺所致原发性肝癌大鼠的治疗作用

目的:研究清肝化瘀颗粒对二乙基亚硝胺(DEN)所致原发性肝癌大鼠的治疗作用。方法:将162只雄性SD大鼠随机平均分为模型组、肝复乐组、化疗药组及清肝化瘀颗粒低、中、高剂量组。应用DEN腹腔注射法制备原发性肝癌大鼠模型,分别给予生理盐水10 mL/(kg·d)灌胃,肝复乐组0.94 g/(kg·d)灌胃,氟尿嘧啶注射液50 mg/(kg·w)腹腔注射,清肝化瘀颗粒0.47、0.93、1.86 g/(kg·d)灌胃,连续给药8周。末次给药后各组随机选取6只大鼠解剖,观察肝脏成癌情况,检测血清肝功能。结果:清肝化瘀颗粒组大鼠的肝脏大体与病理组织学癌变程度均较模型组减轻明显;清肝化瘀颗粒组肝指数较模型组显著降低,中、高剂量组肝脏表面癌结节数显著低于模型组(P<0.05);清肝化瘀颗粒可显著降低血清TBIL、GGT、AFU水平(P<0.05或P<0.01),且中、高剂量组以及化疗药组分别具有显著降低血清ALP、AST水平的作用(P<0.05)。结论:清肝化瘀颗粒能够有效缓解DEN诱导原发性肝癌大鼠的肝损伤,改善其肝功能。     

赶黄草对大鼠酒精性脂肪肝的保护作用及机制

目的探讨赶黄草对大鼠酒精性脂肪肝的保护作用及机制。方法随机选择140例大鼠,喂以1.5%的硫酸亚铁饲料进行饲养,并进行灌胃乙醇制作酒精性脂肪肝大鼠模型。将所有大鼠随机分为正常对照组、模型组、赶黄草提取物高剂量、低剂量组、槲皮素高剂量、低剂量组、硫普罗宁组共七组,用药大鼠均灌胃给药,1次/d,连用6 w。计算肝脏系数,并行肝组织油红O染色,于光镜下观察肝脏脂肪浸润情况,对比肝细胞脂滴面积,并检测谷丙转氨酶(ALT)、谷草转氨酶(AST)、血清总胆固醇(TC)及甘油三酯(TG)含量。结果 1相比正常对照组,模型组大鼠反应迟钝,体重明显减轻,肝脏指数明显增加(P0.05);相比模型组,各用药组大鼠体重增加显著,肝脏指数明显下降(P0.05)。2油红O染色脂滴半定量分析后显示,赶黄草提取物各剂量组同模型组比较均有明显差异(P0.05)。3相比正常对照组,模型组血清ALT、AST、TC、TG水平均增加(P0.05);相比模型组,各用药组血清ALT、AST、TC、TG水平均降低(P0.05);相比槲皮素各组,赶黄草各提取物组ALT、AST、TC、TG水平均降低(P0.05)。结论赶黄草对大鼠酒精性脂肪肝有明显保护作用,与其中含有的槲皮素及其他化学成分有关。     

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.