叔丁基羟基茴香醚对衰老大鼠肾脏缺血/再灌注损伤的保护作用

目的观察老年大鼠肾脏缺血／再灌注（I／R）模型中肾小管上皮细胞的损伤变化，探讨ROS清除剂对I／R损伤的保护作用。方法27月龄大鼠分别随机分为假手术组、I／R模型组、活性氧清除剂——叔丁基羟基茴香醚（BHA）干预组。夹闭双侧肾动脉30min再灌注18h制成I／R模型。观察肾功能、肾脏病理改变、肾小管上皮细胞凋亡情况，检测肾组织caspase-3，测定肾组织脂质过氧化物丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性。结果（1）肾脏I／R损伤时，老年大鼠肾功能明显减退，肾组织病理改变比较明显，大量肾小管上皮细胞凋亡，肾组织caspase-3、肾组织中MDA含量增加、SOD活性下降（P〈0．05）。（2）BHA能明显的改善肾功能、组织病理改变和凋亡相关指标（P〈0、05）；BHA能减少组织中MDA含量，部分恢复组织中SOD含量。结论老年大鼠肾脏I／R损伤时肾小管上皮细胞凋亡增加，肾功能减退。ROS堆积后，线粒体损伤导致肾小管上皮细胞凋亡。清除ROS可以抑制肾小管上皮细胞凋亡，减轻I／R损伤。     

维生素C、E对氟中毒大鼠不同组织抗氧化酶活性影响的研究

目的探讨氟中毒大鼠肝、肾、脑组织抗氧化酶类及脂质过氧化物的变化以及维生素 C、E 单独和联合干预以及不同剂量干预对高氟状态下大鼠抗氧化酶活性及脂质过氧化物的影响。方法将120只 Wistar 大鼠随机分为9绀,饮水染氟建立氟中毒大鼠模型,并灌胃给予维生素 C 和/或维生素 E;9月后处死大鼠取肝、肾、腑组织测定超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氧酶(CAT)活性和脂质过氧化物丙二醛(MDA)含量。结果染氟组大鼠肝、肾、脑组织 MDA 含量显著增加,肝和腑绀织 SOD、GSH-Px 和 CAT 活性以及肾组织 GSH-Px 活性均显著降低(P<0.05),而肾组织 SOD、CAT 活性无明显变化;维生素 C、E 可不同程度地增强 SOD、GSH-Px 和 CAT 活性,降低 MDA 水平;联合干预维生素 C、E 可明显拮抗氟诱导的脂质过氧化作用,显著增强大鼠肝组织 SOD、GSH-Px 和 CAT活性;维生素 C 低制量干预对肾脏 SOD 和 CAT 以及脑 GSH-Px 和 CAT 具有明显的保护作用;维生素 E 高剂量干预显著增加脑 SOD 活性。结论维生素 C 和维生素 E 在一定剂量范围内可有效拮抗过量氟导敛的脂质过氧化作用,对氟中毒大鼠肝、肾、脑组织有明显的保护作用。     

氟化钠对体外培养肾小管上皮细胞的毒性作用

目的观察氟对肾小管上皮细胞增殖活性的影响以及氟处理该细胞时其氧化应激水平是否发生变化.方法①原代肾小管上皮细胞的培养;②细胞增殖活性的检测采用四甲基偶氮唑蓝(MTT)法;③细胞氧化应激水平的检测脂质过氧化产物丙二醛(MDA)的测定用硫代巴比妥钠法;细胞超氧化物歧化酶(SOD)检测用邻苯三酚自氧化法;细胞过氧化氢酶(CAT)的检测用改良比色法.结果①在24 h时间段0.1～15mg/LF-组肾小管上皮细胞的增殖活性有不同程度的升高,在各时间段25 mg/LF-组的细胞增殖活性下降明显②在24 h时间段的MDA含量在1～15mg/LF-组肾小管上皮细胞呈下降趋势,在25mg/LF-组细胞MDA含量明显升高;在加氟培养48、72 h时间段表现为随着氟浓度的升高,细胞MDA含量先有显著的升高,而后又有下降趋势;③肾小管上皮细胞SOD酶活性在24、48 h时间段(除外1 mg/LF-L组)随着氟浓度的增加而有显著的升高,在加氟72 h时间段的SOD酶活性较24、48 h段上升幅度低;④肾小管上皮细胞(除外1mg/LF-组)CAT酶活性在5、1 5、25 mg/LF-组有显著的升高.结论低氟浓度、短时间作用下对细胞起促增殖作用,而高氟环境下和(或)长时间作用均可抑制细胞的分裂增殖;在短时间氟处理肾小管上皮细胞的抗氧化酶活性显著升高,细胞MDA含量呈下降趋势;而在氟处理长时间的情况下肾小管上皮细胞的SOD、CAT的酶活性较之相同投氟量投氟时间短的细胞明显下降.     

过量氟对大鼠肾组织碱性成纤维细胞生长因子表达的影响

目的检测成纤维细胞生长因子(bFGF)蛋白在氟处理大鼠肾组织表达差异和蛋白定位,并探讨bFGF与氟中毒肾损害的关系。方法经饮水投氟喂养W istar大鼠48只,用免疫组织化学法进行bFGF的组织学检测。结果免疫组织化学结果表明,bFGF蛋白主要定位于肾组织的肾小管上皮细胞细胞质中,常食和偏食对照组肾组织bFGF蛋白只是散在表达,而常食和偏食投氟组的bFGF蛋白表达较相应对照组明显增强。结论在肾组织中肾小管上皮细胞对氟的毒性作用更为敏感,过量氟可促进肾小管上皮细胞bFGF表达,且随着投氟量的增加bFGF伴随着肾损伤加重而表达增强,提示bFGF与氟中毒肾损伤程度密切相关。     

硒锗联合对氟致大鼠血清和肝肾抗氧化酶及钙镁元素变化的影响

目的研究硒锗联合作用对染氟大鼠血清、肝、肾中脂质过氧化物（MDA）水平和谷胱甘肽过氧化物酶（GSH-Px）活性及钙、镁的影响。方法给SD大鼠饮用含NaF（100mg／L）的蒸馏水90d，同时每天灌胃给予Na2seO30．1mg／kg和（或）锗-13210mg／kg。对大鼠血清、肝、肾组织中的GSH-Px活性、MDA、钙、镁水平进行测定。结果硒锗联合增加了GSH-Px活性，降低MDA水平；硒和（或）锗对氟诱导的大鼠血清、肝脏、肾脏中的钙水平降低具有明显抑制作用，硒锗联合对氟诱导的大鼠肝脏、肾脏中钙抑制作用强于单纯给予硒或锗；硒和（或）锗对氟诱导的大鼠血清、肾脏中的镁水平降低具有明显抑制作用，硒锗联合对氟诱导的大鼠肝脏的镁水平降低具有明显抑制作用。结论硒锗联合对氟毒性具有明显的拮抗作用，其机制与抗脂质过氧化作用有关；硒锗联合对氟诱导的大鼠钙镁变化的影响具有协同作用。     

Bcl-2在染氟大鼠肾小管上皮细胞氧化应激态中的表达

目的观察不同染氟(NaF,F-)条件下大鼠肾小管上皮细胞氧化应激能力变化及Bcl-2在氧化应激时的表达。方法采用体外原代细胞培养方法,相差显微镜观察大鼠肾小管上皮细胞形态结构变化;测定大鼠肾小管上皮细胞在染氟(F-)0.050、0.250、0.750、1.250mmol/L和不同氟暴露时间条件下,肾小管上皮细胞的增殖活性和丙二醛(MDA)水平、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性;利用半定量RT-PCR方法分析大鼠肾小管上皮细胞在氟暴露0.050～0.625mmol/L48hBcl-2的表达。结果相差显微镜下,染氟0.750、1.250mmol/L组部分肾小管上皮细胞缩为圆形和有细胞脱落现象。在24h,0.005mmol/L组(0.48±0.10)、0.025mmol/L组(0.46±0.12)、0.250mmol/L组(0.36±0.04)肾小管上皮细胞的增殖活性较对照组(0.29±0.09)有不同程度升高,但在72h,1.250mmol/L组(0.16±0.02)细胞的增殖活性明显降低。肾小管上皮细胞MDA水平在染氟48h内,0.25mmol/L组(626.15±124.02)、0.75mmol/L组(498.74±119.88)、1.250mmol/L组(441.99±53.57)与对照组(232.62±21.00)比较,升高显著;SOD酶活性在48h内,随着染氟量的增加而有升高,在0.750mmol/L组(1298.66±248.53)、1.250mmol/L组(1664.70±277.68),酶活性明显高于对照组(741.67±265.56);CAT酶活性,在0.7     

葡萄籽提取物对缺血再灌注导致衰老大鼠肾小管上皮细胞凋亡的保护作用

目的 探讨葡萄籽提取物(Grape seed extract proanthocyanidin,GSPE)对缺血再灌注(I/R)导致衰老大鼠肾小管上皮细胞凋亡的保护作用.方法 分离培养24月龄Wistar雄性大鼠的原代肾小管上皮细胞,第3代后,将细胞分为对照组、10 μmol/L Antimycin A处理组、GSPE干预组以及Antimysin A+GSPE 组.Anexin V/PI染色,流式细胞仪检测肾小管上皮细胞凋亡情况,定量PCR和Western印迹法分别检测Caspase-3mRNA和蛋白表达水平,化学发光法检测细胞Capsase-3活性及过氧化物丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性.激光共聚焦检测细胞内活性氧(ROS)的浓度.结果 (1)衰老大鼠肾小管细胞经Antimycin A处理后,凋亡率增高,Caspase-3,MDA,ROS明显增加,SOD下降;(2)经GSPE干预后,其凋亡情况明显好转,caspase-3、MDA、ROS明显降低.SOD含量部分恢复(P＜0.05).结论 老年大鼠肾小管细胞在I/R损伤时,ROS 堆积,线粒体损伤导致肾小管上皮细胞凋亡.GSPE可清除ROS从而达到抑制肾小管上皮细胞凋亡、减轻I/R损伤的作用.     

氟中毒大鼠肾组织抗氧化酶基因水平的变化

目的探讨氧化应激在慢性氟中毒大鼠肾脏损伤机制的作用。方法给大鼠饮水投氟3个月,通过生化技术测定血清中尿酸(UA)与脂质过氧化产物丙二醛(MDA)的含量及抗氧化酶超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的活力;抽提肾组织的总RNA并利用RT-PCR方法检测组织中GSH-Px、SOD、硫氧还蛋白(Trx)的mRNA表达水平。结果常食投氟组大鼠血清中GSH-Px、SOD及MDA含量均有不同程度升高,其中GSH-Px的升高有统计学意义(P<0.05),而低钙加氟组的血清MDA含量较之对照组明显升高;血清的尿酸含量在常食100 mg F-/L组和低钙100 mg F-/L组较之相应的对照组明显降低。常食投氟组肾组织的GSH-Px、SOD,Trx在mRNA水平上含量已有不同程度升高,SOD基因表达显著升高(P<0.05),偏食对照组大鼠肾组织SOD基因表达水平亦显著升高。结论一定浓度的氟刺激肾组织抗氧化酶基因的表达,与血清内抗氧化酶活性升高相一致;低钙协同氟的毒性作用,进一步加剧机体的氧化应激态,尿酸在拮抗氟引起的氧化应激中具有一定作用。     

氟对大鼠脂质过氧化和抗氧化能力的影响

目的 探讨氟对大鼠血和各组织丙二醛（MDA）水平、超氧化物歧化物（SOD）活力及全血谷胱苷肽过氧化物酶（GSH-Px）活力的影响。方法 运用动物实验,采用饮水加氟的方法。结果 染氟可使大鼠血清、肝脏、肾脏、脑中MDA含量显著增加;全血和肝脏、肾、心脏、睾丸的SOD活性显著降低;全血GSH-Px活性降低。结果 氟可促进机体脂质过氧化,抑制抗氧化酶（SOD,GSH-Px）的活力。     

过量氟对肾细胞内游离钙及钙泵的影响

目的探讨过量氟对肾细胞内游离钙([Ca2 ]i)及钙泵(Ca2 -ATPase)的影响及[Ca2 ]i在肾损害发生机制中的作用。方法应用饮水投氟方式喂养Wistar大鼠20周和原代培养肾小管上皮细胞染氟,采用生物化学方法检测血清内离子钙和总钙水平及肾细胞Ca2 -ATPase活性变化;使用Ca2 指示剂Fura-2测定肾细胞[Ca2 ]i。结果肾细胞[Ca2 ]i水平在常食投氟组和偏食投氟组较相应对照组明显增多;暴露于低钙高氟环境中的大鼠血清总钙降低,离子钙降低达到显著程度,该组肾细胞的钙泵(Ca2 -ATPase)活性比富钙投氟组明显低;低氟(1.0-5.0mg/L)处理肾小管上皮细胞钙泵活力明显增高,但随着氟水平的提高(>7．5mg／L),Ca2 -ATPase活力明显下降。结论高氟直接抑制钙泵活性很可能造成肾细胞内[Ca2 ]i潴留,而[Ca2 ]i升高很可能是过量氟导致肾损害的一种重要机制。     

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.