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.     

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.     

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.     

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.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.