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Sample records for adult rat cardiomyocytes

  1. C-phycocyanin ameliorates doxorubicin-induced oxidative stress and apoptosis in adult rat cardiomyocytes.

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    Khan, Mahmood; Varadharaj, Saradhadevi; Shobha, Jagdish C; Naidu, Madireddi U; Parinandi, Narasimham L; Kutala, Vijay Kumar; Kuppusamy, Periannan

    2006-01-01

    Doxorubicin (DOX), a potent antineoplastic agent, poses limitations for its therapeutic use due to the associated risk of developing cardiomyopathy and congestive heart failure. The cardiotoxicity of doxorubicin is associated with oxidative stress and apoptosis. We have recently shown that Spirulina, a blue-green alga with potent antioxidant properties, offered significant protection against doxorubicin-induced cardiotoxicity in mice. The aim of the present study was to establish the possible protective role of C-phycocyanin, one of the active ingredients of Spirulina, against doxorubicin-induced oxidative stress and apoptosis. The study was carried out using cardiomyocytes isolated from adult rat hearts. Doxorubicin significantly enhanced the formation of reactive oxygen species (ROS) in cells as measured by the 2',7'-dichlorodihydrofluorescein diacetate and dihydroethidium fluorescence. The doxorubicin-induced reactive oxygen species formation was significantly attenuated in cells pretreated with C-phycocyanin. It was further observed that the doxorubicin-induced DNA fragmentation and apoptosis, as assayed by TUNEL assay and flow cytometry coupled with BrdU-FITC/propidium iodide staining, were markedly attenuated by C-phycocyanin. C-phycocyanin also significantly attenuated the doxorubicin-induced increase in the expression of Bax protein, release of cytochrome c, and increase in the activity of caspase-3 in cells. In summary, C-phycocyanin ameliorated doxorubicin-induced oxidative stress and apoptosis in cardiomyocytes. This study further supports the crucial role of the antioxidant nature of C-phycocyanin in its cardioprotection against doxorubicin-induced oxidative stress and apoptosis.

  2. The human adult cardiomyocyte phenotype

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    Bird, SD; Doevendans, PA; van Rooijen, MA; de la Riviere, AB; Hassink, RJ; Passier, R; Mummery, CL

    2003-01-01

    Aim: Determination of the phenotype of adult human atrial and ventricular myocytes based on gene expression and morphology. Methods: Atrial and ventricular cardiomyocytes were obtained from patients undergoing cardiac surgery using a modified isolation procedure. Myocytes were isolated and cultured

  3. Rat Cardiomyocytes Express a Classical Epithelial Beta-Defensin

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    Annika Linde

    2008-01-01

    Full Text Available Beta-defensins (BDs are classical epithelial antimicrobial peptides of immediate importance in innate host defense. Since recent studies have suggested that certain BDs are also expressed in non-traditional tissues, including whole heart homogenate and because effector molecules of innate immunity and inflammation can influence the development of certain cardiovascular disease processes, we hypothesized that BDs are produced by cardiomyocytes as a local measure of cardioprotection against danger signals. Here we report that at least one rat beta-defensin, rBD1, is expressed constitutively in cardiomyocytes specifically isolated using position-ablation-laser-microdissection (P.A.L.M. Microlaser Technologies. RT-PCR analysis showed expression of a single 318 bp transcript in adult rat heart (laser-excised cardiomyocytes and H9c2 cells (neonatal rat heart myoblasts. Moreover, the full length cDNA of rBD1 was established and translated into a putative peptide with 69 amino acid residues. The predicted amino acid sequence of the adult rat cardiac BD-1 peptide displayed 99% identity with the previously reported renal rBD1 and 88, 53, 53 and 50% identity with mouse, human, gorilla and rhesus monkey BD1 respectively. Furthermore, structural analysis of the cardiac rBD1 showed the classical six-cysteine conserved motif of the BD family with an alpha-helix and three beta-sheets. Additionally, rBD1 displayed a significantly greater number of amphoteric residues than any of the human analogs, indicating a strong pH functional dependence in the rat. We suggest that rBD1, which was initially believed to be a specific epithelium-derived peptide, may be also involved in local cardiac innate immune defense mechanisms.

  4. Ordered Assembly of the Adhesive and Electrochemical Connections within Newly Formed Intercalated Disks in Primary Cultures of Adult Rat Cardiomyocytes

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    Sarah B. Geisler

    2010-01-01

    Full Text Available The intercalated disk (ID is a complex structure that electromechanically couples adjoining cardiac myocytes into a functional syncitium. The integrity of the disk is essential for normal cardiac function, but how the diverse elements are assembled into a fully integrated structure is not well understood. In this study, we examined the assembly of new IDs in primary cultures of adult rat cardiac myocytes. From 2 to 5 days after dissociation, the cells flatten and spread, establishing new cell-cell contacts in a manner that recapitulates the in vivo processes that occur during heart development and myocardial remodeling. As cells make contact with their neighbors, transmembrane adhesion proteins localize along the line of apposition, concentrating at the sites of membrane attachment of the terminal sarcomeres. Cx43 gap junctions and ankyrin-G, an essential cytoskeletal component of voltage gated sodium channel complexes, were secondarily recruited to membrane domains involved in cell-cell contacts. The consistent order of the assembly process suggests that there are specific scaffolding requirements for integration of the mechanical and electrochemical elements of the disk. Defining the relationships that are the foundation of disk assembly has important implications for understanding the mechanical dysfunction and cardiac arrhythmias that accompany alterations of ID architecture.

  5. Activation of calcium-sensing receptor increases TRPC3 expression in rat cardiomyocytes

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    Feng, Shan-Li [Department of Clinical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086 (China); Sun, Ming-Rui [Department of Pharmacology, Qiqihaer Medical College, Qiqihaer 160001 (China); Li, Ting-Ting; Yin, Xin [Department of Clinical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086 (China); Xu, Chang-Qing [Department of Pathophysiology, Harbin Medical University, Harbin 150086 (China); Sun, Yi-Hua, E-mail: syh200415@126.com [Department of Clinical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086 (China)

    2011-03-11

    Research highlights: {yields} Calcium-sensing receptor (CaR) activation stimulates TRP channels. {yields} CaR promoted transient receptor potential C3 (TRPC3) expression. {yields} Adult rat ventricular myocytes display capacitative calcium entry (CCE), which was operated by TRPCs. {yields} TRPC channels activation induced by CaR activator sustained the increased [Ca{sup 2+}]{sub i} to evoke cardiomyocytes apoptosis. -- Abstract: Transient receptor potential (TRP) channels are expressed in cardiomyocytes, which gate a type of influx of extracellular calcium, the capacitative calcium entry. TRP channels play a role in mediating Ca{sup 2+} overload in the heart. Calcium-sensing receptors (CaR) are also expressed in rat cardiac tissue and promote the apoptosis of cardiomyocytes by Ca{sup 2+} overload. However, data about the link between CaR and TRP channels in rat heart are few. In this study, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting were used to examine the expression of the TRP canonical proteins TRPC1 and TRPC3 in adult and neonatal rat cardiomyocytes. Laser scan confocal microscopy was used to detect intracellular [Ca{sup 2+}]{sub i} levels in isolated adult rat ventricular myocytes. The results showed that, in adult rat cardiomyocytes, the depletion of Ca{sup 2+} stores in the endoplasmic/sarcoplasmic reticulum (ER/SR) by thapsigargin induced a transient increase in [Ca{sup 2+}]{sub i} in the absence of [Ca{sup 2+}]{sub o} and the subsequent restoration of [Ca{sup 2+}]{sub o} sustained the increased [Ca{sup 2+}]{sub i} for a few minutes, whereas, the persisting elevation of [Ca{sup 2+}]{sub i} was reduced in the presence of the TRPC inhibitor SKF96365. The stimulation of CaR by its activator gadolinium chloride (GdCl{sub 3}) or spermine also resulted in the same effect and the duration of [Ca{sup 2+}]{sub i} increase was also shortened in the absence of [Ca{sup 2+}]{sub o}. In adult and neonatal rat cardiomyocytes, GdCl{sub 3

  6. Antioxidant treatment attenuates hyperglycemia-induced cardiomyocyte death in rats.

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    Fiordaliso, Fabio; Bianchi, Roberto; Staszewsky, Lidia; Cuccovillo, Ivan; Doni, Mirko; Laragione, Teresa; Salio, Monica; Savino, Costanza; Melucci, Silvia; Santangelo, Francesco; Scanziani, Eugenio; Masson, Serge; Ghezzi, Pietro; Latini, Roberto

    2004-11-01

    Diabetes and oxidative stress concur to cardiac myocyte death in various experimental settings. We assessed whether N-acetyl-L-cysteine (NAC), an antioxidant and glutathione precursor, has a protective role in a rat model of streptozotocin (STZ)-induced diabetes and in isolated myocytes exposed to high glucose (HG). Diabetic rats were treated with NAC (0.5 g/kg per day) or vehicle for 3 months. At sacrifice left ventricle (LV) myocyte number and size, collagen deposition and reactive oxygen species (ROS) were measured by quantitative histological methods. Diabetes reduced LV myocyte number by 29% and increased myocyte volume by 20% compared to non-diabetic controls. NAC protected from myocyte loss (+25% vs. untreated diabetics, P < 0.05) and reduced reactive hypertrophy (-16% vs. untreated diabetics, P < 0.05). Perivascular fibrosis was high in diabetic rats (+88% vs. control, P < 0.001) but prevented by NAC. ROS production and fraction of ROS-positive cardiomyocyte nuclei were drastically raised in diabetic rats (2.4- and 5.1-fold vs. control, P < 0.001) and normalized by NAC. In separate experiments, isolated adult rat ventricular myocytes were incubated in a medium containing high concentrations of glucose (HG, 25 mM) +/- 0.01 mM NAC; myocyte survival (Trypan blue exclusion and apoptosis by TUNEL) and glutathione content were evaluated. The number of dead and apoptotic myocytes increased five and 6.7-fold in HG and glutathione decreased by 48% (P < 0.05). NAC normalized cell death and apoptosis and prevented glutathione loss. NAC effectively protects from hyperglycemia-induced myocyte cell death and compensatory hypertrophy through direct scavenging of ROS and replenishment of the intracellular glutathione content.

  7. Pharmacological and molecular characterization of functional P2 receptors in rat embryonic cardiomyocytes.

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    Cheung, Kwok-Kuen; Marques-da-Silva, Camila; Vairo, Leandro; dos Santos, Danúbia Silva; Goldenberg, Regina; Coutinho-Silva, Robson; Burnstock, Geoffrey

    2015-03-01

    Purinergic receptors activated by extracellular nucleotides (adenosine 5'-triphosphate (ATP) and uridine 5'-triphosphate (UTP)) are well known to exert physiological effects on the cardiovascular system, whether nucleotides participate functionally in embryonic heart development is not clear. The responsiveness of embryonic cardiomyocytes (E) 12 to P2 receptor agonists by measuring Ca(2+) influx did not present response to ATP, but responses to P2 agonists were detected in cardiomyocytes taken from E14 and E18 rats. Photometry revealed that the responses to ATP were concentration-dependent with an EC50 of 1.32 μM and 0.18 μM for E14 and E18 cardiomyocytes, respectively. In addition, other P2 agonists were also able to induce Ca(2+) mobilization. RT-PCR showed the presence of P2X2 and P2X4 receptor transcripts on E14 cardiomyocytes with a lower expression of P2X3 and P2X7 receptors. P2X1 and a low level of P2X5 receptor messenger RNA (mRNA) were also expressed at E18. Immunofluorescence data indicated that only P2X2 and P2X4 receptor proteins were expressed in E14 cardiomyocytes while protein for all the P2X receptor subtypes was expressed in E18, except for P2X3 and P2X6. Responses mediated by agonists specific for P2Y receptors subtypes showed that P2Y receptors (P2Y1, P2Y2, P2Y4 and P2Y6) were also present in both E14 and E18 cardiomyocytes. Dye transfer experiments showed that ATP induces coupling of cells at E12, but this response is decreased at E14 and lost at E18. Conversely, UTP induced coupling with five or more cells in most cells from E12 to E18. Our results show that specific P2 receptor subtypes are present in embryonic rat cardiomyocytes, including P2X7 and P2Y4 receptors that have not been identified in adult rat cardiomyocytes. The responsiveness to ATP stimulation even before birth, suggests that ATP may be an important messenger in embryonic as well as in adult hearts.

  8. Hypoxia reoxygenation induces premature senescence in neonatal SD rat cardiomyocytes

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    Feng-xiang ZHANG; Ming-long CHEN; Qi-jun SHAN; Jian-gang ZOU; Chun CHEN; Bing YANG; Dong-jie XU; Yu JIN; Ke-jiang CAO

    2007-01-01

    Aim: To investigate whether hypoxia reoxygenation induces premature senes-cence in neonatal Sprague-Dawley (SD) rat cardiomyocytes. Methods: Cardio-myocytes were isolated from neonatal SD rat heart and identified by immunohisto-chemistry. The control cultures were incubated at 37 ℃ in a humidified atmo-sphere of 5% CO and 95% air. The hypoxic cultures were incubated in a modular incubator chamber filled with 1% O2, 5% CO2, and balance N2 for 6 h. The reoxygen-ated cultures were subjected to 1% O2 and 5% CO2 for 6 h, then 21% oxygen for 4,8, 12, 24, and 48 h, respectively. Cell proliferation was determined using bromo-deoxyuridine labeling. The ultrastructure of cardiomyocytes was observed by using an electron microscope. Β-Galactosidase activity was determined by using a senescence β-galactosidase Staining Kit. P16INK4a and telomerase reverse tran-scriptase (TERT) mRNA levels were measured by real time quantitative PCR. TERT protein expression was determined by immunohistochemistry. Telomerase activi-ties were assayed by using the Telo TAGGG Telomerase PCR ELISApplus kit. Results:The initial cultures consisted of pure cardiomyocytes identified by immunohisto-chemistry. The proportion of BrdU positive cells was reduced significantly in the hypoxia reoxygenation-treated group (P<0.01). Under the condition of hypoxia reoxygenation, mitochondrial dehydration appeared; p16'INK4a and TERT mRNA levels, β-galactosidase activity, TERT protein expression and telomerase activi-ties were all significantly increased (P<0.01 or P<0.05). Conclusion: These data indicate that premature senescence could be induced in neonatal SD rat cardiomyo-cytes exposed to hypoxia reoxygenation. Although TERT significantly increased,it could not block senescence.

  9. Dedifferentiated fat cells convert to cardiomyocyte phenotype and repair infarcted cardiac tissue in rats.

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    Jumabay, Medet; Matsumoto, Taro; Yokoyama, Shin-ichiro; Kano, Koichiro; Kusumi, Yoshiaki; Masuko, Takayuki; Mitsumata, Masako; Saito, Satoshi; Hirayama, Atsushi; Mugishima, Hideo; Fukuda, Noboru

    2009-11-01

    Adipose tissue-derived stem cells have been demonstrated to differentiate into cardiomyocytes and vascular endothelial cells. Here we investigate whether mature adipocyte-derived dedifferentiated fat (DFAT) cells can differentiate to cardiomyocytes in vitro and in vivo by establishing DFAT cell lines via ceiling culture of mature adipocytes. DFAT cells were obtained by dedifferentiation of mature adipocytes from GFP-transgenic rats. We evaluated the differentiating ability of DFAT cells into cardiomyocytes by detection of the cardiac phenotype markers in immunocytochemical and RT-PCR analyses in vitro. We also examined effects of the transplantation of DFAT cells into the infarcted heart of rats on cardiomyocytes regeneration and angiogenesis. DFAT cells expressed cardiac phenotype markers when cocultured with cardiomyocytes and also when grown in MethoCult medium in the absence of cardiomyocytes, indicating that DFAT cells have the potential to differentiate to cardiomyocyte lineage. In a rat acute myocardial infarction model, transplanted DFAT cells were efficiently accumulated in infarcted myocardium and expressed cardiac sarcomeric actin at 8 weeks after the cell transplantation. The transplantation of DFAT cells significantly (pDFAT cells have the ability to differentiate to cardiomyocyte-like cells in vitro and in vivo. In addition, transplantation of DFAT cells led to neovascuralization in rats with myocardial infarction. We propose that DFAT cells represent a promising candidate cell source for cardiomyocyte regeneration in severe ischemic heart disease.

  10. EXPERIMENT STUDY OF CARDIOMYOCYTE APOPTOSIS AND CARDIOMYOCYTE PROLIFERATION DURING THE DEVELOPMENT OF CARDIAC HYPERTROPHY IN SPONTANEOUSLY HYPERTENSIVE RATS

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    江立生; 方宁远; 高天; 孟超

    2005-01-01

    Objective To investigate the effect and significance of cardiomyocyte apoptosis and cardiomyocyte proliferation on cardiac hypertrophy by observing the dynamic changes of them during the development of cardiac hypertrophy in spontaneously hypertensive rats (SHR). Methods Hearts were excised from SHR and Wistar-Kyoto rats(WKY) at different ages. Cardiac hypertrophic index (CHI) was calculated as the radio of heart weight to body weight; Cardiomyocyte apoptosis was identified by in situ TDT-mediated dUTP nick end labeling (TUNEL); Localization and expression of proliferating cell nuclear antigen (PCNA) were examined by immunohistochemistry. Results Compared with age-matched WKY, CHI in SHR was significantly increased at 12 weeks old and 24 weeks old (3. 604 ± 0. 089 vs 2. 997 ± 0. 166, P<0.01; 4. 156 ± 0. 385 vs 3. 119 ± 0. 208, P < 0. 01 ) ,and CHI in SHR was increased little by little with the age increasing and attained plaiform since 20 weeks old. In contrast with age-matched WKY, cardiomyocyte apoptotic index (APOI) in SHR at 12 weeks was not increased significantly (4. 248 ± 1. 592 vs 3. 678 ± 0. 856, P > 0. 05 ), but decreased markedly when their age were 24 weeks (3. 207 ± 1. 794 vs 5. 494 ± 1. 372, P <0. 05); APOI in SHR at 12 weeks old, 16 weeks old, 20 weeks old and 24weeks old were 4. 248 ± 1. 592, 5. 707 ± 1. 322, 7. 436 ± 1. 128, 3. 207 ± 1. 794, respectively. On the other hand,APOI in SHR from 12 weeks old to 20 weeks old increased gradually, and attained peak at 20 weeks old, but decreased markedly after 20 weeks old ( P <0. 01 ). Compared with age-matched WKY, the rate of cardiomyocyte PCNA positive labeling (PCNAR) in SHR at 12 weeks old and 24 weeks old didn' t have obvious difference. Conclusion Imbalance of cardiomyocyte apoptosis and cardiomyocyte proliferation existed during the development of cardiac hypertrophy in spontaneously hypertensive rats.

  11. Isolation and culture of cardiomyocytes in adult rat of heart failure and study of pathophysiological characteristics%心力衰竭大鼠心肌细胞的分离培养和病理生理特性研究

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    王彤; 万智; 黄辉; 符岳; 黄子通

    2008-01-01

    Objective To isolate and culture of cardiomyocytes in adult rat of heart failure and observe pathophysiological characteristics of single cardiomyocytes with a IonOptix TM system. Methods Opened chest of 5 rats and ligated the left anterior descending coronary artery (LAD). Four weeks later, finished echocardiographically measured ejection fraction (EF) , the heart was cut and hanged on to the Langendorff apparatus for perfusion and collagenase digestion. The single cardiomyocytes were cultured in serum -free medium with laminin - covered dishes. The morphological features of cardiomyocytes of heart failure rats were observed with microscope. With perfusion and field - stimulation (0.5 Hz ,3 ms) ,the cardiomyocytes contraction were simultaneously recorded by IonOptix TM and compared with the cardiomyocytes of 5 normal rats. Results There were obvious symptoms in heart failure rats. EF was significantly decreased in rats 4 weeks after LAD ligated[ (55 + 3 ) % vs (78 ± 4) %, P = 0. 00002 ]. The total of freshly isolated cardiomyocytes in heart failure rats was significantly lower than normal rats [ (5.6±0.3 )×106vs ( 8. 1±1. 2 ) × 106, P = 0. 0014 ]. Rodshaped cells in heart failure rats became longer significantly than rod - shaped cells in normal rats [ ( 152±19 )μm vs (133±17 )μm, P = 0.03 ]. The amplitude of shortening/relengthening and contractile velocity of these cells in heart failure rats was significantly lessen than these cells in normal rats [ ( 7.5±3.2 )% vs ( 13±3)%, P = 0.0016;(36±18)μm/ms vs (60±19)μm/ms, P =0.009]. Conclusion Compared with cardiomyocytes obtained from normal rats, cardiomyocytes obtained from heart failure rats have obvious pathophysiological characteristics. These data can describe the cell level change of myocardial dysfunction induced by different diseases and drugs treatment.%目的 分离培养心力衰竭(心衰)大鼠心肌细胞,以及利用IonOptix TM系统观察心衰大鼠离体心肌细胞的收缩舒张

  12. EGCG inhibits cardiomyocyte apoptosis in pressure overload-induced cardiac hypertrophy and protects cardiomyocytes from oxidative stress in rats

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    Rui SHENG; Zhen-lun GU; Mei-lin XIE; Wen-xuan ZHOU; Ci-yi GUO

    2007-01-01

    Aim: To investigate the effects of epigallocatechin gallate (EGCG) on pressure overload and hydrogen peroxide (H2O2) induced cardiac myocyte apoptosis. Methods: Cardiac hypertrophy was established in rats by abdominal aortic constriction. EGCG 25, 50 and 100 mg/kg were administered intragastrically (ig). Cultured newborn rat cardiomyocytes were preincubated with EGCG, and oxidative stress injury was induced by H2O2. Results: In cardiac hypertrophy induced by AC in rats, relative to the model group, EGCG 25, 50 and 100 mg/kg ig for 6weeks dose-dependently reduced systolic blood pressure (SBP) and heart weight indices, decreased malondialdehyde (MDA) content, and increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activity, both in serum and in the myocardium. Also, treatment with EGCG 50 and 100 mg/kg markedly improved cardiac structure and inhibited fibrosis in HE and van Gieson (VG) stain, and reduced apoptotic myocytes in the hypertrophic myocardium detected by terminal transferase-mediated dUTP-biotin nick end-labeling (TUNEL) assay. Inthe Western blot analysis, EGCG significantly inhibited pressure overload-inducedp53 increase and bcl-2 decrease. In H2O2-induced cardiomyocyte injury, when preincubated with myocytes for 6-48 h, EGCG 12.5-200 mg/L increased cell viability determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay. EGCG also attenuated H2O2-induced lactate dehydrogenase (LDH) release and MDA formation. Meanwhile, EGCG 50 and 100 mg/L significantly inhibited the cardiomyocyte apoptotic rate in flow cytometry. Conclusion: EGCG inhibits cardiac myocyte apoptosis and oxidative stress in pressure overload in-duced cardiac hypertrophy. Also, EGCG prevented cardiomyocyte apoptosis from oxidative stress in vitro. The mechanism might be related to the inhibitory effects of EGCG on p53 induction and bcl-2 decrease.

  13. The antiapoptotic effect of insulin against anoxia/reoxygenation injury in cultured cardiomyocyte of neonatal rat

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    2005-01-01

    Objective: To study protective effect of insulin against cardiomyocyte apoptosis in anoxia/reoxygenation (A/R)injury of neonatal rat. Methods: The model of A/R injury was finished through receiving anoxia for 2 h and reoxygenation for 4 h in cultured cardiomyocytes of neonatal rat. The cardiomyocytes were divided randomly into 3 groups: control group (CON), anoxia/reoxygenation group (A/R) and insulin-treated group (INS). At the end of reoxygenation of 4 hours, activities of lactate dehydrogenase (LDH),contents of malondialdehyde (MDA) were assessed through spectrophotometric procedures, myocyte apoptosis were detected through TUNEL and DNA Ladder. Results: MDA, LDH, and Apoptosis Index were significantly decreased in INS group compared with A/R group (P<0.01). Conclusion: Insulin has a protective effect against A/R injury in cultured cardiomyocyte of neonatal rat; the protective mechanism may contribute to antiapoptosis of insulin.

  14. Transplantation of neonatal cardiomyocytes plus fibrin sealant restores myocardial function in a rat model of myocardial infarction

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    LI Yong-shun; GAO Bing-ren

    2007-01-01

    Background Most cardiac regenerative approaches can restore injured heart muscles. In this study, we investigated if fibrin sealant could help neonatal cardiomyocytes restore myocardial function in a rat model of myocardial infarction.Methods The left anterior descending artery in adult female Sprague-Dawley (SD) rats was ligated to make a myocardial infarction model. Neonatal ventricular cardiomyocytes from one-day male SD rats were isolated, labeled and cultured. The cells were injected into the infarcted area three weeks later. The animals were randomized into four recipient groups: (1) cardiomyocytes plus fibrin sealant (group CF, n=10); (2) cardiomyocytes alone (group C, n=10); (3)fibrin sealant recipients alone (group F, n=10); (4) control group (n=10). Four weeks after transplantation,echocardiography and Langerdoff model were used to assess heart function. Immunohistochemical staining and polymerase chain reaction (PCR) were performed to track the implanted cardiomyocytes and detect the sex-determining region Y gene on Y chromosome.Results Echocardiography showed the fraction shortening (FS) in groups CF, C, F and control group was (27.80±6.32)%, (22.29±4.54)%, (19.24±6.29)% and (20.36±3.29)% respectively with statistically significant differences in group CF compared with the other groups (P<0.05). The Langendoff model revealed that the left ventricular development of peak pressure (LVDPmax, mmHg) in groups CF, C, F and control group was 104.81±17.05, 80.97±21.60, 72.07±26.17 and 71.42±17.55 respectively with statistically significant differences in group CF compared with the other groups (P<0.05). Pathological examination and PCR indicated that transplanted cardiomyocytes in group CF survived better than those in the other groups.Conclusion Transplanted neonatal cardiomyocytes plus fibrin sealant can survive in myocardial infarctioned area and improve heart function greatly in rat models.

  15. Antioxidant Effect of Selenium-containing Glutathione S-Transferase in Rat Cardiomyocytes

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    YIN Li; HAN Xiao; YU Yang; GUO Xiao; REN Li-qun; FANG Jing-qi; LIU Zhi-yi; YAN Gang-lin; WEI Jing-yan

    2012-01-01

    As one of the most important antioxidant enzymes,glutathione peroxidase(GPX) protects cells and tissues from oxidative damage,and plays an important role in cardiovascular and cerebrovascular injuries induced by oxidative stress.The antioxidant effect of selenium-containing glutathione S-transferase(Se-GST),a mimic of GPX was investigated on rat cardiomyocytes.To explore the protection function of Se-GST in hydrogen peroxide(H2O2) challenged rat cardiomyocytes,we examined malondialdehyde(MDA),lactate dehydrogenase(LDH),superoxide dismutase(SOD) and cell apoptosis.The results demonstrate exposure of rat cardiomyocytes to H2O2 for 6 and 12 h induced the significant increases of MDA,LDH and apoptosis rate of cardiomyocytes,but pretreatment of rat cardiomyocytes with Se-GST at 0.0005 or 0.001 unit/mL prevents oxidative stress induced by H2O2 with the decreases of cell apoptosis.All the results him Se-GST has antioxidant activity for oxidative stress challenged rat cardiomyocytes.

  16. [In vitro experimental study of rat cardiomyocyte injury with targeting of perfluorocarbon lipid particles].

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    He, Baiyong; Li, Zhaohuan; Tang, Hong; Li, Guohua; Chen, Song; Wang, Lian; Song, Haibo; Fang, Hua; Zeng, Jun

    2011-12-01

    The present study was to investigate in vitro the rat cardiomyocyte injury with targeting of home-made perfluorocarbon lipid particles with avidin-biotin interaction. Neonatal rat cardiomyocytes were cultured in vitro and divided into two groups: TNF-alpha activated group and non-activated group. Those in the TNF-alpha activated group were exposed to 200 ng/ml TNF-alpha solution for 6 hours and then cardiomyocytes in both groups were pretargeted with biotinylated ICAM-1 monoclonal antibodies, and were exposed to streptavidin, and then to homemade green fluorescently-labeled biotinylated perfluorocarbon lipid particles. Cardiomyocytes nucleus stained with Hoechst. The results were detected with fluorescence microscope. As a result, in TNF-alpha activated group, around blue fluorescent cardiomyocytes nucleus, a great amount of green fluorescent particles were found, while there were few green fluorescent particles in non-TNF activated group. It has been shown that ICAM-1 is expressed in the surface of cardiomyocytes when they are stimulated by TNF-alpha. Perfluorocarbon lipid particles associated with ICAM-1 monoclonal antibodies can be targeted to injured cardiomyocytes by avidin-biotin interaction.

  17. Dexamethasone Treatment of Newborn Rats Decreases Cardiomyocyte Endowment in the Developing Heart through Epigenetic Modifications.

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    Maresha S Gay

    Full Text Available The potential adverse effect of synthetic glucocorticoid, dexamethasone therapy on the developing heart remains unknown. The present study investigated the effects of dexamethasone on cardiomyocyte proliferation and binucleation in the developing heart of newborn rats and evaluated DNA methylation as a potential mechanism. Dexamethasone was administered intraperitoneally in a three day tapered dose on postnatal day 1 (P1, 2 and 3 to rat pups in the absence or presence of a glucocorticoid receptor antagonist Ru486, given 30 minutes prior to dexamethasone. Cardiomyocytes from P4, P7 or P14 animals were analyzed for proliferation, binucleation and cell number. Dexamethasone treatment significantly increased the percentage of binucleated cardiomyocytes in the hearts of P4 pups, decreased myocyte proliferation in P4 and P7 pups, reduced cardiomyocyte number and increased the heart to body weight ratio in P14 pups. Ru486 abrogated the effects of dexamethasone. In addition, 5-aza-2'-deoxycytidine (5-AZA blocked the effects of dexamethasone on binucleation in P4 animals and proliferation at P7, leading to recovered cardiomyocyte number in P14 hearts. 5-AZA alone promoted cardiomyocyte proliferation at P7 and resulted in a higher number of cardiomyocytes in P14 hearts. Dexamethasone significantly decreased cyclin D2, but not p27 expression in P4 hearts. 5-AZA inhibited global DNA methylation and blocked dexamethasone-mediated down-regulation of cyclin D2 in the heart of P4 pups. The findings suggest that dexamethasone acting on glucocorticoid receptors inhibits proliferation and stimulates premature terminal differentiation of cardiomyocytes in the developing heart via increased DNA methylation in a gene specific manner.

  18. Simvastatin inhibits leptin-induced hypertrophy in cultured neonatal rat cardiomyocytes

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    Tai-ping HU; Fang-ping XU; Yuan-jian LI; Jian-dong LUO

    2006-01-01

    Aim:To test the hypothesis that statins inhibit leptin-induced hypertrophy in cultured neonatal rat cardiomyocytes.Methods:Cultured neonatal rat cardiomyocytes were used to evaluate the effects of simvastatin on leptininduced hypertrophy.Intracellular reactive oxygen species (ROS) levels were determined by using 2',7'-dichlorofluorescein diacetate (DCF-DA) fluorescence.Total intracellular RNA and cell protein content,which serve as cell proliferative markers,were assayed by using propidium iodide (PI) fluorescence and the Bio-Rad DC protein assay.respectively.The cell surface area,an indicator of cell hypertrophy,was quantified by using Leica image analysis software.Results:After 72 h treatment,1eptin markedly increased RNA 1evels,cell surface area,and total cell protein levels in cardiomyocytes,which were significantly inhibited by simvastatin or catalase treatment.ROS levels were significantly elevated in cardiomyocytes treated with leptin for 4 h compared with those cells without leptin treatment.The increase in ROS levels in cardiomyocytes induced by leptin was reversed by treatment with simvastatin and catalase.Conclusion:Simvastatin inhibits leptin-induced ROS-mediated hyperophy in cultured neonatal rat cardiac myocytes.Statin therapy may provide an effective means of improving cardiac dysfunction in obese humans.

  19. Safflor yellow A protects neonatal rat cardiomyocytes against anoxia/reoxygenation injury in vitro

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    Jia-lin DUAN; Jing-wen WANG; Yue GUAN; Ying YIN; Guo WEI; Jia CUI; Dan ZHOU

    2013-01-01

    Aim:To investigate the effects of safflor yellow A (SYA),a flavonoid extracted from Carthamus tinctorius L,on cultured rat cardiomyocytes exposed to anoxia/reoxygenation (A/R).Methods:Primary cultured neonatal rat cardiomyocytes were exposed to anoxia for 3 h followed by reoxygenation for 6 h.The cell viability was measured using MTT assay.The releases of lactate dehydrogenase (LDH) and creatine kinase (CK),level of malondialdehyde (MDA),and activities of glutathione (GSH),superoxide dismutase (SOD),catalase (CAT) and glutathione peroxidase (GSH-Px) were analyzed.Hoechst 33258 staining and changes in Bcl-2/Bax ratio and caspase 3 activity were used to examine A/R-induced apoptosis.Results:The A/R exposure markedly decreased the viability of cardiomyocytes,suppressed the activities of SOD,GSH,CAT and GSH-Px,and Bcl-2 protein expression.Meanwhile,the A/R exposure markedly increased the release of LDH and CK,and MDA production in the cardiomyocytes,and increased the rate of apoptosis,caspase 3 activity,Bax protein expression.Pretreatment with SYA (40,60 and 80 nmol/L) concentration-dependently blocked the A/R-induced changes in the cardiomyocytes.Pretreatment of the cardiomyocytes with the antioxidant N-acetylcysteine (NAC,200 μmol/L) produced protective effects that were comparable to those caused by SYA (80nmol/L).Conclusion:SYA protects cultured rat cardiomyocytes against A/R injury,maybe via inhibiting cellular oxidative stress and apoptosis.

  20. Dietary levels of acrylamide affect rat cardiomyocyte properties.

    Science.gov (United States)

    Walters, Brandan; Hariharan, Venkatesh; Huang, Hayden

    2014-09-01

    The toxic effects of acrylamide on cytoskeletal integrity and ion channel balance is well-established in many cell types, but there has been little examination regarding the effects of acrylamide on primary cardiomyocytes, despite the importance of such components in their function. Furthermore, acrylamide toxicity is generally examined using concentrations higher than those found in vivo under starch-rich diets. Accordingly, we sought to characterize the dose-dependent effects of acrylamide on various properties, including cell morphology, contraction patterns, and junctional connexin 43 staining, in primary cardiomyocytes. We show that several days exposure to 1-100 μM acrylamide resulted in altered morphology, irregular contraction patterns, and an increase in the amount of immunoreactive signal for connexin 43 at cell junctions. We conclude that dietary levels of acrylamide may alter cellular function with prolonged exposure, in primary cardiomyocytes.

  1. Cytoprotective Effect of Silymarin against Diabetes-Induced Cardiomyocyte Apoptosis in Diabetic Rats

    Institute of Scientific and Technical Information of China (English)

    Muobarak J Tuorkey; Nabila I El-Desouki; Rabab A Kamel

    2015-01-01

    Objective The beneficial effects of silymarin have been extensively studied in the context of inflammation and cancer treatment, yet much less is known about its therapeutic effect on diabetes. The present study was aimed to investigate the cytoprotective activity of silymarin against diabetes-induced cardiomyocyte apoptosis. Methods Rats were randomly divided into: control group, untreated diabetes group and diabetes group treated with silymarin (120 mg/kg·d) for 10 d. Rats were sacrificed, and the cardiac muscle specimens and blood samples were collected. The immunoreactivity of caspase-3 and Bcl-2 in the cardiomyocytes was measured. Total proteins, glucose, insulin, creatinine, AST, ALT, cholesterol, and triglycerides levels were estimated. Results Unlike the treated diabetes group, cardiomyocyte apoptosis increased in the untreated rats, as evidenced by enhanced caspase-3 and declined Bcl-2 activities. The levels of glucose, creatinine, AST, ALT, cholesterol, and triglycerides declined in the treated rats. The declined levels of insulin were enhanced again after treatment of diabetic rats with silymarin, reflecting a restoration of the pancreaticβ-cells activity. Conclusion The findings of this study are of great importance, which confirmed for the first time that treatment of diabetic subjects with silymarin may protect cardiomyocytes against apoptosis and promote survival-restoration of the pancreaticβ-cells.

  2. Autoantibody against Cardiac β1-Adrenoceptor Induces Apoptosis in Cultured Neonatal Rat Cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    Yan GAO; Hui-Rong LIU; Rong-Rui ZHAO; Jian-Ming ZHI

    2006-01-01

    To clarify whether apoptosis is involved in the injury processes induced by autoantibody against cardiac β1-adrenoceptor, we investigated the biological and apoptotic effects of antibodies on cultured neonatal rat cardiomyocytes. Wistar rats were immunized with peptides corresponding to the second extracellular loop of the β1-adrenoceptor to induce the production of anti-β1-adrenoceptor antibodies in the sera.Immunoglobulin (Ig) G in the sera was detected using synthetic antigen enzyme-linked immunosorbent assay and purified using the diethylaminoethyl cellulose ion exchange technique. Apoptosis of cardiomyocytes was evaluated using agarose gel electrophoresis and flow cytometry. Our results showed that the positive serum IgG greatly increased the beating rates of cardiomyocytes and showed an "agonist-like" activity. Furthermore, positive serum IgG induced cardiomyocyte apoptosis after treatment with β1adrenoceptor overstimulation for 48 h. The effects of monoclonal antibody against β1-adrenoceptor were also found to be similar to those of positive serum IgG. It was suggested that the autoantibody could induce cardiomyocyte apoptosis by excessive stimulation of β1-adrenoceptor.

  3. Uptake of triiodothyronine and triiodothyroacetic acid in neonatal rat cardiomyocytes: effects of metabolites and analogs

    NARCIS (Netherlands)

    F.A. Verhoeven; H.H. van der Putten; G. Hennemann; J.M.J. Lamers (Jos); T.J. Visser (Theo); M.E. Everts (Maria)

    2002-01-01

    textabstractCellular and nuclear uptake of [125I]tri-iodothyronine (T3) and [125I]triiodothyroacetic acid (Triac) were compared in cardiomyocytes of 2-3 day old rats, and the effect of thyroid hormone analogs on cellular T(3) uptake was measured. Cells (5-10 x 10(5) per well) were

  4. Inhibitory effects of calcium channel blockers on thyroid hormone uptake in neonatal rat cardiomyocytes

    NARCIS (Netherlands)

    F.A. Verhoeven; E.P.C.M. Moerings (Ellis); J.M.J. Lamers (Jos); G. Hennemann; T.J. Visser (Theo); M.E. Everts (Maria)

    2001-01-01

    textabstractThe effects of the Ca2+ channel blockers verapamil, nifedipine, and diltiazem on triiodothyronine (T3) and thyroxine (T4) uptake were tested in cultured cardiomyocytes from 2-day-old rats. Experiments were performed at 37 degrees C in medium with 0.5% BSA for [125I]T3 (

  5. Vanadate induces necrotic death in neonatal rat cardiomyocytes through mitochondrial membrane depolarization.

    Science.gov (United States)

    Soares, Sandra Sofia; Henao, Fernando; Aureliano, Manuel; Gutiérrez-Merino, Carlos

    2008-03-01

    Besides the well-known inotropic effects of vanadium in cardiac muscle, previous studies have shown that vanadate can stimulate cell growth or induce cell death. In this work, we studied the toxicity to neonatal rat ventricular myocytes (cardiomyocytes) of two vanadate solutions containing different oligovanadates distribution, decavanadate (containing decameric vanadate, V 10) and metavanadate (containing monomeric vanadate and also di-, tetra-, and pentavanadate). Incubation for 24 h with decavanadate or metavanadate induced necrotic cell death of cardiomyocytes, without significant caspase-3 activation. Only 10 microM total vanadium of either decavanadate (1 microM V 10) or metavanadate (10 microM total vanadium) was needed to produce 50% loss of cell viability after 24 h (assessed with MTT and propidium iodide assays). Atomic absorption spectroscopy showed that vanadium accumulation in cardiomyocytes after 24 h was the same when incubation was done with decavanadate or metavanadate. A decrease of 75% of the rate of mitochondrial superoxide anion generation, monitored with dihydroethidium, and a sustained rise of cytosolic calcium (monitored with Fura-2-loaded cardiomyocytes) was observed after 24 h of incubation of cardiomyocytes with decavanadate or metavanadate concentrations close to those inducing 50% loss of cell viability produced. In addition, mitochondrial membrane depolarization within cardiomyocytes, monitored with tetramethylrhodamine ethyl esther or with 3,3',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide, were observed after only 6 h of incubation with decavanadate or metavanadate. The concentration needed for 50% mitochondrial depolarization was 6.5 +/- 1 microM total vanadium for both decavanadate (0.65 microM V 10) and metavanadate. In conclusion, mitochondrial membrane depolarization was an early event in decavanadate- and monovanadate-induced necrotic cell death of cardiomyocytes.

  6. RAGE modulates hypoxia/reoxygenation injury in adult murine cardiomyocytes via JNK and GSK-3beta signaling pathways.

    Directory of Open Access Journals (Sweden)

    Linshan Shang

    Full Text Available BACKGROUND: Advanced glycation end-products (AGEs have been implicated in diverse pathological settings including diabetes, inflammation and acute ischemia/reperfusion injury in the heart. AGEs interact with the receptor for AGEs (RAGE and transduce signals through activation of MAPKs and proapoptotic pathways. In the current study, adult cardiomyocytes were studied in an in vitro ischemia/reperfusion (I/R injury model to delineate the molecular mechanisms underlying RAGE-mediated injury due to hypoxia/reoxygenation (H/R. METHODOLOGY/PRINCIPAL FINDINGS: Cardiomyocytes isolated from adult wild-type (WT, homozygous RAGE-null (RKO, and WT mice treated with soluble RAGE (sRAGE were subjected to hypoxia for 30 minutes alone or followed by reoxygenation for 1 hour. In specific experiments, RAGE ligand carboxymethyllysine (CML-AGE (termed "CML" in this manuscript was evaluated in vitro. LDH, a marker of cellular injury, was assayed in the supernatant in the presence or absence of signaling inhibitor-treated cardiomyocytes. Cardiomyocyte levels of heterogeneous AGEs were measured using ELISA. A pronounced increase in RAGE expression along with AGEs was observed in H/R vs. normoxia in WT cardiomyocytes. WT cardiomyocytes after H/R displayed increased LDH release compared to RKO or sRAGE-treated cardiomyocytes. Our results revealed significant increases in phospho-JNK in WT cardiomyocytes after H/R. In contrast, neither RKO nor sRAGE-treated cardiomyocytes exhibited increased phosphorylation of JNK after H/R stress. The impact of RAGE deletion on GSK-3beta phosphorylation in the cardiomyocytes subjected to H/R revealed significantly higher levels of phospho-GSK-3beta/total GSK-3beta in RKO, as well as in sRAGE-treated cardiomyocytes versus WT cardiomyocytes after H/R. Further investigation established a key role for Akt, which functions upstream of GSK-3beta, in modulating H/R injury in adult cardiomyocytes. CONCLUSIONS/SIGNIFICANCE: These data illustrate

  7. Reciprocal regulation of transcription factors and PLC isozyme gene expression in adult cardiomyocytes.

    Science.gov (United States)

    Singal, Tushi; Dhalla, Naranjan S; Tappia, Paramjit S

    2010-06-01

    By employing a pharmacological approach, we have shown that phospholipase C (PLC) activity is involved in the regulation of gene expression of transcription factors such as c-Fos and c-Jun in cardiomyocytes in response to norepinephrine (NE). However, there is no information available regarding the identity of specific PLC isozymes involved in the regulation of c-Fos and c-Jun or on the involvement of these transcription factors in PLC isozyme gene expression in adult cardiomyocytes. In this study, transfection of cardiomyocytes with PLC isozyme specific siRNA was found to prevent the NE-mediated increases in the corresponding PLC isozyme gene expression, protein content and activity. Unlike PLC gamma(1) gene, silencing of PLC beta(1), beta(3) and delta(1) genes with si RNA prevented the increases in c-Fos and c-Jun gene expression in response to NE. On the other hand, transfection with c-Jun si RNA suppressed the NE-induced increase in c-Jun as well as PLC beta(1), beta(3) and delta(1) gene expression, but had no effect on PLC gamma(1) gene expression. Although transfection of cardiomyocytes with c-Fos si RNA prevented NE-induced expression of c-Fos, PLC beta(1) and PLC beta(3) genes, it did not affect the increases in PLC delta(1) and PLC gamma(1) gene expression. Silencing of either c-Fos or c-Jun also depressed the NE-mediated increases in PLC beta(1), beta(3) and gamma(1) protein content and activity in an isozyme specific manner. Furthermore, silencing of all PLC isozymes as well as of c-Fos and c-Jun resulted in prevention of the NE-mediated increase in atrial natriuretic factor gene expression. These findings, by employing gene silencing techniques, demonstrate that there occurs a reciprocal regulation of transcription factors and specific PLC isozyme gene expression in cardiomyocytes.

  8. Computational tool for morphological analysis of cultured neonatal rat cardiomyocytes.

    Science.gov (United States)

    Leite, Maria Ruth C R; Cestari, Idágene A; Cestari, Ismar N

    2015-08-01

    This study describes the development and evaluation of a semiautomatic myocyte edge-detector using digital image processing. The algorithm was developed in Matlab 6.0 using the SDC Morphology Toolbox. Its conceptual basis is the mathematical morphology theory together with the watershed and Euclidean distance transformations. The algorithm enables the user to select cells within an image for automatic detection of their borders and calculation of their surface areas; these areas are determined by adding the pixels within each myocyte's boundaries. The algorithm was applied to images of cultured ventricular myocytes from neonatal rats. The edge-detector allowed the identification and quantification of morphometric alterations in cultured isolated myocytes induced by 72 hours of exposure to a hypertrophic agent (50 μM phenylephrine). There was a significant increase in the mean surface area of the phenylephrine-treated cells compared with the control cells (p<;0.05), corresponding to cellular hypertrophy of approximately 50%. In conclusion, this edge-detector provides a rapid, repeatable and accurate measurement of cell surface areas in a standardized manner. Other possible applications include morphologic measurement of other types of cultured cells and analysis of time-related morphometric changes in adult cardiac myocytes.

  9. Cardiomyocyte proliferation and progenitor cell recruitment underlie therapeutic regeneration after myocardial infarction in the adult mouse heart.

    Science.gov (United States)

    Malliaras, Konstantinos; Zhang, Yiqiang; Seinfeld, Jeffrey; Galang, Giselle; Tseliou, Eleni; Cheng, Ke; Sun, Baiming; Aminzadeh, Mohammad; Marbán, Eduardo

    2013-02-01

    Cardiosphere-derived cells (CDCs) have been shown to regenerate infarcted myocardium in patients after myocardial infarction (MI). However, whether the cells of the newly formed myocardium originate from the proliferation of adult cardiomyocytes or from the differentiation of endogenous stem cells remains unknown. Using genetic fate mapping to mark resident myocytes in combination with long-term BrdU pulsing, we investigated the origins of postnatal cardiomyogenesis in the normal, infarcted and cell-treated adult mammalian heart. In the normal mouse heart, cardiomyocyte turnover occurs predominantly through proliferation of resident cardiomyocytes at a rate of ∼1.3-4%/year. After MI, new cardiomyocytes arise from both progenitors as well as pre-existing cardiomyocytes. Transplantation of CDCs upregulates host cardiomyocyte cycling and recruitment of endogenous progenitors, while boosting heart function and increasing viable myocardium. The observed phenomena cannot be explained by cardiomyocyte polyploidization, bi/multinucleation, cell fusion or DNA repair. Thus, CDCs induce myocardial regeneration by differentially upregulating two mechanisms of endogenous cell proliferation.

  10. Experimental research on recombinant human endostatin-induced cardiomyocyte apoptosis in rats

    Directory of Open Access Journals (Sweden)

    Jing QIN

    2014-03-01

    Full Text Available Objective To explore the recombinant human endostatin (rh-ES-induced cardiotoxicity in rats and its mechanism. Methods Twenty four female Wistar rats were randomly divided into four groups (6 each. Rats in low, moderate and high dose group received rh-ES with a dosage of 3, 6 and 12mg/(kg·d, respectively, by intraperitoneal injection, and rats in control group received the same amount of normal saline alone. Half of rats in each group were sacrificed by spinal dislocation after 4 weeks and 8 weeks of the treatment. Pathomorphologic and ultrastructural changes in rat's myocardial tissue were evaluated by light microscopy and transmission electron microscopy. Cardiomyocyte apoptosis was detected with TdT-mediated dUTP nick end labeling (TUNEL assay. Microvessel density (MVD in myocardial tissue was measured by immunohistochemically marking endothelial cell with CD34. Results No pathomorphologic and ultrastrucural changes were found under light microscope and transmission electron microscope in the low dose and moderate dose groups, but cardiomyocyte damage were found in the high dose group. TUNEL assay revealed more apoptotic cells in high and moderate (only 8 weeks dose groups than in control group (P=0.033, P=0.000, and the apoptosis index was highest in the high dose group at 8 weeks. In addition, compared with the control group, MVD significantly increased in high dose groups at 4 weeks and 8 weeks (P<0.05. Conclusions rh-ES induces the cardiotoxicity in rats, and cardiomyocyte apoptosis is involved in the pathological course of cardiac toxicity. DOI: 10.11855/j.issn.0577-7402.2014.01.02

  11. In vitro differentiation of rat embryonic stem cells into functional cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    Nan Cao; Jing Liao; Zumei Liu; Wen min Zhu; Jia Wang; Lijun Liu; Lili Yu

    2011-01-01

    The recent breakthrough in the generation of rat embryonic stem cells (rESCs) opens the door to application of gene targeting to create models for the study of human diseases.In addition,the in vitro differentiation system from rESCs into derivatives of three germ layers will serve as a powerful tool and resource for the investigation of mammalian development,cell function,tissue repair,and drug discovery.However,these uses have been limited by the difficulty of in vitro differentiation.The aims of this study were to establish an in vitro differentiation system from rESCs and to investigate whether rESCs are capable of forming terminal-differentiated cardiomyocytes.Using newly established rESCs,we found that embryoid body (EB)-based method used in mouse ESC (mESC) differentiation failed to work for the serum-free cultivated rESCs.We then developed a protocol by combination of three chemical inhibitors and feeder-conditioned medium.Under this condition,rESCs formed EBs,propagated and differentiated into three embryonic germ layers.Moreover,rESC-formed EBs could differentiate into spontaneously beating cardiomyocytes after plating.Analyses of molecular,structural,and functional properties revealed that rESC-derived cardiomyocytes were similar to those derived from fetal rat hearts and mESCs.In conclusion,we successfully developed an in vitro differentiation system for rESCs through which functional myocytes were generated and displayed phenotypes of rat fetal cardiomyocytes.This unique cellular system will provide a new approach to study the early development and cardiac function,and serve as an important tool in pharmacological testing and cell therapy.

  12. Antifungal miconazole induces cardiotoxicity via inhibition of APE/Ref-1-related pathway in rat neonatal cardiomyocytes.

    Science.gov (United States)

    Won, Kyung-Jong; Lin, Hai Yue; Jung, Soohyun; Cho, Soo Min; Shin, Ho-Chul; Bae, Young Min; Lee, Seung Hyun; Kim, Hyun-Jung; Jeon, Byeong Hwa; Kim, Bokyung

    2012-04-01

    Effects of miconazole, an azole antifungal, have not been fully determined in cardiomyocytes. We therefore identified the transcriptome in neonatal rat cardiomyocytes responding to miconazole using DNA microarray analysis and selected a gene and investigated its role in cardiomyocytes. Miconazole dose-dependently increased the levels of superoxide (O(2)(-)) and apoptosis in cardiomyocytes; these increases were inhibited by treatment with antioxidants. The DNA microarray revealed that 4163 genes were upregulated and 4829 genes downregulated by more than threefold in miconazole-treated cardiomyocytes compared with the vehicle-treated control. Moreover, redox homeostasis-, oxidative stress-, and reactive oxygen species (ROS)-related categories of genes were strongly affected by miconazole treatment. Among genes overlapped in all these categories, apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE/Ref-1), a redox-related gene, was prominent and was diminished in the miconazole-treated group. Changes in the O(2)(-) production and apoptosis induction in response to miconazole were inhibited in cardiomyocytes transfected with adenoviral APE/Ref-1. Overexpression of APE/Ref-1 reversed the reduction in beating frequency induced by miconazole. Our results demonstrate that miconazole may induce rat cardiotoxicity via a ROS-mediated pathway, which is initiated by the inhibition of APE/Ref-1 expression. This possible new adverse event in cardiomyocyte function caused by miconazole may provide a basis for the development of novel antifungal agents.

  13. Temporal changes in integrin-mediated cardiomyocyte adhesion secondary to chronic cardiac volume overload in rats

    Science.gov (United States)

    Stewart, James A.; Gardner, Jason D.; Brower, Gregory L.

    2013-01-01

    Previous studies have established integrins as cell surface receptors that mediate cardiomyocyte-extracellular matrix (ECM) attachments. This study sought to determine the contributions of the myocardial β1- and β3-integrin subunits to ventricular dilatation and coronary flow regulation using a blood-perfused isolated heart preparation. Furthermore, cardiomyocyte adhesion to collagen types I and IV, fibronectin, and laminin with and without a β1-integrin subunit neutralizing antibody was assessed during the course of remodeling secondary to a sustained cardiac volume overload, including the onset of heart failure. Isolated cardiomyocytes were obtained during the initial, compensated, and decompensated phases of remodeling resulting from an aortocaval fistula created in 8-wk-old male Sprague-Dawley rats. Blocking the β1-integrin subunit in isolated normal hearts produced ventricular dilatation, whereas this was not the case when the β3-subunit was blocked. Substantial reductions in cardiomyocyte adhesion coincided with the previously documented development of ventricular dilatation and decreased contractility postfistula, with the β1-integrin contribution to adhesion ranging from 28% to 73% over the course of remodeling being essentially substrate independent. In contrast, both integrin subunits were found to be involved in regulating coronary vascular resistance. It is concluded that marked reductions in integrin-mediated cardiomyocyte adhesion to the ECM play a significant role in the progression of adverse myocardial remodeling that leads to heart failure. Furthermore, although both the β1- and β3-integrin subunits were involved in regulating coronary vascular resistance, only inhibition of β1-integrin-mediated adhesion resulted in ventricular dilatation of the normal heart. PMID:24163072

  14. Hybrid mathematical model of cardiomyocyte turnover in the adult human heart.

    Directory of Open Access Journals (Sweden)

    Jeremy A Elser

    Full Text Available RATIONALE: The capacity for cardiomyocyte regeneration in the healthy adult human heart is fundamentally relevant for both myocardial homeostasis and cardiomyopathy therapeutics. However, estimates of cardiomyocyte turnover rates conflict greatly, with a study employing C14 pulse-chase methodology concluding 1% annual turnover in youth declining to 0.5% with aging and another using cell population dynamics indicating substantial, age-increasing turnover (4% increasing to 20%. OBJECTIVE: Create a hybrid mathematical model to critically examine rates of cardiomyocyte turnover derived from alternative methodologies. METHODS AND RESULTS: Examined in isolation, the cell population analysis exhibited severe sensitivity to a stem cell expansion exponent (20% variation causing 2-fold turnover change and apoptosis rate. Similarly, the pulse-chase model was acutely sensitive to assumptions of instantaneous incorporation of atmospheric C14 into the body (4-fold impact on turnover in young subjects while numerical restrictions precluded otherwise viable solutions. Incorporating considerations of primary variable sensitivity and controversial model assumptions, an unbiased numerical solver identified a scenario of significant, age-increasing turnover (4-6% increasing to 15-22% with age that was compatible with data from both studies, provided that successive generations of cardiomyocytes experienced higher attrition rates than predecessors. CONCLUSIONS: Assignment of histologically-observed stem/progenitor cells into discrete regenerative phenotypes in the cell population model strongly influenced turnover dynamics without being directly testable. Alternatively, C14 trafficking assumptions and restrictive models in the pulse-chase model artificially eliminated high-turnover solutions. Nevertheless, discrepancies among recent cell turnover estimates can be explained and reconciled. The hybrid mathematical model provided herein permits further examination of

  15. EPA or DHA supplementation increases triacylglycerol, but not phospholipid, levels in isolated rat cardiomyocytes.

    Science.gov (United States)

    Righi, Valeria; Di Nunzio, Mattia; Danesi, Francesca; Schenetti, Luisa; Mucci, Adele; Boschetti, Elisa; Biagi, Pierluigi; Bonora, Sergio; Tugnoli, Vitaliano; Bordoni, Alessandra

    2011-07-01

    It is well recognized that a high dietary intake of long-chain polyunsaturated fatty acids (LC-PUFA) has profound benefits on health and prevention of chronic diseases. In particular, in recent years there has been a dramatic surge of interest in the health effects of n-3 LC-PUFA derived from fish, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Notwithstanding, the metabolic fate and the effects of these fatty acids once inside the cell has seldom been comprehensively investigated. Using cultured neonatal rat cardiomyocytes as model system we have investigated for the first time, by means of high-resolution magic-angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy in combination with gas chromatography (GC), the modification occurring in the cell lipid environment after EPA and DHA supplementation. The most important difference between control and n-3 LC-PUFA-supplemented cardiomyocytes highlighted by HR-MAS NMR spectroscopy is the increase of signals from mobile lipids, identified as triacylglycerols (TAG). The observed increase of mobile TAG is a metabolic response to n-3 LC-PUFA supplementation, which leads to an increased lipid storage. The sequestration of mobile lipids in lipid bodies provides a deposit of stored energy that can be accessed in a regulated fashion according to metabolic need. Interestingly, while n-3 LC-PUFA supplementation to neonatal rat cardiomyocytes causes a huge variation in the cell lipid environment, it does not induce detectable modifications in water-soluble metabolites, suggesting negligible interference with normal metabolic processes.

  16. Functional state of rat cardiomyocytes and blood antioxidant system under psycho-emotional stress

    Institute of Scientific and Technical Information of China (English)

    Zurab Kuchukashvili; Ketevan Menabde; Matrona Chachua; George Burjanadze; Manana Chipashvili; Nana Koshoridze

    2011-01-01

    We studied the functionality of the antioxidant system in laboratory rat cardiomyocytes and blood under psychoemotional stress.It was found that 40-day isolation and violation of diurnal cycle among the animals were accompanied by the intensification of lipid peroxidation process and marked with a reduced activity of antioxidant system enzymes, such as catalase and superoxide dismutase activity.The results suggested that psycho-emotional stress was accompanied by oxidative stress, causing a reduction in the intensity of energy metabolism in cardiomyocytes, which was further strengthened by the fact that the activity of the enzymes involved in ATP synthesis in mitochondria was reduced.Based on the results, we proposed that psychological stress is one of the factors contributing to the development of various cardiac diseases.

  17. A role for Gcn5 in cardiomyocyte differentiation of rat mesenchymal stem cells.

    Science.gov (United States)

    Li, Li; Zhu, Jing; Tian, Jie; Liu, Xiaoyan; Feng, Chuan

    2010-12-01

    MSCs possess the capacity of self-renewal and potential of differentiation into various kinds of specialized tissue cells including myocardiocytes. From self-renewing to oriented differentiation, chromatin is remodeled into heritable states that allow activation or maintain the repression of regulatory genes, which means specific genes in self-renewing switched off and specific genes in oriented differentiation activated (Bernstein et al. Cell 125:315-326, 2006). These epigenetic states are established and controlled largely by specific patterns of histone posttranslational modifications, in particular, histone acetylation (Li Nat Rev Genet 3:662-673, 2002). In cardiomyocyte differentiation of rat MSCs, we focused on Gcn5, which linked a known transcriptional coactivator with catalytic histone acetyltransferase activity (Brownell et al. Cell 84:843-851, 1996). To clarify participatory in vivo role of Gcn5, using an RNA interference (RNAi) strategy employing shRNA to specifically knockdown Gcn5 expression in MSCs, we found that HAT activity altered dynamically depended on the inhibition of Gcn5 during MSCs differentiation. Chromatin immunoprecipitation (ChIP) assay showed the increased binding of acetyl histone H3 to the early cardiomyocyte-specific genes GATA4 and NKx2.5 promoters in cardiomyocyte differentiation of MSCs by 5-azacytidine inducing, whereas the decreased binding with lower Gcn5 expression. Cell ultrastructure analysis revealed that MSCs induced by 5-azacytidine possess morphological characteristics of cardiomyocyte cells. The shape of MSCs transfected by Gcn5 RNAi was similar to normal MSCs, but the chromatin showed heavy electron-density and a hard-packed structure. This intermediate state of chromatin may be an inactive part of MSCs differentiation. These results demonstrate that Gcn5, possessing acetyltransferase activity, is involved in regulating chromatin configuration around GATA4 and NKx2.5 in cardiomyocyte differentiation of rat MSCs by

  18. Regulation of myoglobin in hypertrophied rat cardiomyocytes in experimental pulmonary hypertension.

    Science.gov (United States)

    Peters, E L; Offringa, C; Kos, D; Van der Laarse, W J; Jaspers, R T

    2016-10-01

    A major problem in chronic heart failure is the inability of hypertrophied cardiomyocytes to maintain the required power output. A Hill-type oxygen diffusion model predicts that oxygen supply is limiting in hypertrophied cardiomyocytes at maximal rates of oxygen consumption and that this limitation can be reduced by increasing the myoglobin (Mb) concentration. We explored how cardiac hypertrophy, oxidative capacity, and Mb expression in right ventricular cardiomyocytes are regulated at the transcriptional and translational levels in an early stage of experimental pulmonary hypertension, in order to identify targets to improve the oxygen supply/demand ratio. Male Wistar rats were injected with monocrotaline to induce pulmonary hypertension (PH) and right ventricular heart failure. The messenger RNA (mRNA) expression levels per nucleus of growth factors insulin-like growth factor-1Ea (IGF-1Ea) and mechano growth factor (MGF) were higher in PH than in healthy controls, consistent with a doubling in cardiomyocyte cross-sectional area (CSA). Succinate dehydrogenase (SDH) activity was unaltered, indicating that oxidative capacity per cell increased. Although the Mb protein concentration was unchanged, Mb mRNA concentration was reduced. However, total RNA per nucleus was about threefold higher in PH rats versus controls, and Mb mRNA content expressed per nucleus was similar in the two groups. The increase in oxidative capacity without an increase in oxygen supply via Mb-facilitated diffusion caused a doubling of the critical extracellular oxygen tension required to prevent hypoxia (PO2crit). We conclude that Mb mRNA expression is not increased during pressure overload-induced right ventricular hypertrophy and that the increase in myoglobin content per myocyte is likely due to increased translation. We conclude that increasing Mb mRNA expression may be beneficial in the treatment of experimental PH.

  19. Mesenchymal stem cells from rat olfactory bulbs can differentiate into cells with cardiomyocyte characteristics.

    Science.gov (United States)

    Huang, Yuahn-Sieh; Li, I-Hsun; Chueh, Sheau-Huei; Hueng, Dueng-Yuan; Tai, Ming-Cheng; Liang, Chang-Min; Lien, Shiu-Bii; Sytwu, Huey-Kang; Ma, Kuo-Hsing

    2015-12-01

    Mesenchymal stromal/stem cells (MSCs) are widely distributed in different tissues such as bone marrow, adipose tissues, peripheral blood, umbilical cord and amnionic fluid. Recently, MSC-like cells were also found to exist in rat olfactory bulb and are capable of inducing differentiation into mesenchymal lineages - osteocytes, chondrocytes and adipocytes. However, whether these cells can differentiate into myocardial cells is not known. In this study, we examined whether olfactory bulb-derived MSCs could differentiate into myocardial cells in vitro. Fibroblast-like cells isolated from the olfactory bulb of neonatal rats were grown under four conditions: no treatment; in the presence of growth factors (neuregulin-1, bFGF and forskolin); co-cultured with cardiomyocytes; and co-cultured with cardiomyocytes plus neuregulin-1, bFGF and forskolin. Cell differentiation into myocardial cells was monitored by RT-PCR, light microscopy immunofluorescence, western blot analysis and contractile response to pharmacological treatments. The isolated olfactory bulb-derived fibroblast-like cells expressed CD29, CD44, CD90, CD105, CD166 but not CD34 and CD45, consistent with the characteristics of MSCs. Long cylindical cells that spontaneously contracted were only observed following 7 days of co-culture of MSCs with rat cardiomyocytes plus neuregulin-1, bFGF and forskolin. RT-PCR and western blot analysis indicated that the cylindrical cells expressed myocardial markers, such as Nkx2.5, GATA4, sarcomeric α-actinin, cardiac troponin I, cardiac myosin heavy chain, atrial natriuretic peptide and connexin 43. They also contained sarcomeres and gap junction and were sensitive to pharmacological treatments (adrenal and cholinergic agonists and antagonists). These findings indicate that rat olfactory bulb-derived fibroblast-like cells with MSC characteristics can differentiate into myocardial-like cells.

  20. Exogenous taurine attenuates mitochondrial oxidative stress and endoplasmic reticulum stress in rat cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    Yujie Yang; Yue Zhang; Xiaoyu Liu; Ji Zuo; Keqiang Wang; Wen Liu; Junbo Ge

    2013-01-01

    Taurine,a conditionally essential amino acid,plays a critical role in cardiovascular function.Here we examined the effect of taurine on mitochondria and endoplasmic reticulum in rat cardiomyocytes during glucose deprivation (GD).Data showed that cell viability,intracellular taurine contents,and taurine transporter expression were decreased during GD.In contrast,an increase in reactive oxygen species and intracellular Ca2+ contents was observed.GD also caused disrupted mitochondrial membrane potential,apoptotic cell death,and dissociation of unfolded protein response (UPR)-relative proteins in cardiomyocytes.Signal transduction analysis showed that Bcl-2 family protein balance was disturbed,caspase-12 was activated and UPR-relative protein levels were up-regulated.Moreover,pre-treatment with 80 mM exogenous taurine attenuated GD effect in cardiomyocytes.Our results suggest that taurine have beneficial effects on inhibiting mitochondria-dependent cell apoptosis and UPR-associated cell apoptosis and might have clinical impfications on acute myocardial infarction in future.

  1. Exogenous spermine contributes to prevent apoptosis in the rat hearts and cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    WEI Can; WANG Yue-hong; LI Mei-xiu; LI Hong-zhu; SHAO Hong-jiang; XU Chang-qing

    2016-01-01

    AIM:To investigate the relationship between polyamine metabolism and hypoxia /ischemia ( H/I)-induced cell apoptosis and to determine the mechanisms by which exogenous spermine protects cell apoptosis against AMI in rats .METHOD:The left anterior de-scending coronary artery ( LAD) of the Wistar rats were ligated , and neonatal rat cardiomyocytes were placed under hypoxic conditions for 24 h to establish the model of AMI (or H/I).Exogenous spermine was administered by intraperitoneal injection (2.5 mg/kg daily for 7 days) in vitro and subjected to the cell medium at 5μmol/L as a pre-treatment therapy.RESULTS:AMI (or H/I) induced an increase in polyamine catabolized enzyme SSAT and a decrease in polyamine biosynthesis enzyme ODC , which result in endogenous spermine and spermidine decrease and putrescine increase .At the same time, AMI ( or H/I) lowered cardiac function , increased cTnI and CK-MB concentrations , aggravated myocardial infarct size , cardiomyocyte damage and apoptosis , raised ROS generation , increased the expression of cleaved caspase-3, cleaved caspase-9 and endoplasmic reticulum stress (ERS)-related proteins, promoted the release of cytochrome C and mPTP opening , down-regulated Bcl-2 expression and the phosphorylation of ERK 1/2, PI3K, Akt and GSK-3β, and activated PERK and eIF 2αphosphorylation .Spermine pre-treatment reversed the above-motioned changes .CONCLUSION:AMI ( or H/I ) could induce cardiomyocyte apoptosis and polyamine metabolism disorder .Exogenous spermine attenuates cardiac injury through scavenging the ROS and inhibiting mPTP opening and ERS injury .These findings provide a novel target for the prevention of apoptosis in the setting of AMI .

  2. Antibodies against potassium channel interacting protein 2 induce necrosis in isolated rat cardiomyocytes.

    Science.gov (United States)

    Choudhury, Sangita; Schnell, Michael; Bühler, Thomas; Reinke, Yvonne; Lüdemann, Jan; Nießner, Felix; Brinkmeier, Heinrich; Herda, Lars R; Staudt, Alexander; Kroemer, Heyo K; Völker, Uwe; Felix, Stephan B; Landsberger, Martin

    2014-04-01

    Auto-antibodies against cardiac proteins have been described in patients with dilated cardiomyopathy. Antibodies against the C-terminal part of KChIP2 (anti-KChIP2 [C-12]) enhance cell death of rat cardiomyocytes. The underlying mechanisms are not fully understood. Therefore, we wanted to explore the mechanisms responsible for anti-KChIP2-mediated cell death. Rat cardiomyocytes were treated with anti-KChIP2 (C-12). KChIP2 RNA and protein expressions, nuclear NF-κB, mitochondrial membrane potential Δψm, caspase-3 and -9 activities, necrotic and apoptotic cells, total Ca(2+) and K(+) concentrations, and the effects on L-type Ca(2+) channels were quantified. Anti-KChIP2 (C-12) induced nuclear translocation of NF-κB. Anti-KChIP2 (C-12)-treatment for 2 h significantly reduced KChIP2 mRNA and protein expression. Anti-KChIP2 (C-12) induced nuclear translocation of NF-κB after 1 h. After 6 h, Δψm and caspase-3 and -9 activities were not significantly changed. After 24 h, anti-KChIP2 (C-12)-treated cells were 75 ± 3% necrotic, 2 ± 1% apoptotic, and 13 ± 2% viable. Eighty-six ± 1% of experimental buffer-treated cells were viable. Anti-KChIP2 (C-12) induced significant increases in total Ca(2+) (plus 11 ± 2%) and K(+) (plus 18 ± 2%) concentrations after 5 min. Anti-KChIP2 (C-12) resulted in an increased Ca(2+) influx through L-type Ca(2+) channels. In conclusion, our results suggest that anti-KChIP2 (C-12) enhances cell death of rat cardiomyocytes probably due to necrosis.

  3. Different concentration of ox-LDL on the damage of adult rat cardiomyocytes%不同浓度氧化性低密度脂蛋白对成年大鼠心肌细胞的损伤作用

    Institute of Scientific and Technical Information of China (English)

    王洁; 刘颖; 王雷; 宫海滨

    2013-01-01

    目的:研究不同浓度氧化性低密度脂蛋白(ox-LDL)对成年大鼠心肌细胞的损伤作用。方法本实验采用铜氧化LDL法制备ox-LDL,分为1μg/ml、2.5μg/ml、5μg/ml、7.5μg/ml、10μg/ml 5个浓度组和PBS对照组。LDL亦分为相应浓度组。测定培养的心肌细胞的存活率。结果与对照组相比,2.5μg/ml ox-LDL组心肌细胞培养24 h、5μg/ml ox-LDL组培养8 h、10μg/ml ox-LDL组培养4 h,心肌细胞存活率均明显降低(P<0.05)。LDL组与对照组相比心肌细胞存活率无明显差异,随着ox-LDL作用时间的延长,心肌细胞的存活率逐渐下降。结论 ox-LDL的浓度和作用的时间与心肌细胞损伤的程度有着密切的关系。%Objective To investigate different concentration of ox-LDL on the damage of adult rat myocardial cell. Methods LDL was oxidized by method of copper oxide.Experiment was divided into 1μg/ml, 2.5μg/ml, 5μg/ml, 7.5μg/ml, 10μg/ml ox-LDL groups and PBS control group,and so was LDL. Survival rate was determined in cultured myocardial cells. Results Compared with control group, 2.5μg/ml ox-LDL significantly decreased the survival rate of cardiomyocytes when incubation for 24 h (P<0.05);5μg/ml ox-LDL significantly decreased the survival rate of cardiomyocytes when incubation for 8 h (P<0.05);10μg/ml ox-LDL significantly decreased the survival rate of cardiomyocytes when incubation for 4 h (P<0.05). There was no significantly difference between LDL group and control group. As the increasing of the concentration and the prolonging of time, the survival rate of myocardial cells became smaller. Conclusion The degree of damage to myocardial cells is related to both action time and action concentrations of ox-LDL.

  4. Zinc-induced cardiomyocyte relaxation in a rat model of hyperglycemia is independent of myosin isoform

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    Yi Ting

    2012-11-01

    Full Text Available Abstract It has been reported previously that diabetic cardiomyopathy can be inhibited or reverted with chronic zinc supplementation. In the current study, we hypothesized that total cardiac calcium and zinc content is altered in early onset diabetes mellitus characterized in part as hyperglycemia (HG and that exposure of zinc ion (Zn2+ to isolated cardiomyocytes would enhance contraction-relaxation function in HG more so than in nonHG controls. To better control for differential cardiac myosin isoform expression as occurs in rodents after β-islet cell necrosis, hypothyroidism was induced in 16 rats resulting in 100% β-myosin heavy chain expression in the heart. β-Islet cell necrosis was induced in half of the rats by streptozocin administration. After 6 wks of HG, both HG and nonHG controls rats demonstrated similar myofilament performance measured as thin filament calcium sensitivity, native thin filament velocity in the myosin motility assay and contractile velocity and power. Extracellular Zn2+ reduced cardiomyocyte contractile function in both groups, but enhanced relaxation function significantly in the HG group compared to controls. Most notably, a reduction in diastolic sarcomere length with increasing pacing frequencies, i.e., incomplete relaxation, was more pronounced in the HG compared to controls, but was normalized with extracellular Zn2+ application. This is a novel finding implicating that the detrimental effect of HG on cardiomyocyte Ca2+ regulation can be amelioration by Zn2+. Among the many post-translational modifications examined, only phosphorylation of ryanodine receptor (RyR at S-2808 was significantly higher in HG compared to nonHG. We did not find in our hypothyroid rats any differentiating effects of HG on myofibrillar protein phosphorylation, lysine acetylation, O-linked N-acetylglucosamine and advanced glycated end-products, which are often implicated as complicating factors in cardiac performance due to HG. Our

  5. Zinc-induced cardiomyocyte relaxation in a rat model of hyperglycemia is independent of myosin isoform.

    Science.gov (United States)

    Yi, Ting; Cheema, Yaser; Tremble, Sarah M; Bell, Stephen P; Chen, Zengyi; Subramanian, Meenakumari; LeWinter, Martin M; VanBuren, Peter; Palmer, Bradley M

    2012-11-02

    It has been reported previously that diabetic cardiomyopathy can be inhibited or reverted with chronic zinc supplementation. In the current study, we hypothesized that total cardiac calcium and zinc content is altered in early onset diabetes mellitus characterized in part as hyperglycemia (HG) and that exposure of zinc ion (Zn2+) to isolated cardiomyocytes would enhance contraction-relaxation function in HG more so than in nonHG controls. To better control for differential cardiac myosin isoform expression as occurs in rodents after β-islet cell necrosis, hypothyroidism was induced in 16 rats resulting in 100% β-myosin heavy chain expression in the heart. β-Islet cell necrosis was induced in half of the rats by streptozocin administration. After 6 wks of HG, both HG and nonHG controls rats demonstrated similar myofilament performance measured as thin filament calcium sensitivity, native thin filament velocity in the myosin motility assay and contractile velocity and power. Extracellular Zn2+ reduced cardiomyocyte contractile function in both groups, but enhanced relaxation function significantly in the HG group compared to controls. Most notably, a reduction in diastolic sarcomere length with increasing pacing frequencies, i.e., incomplete relaxation, was more pronounced in the HG compared to controls, but was normalized with extracellular Zn2+ application. This is a novel finding implicating that the detrimental effect of HG on cardiomyocyte Ca2+ regulation can be amelioration by Zn2+. Among the many post-translational modifications examined, only phosphorylation of ryanodine receptor (RyR) at S-2808 was significantly higher in HG compared to nonHG. We did not find in our hypothyroid rats any differentiating effects of HG on myofibrillar protein phosphorylation, lysine acetylation, O-linked N-acetylglucosamine and advanced glycated end-products, which are often implicated as complicating factors in cardiac performance due to HG. Our results suggest that the

  6. Electrical Properties of Isolated Cardiomyocytes in a Rat Model of Thiamine Deficiency

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    Artur Santos-Miranda

    2015-03-01

    Full Text Available In modern society, thiamine deficiency (TD remains an important medical condition linked to altered cardiac function. There have been contradictory reports about the impact of TD on heart physiology, especially in the context of cardiac excitability. In order to address this particular question, we used a TD rat model and patch-clamp technique to investigate the electrical properties of isolated cardiomyocytes from epicardium and endocardium. Neither cell type showed substantial differences on the action potential waveform and transient outward potassium current. Based on our results we can conclude that TD does not induce major electrical remodeling in isolated cardiac myocytes in either endocardium or epicardium cells.

  7. Nemopilema nomurai Jellyfish venom treatment leads to alterations in rat cardiomyocytes proteome

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    Indu Choudhary

    2015-12-01

    Full Text Available This data article restrains data associated to the Choudhary et al. [1]. Nemopilema nomurai Jellyfish venom (NnV can lead to cardiac toxicity. Here we analyzed the effect of NnV on rat cardiomyocytes cell line H9c2 at the proteome level using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS. This analysis resulted in 34 proteins with differential expression. Here we provide the dataset for the proteins with amplified or reduced level as compare to control.

  8. Barnidipine block of L-type Ca2+ channel currents in rat ventricular cardiomyocytes

    OpenAIRE

    Wegener, Jörg W.; Meyrer, Hans; Rupp, Johanna; Nawrath, Hermann

    2000-01-01

    The effects of barnidipine and nifedipine on L-type Ca2+ current (ICa(L)) were investigated in ventricular cardiomyocytes from rats.Both barnidipine and nifedipine reduced ICa(L) in a concentration and voltage dependent manner; the EC50 were 80 and 130 nM at a holding potential of −80 mV, respectively, and 18 and 6 nM at −40 mV, respectively.Both drugs induced a leftward shift of the steady-state inactivation curve of ICa(L).Using a twin pulse protocol, the relationships between the amount of...

  9. Different Densities of Na-Ca Exchange Current in T-Tubular and Surface Membranes and Their Impact on Cellular Activity in a Model of Rat Ventricular Cardiomyocyte

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    M. Pásek

    2017-01-01

    Full Text Available The ratio of densities of Na-Ca exchanger current (INaCa in the t-tubular and surface membranes (INaCa-ratio computed from the values of INaCa and membrane capacitances (Cm measured in adult rat ventricular cardiomyocytes before and after detubulation ranges between 1.7 and 25 (potentially even 40. Variations of action potential waveform and of calcium turnover within this span of the INaCa-ratio were simulated employing previously developed model of rat ventricular cell incorporating separate description of ion transport systems in the t-tubular and surface membranes. The increase of INaCa-ratio from 1.7 to 25 caused a prolongation of APD (duration of action potential at 90% repolarisation by 12, 9, and 6% and an increase of peak intracellular Ca2+ transient by 45, 19, and 6% at 0.1, 1, and 5 Hz, respectively. The prolonged APD resulted from the increase of INaCa due to the exposure of a larger fraction of Na-Ca exchangers to higher Ca2+ transients under the t-tubular membrane. The accompanying rise of Ca2+ transient was a consequence of a higher Ca2+ load in sarcoplasmic reticulum induced by the increased Ca2+ cycling between the surface and t-tubular membranes. However, the reason for large differences in the INaCa-ratio assessed from measurements in adult rat cardiomyocytes remains to be explained.

  10. Hydrogen sulfide inhibits L-type calcium currents depending upon the protein sulfhydryl state in rat cardiomyocytes.

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    Rongyuan Zhang

    Full Text Available Hydrogen sulfide (H(2S is a novel gasotransmitter that inhibits L-type calcium currents (I (Ca, L. However, the underlying molecular mechanisms are unclear. In particular, the targeting site in the L-type calcium channel where H(2S functions remains unknown. The study was designed to investigate if the sulfhydryl group could be the possible targeting site in the L-type calcium channel in rat cardiomyocytes. Cardiac function was measured in isolated perfused rat hearts. The L-type calcium currents were recorded by using a whole cell voltage clamp technique on the isolated cardiomyocytes. The L-type calcium channel containing free sulfhydryl groups in H9C2 cells were measured by using Western blot. The results showed that sodium hydrosulfide (NaHS, an H(2S donor produced a negative inotropic effect on cardiac function, which could be partly inhibited by the oxidant sulfhydryl modifier diamide (DM. H(2S donor inhibited the peak amplitude of I( Ca, L in a concentration-dependent manner. However, dithiothreitol (DTT, a reducing sulfhydryl modifier markedly reversed the H(2S donor-induced inhibition of I (Ca, L in cardiomyocytes. In contrast, in the presence of DM, H(2S donor could not alter cardiac function and L type calcium currents. After the isolated rat heart or the cardiomyocytes were treated with DTT, NaHS could markedly alter cardiac function and L-type calcium currents in cardiomyocytes. Furthermore, NaHS could decrease the functional free sulfhydryl group in the L-type Ca(2+ channel, which could be reversed by thiol reductant, either DTT or reduced glutathione. Therefore, our results suggest that H(2S might inhibit L-type calcium currents depending on the sulfhydryl group in rat cardiomyocytes.

  11. Propofol ameliorates doxorubicin-induced oxidative stress and cellular apoptosis in rat cardiomyocytes

    Energy Technology Data Exchange (ETDEWEB)

    Lai, H.C. [Cardiovascular Center and Department of Anesthesiology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Department of Medicine and Cardiovascular Research Center, National Yang-Ming University School of Medicine, Taipei, Taiwan (China); Yeh, Y.C. [Graduate Institute of Natural Healing Sciences, Nanhua University, Chiayi, Taiwan (China); Wang, L.C. [Cardiovascular Center and Department of Anesthesiology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Ting, C.T.; Lee, W.L. [Cardiovascular Center and Department of Anesthesiology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Department of Medicine and Cardiovascular Research Center, National Yang-Ming University School of Medicine, Taipei, Taiwan (China); Lee, H.W. [Cardiovascular Center and Department of Anesthesiology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Wang, K.Y. [Cardiovascular Center and Department of Anesthesiology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Department of Medicine, Chung-Shan Medical University, Taichung, Taiwan (China); Wu, A. [College of Biological Science, University of California, Davis (United States); Su, C.S. [Cardiovascular Center and Department of Anesthesiology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Department of Medicine and Cardiovascular Research Center, National Yang-Ming University School of Medicine, Taipei, Taiwan (China); Liu, T.J., E-mail: trliu@vghtc.gov.tw [Cardiovascular Center and Department of Anesthesiology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Department of Medicine and Cardiovascular Research Center, National Yang-Ming University School of Medicine, Taipei, Taiwan (China)

    2011-12-15

    Background: Propofol is an anesthetic with pluripotent cytoprotective properties against various extrinsic insults. This study was designed to examine whether this agent could also ameliorate the infamous toxicity of doxorubicin, a widely-used chemotherapeutic agent against a variety of cancer diseases, on myocardial cells. Methods: Cultured neonatal rat cardiomyocytes were administrated with vehicle, doxorubicin (1 {mu}M), propofol (1 {mu}M), or propofol plus doxorubicin (given 1 h post propofol). After 24 h, cells were harvested and specific analyses regarding oxidative/nitrative stress and cellular apoptosis were conducted. Results: Trypan blue exclusion and MTT assays disclosed that viability of cardiomyocytes was significantly reduced by doxorubicin. Contents of reactive oxygen and nitrogen species were increased and antioxidant enzymes SOD1, SOD2, and GPx were decreased in these doxorubicin-treated cells. Mitochondrial dehydrogenase activity and membrane potential were also depressed, along with activation of key effectors downstream of mitochondrion-dependent apoptotic signaling. Besides, abundance of p53 was elevated and cleavage of PKC-{delta} was induced in these myocardial cells. In contrast, all of the above oxidative, nitrative and pro-apoptotic events could be suppressed by propofol pretreatment. Conclusions: Propofol could extensively counteract oxidative/nitrative and multiple apoptotic effects of doxorubicin in the heart; hence, this anesthetic may serve as an adjuvant agent to assuage the untoward cardiac effects of doxorubicin in clinical application. -- Highlights: Black-Right-Pointing-Pointer We evaluate how propofol prevents doxorubicin-induced toxicity in cardiomyocytes. Black-Right-Pointing-Pointer Propofol reduces doxorubicin-imposed nitrative and oxidative stress. Black-Right-Pointing-Pointer Propofol suppresses mitochondrion-, p53- and PKC-related apoptotic signaling. Black-Right-Pointing-Pointer Propofol ameliorates apoptosis and

  12. Effects of transforming growth factor-β1 and signal protein Smad3 on rat cardiomyocyte hypertrophy

    Institute of Scientific and Technical Information of China (English)

    黄俊; 覃国辉; 胡昌兴; 龚丽娅; 程芳舟; 马业新; 陆再英

    2004-01-01

    Background SMAD proteins have recently been identified as the first family of putative transforming growth factor-β1(TGF-β1) signal transducers. This study was to investigate the effects of TGF-β1 and signal protein Smad3 on rat cardiac hypertrophy.Methods The incorporation of [3H]-leucine was measured to determine the hypertrophy of cardiomyocyte incubated with different doses of TGF-β1 in cultured neonatal cardiomyocytes. The model of rat cardiac hypertrophy was produced with constriction of the abdominal aorta. At different times after the operation, rats were killed, and their left ventricular mass index (LVMI) determined. The mRNA expression of TGF-β1 and Smad3 of cultured cells and hypertrophic left ventricles were assessed by RT-PCR. The protein expression of Smad3 was assessed by Western blot.Results In cultured neonatal cardiomyocytes, TGF-β1 significantly promoted incorporation of [3H]-leucine. With the concentration of 3 pg/L, it increased the expression of Smad3 in mRNA and protein levels after 15 minutes, and continued for up to 8 hours of cultured cardiomyocytes. The LVMI and the expression of TGF-β1 (mRNA) and Smad3 (mRNA and protein) of hypertrophic left ventricle were increased by day 3 after the operation and continued to the 4th week. The peak expression of these was in the second week after operation.Conclusion TGF-β1 has positive effects on rat cardiomyocyte hypertrophy. Signal protein Smad3 could be related to the pathologic progression of rat cardiac hypertrophy.

  13. Membrane cholesterol modulates Kv1.5 potassium channel distribution and function in rat cardiomyocytes.

    Science.gov (United States)

    Abi-Char, Joëlle; Maguy, Ange; Coulombe, Alain; Balse, Elise; Ratajczak, Philippe; Samuel, Jane-Lise; Nattel, Stanley; Hatem, Stéphane N

    2007-08-01

    Membrane lipid composition is a major determinant of cell excitability. In this study, we assessed the role of membrane cholesterol composition in the distribution and function of Kv1.5-based channels in rat cardiac membranes. In isolated rat atrial myocytes, the application of methyl-beta-cyclodextrin (MCD), an agent that depletes membrane cholesterol, caused a delayed increase in the Kv1.5-based sustained component, I(kur), which reached steady state in approximately 7 min. This effect was prevented by preloading the MCD with cholesterol. MCD-increased current was inhibited by low 4-aminopyridine concentration. Neonatal rat cardiomyocytes transfected with Green Fluorescent Protein (GFP)-tagged Kv1.5 channels showed a large ultrarapid delayed-rectifier current (I(Kur)), which was also stimulated by MCD. In atrial cryosections, Kv1.5 channels were mainly located at the intercalated disc, whereas caveolin-3 predominated at the cell periphery. A small portion of Kv1.5 floated in the low-density fractions of step sucrose-gradient preparations. In live neonatal cardiomyocytes, GFP-tagged Kv1.5 channels were predominantly organized in clusters at the basal plasma membrane. MCD caused reorganization of Kv1.5 subunits into larger clusters that redistributed throughout the plasma membrane. The MCD effect on clusters was sizable 7 min after its application. We conclude that Kv1.5 subunits are concentrated in cholesterol-enriched membrane microdomains distinct from caveolae, and that redistribution of Kv1.5 subunits by depletion of membrane cholesterol increases their current-carrying capacity.

  14. Photocontrol of Voltage-Gated Ion Channel Activity by Azobenzene Trimethylammonium Bromide in Neonatal Rat Cardiomyocytes.

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    Sheyda R Frolova

    Full Text Available The ability of azobenzene trimethylammonium bromide (azoTAB to sensitize cardiac tissue excitability to light was recently reported. The dark, thermally relaxed trans- isomer of azoTAB suppressed spontaneous activity and excitation propagation speed, whereas the cis- isomer had no detectable effect on the electrical properties of cardiomyocyte monolayers. As the membrane potential of cardiac cells is mainly controlled by activity of voltage-gated ion channels, this study examined whether the sensitization effect of azoTAB was exerted primarily via the modulation of voltage-gated ion channel activity. The effects of trans- and cis- isomers of azoTAB on voltage-dependent sodium (INav, calcium (ICav, and potassium (IKv currents in isolated neonatal rat cardiomyocytes were investigated using the whole-cell patch-clamp technique. The experiments showed that azoTAB modulated ion currents, causing suppression of sodium (Na+ and calcium (Ca2+ currents and potentiation of net potassium (K+ currents. This finding confirms that azoTAB-effect on cardiac tissue excitability do indeed result from modulation of voltage-gated ion channels responsible for action potential.

  15. Angiotensin Ⅱ type Ⅰ receptor agonistic autoantibody-induced apoptosis in neonatal rat cardiomyocytes is dependent on the generation of tumor necrosis factor-α

    Institute of Scientific and Technical Information of China (English)

    Weiran Chai; Wenhui Zhang; Zhu Jin; Yiping Feng; Yanping Kuang; Jianming Zhi

    2012-01-01

    Angiotensin Ⅱ type Ⅰ receptor agonistic autoantibodies (AT1-AA) are related to pre-eclampsia and hypertension and have a direct effect of stimulating the production of tumor necrosis factor-alpha (TNF-α) in the placenta.TNF-α is a known mediator of apoptosis.However,few studies have reported the role of TNF-α and its relationship within AT1-AA-induced apoptosis of cardiomyocytes.In this study,neonatal rat cardiomyocytes were treated with various concentrations of AT1-AA.The apoptosis of neonatal rat cardiomyocytes was determined using TUNEL assay and flow cytometry.The level of secreted TNF-α was measured by enzyme-linked immunosorbent assay,and caspase-3 activity was measured by a fluorogenic protease assay kit.AT1 receptor blockade and TNF inhibitor were added to determine whether they could inhibit the apoptotic effect of AT1-AA.Results showed that AT1-AA induced the apoptosis of neonatal rat cardiomyocytes in a dose-dependent and time-dependent manner.AT1-AA increased TNF secretion and caspase-3activities.AT1 receptor blockade completely abrogated AT1-AA-induced TNF-α secretion,caspase-3 activation,and cardiomyocyte apoptosis.TNF-α receptor inhibitor significantly attenuated AT1-AA-induced neonatal rat cardiomyocyte apoptosis.AT1-AA in the plasma of preeclamptic patients promoted neonatal rat cardiomyocyte apoptosis through a TNF-caspase signaling pathway.

  16. From fetus towards adult : maturation and functional analysis of pluripotent stem cell-derived cardiomyocytes

    NARCIS (Netherlands)

    Catarino, Ribeiro M.

    2016-01-01

    This thesis describes research about the differentiation of human stem cells into cardiomyocytes (heart cells). During the differentiation process the stem cells become contractile myocytes that resemble the native heart cells. Nevertheless, the phenotype of these cardiomyocytes is comparable to a s

  17. Stroma cell-derived factor-1α signaling enhances calcium transients and beating frequency in rat neonatal cardiomyocytes.

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    Ielham Hadad

    Full Text Available Stroma cell-derived factor-1α (SDF-1α is a cardioprotective chemokine, acting through its G-protein coupled receptor CXCR4. In experimental acute myocardial infarction, administration of SDF-1α induces an early improvement of systolic function which is difficult to explain solely by an anti-apoptotic and angiogenic effect. We wondered whether SDF-1α signaling might have direct effects on calcium transients and beating frequency.Primary rat neonatal cardiomyocytes were culture-expanded and characterized by immunofluorescence staining. Calcium sparks were studied by fluorescence microscopy after calcium loading with the Fluo-4 acetoxymethyl ester sensor. The cardiomyocyte enriched cellular suspension expressed troponin I and CXCR4 but was vimentin negative. Addition of SDF-1α in the medium increased cytoplasmic calcium release. The calcium response was completely abolished by using a neutralizing anti-CXCR4 antibody and partially suppressed and delayed by preincubation with an inositol triphosphate receptor (IP3R blocker, but not with a ryanodine receptor (RyR antagonist. Calcium fluxes induced by caffeine, a RyR agonist, were decreased by an IP3R blocker. Treatment with forskolin or SDF-1α increased cardiomyocyte beating frequency and their effects were additive. In vivo, treatment with SDF-1α increased left ventricular dP/dtmax.These results suggest that in rat neonatal cardiomyocytes, the SDF-1α/CXCR4 signaling increases calcium transients in an IP3-gated fashion leading to a positive chronotropic and inotropic effect.

  18. Engineered myocardial tissues constructed in vivo using cardiomyocyte-like cells derived from bone marrow mesenchymal stem cells in rats

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    Xing Yujie

    2012-01-01

    Full Text Available Abstract Background To explore the feasibility of constructing engineered myocardial tissues (EMTs in vivo, using polylactic acid -co-glycolic acid (PLGA for scaffold and cardiomyocyte-like cells derived from bone marrow mesenchymal stem cells (BMMSCs for seeded cells. Methods BMMSCs were isolated from femur and tibia of Sprague-Dawley (SD rats by density-gradient centrifugation. The third passage cells were treated with 10 μmol/L 5-azacytidine (5-aza and 0.1 μmol/L angiotensin II (Ang II for 24 h, followed by culturing in complete medium for 3 weeks to differentiated into cardiomyocyte-like cells. The cardiomyocyte-like cells were seeded into PLGA scaffolds to form the grafts. The grafts were cultured in the incubator for three days and then implanted into the peritoneal cavity of SD rats. Four weeks later, routine hematoxylin-eosin (HE staining, immunohistochemical staining for myocardium-specific cardiac troponin I (cTnI, scanning electron microscopy and transmission electron microscopy were used to analyze the morphology and microconstruction of the EMTs in host rats. Results HE staining showed that the cardiomyocyte-like cells distributed equally in the PLGA scaffold, and the nuclei arranged in the spindle shape. Immunohistochemical staining revealed that majority of engrafted cells in the PLGA -Cardiomyocyte-like cells group were positive for cTnI. Scanning electron microscopy showed that the inoculated cells well attached to PLGA and grew in 3 dimensions in construct. Transmission electron microscopy showed that the EMTs contained well arranged myofilaments paralleled to the longitudinal cell axis, the cells were rich in endoplasmic reticulum and mitochondria, while desmosomes, gap junction and Z line-like substances were also can be observed as well within the engrafted cells. Conclusion We have developed an in vivo method to construct engineered myocardial tissue. The in vivo microenvironment helped engrafted cells/tissue survive and

  19. Protective Effect and Mechanism of Total Flavones from Rhododendron simsii Planch Flower on Cultured Rat Cardiomyocytes with Anoxia and Reoxygenation

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    Yi Jiao

    2015-01-01

    Full Text Available Many flavonoids have cardioprotection against myocardial ischemia/reperfusion (I/R injury. Total flavones from Rhododendron simsii Planch flower (TFR can protect myocardial ischemic injuries. However, its protective mechanism is still unknown. The present study was designed to investigate the mechanism of TFR on myocardial I/R and anoxia/reoxygenation (A/R injuries. Rat model of myocardial I/R injury was made, and myocardial infarction was determined. A/R injury was induced in cultured rat cardiomyocytes; cellular damage was evaluated by measuring cell viability, LDH and cTnT releases, and MDA content. Expressions of ROCK1 and ROCK2 protein were examined by Western blot analysis, and K+ currents were recorded by using whole-cell patch clamp technique. TFR 20~80 mg/kg markedly reduced I/R-induced myocardial infarction. TFR 3.7~300 mg/L significantly inhibited A/R-induced reduction of cell viability, LDH and cTnT releases, and MDA production. Exposure to A/R significantly increased ROCK1 and ROCK2 expressions in rat cardiomyocytes, but TFR 33.3~300 mg/L obviously inhibited this increase. 300 mg/L TFR significantly augmented inward rectifier K+ current and other K+ currents in rat cardiomyocytes. These results indicate that TFR has a protective effect on rat cardiomyocytes A/R damage, and the protective mechanism may be engaged with the inhibition of ROCK1 and ROCK2 and activation of K+ channels.

  20. Interaction between Overtraining and the Interindividual Variability May (Not Trigger Muscle Oxidative Stress and Cardiomyocyte Apoptosis in Rats

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    Rodrigo Luiz Perroni Ferraresso

    2012-01-01

    Full Text Available Severe endurance training (overtraining may cause underperformance related to muscle oxidative stress and cardiomyocyte alterations. Currently, such relationship has not been empirically established. In this study, Wistar rats (n=19 underwent eight weeks of daily exercise sessions followed by three overtraining weeks in which the daily frequency of exercise sessions increased. After the 11th training week, eight rats exhibited a reduction of 38% in performance (nonfunctional overreaching group (NFOR, whereas eleven rats exhibited an increase of 18% in performance (functional overreaching group (FOR. The red gastrocnemius of NFOR presented significantly lower citrate synthase activity compared to FOR, but similar to that of the control. The activity of mitochondrial complex IV in NFOR was lower than that of the control and FOR. This impaired mitochondrial adaptation in NFOR was associated with increased antioxidant enzyme activities and increased lipid peroxidation (in muscle and plasma relative to FOR and control. Cardiomyocyte apoptosis was higher in NFOR. Plasma creatine kinase levels were unchanged. We observed that some rats that presented evidence of muscle oxidative stress are also subject to cardiomyocyte apoptosis under endurance overtraining. Blood lipid peroxides may be a suitable biomarker for muscle oxidative stress that is unrelated to severe muscle damage.

  1. Effect of Arachidonic Acid on the Rate of Oxygen Consumption in Isolated Cardiomyocytes from Intact Rats and Animals with Ischemic or Diabetic Injury to the Heart.

    Science.gov (United States)

    Egorova, M V; Kutsykova, T V; Afanas'ev, S A; Popov, S V

    2015-12-01

    We studied the rate of oxygen consumption by isolated cardiomyocytes from intact rats and animals with experimental myocardial infarction or streptozotocin-induced diabetes mellitus. The measurements were performed in standard incubation medium under various conditions of oxygenation and after addition of arachidonic acid (20 μmol/liter). Under normoxic conditions, arachidonic acid improves respiration of cardiomyocytes from intact animals, but reduces this parameter in cells isolated from animals with pathologies. The intensity of O2 consumption by cardiomyocytes from intact rats and animals with pathologies was shown to decrease during hypoxia. Addition of arachidonic acid aggravated inhibition of respiration for cardiomyocytes from intact rats and specimens with myocardial infarction, but had no effect in diabetes mellitus. The effect of arachidonic acid on oxygen consumption rate is probably mediated by a nonspecific mechanism realized at the mitochondrial level.

  2. Breviscapine ameliorates hypertrophy of cardiomyocytes induced by high glucose in diabetic rats via the PKC signaling pathway

    Institute of Scientific and Technical Information of China (English)

    Min WANG; Wen-bin ZHANG; Jun-hui ZHU; Guo-sheng FU; Bin-quan ZHOU

    2009-01-01

    Aim: To investigate the influence of breviscapine on high glucose-induced hypertrophy of cardiomyocytes and the relevant mechanism in vitro and in vivo.Methods: Cultured neonatal cardiomyocytes were divided into ⅰ) control; ⅱ) high glucose concentrations; ⅲ) high glucose+PKC inhibi-tor Ro-31-8220; ⅳ) high glucose+breviscapine; or ⅴ) high glucose+NF-κB inhibitor BAY11-7082. Cellular contraction frequency and volumes were measured; the expression of protein kinase C (PKC), NF-κB, TNF-α, and c-los were assessed by Western blot or reverse transcription-polymerase chain reaction (RT-PCR). Diabetic rats were induced by a single intraperitoneal injection of streptozotocin,and randomly divided into ⅰ) control rats; ⅱ) diabetic rats; or ⅲ) diabetic rats administered with breviscapine (10 or 25 mg·kg-1·d-1). After treatment with breviscapine for six weeks, the echocardiographic parameters were measured. All rats were then sacrificed and heart tissue was obtained for microscopy. The expression patterns of PKC, NF-κB, TNF-α, and c-los were measured by Western blot or RT-PCR.Results: Cardiomyocytes cultured in a high concentration of glucose showed an increased pulsatile frequency and cellular volume, as well as a higher expression of PKC, NF-κB, TNF-α, and c-fos compared with the control group. Breviscapine could partly prevent these changes. Diabetic rats showed relative cardiac hypertrophy and a higher expression of PKC, NF-κB, TNF-α, and c-los; treatment with breviscapine could ameliorate these changes in diabetic cardiomyopathy.Conclusion: Breviscapine prevented cardiac hypertrophy in diabetic rats by inhibiting the expression of PKC, which may have a protec-tive effect in the pathogenesis of diabetic cardiomyopathy via the PKC/NF-κB/C-fos signal transduction pathway.

  3. Intracellular diffusion restrictions in isolated cardiomyocytes from rainbow trout

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    Birkedal Rikke

    2009-12-01

    Full Text Available Abstract Background Restriction of intracellular diffusion of adenine nucleotides has been studied intensively on adult rat cardiomyocytes. However, their cause and role in vivo is still uncertain. Intracellular membrane structures have been suggested to play a role. We therefore chose to study cardiomyocytes from rainbow trout (Oncorhynchus mykiss, which are thinner and have fewer intracellular membrane structures than adult rat cardiomyocytes. Previous studies suggest that trout permeabilized cardiac fibers also have diffusion restrictions. However, results from fibers may be affected by incomplete separation of the cells. This is avoided when studying permeabilized, isolated cardiomyocytes. The aim of this study was to verify the existence of diffusion restrictions in trout cardiomyocytes by comparing ADP-kinetics of mitochondrial respiration in permeabilized fibers, permeabilized cardiomyocytes and isolated mitochondria from rainbow trout heart. Experiments were performed at 10, 15 and 20°C in the absence and presence of creatine. Results Trout cardiomyocytes hypercontracted in the solutions used for mammalian cardiomyocytes. We developed a new solution in which they retained their shape and showed stable steady state respiration rates throughout an experiment. The apparent ADP-affinity of permeabilized cardiomyocytes was different from that of fibers. It was higher, independent of temperature and not increased by creatine. However, it was still about ten times lower than in isolated mitochondria. Conclusions The differences between fibers and cardiomyocytes suggest that results from trout heart fibers were affected by incomplete separation of the cells. However, the lower ADP-affinity of cardiomyocytes compared to isolated mitochondria indicate that intracellular diffusion restrictions are still present in trout cardiomyocytes despite their lower density of intracellular membrane structures. The lack of a creatine effect indicates that

  4. A novel dihydropyridine with 3-aryl meta-hydroxyl substitution blocks L-type calcium channels in rat cardiomyocytes

    Energy Technology Data Exchange (ETDEWEB)

    Galvis-Pareja, David [Advanced Center for Chronic Diseases (ACCDiS), Facultad de Ciencias Químicas y Farmacéuticas and Facultad Medicina, Universidad de Chile, Santiago (Chile); Centro Estudios Moleculares de la Célula (CEMC), Facultad de Ciencias Químicas y Farmacéuticas and Facultad Medicina, Universidad de Chile, Santiago (Chile); Zapata-Torres, Gerald [Departamento de Química Inorgánica y Analítica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago (Chile); Hidalgo, Jorge [Centro Estudios Moleculares de la Célula (CEMC), Facultad de Ciencias Químicas y Farmacéuticas and Facultad Medicina, Universidad de Chile, Santiago (Chile); Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago (Chile); Ayala, Pedro [Centro Estudios Moleculares de la Célula (CEMC), Facultad de Ciencias Químicas y Farmacéuticas and Facultad Medicina, Universidad de Chile, Santiago (Chile); and others

    2014-08-15

    Rationale: Dihydropyridines are widely used for the treatment of several cardiac diseases due to their blocking activity on L-type Ca{sup 2+} channels and their renowned antioxidant properties. Methods: We synthesized six novel dihydropyridine molecules and performed docking studies on the binding site of the L-type Ca{sup 2+} channel. We used biochemical techniques on isolated adult rat cardiomyocytes to assess the efficacy of these molecules on their Ca{sup 2+} channel-blocking activity and antioxidant properties. The Ca{sup 2+} channel-blocking activity was evaluated by confocal microscopy on fluo-3AM loaded cardiomyocytes, as well as using patch clamp experiments. Antioxidant properties were evaluated by flow cytometry using the ROS sensitive dye 1,2,3 DHR. Results: Our docking studies show that a novel compound with 3-OH substitution inserts into the active binding site of the L-type Ca{sup 2+} channel previously described for nitrendipine. In biochemical assays, the novel meta-OH group in the aryl in C4 showed a high blocking effect on L-type Ca{sup 2+} channel as opposed to para-substituted compounds. In the tests we performed, none of the molecules showed antioxidant properties. Conclusions: Only substitutions in C2, C3 and C5 of the aryl ring render dihydropyridine compounds with the capacity of blocking LTCC. Based on our docking studies, we postulate that the antioxidant activity requires a larger group than the meta-OH substitution in C2, C3 or C5 of the dihydropyridine ring. - Highlights: • Dihydropyridine (DHP) molecules are widely used in cardiovascular disease. • DHPs block Ca{sup 2+} entry through LTCC—some DHPs have antioxidant activity as well. • We synthesized 6 new DHPs and tested their Ca{sup 2+} blocking and antioxidant activities. • 3-Aryl meta-hydroxyl substitution strongly increases their Ca{sup 2+} blocking activity. • 3-Aryl meta-hydroxyl substitution did not affect the antioxidant properties.

  5. Assessment of the Effect of Cardiomyocyte Transplantation on Left Ventricular Remodeling and Function in Post-Infarction Wister Rats by Using High-frequency Ultrasound

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing; XIE Mingxing; WANG Xinfang; L(U) Qing; LANG Mingjian; DENG Binhua

    2007-01-01

    The effects of cardiomyocyte grafting on left ventricular (LV) remodeling and function in rats with chronic myocardial infarction were evaluated using high-frequency ultrasound. Chronic myocardial infarction was induced in 50 Wister rats by ligating the left anterior descending artery. They were randomized into two groups: a trial group that received neonatal rat cardiomyocyte trans- plantation (n=25) and a control group which were given intramyocardial injection of culture medium (n=25). The left ventricular (LV) geometry and function were evaluated by high-frequency ultrasound before and 4 weeks after the cell transplantation. After the final evaluation, all rats were sacrificed for histological study. The results showed that 4 weeks after the cell transplantation, as compared with the control group, the LV end-systolic dimension, end-diastolic dimension, end-systolic volume and end-diastolic volume were significantly decreased and the LV anterior wall end-diastolic thickness, LV ejection fraction and fractional shortening were significantly increased in the trial group (P<0.01). Histological study showed that transplanted neonatal rat cardiomyocytes were found in all host hearts and identified by Brdu staining. It was suggested that transplantation of neonatal rat cardiomyocytes can reverse cardiac remodeling and improve heart function in chronic myocardial infarction rats. High-frequency ultrasound can be used as a reliable technique for the non-invasive evaluation of the effect of cardiomyocyte transplantation.

  6. Simvastatin Modulates Remodeling of Kv4.3 Expression in Rat Hypertrophied Cardiomyocytes

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    Feifei Su, Miaoqian Shi, Zhiqiang Yan, Dongbo Ou, Juntang Li, Zifan Lu, Qiangsun Zheng

    2012-01-01

    Full Text Available Objectives: Hypertrophy has been shown to be associated with arrhythmias which can be caused by abnormal remodeling of the Kv4-family of transient potassium channels. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins have recently been shown to exert pleiotropic protective effects in cardiovascular diseases, including anti-arrhythmias. It is hypothesized that remodeling of Kv4.3 occurs in rat hypertrophied cardiomyocytes and is regulated by simvastatin.Methods: Male Sprague-Dawley rats and neonatal rat ventricular myocytes (NRVMs underwent abdominal aortic banding (AAB for 7 weeks and angiotensin II (AngII treatment, respectively, to induce cardiac hypertrophy. Kv4.3 expression by NRVMs and myocardium (subepicardial and subendocardial in the left ventricle was measured. The transient outward potassium current (Ito of NRVMs was recorded using a whole-cell patch-clamp method.Results: Expression of the Kv4.3 transcript and protein was significantly reduced in myocardium (subepicardial and subendocardial in the left ventricle and in NRVMs. Simvastatin partially prevented the reduction of Kv4.3 expression in NRVMs and subepicardial myocardium but not in the subendocardial myocardium. Hypertrophied NRVMs exhibited a significant reduction in the Ito current and this effect was partially reversed by simvastatin.Conclusions: Simvastatin alleviated the reduction of Kv4.3 expression, Ito currents in hypertrophied NRVMs and alleviated the reduced Kv4.3 expression in subepicardial myocardium from the hypertrophied left ventricle. It can be speculated that among the pleiotropic effects of simvastatin, the anti-arrhythmia effect is partly mediated by its effect on Kv4.3.

  7. Anti-apoptosis effect of polysaccharide isolated from the seeds of Cuscuta chinensis Lam on cardiomyocytes in aging rats.

    Science.gov (United States)

    Sun, Shou-Li; Guo, Li; Ren, Ya-Chao; Wang, Bing; Li, Rong-Hui; Qi, Yu-Shan; Yu, Hui; Chang, Nai-Dan; Li, Ming-Hui; Peng, Hai-Sheng

    2014-09-01

    To investigate the mechanism of apoptosis in myocardial cells of aging rats induced by D-galactose and to study the effect of the Polysaccharide isolated from the seeds of Cuscuta chinensis Lam (PCCL) on apoptosis of cardiomyocytes and its corresponding machinasim in aging rat model. Fifty male SD rats were randomly divided into 5 groups. Normal control group (NC). D-galactose (100 mg · kg(-1)d(-1) for 56 day) indued aging group (MC), D-galactose plus 100 mg kg(-1) d(-1) PCCL group (ML), D-galactose plus 200 mg kg(-1) d(-1) PCCL group (MM), and D-galactose plus 400 mg kg(-1) d(-1) PCCL group (MH). Same volume of solution (water, or PCCL aqueous solution) was given by gavage for 56 days. Then the hearts were collected and apoptosis parameters were evaluated. Caspase-3 and Cyt c were determined by fluorescence spectrometer, the apoptosis rate was assessed by AnnexinV-FITC method by Flow-Cytometry, [Ca(2+)]i and [Ca(2+)]i overloaded by KCL were observed by laser scanning confocal microscopy (LSCM); Bcl-2 and Bax were examined by immunohistochemistry. The content of Cyt C, [Ca(2+)]i of cardiomyocytes, the activity of Caspase-3, Bax expression level in D-galactose induced aging group were higher than NC (p aging group compared to NC. On the other hand, the content of Cyt C, [Ca(2+)]i of cardiomyocytes, the activity of Caspase-3 and apoptosis rate, as well as Bax expression level in all three PCCL groups were decreased compared to galactose induced group (p aging group. PCCL could decrease the apoptosis of cardiomyocytes by the mitochondria apoptosis pathway.

  8. KCNQ channels are involved in the regulatory volume decrease response in primary neonatal rat cardiomyocytes

    DEFF Research Database (Denmark)

    Calloe, Kirstine; Nielsen, Morten Schak; Grunnet, Morten;

    2007-01-01

    Cardiomyocytes may experience significant cell swelling during ischemia and reperfusion. Such changes in cardiomyocyte volume have been shown to affect the electrical properties of the heart, possibly leading to cardiac arrhythmia. In the present study the regulatory volume decrease (RVD) response...

  9. Low Molecular Weight Fucoidan Alleviates Cardiac Dysfunction in Diabetic Goto-Kakizaki Rats by Reducing Oxidative Stress and Cardiomyocyte Apoptosis

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    Xinfeng Yu

    2014-01-01

    Full Text Available Diabetic cardiomyopathy (DCM is characterized by cardiac dysfunction and cardiomyocyte apoptosis. Oxidative stress is suggested to be the major contributor to the development of DCM. This study was intended to evaluate the protective effect of low molecular weight fucoidan (LMWF against cardiac dysfunction in diabetic rats. Type 2 diabetic goto-kakizaki rats were untreated or treated with LMWF (50 and 100 mg/kg/day for three months. The establishment of DCM model and the effects of LMWF on cardiac function were evaluated by echocardiography and isolated heart perfusion. Ventricle staining with H-E or Sirius Red was performed to investigate the structural changes in myocardium. Functional evaluation demonstrated that LMWF has a beneficial effect on DCM by enhancing myocardial contractility and mitigating cardiac fibrosis. Additionally, LMWF exerted significant inhibitory effects on the reactive oxygen species production and myocyte apoptosis in diabetic hearts. The depressed activity of superoxide dismutase in diabetic heart was also improved by intervention with LMWF. Moreover, LMWF robustly inhibited the enhanced expression of protein kinase C β, an important contributor to oxidative stress, in diabetic heart and high glucose-treated cardiomyocytes. In conclusion, LMWF possesses a protective effect against DCM through ameliorations of PKCβ-mediated oxidative stress and subsequent cardiomyocyte apoptosis in diabetes.

  10. Barnidipine block of L-type Ca(2+) channel currents in rat ventricular cardiomyocytes.

    Science.gov (United States)

    Wegener, J W; Meyrer, H; Rupp, J; Nawrath, H

    2000-08-01

    The effects of barnidipine and nifedipine on L-type Ca(2+) current (I(Ca(L))) were investigated in ventricular cardiomyocytes from rats. Both barnidipine and nifedipine reduced I(Ca(L)) in a concentration and voltage dependent manner; the EC(50) were 80 and 130 nM at a holding potential of -80 mV, respectively, and 18 and 6 nM at -40 mV, respectively. Both drugs induced a leftward shift of the steady-state inactivation curve of I(Ca(L)). Using a twin pulse protocol, the relationships between the amount of block of I(Ca(L)) by either drug, seen during the second pulse, and the length of the first pulse were described by monoexponential functions reflecting onset of block, dependent on drug concentration. The onset of block by barnidipine was three times faster than that by nifedipine. With both drugs, recovery of I(Ca(L)) was 50 times slower than under control conditions and described by monoexponential functions reflecting offset of block (independent of drug concentration). The offset of block with barnidipine was three times slower than that with nifedipine. The time constants of block and unblock of I(Ca(L)) by both drugs were used to calculate binding and unbinding and to predict their effects at two frequencies. It is suggested that barnidipine exhibits a higher affinity to the inactivated Ca(2+) channel state as compared to nifedipine.

  11. Barnidipine block of L-type Ca2+ channel currents in rat ventricular cardiomyocytes

    Science.gov (United States)

    Wegener, Jörg W; Meyrer, Hans; Rupp, Johanna; Nawrath, Hermann

    2000-01-01

    The effects of barnidipine and nifedipine on L-type Ca2+ current (ICa(L)) were investigated in ventricular cardiomyocytes from rats.Both barnidipine and nifedipine reduced ICa(L) in a concentration and voltage dependent manner; the EC50 were 80 and 130 nM at a holding potential of −80 mV, respectively, and 18 and 6 nM at −40 mV, respectively.Both drugs induced a leftward shift of the steady-state inactivation curve of ICa(L).Using a twin pulse protocol, the relationships between the amount of block of ICa(L) by either drug, seen during the second pulse, and the length of the first pulse were described by monoexponential functions reflecting onset of block, dependent on drug concentration. The onset of block by barnidipine was three times faster than that by nifedipine.With both drugs, recovery of ICa(L) was 50 times slower than under control conditions and described by monoexponential functions reflecting offset of block (independent of drug concentration). The offset of block with barnidipine was three times slower than that with nifedipine.The time constants of block and unblock of ICa(L) by both drugs were used to calculate binding and unbinding and to predict their effects at two frequencies.It is suggested that barnidipine exhibits a higher affinity to the inactivated Ca2+ channel state as compared to nifedipine. PMID:10952695

  12. Novel distribution of calreticulin to cardiomyocyte mitochondria and its increase in a rat model of dilated cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ming [Department of Cardiology, Second Affiliated Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi (China); Department of Respiratory Medicine, Second Affiliated Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi (China); Wei, Jin, E-mail: weijindr@163.com [Department of Cardiology, Second Affiliated Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi (China); Li, Yali [Department of Respiratory Medicine, Second Affiliated Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi (China); Shan, Hu; Yan, Rui; Lin, Lin [Department of Cardiology, Second Affiliated Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi (China); Zhang, Qiuhong [Department of Respiratory Medicine, Second Affiliated Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi (China); Xue, Jiahong [Department of Cardiology, Second Affiliated Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi (China)

    2014-06-20

    Highlights: • Calreticulin can also be found in cardiomyocyte mitochondria. • The mitochondrial content of calreticulin is increased in DCM hearts. • Increased expression of mitochondrial CRT may induce mitochondrial damage. • Mitochondrial CRT may inhibit the phosphorylation of mitochondrial STAT3. - Abstract: Background: Calreticulin (CRT), a Ca{sup 2+}-binding chaperone of the endoplasmic reticulum, can also be found in several other locations including the cytosol, nucleus, secretory granules, the outer side of the plasma membrane, and the extracellular matrix. Whether CRT is localized at mitochondria of cardiomyocytes and whether such localization is affected under DCM are still unclear. Methods and results: The DCM model was generated in rats by the daily oral administration of furazolidone for thirty weeks. Echocardiographic and hemodynamic studies demonstrated enlarged left ventricular dimensions and reduced systolic and diastolic function in DCM rats. Immuno-electron microscopy and Western blot showed that CRT was present in cardiomyocyte mitochondria and the mitochondrial content of CRT was increased in DCM hearts (P < 0.05). Morphometric analysis showed notable myocardial apoptosis and mitochondrial swelling with fractured or dissolved cristae in the DCM hearts. Compared with the control group, the mitochondrial membrane potential level of the freshly isolated cardiac mitochondria and the enzyme activities of cytochrome c oxidase and succinate dehydrogenase in the model group were significantly decreased (P < 0.05), and the myocardial apoptosis index and the caspase activities of caspase-9 and caspase-3 were significantly increased (P < 0.05). Pearson linear correlation analysis showed that the mitochondrial content of CRT had negative correlations with the mitochondrial function, and a positive correlation with myocardial apoptosis index (P < 0.001). The protein expression level of cytochrome c and the phosphorylation activity of STAT3 in the

  13. Bile acid-induced arrhythmia is mediated by muscarinic M2 receptors in neonatal rat cardiomyocytes.

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    Siti H Sheikh Abdul Kadir

    Full Text Available BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP is a common disease affecting up to 5% of pregnancies and which can cause fetal arrhythmia and sudden intrauterine death. We previously demonstrated that bile acid taurocholate (TC, which is raised in the bloodstream of ICP, can acutely alter the rate and rhythm of contraction and induce abnormal calcium destabilization in cultured neonatal rat cardiomyocytes (NRCM. Apart from their hepatic functions bile acids are ubiquitous signalling molecules with diverse systemic effects mediated by either the nuclear receptor FXR or by a recently discovered G-protein coupled receptor TGR5. We aim to investigate the mechanism of bile-acid induced arrhythmogenic effects in an in-vitro model of the fetal heart. METHODS AND RESULTS: Levels of bile acid transporters and nuclear receptor FXR were studied by quantitative real time PCR, western blot and immunostaining, which showed low levels of expression. We did not observe functional involvement of the canonical receptors FXR and TGR5. Instead, we found that TC binds to the muscarinic M(2 receptor in NRCM and serves as a partial agonist of this receptor in terms of inhibitory effect on intracellular cAMP and negative chronotropic response. Pharmacological inhibition and siRNA-knockdown of the M(2 receptor completely abolished the negative effect of TC on contraction, calcium transient amplitude and synchronisation in NRCM clusters. CONCLUSION: We conclude that in NRCM the TC-induced arrhythmia is mediated by the partial agonism at the M(2 receptor. This mechanism might serve as a promising new therapeutic target for fetal arrhythmia.

  14. Evans blue staining of cardiomyocytes induced by myocardial contrast echocardiography in rats: evidence for necrosis instead of apoptosis.

    Science.gov (United States)

    Miller, Douglas L; Li, Peng; Dou, Chunyan; Armstrong, William F; Gordon, David

    2007-12-01

    High mechanical index (MI) echocardiography with contrast agent has been shown to induce Evans blue staining of cardiomyocytes, seen 1 d after exposure, in addition to contraction band necrosis, seen immediately after exposure. This research examined the roles of necrosis vs. apoptosis in these bioeffects. Myocardial contrast echocardiography at high MI with 1:4 electrocardiogram triggering was performed in anesthetized rats at 1.5 MHz. Histologically observable cell injury was accumulated by infusing a high dose of 50 microL/kg ultrasound contrast media via tail vein for 5 min at the start of 10 min of scanning. Evans blue dye or propidium iodide was injected as an indicator of cardiomyocyte plasma membrane integrity. Histologic sections were stained using the terminal dUTP nick-end labeling (TUNEL) method for labeling nuclei with DNA degradation (e.g., apoptosis). Evans blue fluorescent cells were counted on frozen sections or on hematoxylin-stained and TUNEL-labeled paraffin sections. In addition, transmission electron microscopy was used to assess potential apoptotic nuclei. Hypercontraction and propidium iodide staining were observed immediately after imaging exposure. Although TUNEL-positive cells were evident after 4 h, these also had indications of contraction band necrosis, and features of apoptosis were not confirmed by electron microscopy. Inflammatory cell infiltration was evident after 24 h. A second, more subtle injury was recognized by Evans blue staining, with minimal inflammatory cell infiltration at the morphologically intact stained cells after 24 h. Apoptosis was not detected by the TUNEL method in the cardiomyocytes stained with Evans blue at 24 h. However, Evans blue-stained cell numbers declined after 48 h, with continued inflammatory cell infiltration. The initial insult for Evans blue-stained cardiomyocytes apparently induced partial permeability of the plasma membrane, which led to gradual degeneration (but not apoptosis) and necrosis

  15. 2,3-Butanedione monoxime attenuates the β-adrenergic response of the L-type Ca2+ current in rat ventricular cardiomyocytes

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    Julio Alvarez-Collazo

    2016-12-01

    Full Text Available Context: 2,3-Butanedione monoxime (BDM, an uncoupler of cardiac contraction, is commonly used in enzymatic dissociations to prevent hypercontraction of cardiomyocytes and in cardioplegic solutions to decrease oxygen demand during surgery. However, BDM affects multiple cellular systems including the L-type Ca2+ current (ICaL. If its phosphatase activity is the mechanism underlying the decrease ICaL in cardiomyocytes is a still unresolved question. Aims: To study the effects of BDM on ICaL of rat ventricular cardiomyocytes focusing our attention on the response of ICaL to β-adrenergic stimulation. Methods: The whole-cell patch-clamp method was used to study ICaL in enzymatically dissociated rat ventricular cardiomyocytes. Results: Extracellular BDM (5 mM decreased peak ICaL by ≈45%, slowed its fast inactivation but accelerated its slow inactivation. Cardiomyocytes incubated in BDM (≥ 30 min; 5 mM perfused with normal extracellular solution, showed normal ICaL properties. However, extracellular BDM (in cardiomyocytes incubated in BDM or not markedly reduced the response of ICaL to isoproterenol (1 µM. BDM also strongly attenuated the increase of ICaL in cardiomyocytes intracellularly perfused with cyclic AMP (50 µM. Conclusions: The decrease of basal ICaL by BDM is not related to its dephosphorylation action. Its effect on the Ca2+ channel occurs most probably in a site in the extracellular side or within the sarcolemmal membrane. Due to its phosphatase action, BDM strongly attenuates the response of ICaL to β-adrenergic stimulation. These actions of BDM must be taken into account both for its use in the dissociation of cardiomyocytes and in cardioplegic solutions and myocardial preservation.

  16. Vitamin E ameliorates the decremental effect of paraquat on cardiomyocyte contractility in rats.

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    Mohamed Abdelmonem Fahim

    Full Text Available BACKGROUND: Exposure to pesticides and industrial toxins are implicated in cardiovascular disease. Paraquat (PAR is a toxic chemical widely used as an herbicide in developing countries and described as a major suicide agent. The hypothesis tested here is that PAR induced myocardial dysfunction may be attributed to altered mechanisms of Ca(2+ transport which are in turn possibly linked to oxidative stress. The mechanisms of PAR induced myocardial dysfunction and the impact of antioxidant protection was investigated in rat ventricular myocytes. METHODOLOGY: Forty adult male Wistar rats were divided into 4 groups receiving the following daily intraperitoneal injections for 3 weeks: Group 1 PAR (10 mg/kg, Control Group 2 saline, Group 3 vitamin E (100 mg/kg and Group 4 PAR (10 mg/kg and vitamin E (100 mg/kg. Ventricular action potentials were measured in isolated perfused heart, shortening and intracellular Ca(2+ in electrically stimulated ventricular myocytes by video edge detection and fluorescence photometry techniques, and superoxide dismutase (SOD and catalase (CAT levels in heart tissue. PRINCIPAL FINDINGS: Spontaneous heart rate, resting cell length, time to peak (TPK and time to half (THALF relaxation of myocyte shortening were unaltered. Amplitude of shortening was significantly reduced in PAR treated rats (4.99±0.26% and was normalized by vitamin E (7.46±0.44% compared to controls (7.87±0.52%. PAR significantly increased myocytes resting intracellular Ca(2+ whilst TPK and THALF decay and amplitude of the Ca(2+ transient were unaltered. The fura-2-cell length trajectory during the relaxation of the twitch contraction was significantly altered in myocytes from PAR treated rats compared to controls suggesting altered myofilament sensitivity to Ca(2+ as it was normalized by vitamin E treatment. A significant increase in SOD and CAT activities was observed in both PAR and vitamin E plus PAR groups. CONCLUSIONS: PAR exposure compromised rats

  17. Effects of interleukin-18 on bioelectric activity of rat atrial cardiomyocytes under normal conditions and during gradual stretching of the tissue.

    Science.gov (United States)

    Mitrokhin, V M; Makarenko, E Yu; Abramochkin, D V; Sutyagin, P V; Kamkin, A G

    2014-08-01

    Effects of IL-18 (50 ng/ml) on bioelectric activity of rat atrial cardiomyocytes under normal conditions and after gradual stretching of the tissue was studied using microelectrode technique. It was shown that in 85% experiments, IL-18 increased the duration of action potential at the level of 25, 50, and 90% repolarization without changing the magnitude of the resting potential, amplitude and repetition rate of action potentials, and cardiomyocyte contraction force. In addition, IL-18 abolished mechanically induced changes in the shape of action potentials during stretching.

  18. Antihistamines modulate the integrin signaling pathway in h9c2 rat cardiomyocytes: Possible association with cardiotoxicity.

    Science.gov (United States)

    Yun, J S; Kim, S Y

    2015-08-01

    The identification of biomarkers for toxicity prediction is crucial for drug development and safety evaluation. The selective and specific biomarkers for antihistamines-induced cardiotoxicity is not well identified yet. In order to evaluate the mechanism of the life-threatening effects caused by antihistamines, we used DNA microarrays to analyze genomic profiles in H9C2 rat cardiomyocytes that were treated with antihistamines. The gene expression profiles from drug-treated cells revealed changes in the integrin signaling pathway, suggesting that cardiac arrhythmias induced by antihistamine treatment may be mediated by changes in integrin-mediated signaling. It has been reported that integrin plays a role in QT prolongation that may induce cardiac arrhythmia. These results indicate that the integrin-mediated signaling pathway induced by antihistamines is involved in various biological mechanisms that lead to cardiac QT prolongation. Therefore, we suggest that genomic profiling of antihistamine-treated cardiomyocytes has the potential to reveal the mechanism of adverse drug reactions, and this signal pathway is applicable to prediction of in vitro cardiotoxicity induced by antihistamines as a biomarker candidate.

  19. Protective effect of pioglitazone on cardiomyocyte apoptosis in low-dose streptozotocin & high-fat diet-induced type-2 diabetes in rats

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    Uma Bhandari

    2015-01-01

    Full Text Available Background & objectives: Cardiomyocyte apoptosis is one of the pathologic phenomena associated with diabetes and related conditions including obesity, insulin resistance and hyperlipidaemia. In the present study, the protective effects of pioglitazone on cardiomyocyte apoptosis was evaluated in experimental diabetes induced by low dose of streptozoticin (STZ combined with high fat diet (HFD in rats. Methods: Male Wistar rats (150-200 g were injected with low-dose STZ (45 mg/kg, i.v., single dose and orally fed with a HFD (20 g/day/rat for a period of 28 days and simultaneously treated with pioglitazone (20 mg/kg/p.o. for a period of 21 days (from 8 th day to 28 th day. On 29 th day blood was collected, serum separated and used for biochemical parameters. Heart tissue was used for cardiomyocyte apoptosis measurement and also for histopathological examination. Results: Pioglitazone treatment resulted in a decrease in cardiomyocyte apoptosis as revealed by a decrease in cardiac caspase-3, lactate dehydrogenase (LDH levels and DNA fragmentation, and an increase in Na+K+ATPase levels in diabetic rats. Cardiac histology of diabetic control rats showed dense focal fatty infiltration in the myocardial cells whereas normal architecture with regular morphology and well preserved cytoplasm was observed with pioglitazone treatment. Pioglitazone treatment significantly reduced the heart rate, mean arterial blood pressure, body mass index (BMI and levels of serum glucose, leptin, insulin, HOMA-IR, total cholesterol (TC and triglycerides (TGs, apoliproprotein-B glycosylated haemoglobin (HbA1c levels and atherogenic index, and increased the levels of serum high density lipoprotein cholesterol (HDL-C and cardiac antioxidant enzymes. Interpretation & conclusions: The present study results suggest that pioglitazone possesses cardiac anti-apoptotic potential in diabetic rat model and can be further explored for its use for treatment of diabetic cardiomyopathy.

  20. Effects of neutral sulfate berberine on LPS-induced cardiomyocyte TNF-αsecretion, abnormal calcium cycling, and cardiac dysfunction in rats

    Institute of Scientific and Technical Information of China (English)

    Jing YANG; Hua-dong WANG; Da-xiang LU; Yan-ping WANG; Ren-bin QI; Jing LI; Fei LI; Chu-jie LI

    2006-01-01

    Aim: To evaluate the effect of neutral sulfate berberine on cardiac function, tumornecrosis factor α (TNF-α) release, and intracellular calcium concentration ([Ca2+]i)in cardiomyocytes exposed to lipopolysaccharide (LPS). Methods: Primary cultured rat cardiomyocytes were prepared from ventricles of 3-4-day old SpragueDawley rats. TNF-α concentrations in cell-conditioned media were measured by using a Quantikine enzyme-linked immunosorbent assay kit, and cardiomyocyte [Ca2+]i was measured by using Fura-2/AM. The isolated rat hearts were perfused in the Langendorff mode. Results: LPS at doses of 1, 5, 10, and 20 μg/mL markedly stimulated TNF-α secretion from cardiomyocytes, and neutral sulfate berberine inhibited LPS-induced TNF-α production. Intracellular calcium concentration was significantly decreased after LPS stimulation for 1 h, and increased 2 h after LPS treatment. Pretreatment with neutral sulfate berberine reversed the LPS-induced [Ca2+]i alterations, although neutral sulfate berberine did not inhibit a rapid increase in cardiomyocyte [Ca2+]i induced by LPS. Perfusion of isolated hearts with LPS (100 μg/mL) for 20 min resulted in significantly impaired cardiac performance at 120 min after LPS challenge: the maximal rate of left ventricular pressure rise and fall (±dp/dtmax) decreased compared with the control. In contrast, ±dp/dtmax at 120min in hearts perfused with neutral sulfate berberine (1 μmol/L) for 10 min followed by 20 min LPS (100 μg/mL) was greater than the corresponding value in the LPS group. Conclusion: Neutral sulfate berberine inhibits LPS-stimulated myocardial TNF-α production, impairs calcium cycling, and improves LPS-induced contractile dysfunction in intact heart.

  1. Spatiotemporal stability of neonatal rat cardiomyocyte monolayers spontaneous activity is dependent on the culture substrate.

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    Jonathan Boudreau-Béland

    Full Text Available In native conditions, cardiac cells must continuously comply with diverse stimuli necessitating a perpetual adaptation. Polydimethylsiloxane (PDMS is commonly used in cell culture to study cellular response to changes in the mechanical environment. The aim of this study was to evaluate the impact of using PDMS substrates on the properties of spontaneous activity of cardiomyocyte monolayer cultures. We compared PDMS to the gold standard normally used in culture: a glass substrate. Although mean frequency of spontaneous activity remained unaltered, incidence of reentrant activity was significantly higher in samples cultured on glass compared to PDMS substrates. Higher spatial and temporal instability of the spontaneous rate activation was found when cardiomyocytes were cultured on PDMS, and correlated with decreased connexin-43 and increased CaV3.1 and HCN2 mRNA levels. Compared to cultures on glass, cultures on PDMS were associated with the strongest response to isoproterenol and acetylcholine. These results reveal the importance of carefully selecting the culture substrate for studies involving mechanical stimulation, especially for tissue engineering or pharmacological high-throughput screening of cardiac tissue analog.

  2. Lipotoxic Palmitate Impairs the Rate of β-Oxidation and Citric Acid Cycle Flux in Rat Neonatal Cardiomyocytes

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    Taha Haffar

    2016-12-01

    Full Text Available Background/Aims: Diabetic hearts exhibit intracellular lipid accumulation. This suggests that the degree of fatty acid oxidation (FAO in these hearts is insufficient to handle the elevated lipid uptake. We previously showed that palmitate impaired the rate of FAO in primary rat neonatal cardiomyocytes. Here we were interested in characterizing the site of FAO impairment induced by palmitate since it may shed light on the metabolic dysfunction that leads to lipid accumulation in diabetic hearts. Methods: We measured fatty acid oxidation, acetyl-CoA oxidation, and carnitine palmitoyl transferase (Cpt1b activity. We measured both forward and reverse aconitase activity, as well as NAD+ dependent isocitrate dehydrogenase activity. We also measured reactive oxygen species using the 2', 7'-Dichlorofluorescin Diacetate (DCFDA assay. Finally we used thin layer chromatography to assess diacylglycerol (DAG levels. Results: We found that palmitate significantly impaired mitochondrial β-oxidation as well as citric acid cycle flux, but not Cpt1b activity. Palmitate negatively affected net aconitase activity and isocitrate dehydrogenase activity. The impaired enzyme activities were not due to oxidative stress but may be due to DAG mediated PKC activation. Conclusion: This work demonstrates that palmitate, a highly abundant fatty acid in human diets, causes impaired β-oxidation and citric acid cycle flux in primary neonatal cardiomyocytes. This metabolic defect occurs prior to cell death suggesting that it is a cause, rather than a consequence of palmitate mediated lipotoxicity. This impaired mitochondrial metabolism can have important implications for metabolic diseases such as diabetes and obesity.

  3. Preparation of liposomal amiodarone and investigation of its cardiomyocyte-targeting ability in cardiac radiofrequency ablation rat model

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    Zhuge Y

    2016-05-01

    Full Text Available Ying Zhuge,1,* Zhi-Feng Zheng,1,* Mu-Qing Xie,2 Lin Li,2 Fang Wang,1 Feng Gao2,3 1Department of Cardiology, Shanghai First People’s Hospital of Nanjing Medical University, 2Department of Pharmaceutics, School of Pharmacy, 3Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, People’s Republic of China*These authors contributed equally to this workAbstract: The objective of this study was to develop an amiodarone hydrochloride (ADHC-loaded liposome (ADHC-L formulation and investigate its potential for cardiomyocyte targeting after cardiac radiofrequency ablation (CA in vivo. The ADHC-L was prepared by thin-film method combined with ultrasonication and extrusion. The preparation process was optimized by Box–Behnken design with encapsulation efficiency as the main evaluation index. The optimum formulation was quantitatively obtained with a diameter of 99.9±0.4 nm, a zeta potential of 35.1±10.9 mV, and an encapsulation efficiency of 99.5%±13.3%. Transmission electron microscopy showed that the liposomes were spherical particles with integrated bilayers and well dispersed with high colloidal stability. Pharmacokinetic studies were investigated in rats after intravenous administration, which revealed that compared with free ADHC treatment, ADHC-L treatment showed a 5.1-fold increase in the area under the plasma drug concentration–time curve over a period of 24 hours (AUC0–24 h and an 8.5-fold increase in mean residence time, suggesting that ADHC-L could facilitate drug release in a more stable and sustained manner while increasing the circulation time of ADHC, especially in the blood. Biodistribution studies of ADHC-L demonstrated that ADHC concentration in the heart was 4.1 times higher after ADHC-L treatment in CA rat model compared with ADHC-L sham-operated treatment at 20 minutes postinjection. Fluorescence imaging studies further proved that the heart

  4. Inhibition of aldehyde dehydrogenase 2 activity enhances antimycin-induced rat cardiomyocytes apoptosis through activation of MAPK signaling pathway.

    Science.gov (United States)

    Zhang, Peng; Xu, Danling; Wang, Shijun; Fu, Han; Wang, Keqiang; Zou, Yunzeng; Sun, Aijun; Ge, Junbo

    2011-12-01

    Aldehyde dehydrogenase 2 (ALDH2), a mitochondrial-specific enzyme, has been proved to be involved in oxidative stress-induced cell apoptosis, while little is known in cardiomyocytes. This study was aimed at investigating the role of ALDH2 in antimycin A-induced cardiomyocytes apoptosis by suppressing ALDH2 activity with a specific ALDH2 inhibitor Daidzin. Antimycin A (40μg/ml) was used to induce neonatal cardiomyocytes apoptosis. Daidzin (60μM) effectively inhibited ALDH2 activity by 50% without own effect on cell apoptosis, and significantly enhanced antimycin A-induced cardiomyocytes apoptosis from 33.5±4.4 to 56.5±6.4% (Hochest method, pdaidzin treated cardiomyocytes compared to the cells treated with antimycin A alone. These findings indicated that modifying mitochondrial ALDH2 activity/expression might be a potential therapeutic option on reducing oxidative insults induced cardiomyocytes apoptosis.

  5. Increased expression of 78 kD glucose-regulated protein promotes cardiomyocyte apoptosis in a rat model of liver cirrhosis

    Science.gov (United States)

    Zhang, Lili; Zhang, Huiying; Lv, Minli; Jia, Jiantao; Fan, Yimin; Tian, Xiaoxia; Li, Xujiong; Li, Baohong; Ji, Jingquan; Wang, Limin; Zhao, Zhongfu; Han, Dewu; Ji, Cheng

    2015-01-01

    Aims: This study was to investigate the role and underlying mechanism of 78 kD glucose-regulated protein (GRP78) in cardiomyocyte apoptosis in a rat model of liver cirrhosis. Methods: A rat model of liver cirrhosis was established with multiple pathogenic factors. A total of 42 male SD rats were randomly divided into the liver cirrhosis group and control group. Cardiac structure analysis was performed to assess alterations in cardiac structure. Cardiomyocytes apoptosis was detected by TdT-mediated dUTP nick end labeling method. Expression of GRP78, CCAAT/enhancer-binding protein homologous protein (CHOP), caspase-12, nuclear factor kappa-light-chain-enhancer of activated B cells p65 subunit (NF-κB p65) and B cell lymphoma-2 (Bcl-2) was detected by immunohistochemical staining. Results: The ratios of left ventricular wall thickness to heart weight and heart weight to body weight were significantly increased with the progression of liver cirrhosis (P < 0.05). Apoptosis index of cardiomyocytes was significantly increased with the progression of liver cirrhosis (P < 0.05). The expression levels of GRP78, CHOP and caspase-12 were significantly increased in the progression of liver cirrhosis (P < 0.05). The expression levels of NF-κB p65 and Bcl-2 were highest in the 4-wk liver cirrhosis, and they were decreased in the 6-wk and 8-wk in the progression of liver cirrhosis. GRP78 expression levels were positively correlated with apoptosis index, CHOP and caspase-12 expression levels (P < 0.05). CHOP expression levels were negatively correlated with NF-κB p65 and Bcl-2 expression levels (P < 0.05). Conclusion: Increased expression of GRP78 promotes cardiomyocyte apoptosis in rats with cirrhotic cardiomyopathy. PMID:26464674

  6. Effects of fructose-1,6-diphosphate on concentration of calcium and activities of sarcoplosnic Ca2+-ATPase in cardiomyocytes of Adriamycin-treated rats

    Institute of Scientific and Technical Information of China (English)

    CAI Wei; CHEN Jun-zhu; RUAN Li-ming; WANG Yi-na

    2005-01-01

    Objective: To observe the effects of fructose-1,6-diphosphate (FDP) on serum levels of cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB), as well as the concentration of calcium in cardiomyocytes (Myo[Ca2+]) and activity of sarcoplosnic Ca2+-ATPase (SRCa2+-ATPase) in Adriamycin (ADR)-treated rats. Methods: Rats were intraperitoneally injected with ADR (2.5mg/kg every other day for 6 times) and then with different dosages of FDP (every other day for twenty-one times). Bi-antibodies sandwich Enzyme linked immune absorption assay (ELISA) was performed to detect serum level of cTnI. CK-MB was detected by monoclonal antibody, Myo[Ca2+] was detected by fluorescent spectrophotometry and the activity of SRCa2+-ATPase was detected by inorganic phosphate method. Results: FDP (300, 600, 1200 mg/kg) significantly reduced the serum levels of cTnI and CK-MB, while at the same time decreased calcium concentration and increased SRCa2+-ATPase activity in cardiomyocytes of ADR-treated rats (P<0.01). Conclusions: FDP might alleviate the cardiotoxic effects induced by ADR through decreasing calcium level as well as increasing SRCa2+-ATPase activity in cardiomyocytes.

  7. Activation of β-Adrenoceptors by Dobutamine May Induce a Higher Expression of Peroxisome Proliferator-Activated Receptors δ (PPARδ in Neonatal Rat Cardiomyocytes

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    Ming-Ting Chou

    2012-01-01

    Full Text Available Recent evidence showed the role of peroxisome proliferator-activated receptors (PPARs in cardiac function. Cardiac contraction induced by various agents is critical in restoring the activity of peroxisome proliferator-activated receptors δ (PPARδ in cardiac myopathy. Because dobutamine is an agent widely used to treat heart failure in emergency setting, this study is aimed to investigate the change of PPARδ in response to dobutamine. Neonatal rat cardiomyocytes were used to examine the effects of dobutamine on PPARδ expression levels and cardiac troponin I (cTnI phosphorylation via Western blotting analysis. We show that treatment with dobutamine increased PPARδ expression and cTnI phosphorylation in a time- and dose-dependent manner in neonatal rat cardiomyocytes. These increases were blocked by the antagonist of β1-adrenoceptors. Also, the action of dobutamine was related to the increase of calcium ions and diminished by chelating intracellular calcium. Additionally, dobutamine-induced action was reduced by the inhibition of downstream messengers involved in this calcium-related pathway. Moreover, deletion of PPARδ using siRNA generated the reduction of cTnI phosphorylation in cardiomyocytes treated with dobutamine. Thus, we concluded that PPARδ is increased by dobutamine in cardiac cells.

  8. High-frequency sarcomeric auto-oscillations induced by heating in living neonatal cardiomyocytes of the rat

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    Shintani, Seine A.; Oyama, Kotaro [Department of Pure and Applied Physics, School of Advanced Science and Engineering, Waseda University, Tokyo (Japan); Fukuda, Norio, E-mail: noriof@jikei.ac.jp [Department of Cell Physiology, The Jikei University School of Medicine, Tokyo (Japan); Ishiwata, Shin’ichi, E-mail: ishiwata@waseda.jp [Department of Pure and Applied Physics, School of Advanced Science and Engineering, Waseda University, Tokyo (Japan); WASEDA Bioscience Research Institute in Singapore (WABIOS) (Singapore)

    2015-02-06

    Highlights: • We tested the effects of infra-red laser irradiation on cardiac sarcomere dynamics. • A rise in temperature (>∼38 °C) induced high-frequency sarcomeric auto-oscillations. • These oscillations occurred with and without blockade of intracellular Ca{sup 2+} stores. • Cardiac sarcomeres can play a role as a temperature-dependent rhythm generator. - Abstract: In the present study, we investigated the effects of infra-red laser irradiation on sarcomere dynamics in living neonatal cardiomyocytes of the rat. A rapid increase in temperature to >∼38 °C induced [Ca{sup 2+}]{sub i}-independent high-frequency (∼5–10 Hz) sarcomeric auto-oscillations (Hyperthermal Sarcomeric Oscillations; HSOs). In myocytes with the intact sarcoplasmic reticular functions, HSOs coexisted with [Ca{sup 2+}]{sub i}-dependent spontaneous beating in the same sarcomeres, with markedly varying frequencies (∼10 and ∼1 Hz for the former and latter, respectively). HSOs likewise occurred following blockade of the sarcoplasmic reticular functions, with the amplitude becoming larger and the frequency lower in a time-dependent manner. The present findings suggest that in the mammalian heart, sarcomeres spontaneously oscillate at higher frequencies than the sinus rhythm at temperatures slightly above the physiologically relevant levels.

  9. Regulation of gap-junction protein connexin 43 by β-adrenergic receptor stimulation in rat cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    Yi XIA; Kai-zheng GONG; Ming XU; You-yi ZHANG; Ji-hong GUO; Yao SONG; Ping ZHANG

    2009-01-01

    Aim:β-adrenergic receptor (β-AR) agonists are among the most potent factors regulating cardiac electrophysiological properties.Connexin 43 (Cx43),the predominant gap-junction protein in the heart,has an indispensable role in modulating cardiac electric activities by affecting gap-junction function.The present study investigates the effects of short-term stimulation of β-AR subtypes on Cx43 expression and gap junction intercellular communication (GJIC) function.Methods:The level of Cx43 expression in neonatal rat cardiomyocytes (NRCM) was detected by a Western blotting assay.The GJIC function was evaluated by scrape loading/dye transfer assay.Results:Stimulation of β-AR by the agonist isoproterenol for 5 min induces the up-regulation of nonphosphorylated Cx43 protein level,but not total Cx43.Selective β2-AR inhibitor ICI 118551,but not β-AR inhibitor CGP20712,could fully abolish the effect.Moreover,pretreatment with both protein kinase A inhibitor H89 and G,protein inhibitor pertussis toxin also inhibited the isoproterenol-induced increase of nonphosphorylated Cx43 expression.Isoproterenol-induced up-regulation of nonphosphorylated Cx43 is accompanied with enhanced GJIC function.Conclusion:Taken together,β2-AR stimulation increases the expression of nonphosphorylated Cx43,thereby enhancing the gating function of gap junctions in cardiac myocytes in both a protein kinase A-and G1-dependent manner.

  10. Molecular identity of the late sodium current in adult dog cardiomyocytes identified by Nav1.5 antisense inhibition.

    Science.gov (United States)

    Maltsev, Victor A; Kyle, John W; Mishra, Sudhish; Undrovinas, Abertas

    2008-08-01

    Late Na(+) current (I(NaL)) is a major component of the action potential plateau in human and canine myocardium. Since I(NaL) is increased in heart failure and ischemia, it represents a novel potential target for cardioprotection. However, the molecular identity of I(NaL) remains unclear. We tested the hypothesis that the cardiac Na(+) channel isoform (Na(v)1.5) is a major contributor to I(NaL) in adult dog ventricular cardiomyocytes (VCs). Cultured VCs were exposed to an antisense morpholino-based oligonucleotide (Na(v)1.5 asOligo) targeting the region around the start codon of Na(v)1.5 mRNA or a control nonsense oligonucleotide (nsOligo). Densities of both transient Na(+) current (I(NaT)) and I(NaL) (both in pA/pF) were monitored by whole cell patch clamp. In HEK293 cells expressing Na(v)1.5 or Na(v)1.2, Na(v)1.5 asOligo specifically silenced functional expression of Na(v)1.5 (up to 60% of the initial I(NaT)) but not Na(v)1.2. In both nsOligo-treated controls and untreated VCs, I(NaT) and I(NaL) remained unchanged for up to 5 days. However, both I(NaT) and I(NaL) decreased exponentially with similar time courses (tau = 46 and 56 h, respectively) after VCs were treated with Na(v)1.5 asOligo without changes in 1) decay kinetics, 2) steady-state activation and inactivation, and 3) the ratio of I(NaL) to I(NaT). Four days after exposure to Na(v)1.5 asOligo, I(NaT) and I(NaL) amounted to 68 +/- 6% (mean +/- SE; n = 20, P < 0.01) and 60 +/- 7% (n = 11, P < 0.018) of those in VCs treated by nsOligo, respectively. We conclude that in adult dog heart Na(v)1.5 sodium channels have a "functional half-life" of approximately 35 h (0.69tau) and make a major contribution to I(NaL).

  11. A comparative study of two clerodane diterpenes from Baccharis trimera (Less.) DC. on the influx and mobilization of intracellular calcium in rat cardiomyocytes.

    Science.gov (United States)

    Garcia, Francisca Adilfa de Oliveira; Tanae, Mirtes Midori; Torres, Luce Maria Brandão; Lapa, Antônio José; de Lima-Landman, Maria Teresa Riggio; Souccar, Caden

    2014-01-01

    Baccharis trimera (Less.) D.C. (Asteraceae) is a medicinal species native to South America and used in Brazilian folk medicine to treat gastrointestinal and liver diseases, kidney disorders and diabetes. The aqueous extract (AE) of the aerial parts of this species presented two mainly constituents: the ent-clerodane diterpene (Fig. 1) and the neo-clerodane diterpene (Fig. 2). The objective of this work was to study their activities on the blockade of Ca(2+)-induced contractions in KCL-depolarized rat portal vein preparations, and on the influx and mobilization of cytosolic calcium in rat cardiomyocytes by fluorescence measurements. The results showed that both the neo- and the ent-clerodane diterpenes reduced the maximal contractions induced by CaCl2, in KCl depolarized rat portal vein preparations, without modifying the EC50. The data on the concentration of cytosolic calcium ([Ca(2+)]c) showed that, while the neo-clerodane diterpene stimulates the mobilization of [Ca(2+)]c in rat cardiomyocytes, this effect was not observed with the ent-clerodane diterpene. On the other hand, the influx of calcium was not altered by the neo-clerodane diterpene, but was reduced in the presence of the ent-clerodane diterpene, indicating that this compound induces a blockade of the voltage-dependent calcium channels.

  12. Compensatory function of bradykinin B1 receptor in the inhibitory effect of captopril on cardiomyocyte hypertrophy and cardiac fibroblast proliferation in neonatal rats

    Institute of Scientific and Technical Information of China (English)

    ZOU Jun; REN Jiang-hua; FENG Dan; WANG Hong; XU Jiang

    2008-01-01

    Background Bradykinin(BK)acts mainly on two receptor subtypes:B1 and B2,and activation of B2 receptor mediates the most well-known cardioprotective effects of angiotensin converting enzyme inhibitors(ACEi),however,the role that B1 receptor plays in ACEi has not been fully defined.We examined the role of B1 receptor in the inhibitory effect of ACE inhibitor captopril on rat cardiomyocyte hypertrophy and cardiac fibroblast proliferation induced by angiotensin Ⅱ(Ang Ⅱ) and explored its possible mechanism.Methods Neonatal cardiomyocytes and cardiac fibroblasts(CFs)were randomly treated with Ang Ⅱ,captopril,B2 receptor antagonist(HOE-140)and B1 receptor antagonist(des-Arg10,Leu9-kallidin)alone or in combination.Flow cytometry was used to evaluate cell cycle,size and protein content.Nitric oxide(NO)and intracellular cyclic guanosine monophosphate(cGMP)level were measured by colorimetry and radioimmunoassay.Results After the CFs and cardiomyocytes were incubated with 0.1 μmol/L Ang Ⅱ for 48 hours.the percentage of CFs in the S stage,cardiomyocytes size and protein content significantly increased(both P<0.01 vs control),and these increases were inhibited by 10 μmol/L captopril.However,NO and cGMP levels were significantly higher than that with Ang Ⅱ alone(both P<0.01).1 μmol/L HOE-140 or 0.1 μmol/L des-Arg10,Leu9-kallidin attenuated the effects of captopril,which was blunted further by blockade of both B1 and B2 receptors.Conclusions Acting via B2 receptor,BK contributes to the antihypertrophic and antiproliferative effects of captopril on cardiomyocytes and CFs.In the absence of B2 receptor,B1 receptor may act a compensatory mechanism for the B2 receptor and contribute to the inhibition of cardiomyocyte hypertrophy and CFs proliferation by captopril.NO and cGMP play an important role in the effect of B1 receptor.

  13. Acrolein-induced cell apoptosis in adult mice cardiomyocytes%丙烯醛致成年小鼠心肌细胞凋亡的作用

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    王丽娟; 胡健; 齐国先

    2007-01-01

    目的 丙烯醛是一种具有高反应性的不饱和脂肪醛,它是丙烯胺的代谢产物,在体内外对各种细胞具有毒性作用.本研究探讨丙烯醛对成年小鼠心肌细胞氧自由基及钙浓度的影响及细胞凋亡的作用.方法 采用改良langendorff方法分离成年小鼠心肌细胞.分别应用DCF及Fura-2 AM测定细胞内氧自由基水平及钙离子钙浓度,WST法测定心肌细胞存活率,观察凋亡DNA片段及细胞凋亡的形态变化.结果 应用1 μmol/L丙烯醛可明显增加心肌细胞内氧自由基水平及钙离子浓度,分别达到用药前的12倍及2倍.而且,丙烯醛引起心肌细胞损伤是一种剂量依赖性的,应用25,50及100 μmol/L丙烯醛治疗的心肌细胞存活率明显低于对照组(P<0.01).丙烯醛处理心肌细胞后,可观察到DNA断裂片段及典型的凋亡细胞形态变化.结论 丙烯醛可引起成年小鼠心肌细胞的凋亡,其作用可能是由于细胞内氧自由及钙浓度的增加.%Purpose To investigate the responsiveness of intracellular oxygen free radical and calcium on acrolein exposure and acrolein-induced cardiomyocytes apoptosis. Methods The viable adult mice cardiac myocytes were isolated by modified langendorff methods. We have examined the intracellular oxygen free radical and calcium concentration using DCF and Fura-2 AM, and the cardiomyocytes viability with WST assay. Are evaluated the DNA ladder pattern and cell apoptotic morphology on the adult mice cardiomyocytes that are exposed to acrolein. Results Our results show that acrolein can increase markedly the intracellular oxygen free radical and calcium concentration, that reach 12 fold and twofold respectively compared to the resting value when the cells were exposed to 1 μmol/L of acrolein. Moreover, the injury induced by acrolein in cardiac myocytes is concentration-dependent. The cardiomyocytes viability treated with 25, 50, 100 μmol/L of acrolein respectively were significantly lower

  14. The GSTM2 C-Terminal Domain Depresses Contractility and Ca2+ Transients in Neonatal Rat Ventricular Cardiomyocytes

    Science.gov (United States)

    Hewawasam, Ruwani P.; Liu, Dan; Casarotto, Marco G.; Board, Philip G.; Dulhunty, Angela F.

    2016-01-01

    The cardiac ryanodine receptor (RyR2) is an intracellular ion channel that regulates Ca2+ release from the sarcoplasmic reticulum (SR) during excitation–contraction coupling in the heart. The glutathione transferases (GSTs) are a family of phase II detoxification enzymes with additional functions including the selective inhibition of RyR2, with therapeutic implications. The C-terminal half of GSTM2 (GSTM2C) is essential for RyR2 inhibition, and mutations F157A and Y160A within GSTM2C prevent the inhibitory action. Our objective in this investigation was to determine whether GSTM2C can enter cultured rat neonatal ventricular cardiomyocytes and influence contractility. We show that oregon green-tagged GSTM2C (at 1 μM) is internalized into the myocytes and it reduces spontaneous contraction frequency and myocyte shortening. Field stimulation of myocytes evoked contraction in the same percentage of myocytes treated either with media alone or media plus 15 μM GSTM2C. Myocyte shortening during contraction was significantly reduced by exposure to 15 μM GSTM2C, but not 5 and 10 μM GSTM2C and was unaffected by exposure to 15 μM of the mutants Y160A or F157A. The amplitude of the Ca2+ transient in the 15 μM GSTM2C - treated myocytes was significantly decreased, the rise time was significantly longer and the decay time was significantly shorter than in control myocytes. The Ca2+ transient was not altered by exposure to Y160A or F157A. The results are consistent with GSTM2C entering the myocytes and inhibiting RyR2, in a manner that indicates a possible therapeutic potential for treatment of arrhythmia in the neonatal heart. PMID:27612301

  15. Transformation of adult rat cardiac myocytes in primary culture.

    Science.gov (United States)

    Banyasz, Tamas; Lozinskiy, Ilya; Payne, Charles E; Edelmann, Stephanie; Norton, Byron; Chen, Biyi; Chen-Izu, Ye; Izu, Leighton T; Balke, C William

    2008-03-01

    We characterized the morphological, electrical and mechanical alterations of cardiomyocytes in long-term cell culture. Morphometric parameters, sarcomere length, T-tubule density, cell capacitance, L-type calcium current (I(Ca,L)), inward rectifier potassium current (I(K1)), cytosolic calcium transients, action potential and contractile parameters of adult rat ventricular myocytes were determined on each day of 5 days in culture. We also analysed the health of the myocytes using an apoptotic/necrotic viability assay. The data show that myocytes undergo profound morphological and functional changes during culture. We observed a progressive reduction in the cell area (from 2502 +/- 70 microm(2) on day 0 to 1432 +/- 50 microm(2) on day 5), T-tubule density, systolic shortening (from 0.11 +/- 0.02 to 0.05 +/- 0.01 microm) and amplitude of calcium transients (from 1.54 +/- 0.19 to 0.67 +/- 0.19) over 5 days of culture. The negative force-frequency relationship, characteristic of rat myocardium, was maintained during the first 2 days but diminished thereafter. Cell capacitance (from 156 +/- 8 to 105 +/- 11 pF) and membrane currents were also reduced (I(Ca,L), from 3.98 +/- 0.39 to 2.12 +/- 0.37 pA pF; and I(K1), from 34.34p +/- 2.31 to 18.00 +/- 5.97 pA pF(-1)). We observed progressive depolarization of the resting membrane potential during culture (from 77.3 +/- 2.5 to 34.2 +/- 5.9 mV) and, consequently, action potential morphology was profoundly altered as well. The results of the viability assays indicate that these alterations could not be attributed to either apoptosis or necrosis but are rather an adaptation to the culture conditions over time.

  16. Mechanical stretch induces mitochondria-dependent apoptosis in neonatal rat cardiomyocytes and G2/M accumulation in cardiac fibroblasts

    Institute of Scientific and Technical Information of China (English)

    Xu Dong LIAO; Xiao Hui WANG; Hai Jing JIN; Lan Ying CHEN; Quan CHEN

    2004-01-01

    Heart remodeling is associated with the loss of cardiomyocytes and increase of fibrous tissue owing to abnormal mechanical load in a number of heart disease conditions. In present study,a well-described in vitro sustained stretch model was employed to study mechanical stretch-induced responses in both neonatal cardiomyocytes and cardiac fibroblasts. Cardiomyocytes,but not cardiac fibroblasts,underwent mitochondria-dependent apoptosis as evidenced by cytochrome c (cyto c) and Smac/DIABLO release from mitochondria into cytosol accompanied by mitochondrial membrane potential (△ψm) reduction,indicative of mitochondrial permeability transition pore (PTP)opening. Cyclosporin A,an inhibitor of PTP,inhibited stretch-induced cyto c release,△ψm reduction and apoptosis,suggesting an important role of mitochondrial PTP in stretch-induced apoptosis. The stretch also resulted in increased expression of the pro-apoptotic Bcl-2 family proteins,including Bax and Bad,in cardiomyocytes,but not in fibroblasts. Bax was accumulated in mitochondria following stretch. Cell permeable Bid-BH3 peptide could induce and facilitate stretch-induced apoptosis and △ψm reduction in cardiomyocytes. These results suggest that Bcl-2 family proteins play an important role in coupling stretch signaling to mitochondrial death machinery,probably by targeting to PTP. Interestingly,the levels of p53 were increased at 12 h after stretch although we observed that Bax upregulation and apoptosis occurred as early as 1 h. Adenovirus delivered dominant negative p53 blocked Bax upregulation in cardiomyocytes but showed partial effect on preventing stretch-induced apoptosis,suggesting that p53 was only partially involved in mediating stretch-induced apoptosis. Furthermore,we showed that p21 was upregulated and cyclin B l was downregulated only in cardiac fibroblasts,which may be associated with G2/M accumulation in response to mechanical stretch.

  17. [Mechanism of protective effects of tumor necrosis factor receptor associated protein 1 on hypoxic cardiomyocytes of rats].

    Science.gov (United States)

    Xiang, F; Zhang, D X; Ma, S Y; Huang, Y S

    2016-12-20

    Objective: To investigate the mechanism of protective effects of tumor necrosis factor receptor associated protein 1 (TRAP1) on hypoxic cardiomyocytes of rats. Methods: Primary cultured cardiomyocytes were obtained from neonatal Sprague-Dawley rats (aged 1 to 3 days) and then used in the following experiments. (1) Cells were divided into group TRAP1 and control group according to the random number table (the same grouping method below), and then the total protein of cells was extracted. Total protein of cells in group TRAP1 was added with mouse anti-rat TRAP1 monoclonal antibody, while that in control group was added with the same type of IgG from mouse. Co-immunoprecipitation and protein mass spectrography analysis were used to determine the possible proteins interacted with TRAP1. (2) Cells were divided into normoxia blank control group (NBC), normoxia+ TRAP1 interference control group (NTIC), normoxia+ TRAP1 interference group (NTI), normoxia+ TRAP1 over-expression control group (NTOC), and normoxia+ TRAP1 over-expression group (NTO), with 1 well in each group. Cells in group NBC were routinely cultured, while cells in the latter four groups were respectively added with TRAP1 RNA interference empty virus vector, TRAP1 RNA interference adenovirus vector, TRAP1 over-expression empty virus vector, and TRAP1 over-expression adenovirus vector. Another batch of cells were divided into group NBC, hypoxic blank control group (HBC), hypoxic+ TRAP1 interference control group (HTIC), hypoxic+ TRAP1 interference group (HTI), hypoxic+ TRAP1 over-expression control group (HTOC), and hypoxic+ TRAP1 over-expression group (HTO), with 1 well in each group. Cells in hypoxic groups were under hypoxic condition for 6 hours after being treated as those in the corresponding normoxia groups, respectively. The mRNA expression of cytochrome c oxidase subunit Ⅱ (COXⅡ) of cells in each group was detected by real time fluorescent quantitive reverse transcription polymerase chain

  18. Adenosine improves cardiomyocyte respiratory efficiency.

    Science.gov (United States)

    Babsky, A M; Doliba, M M; Doliba, N M; Osbakken, M D

    1998-01-01

    The role of adenosine on the regulation of mitochondrial function has been studied. In order to evaluate this the following experiments were done in isolated rat cardiomyocites and mitochondria using polarographic techniques. Cardiomyocyte oxygen consumption (MVO2) and mitochondrial respiratory function (State 3 and State 4, respiratory control index, and ADP/O ratio) were evaluated after exposure to adenosine. Cardiomyocyte MVO2 was significantly lower in cells previously exposed to adenosine (10 microM, 15 min or 30 min cell incubation) than in cells not exposed to adenosine (control). Addition of dipyridamole (10 microM) or 8-(p-Sulfophenyl) theophylline (50 microM) to cardiomyocytes before adenosine incubation prevented the adenosine-induced changes in MVO2. Mitochondria obtained from isolated perfused beating heart previously perfused with adenosine (10 microM, 30 min heart perfusion) also resulted in significant increases in ADP/O and respiratory control index compared to matching control. Mitochondria isolated from cardiomyocytes previously exposed to adenosine (10 microM, 15 min or 30 min cell incubation) resulted in a significant increase in mitochondrial ADP/O ratio compared to control. Adenosine-induced decrease in cardiomyocyte MVO2 may be related to an increase in efficiency of mitochondrial oxidative phosphorylation, and more economical use of oxygen, which is necessary for survival under ischemic stress.

  19. Evidence for Cardiomyocyte Renewal in Humans

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, O; Bhardwaj, R D; Bernard, S; Zdunek, S; Barnabe-Heider, F; Walsh, S; Zupicich, J; Alkass, K; Buchholz, B A; Druid, H; Jovinge, S; Frisen, J

    2008-10-14

    It has been difficult to establish whether we are limited to the heart muscle cells we are born with or if cardiomyocytes are generated also later in life. We have taken advantage of the integration of {sup 14}C, generated by nuclear bomb tests during the Cold War, into DNA to establish the age of cardiomyocytes in humans. We report that cardiomyocytes renew, with a gradual decrease from 1% turning over annually at the age of 20 to 0.3% at the age of 75. Less than 50% of cardiomyocytes are exchanged during a normal lifespan. The capacity to generate cardiomyocytes in the adult human heart suggests that it may be rational to work towards the development of therapeutic strategies aiming to stimulate this process in cardiac pathologies.

  20. Plant Natural Product Formononetin Protects Rat Cardiomyocyte H9c2 Cells against Oxygen Glucose Deprivation and Reoxygenation via Inhibiting ROS Formation and Promoting GSK-3β Phosphorylation.

    Science.gov (United States)

    Cheng, Yuanyuan; Xia, Zhengyuan; Han, Yifan; Rong, Jianhui

    2016-01-01

    The opening of mitochondrial permeability transition pore (mPTP) is a major cause of cell death in ischemia reperfusion injury. Based on our pilot experiments, plant natural product formononetin enhanced the survival of rat cardiomyocyte H9c2 cells during oxygen glucose deprivation (OGD) and reoxygenation. For mechanistic studies, we focused on two major cellular factors, namely, reactive oxygen species (ROS) and glycogen synthase kinase 3β (GSK-3β), in the regulation of mPTP opening. We found that formononetin suppressed the formation of ROS and superoxide in a concentration-dependent manner. Formononetin also rescued OGD/reoxygenation-induced loss of mitochondrial membrane integrity. Further studies suggested that formononetin induced Akt activation and GSK-3β (Ser9) phosphorylation, thereby reducing GSK-3β activity towards mPTP opening. PI3K and PKC inhibitors abolished the effects of formononetin on mPTP opening and GSK-3β phosphorylation. Immunoprecipitation experiments further revealed that formononetin increased the binding of phosphor-GSK-3β to adenine nucleotide translocase (ANT) while it disrupted the complex of ANT with cyclophilin D. Moreover, immunofluorescence revealed that phospho-GSK-3β (Ser9) was mainly deposited in the space between mitochondria and cell nucleus. Collectively, these results indicated that formononetin protected cardiomyocytes from OGD/reoxygenation injury via inhibiting ROS formation and promoting GSK-3β phosphorylation.

  1. Plant Natural Product Formononetin Protects Rat Cardiomyocyte H9c2 Cells against Oxygen Glucose Deprivation and Reoxygenation via Inhibiting ROS Formation and Promoting GSK-3β Phosphorylation

    Directory of Open Access Journals (Sweden)

    Yuanyuan Cheng

    2016-01-01

    Full Text Available The opening of mitochondrial permeability transition pore (mPTP is a major cause of cell death in ischemia reperfusion injury. Based on our pilot experiments, plant natural product formononetin enhanced the survival of rat cardiomyocyte H9c2 cells during oxygen glucose deprivation (OGD and reoxygenation. For mechanistic studies, we focused on two major cellular factors, namely, reactive oxygen species (ROS and glycogen synthase kinase 3β (GSK-3β, in the regulation of mPTP opening. We found that formononetin suppressed the formation of ROS and superoxide in a concentration-dependent manner. Formononetin also rescued OGD/reoxygenation-induced loss of mitochondrial membrane integrity. Further studies suggested that formononetin induced Akt activation and GSK-3β (Ser9 phosphorylation, thereby reducing GSK-3β activity towards mPTP opening. PI3K and PKC inhibitors abolished the effects of formononetin on mPTP opening and GSK-3β phosphorylation. Immunoprecipitation experiments further revealed that formononetin increased the binding of phosphor-GSK-3β to adenine nucleotide translocase (ANT while it disrupted the complex of ANT with cyclophilin D. Moreover, immunofluorescence revealed that phospho-GSK-3β (Ser9 was mainly deposited in the space between mitochondria and cell nucleus. Collectively, these results indicated that formononetin protected cardiomyocytes from OGD/reoxygenation injury via inhibiting ROS formation and promoting GSK-3β phosphorylation.

  2. Mechanical stress triggers cardiomyocyte autophagy through angiotensin II type 1 receptor-mediated p38MAP kinase independently of angiotensin II.

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    Li Lin

    Full Text Available Angiotensin II (Ang II type 1 (AT1 receptor is known to mediate a variety of physiological actions of Ang II including autophagy. However, the role of AT1 receptor in cardiomyocyte autophagy triggered by mechanical stress still remains elusive. The aim of this study was therefore to examine whether and how AT1 receptor participates in cardiomyocyte autophagy induced by mechanical stresses. A 48-hour mechanical stretch and a 4-week transverse aorta constriction (TAC were imposed to cultured cardiomyocytes of neonatal rats and adult male C57B/L6 mice, respectively, to induce cardiomyocyte hypertrophy prior to the assessment of cardiomyocyte autophagy using LC3b-II. Losartan, an AT1 receptor blocker, but not PD123319, the AT2 inhibitor, was found to significantly reduce mechanical stretch-induced LC3b-II upregulation. Moreover, inhibition of p38MAP kinase attenuated not only mechanical stretch-induced cardiomyocyte hypertrophy but also autophagy. To the contrary, inhibition of ERK and JNK suppressed cardiac hypertrophy but not autophagy. Intriguingly, mechanical stretch-induced autophagy was significantly inhibited by Losartan in the absence of Ang II. Taken together, our results indicate that mechanical stress triggers cardiomyocyte autophagy through AT1 receptor-mediated activation of p38MAP kinase independently of Ang II.

  3. Adipose stromal cells primed with hypoxia and inflammation enhance cardiomyocyte proliferation rate in vitro through STAT3 and Erk1/2

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    Przybyt Ewa

    2013-02-01

    Full Text Available Abstract Background Experimental clinical stem cell therapy has been used for more than a decade to alleviate the adverse aftermath of acute myocardial infarction (aMI. The post-infarcted myocardial microenvironment is characterized by cardiomyocyte death, caused by ischemia and inflammation. These conditions may negatively affect administered stem cells. As postnatal cardiomyocytes have a poor proliferation rate, while induction of proliferation seems even more rare. Thus stimulation of their proliferation rate is essential after aMI. In metaplastic disease, the pro-inflammatory cytokine interleukin-6 (IL-6 has been identified as potent mediators of the proliferation rate. We hypothesized that IL-6 could augment the proliferation rate of (slow-dividing cardiomyocytes. Methods To mimic the behavior of therapeutic cells in the post-infarct cardiac microenvironment, human Adipose Derived Stromal Cells (ADSC were cultured under hypoxic (2% O2 and pro-inflammatory conditions (IL-1β for 24h. Serum-free conditioned medium from ADSC primed with hypoxia and/or IL-1β was added to rat neonatal cardiomyocytes and adult cardiomyocytes (HL-1 to assess paracrine-driven changes in cardiomyocyte proliferation rate and induction of myogenic signaling pathways. Results We demonstrate that ADSC enhance the proliferation rate of rat neonatal cardiomyocytes and adult HL-1 cardiomyocytes in a paracrine fashion. ADSC under hypoxia and inflammation in vitro had increased the interleukin-6 (IL-6 gene and protein expression. Similar to conditioned medium of ADSC, treatment of rat neonatal cardiomyocytes and HL-1 with recombinant IL-6 alone also stimulated their proliferation rate. This was corroborated by a strong decrease of cardiomyocyte proliferation after addition of IL-6 neutralizing antibody to conditioned medium of ADSC. The stimulatory effect of ADSC conditioned media or IL-6 was accomplished through activation of both Janus Kinase-Signal Transducer and

  4. Leptin suppresses non-apoptotic cell death in ischemic rat cardiomyocytes by reduction of iPLA{sub 2} activity

    Energy Technology Data Exchange (ETDEWEB)

    Takatani-Nakase, Tomoka, E-mail: nakase@mukogawa-u.ac.jp; Takahashi, Koichi, E-mail: koichi@mukogawa-u.ac.jp

    2015-07-17

    Caspase-independent, non-apoptotic cell death is an important therapeutic target in myocardial ischemia. Leptin, an adipose-derived hormone, is known to exhibit cytoprotective effects on the ischemic heart, but the mechanisms are poorly understood. In this research, we found that pretreatment of leptin strongly suppressed ischemic-augmented nuclear shrinkage and non-apoptotic cell death on cardiomyocytes. Leptin was also shown to significantly inhibit the activity of iPLA{sub 2}, which is considered to play crucial roles in non-apoptotic cell death, resulting in effective prevention of ischemia-induced myocyte death. These findings provide the first evidence of a protective mechanism of leptin against ischemia-induced non-apoptotic cardiomyocyte death. - Highlights: • Myocardial ischemia-model induces in caspase-independent, non-apoptotic cell death. • Leptin strongly inhibits ischemic-augmented non-apoptotic cell death. • Leptin reduces iPLA{sub 2} activity, leading to avoidance of non-apoptotic cell death.

  5. Inhibitory effects of Veratrum nigrum L. Var. ussurience Nakai alkaloids on the hypertrophy of cardiomyocytes from neonatal rat

    Institute of Scientific and Technical Information of China (English)

    WANG Li; LI Shu-yuan; LI Hua; ZHOU Qin

    2008-01-01

    Objective To examine the effects of Veratrum nigrum L. Vat. ussurience Nakai alkaloids (VnA) on angiotensin Ⅱ (Ang Ⅱ)-induced cardiomyocyte hypertrophy and to explore its possible mechanism. Methods The cadiocytes were induced by Ang Ⅱ to set up myocardial hypertrophy model, the animals were divided into six groups according to the different treatments: control group, model group, positive control group, VnA group (low, middle and high dose). The cell protein content, the cell diameter and the expression of calcineurin (CAN) were measured respectively by BCA method, the micrometer and immunofluo-rescence analysis. Results VnA (middle and high dose) and Captopril inhibited significantly the increase in the protein content induced by Ang Ⅱ (P<0.01). VnA and Captopril inhibited significantly the increase in the diameters induced by Ang Ⅱ (P< 0.01). By immunofluorescence analysis, the expression of calcineurin (CAN) was obviously increased in the Ang Ⅱ-induced model group. VnA decreased the expression of CaN significantly. Conclusions VnA could inhibit the cardiomyocyte hypertrophy induced by Ang Ⅱ significantly in a dose-dependent manner. The possible mechanism may be related to the inhibition of CAN expression.

  6. Ginsenoside Rb1 Protects Neonatal Rat Cardiomyocytes from Hypoxia/Ischemia Induced Apoptosis and Inhibits Activation of the Mitochondrial Apoptotic Pathway

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    Xu Yan

    2014-01-01

    Full Text Available Aim. To investigate the effect of Ginsenoside Rb1 (GS-Rb1 on hypoxia/ischemia (H/I injury in cardiomyocytes in vitro and the mitochondrial apoptotic pathway mediated mechanism. Methods. Neonatal rat cardiomyocytes (NRCMs for the H/I groups were kept in DMEM without glucose and serum, and were placed into a hypoxic jar for 24 h. GS-Rb1 at concentrations from 2.5 to 40 µM was given during hypoxic period for 24 h. NRCMs injury was determined by MTT and lactate dehydrogenase (LDH leakage assay. Cell apoptosis, ROS accumulation, and mitochondrial membrane potential (MMP were assessed by flow cytometry. Cytosolic translocation of mitochondrial cytochrome c and Bcl-2 family proteins were determined by Western blot. Caspase-3 and caspase-9 activities were determined by the assay kit. Results. GS-Rb1 significantly reduced cell death and LDH leakage induced by H/I. It also reduced H/I induced NRCMs apoptosis induced by H/I, in accordance with a minimal reactive oxygen species (ROS burst. Moreover, GS-Rb1 markedly decreased the translocation of cytochrome c from the mitochondria to the cytosol, increased the Bcl-2/ Bax ratio, and preserved mitochondrial transmembrane potential (ΔΨm. Its administration also inhibited activities of caspase-9 and caspase-3. Conclusion. Administration of GS-Rb1 during H/I in vitro is involved in cardioprotection by inhibiting apoptosis, which may be due to inhibition of the mitochondrial apoptotic pathway.

  7. Fructose modulates cardiomyocyte excitation-contraction coupling and Ca²⁺ handling in vitro.

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    Kimberley M Mellor

    Full Text Available BACKGROUND: High dietary fructose has structural and metabolic cardiac impact, but the potential for fructose to exert direct myocardial action is uncertain. Cardiomyocyte functional responsiveness to fructose, and capacity to transport fructose has not been previously demonstrated. OBJECTIVE: The aim of the present study was to seek evidence of fructose-induced modulation of cardiomyocyte excitation-contraction coupling in an acute, in vitro setting. METHODS AND RESULTS: The functional effects of fructose on isolated adult rat cardiomyocyte contractility and Ca²⁺ handling were evaluated under physiological conditions (37°C, 2 mM Ca²⁺, HEPES buffer, 4 Hz stimulation using video edge detection and microfluorimetry (Fura2 methods. Compared with control glucose (11 mM superfusate, 2-deoxyglucose (2 DG, 11 mM substitution prolonged both the contraction and relaxation phases of the twitch (by 16 and 36% respectively, p<0.05 and this effect was completely abrogated with fructose supplementation (11 mM. Similarly, fructose prevented the Ca²⁺ transient delay induced by exposure to 2 DG (time to peak Ca²⁺ transient: 2 DG: 29.0±2.1 ms vs. glucose: 23.6±1.1 ms vs. fructose +2 DG: 23.7±1.0 ms; p<0.05. The presence of the fructose transporter, GLUT5 (Slc2a5 was demonstrated in ventricular cardiomyocytes using real time RT-PCR and this was confirmed by conventional RT-PCR. CONCLUSION: This is the first demonstration of an acute influence of fructose on cardiomyocyte excitation-contraction coupling. The findings indicate cardiomyocyte capacity to transport and functionally utilize exogenously supplied fructose. This study provides the impetus for future research directed towards characterizing myocardial fructose metabolism and understanding how long term high fructose intake may contribute to modulating cardiac function.

  8. Study on the Effects of Losartan on Cardiomyocyte Apoptosis and Gene Expression After Ischemia and Reperfusion in vivo in Rats

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dongqing; YANG Liming; LIU Zhengxiang; MI Shizan

    2000-01-01

    In order to study the effects of losartan on cardiomyocyte apoptosis following ischemia (0.5 h) and reperfusion (48 h) in vivo and bcl-2 and bax gene expression, TUNEL staining method, immunohistochemistry and in situ hybridization histochemistry (ISHH) were used to monitor the apoptotic cells, mRNA and protein of gene expression, respectively. Image processing system was used to quantitively dispose the positive metric substance of both immunohistochemistry and ISHH through the average optical density (OD) value. The number of the apoptotic cells were 38±9 (control group), 0-1 (sham operation group) and 9±4 (losartan-treated group) in each visual field respectively with the difference among the groups being significant (P<0.001). OD values of bcl-2 (ISHH) were 0.07425±0.02029 (control group), 0.05961±0.009932 (sham operation group) and 0. 07619±0.01445 (losartan-treated group) respectively,while OD values of bcl-2 (immunohistochemistry) were 0.1374 ±0.01367 (control group),0.08510±0.01862 (sham operation group) and 0.1252±0.02064 (losartan-treated group), bcl-2gene expression was increased significantly in the control group and losartan-treated group as compared with sham operation group (P<0.05). OD value of bax (immunohistochemistry) was09727± 0.02230 (control group), 0.06182±0.01430 (sham operation group) and 0.06213 ±0.01420 (losartan-treated group), bax gene expression was decreased very significantly in losartan-treated group and sham operation group as compared with control group (P<0. 001). Bcl-2/bax ratio was 1.413 (control group), 1.376 (sham operation group) and 2.016 (losartan-treated group) respectively. The results indicated that losartan might inhibit cardiomyocyte apoptosis following ischemia and reperfusion. The mechanism might be that bax gene expression was inhibited to increase bcl-2/bax ratio.

  9. Inhibition of MMP-2 Expression with siRNA Increases Baseline Cardiomyocyte Contractility and Protects against Simulated Ischemic Reperfusion Injury

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    Han-Bin Lin

    2014-01-01

    Full Text Available Matrix metalloproteinases (MMPs significantly contribute to ischemia reperfusion (I/R injury, namely, by the degradation of contractile proteins. However, due to the experimental models adopted and lack of isoform specificity of MMP inhibitors, the cellular source and identity of the MMP(s involved in I/R injury remain to be elucidated. Using isolated adult rat cardiomyocytes, subjected to chemically induced I/R-like injury, we show that specific inhibition of MMP-2 expression and activity using MMP-2 siRNA significantly protected cardiomyocyte contractility from I/R-like injury. This was also associated with increased expression of myosin light chains 1 and 2 (MLC1/2 in comparison to scramble siRNA transfection. Moreover, the positive effect of MMP-2 siRNA transfection on cardiomyocyte contractility and MLC1/2 expression levels was also observed under control conditions, suggesting an important additional role for MMP-2 in physiological sarcomeric protein turnover. This study clearly demonstrates that intracellular expression of MMP-2 plays a significant role in sarcomeric protein turnover, such as MLC1 and MLC2, under aerobic (physiological conditions. In addition, this study identifies intracellular/autocrine, cardiomyocyte-produced MMP-2, rather than paracrine/extracellular, as responsible for the degradation of MLC1/2 and consequent contractile dysfunction in cardiomyocytes subjected to I/R injury.

  10. Recombinant proteins secreted from tissue-engineered bioartificial muscle improve cardiac dysfunction and suppress cardiomyocyte apoptosis in rats with heart failure

    Institute of Scientific and Technical Information of China (English)

    RONG Shu-ling; WANG Yong-jin; WANG Xiao-lin; LU Yong-xin; WU Yin; LIU Qi-yun; MI Shao-hua; XU Yu-lan

    2010-01-01

    secrete rhlGF-1 and tissue-engineered into implantable BAMs containing parallel arrays of postmitotic myofibers. In vitro, they secreted consistent levels of hIGF (0.4-1.2 μg·BAM-1·d-1). When implanted into syngeneic rat, IGF-BAMs secreted and delivered rhIGF. Four weeks after therapy,the hemodynamics was improved significantly in MI rats treated with IGF-BAMs compared with those treated with GFP-BAMs. The levels of serum IGF-1 were increased significantly in both MI and sham rats treated with IGF-BAM. The mRNA expression of bax was lower and Bcl-2 expression was higher in MI-IGF group than MI-GFP group (P <0.05).Western blotting assay showed TNF-α and caspase 3 expression was lower in MI-IGF group than MI-GFP group after therapy.Conclusions rhIGF-1 significantly improves left ventricular function and suppresses cardiomyocyte apoptosis in rats with chronic heart failure. Genetically modified tissue- engineered BAMs provide a method delivering recombinant protein for the treatment of heart failure.

  11. 右美托咪定对严重烫伤大鼠心肌细胞PERK信号通路的影响%Effect of dexmedetomidine on PERK signaling pathway in cardiomyocytes of rats with severe scald

    Institute of Scientific and Technical Information of China (English)

    王惠枢; 张良成; 徐世元

    2016-01-01

    Objective To investigate the effect of dexmedetomidine on protein kinase RNA-like endoplasmic reticulum kinase (PERK) signaling pathway in cardiomyocytes of the rats with severe scald.Methods Twenty-four healthy adult male Sprague-Dawley rats,weighing 220-280 g,were randomly divided into 3 groups (n =8 each) using a random number table:control group (group C),severe scald group (group S),and scald + dexmedetomidine group (group D).Thirty percent of the total body surface area was shaved on the back and then exposed to 94 ℃ water for 12 s to establish the model of 3rd degree scald.Dexmedetomidine 30 μg/kg (2 μg/ml) was intraperitoneally injected immediately after scald in group D.Myocardial specimens were obtained at 12 h after scald for examination of the pathological changes and for determination of cell apoptosis and expression of C/EBP-homologous protein (CHOP),PERK,and phosphorylated PERK (p-PERK) by Western blot.The apoptosis index and p-PERK/PERK ratio were calculated.Results Compared with group C,the apoptosis index was significantly increased,the expression of CHOP,PERK and p-PERK was significantly up-regulated,and the p-PERK/PERK ratio was significantly increased in S and D groups (P<0.05).Compared with group S,the apoptosis index was significantly decreased,the expression of CHOP,PERK and p-PERK was significantly down-regulated,and the p-PERK/PERK ratio was significantly decreased (P<0.05),and the pathological changes of myocardium were significantly attenuated in group D.Conclusion The mechanism by which dexmedetomidine inhibits apoptosis in cardiomyocytes is related to inhibition of PERK signaling pathway in the rats with severe scald.%目的 探讨右美托咪定对严重烫伤大鼠心肌细胞蛋白激酶R样内质网激酶(PERK)信号通路的影响.方法 健康成年雄性SD大鼠24只,体重220~ 280 g,采用随机数字表法分为3组(n=8):对照组(C组)、严重烫伤组(S组)、烫伤+右美托咪定组(D组).将大鼠背部浸入94

  12. Adolescent social isolation influences cognitive function in adult rats

    Institute of Scientific and Technical Information of China (English)

    Feng Shao; Xiao Han; Shuang Shao; Weiwen Wang

    2013-01-01

    Adolescence is a critical period for neurodevelopment. Evidence from animal studies suggests that isolated rearing can exert negative effects on behavioral and brain development. The present study aimed to investigate the effects of adolescent social isolation on latent inhibition and brain-derived neurotrophic factor levels in the forebrain of adult rats. Male Wistar rats were randomly divided into adolescent isolation (isolated housing, 38–51 days of age) and social groups. Latent inhibition was tested at adulthood. Brain-derived neurotrophic factor levels were measured in the medial prefrontal cortex and nucleus accumbens by an enzyme-linked immunosorbent assay. Adolescent social isolation impaired latent inhibition and increased brain-derived neurotrophic factor levels in the medial prefrontal cortex of young adult rats. These data suggest that adolescent social isolation has a profound effect on cognitive function and neurotrophin levels in adult rats and may be used as an animal model of neurodevelopmental disorders.

  13. The Adipokine Chemerin Induces Apoptosis in Cardiomyocytes

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    Diego Rodríguez-Penas

    2015-08-01

    Full Text Available Background: The adipokine chemerin has been associated with cardiovascular disease. We investigated the effects of chemerin on viability and intracellular signalling in murine cardiomyocytes, and the effects of insulin and TNF-α on cardiomyocyte chemerin production. Methods: Hoechst dye vital staining and cell cycle analysis were used to analyse the viability of murine cardiac cells in culture. Western blot was used to explore the phosphorylation of AKT and caspase-9 activity in neonatal rat cardiomyocytes and HL-1 cells. Finally, RT-qPCR, ELISA and western blot were performed to examine chemerin and CMKLR1 expression after insulin and TNF-α treatment in cardiac cells. Results: Chemerin treatment increased apoptosis, reduced phosphorylation of AKT at Thr308 and increased caspase-9 activity in murine cardiomyocytes. Insulin treatment lowered chemerin and CMKLR1 mRNA and protein levels, and the amount of chemerin in the cell media, while TNF-α treatment increased chemerin mRNA and protein levels but decreased expression of the CMKLR1 gene. Conclusion: Chemerin induces apoptosis, reduces AKT phosphorylation and increases the cleavage of caspase-9 in murine cardiomyocytes. The expression of chemerin is regulated by important metabolic (insulin and inflammatory (TNF-α mediators at cardiac level. Our results suggest that chemerin could play a role in the physiopathology of cardiac diseases.

  14. Mechanisms Responsible for the Trophic Effect of Beta-Adrenoceptors on the Ito Current Density in Type 1 Diabetic Rat Cardiomyocytes

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    Raúl Setién

    2013-01-01

    Full Text Available Background/Aims: In diabetic ventricular myocytes, transient outward potassium current (Ito amplitude is severely reduced because of the impaired catecholamine release that characterizes diabetic autonomic neuropathy. Sympathetic nervous system exhibits a trophic effect on Ito since incubation of myocytes with noradrenaline restores current amplitude via beta-adrenoceptor (βAR stimulation. Here, we investigate the intracellular signalling pathway though which incubation of diabetic cardiomyocytes with the βAR agonist isoproterenol recovers Ito amplitude to normal values. Methods: Experiments were performed in ventricular myocytes isolated from streptozotocin-diabetic rats. Ito current was recorded by using the patch-clamp technique. Kv4 channel expression was determined by immunofluorescence. Protein-protein interaction was determined by coimmunoprecipitation. Results: Stimulation of βAR activates first a Gαs protein, adenylyl cyclase and Protein Kinase A. PKA-phosphorylated receptor then switches to the Gαi protein. This leads to the activation of the βAR-Kinase-1 and further receptor phosphorylation and arrestin dependent internalization. The internalized receptor-arrestin complex recruits and activates cSrc and the MAPK cascade, where Ras, c-Raf1 and finally ERK1/2 mediate the increase in Kv4.2 and Kv4.3 protein abundance in the plasma membrane. Conclusion: β2AR stimulation activates a Gαs and Gαi protein dependent pathway where the ERK1/2 modulates the Ito current amplitude and the density of the Kv4.2 and Kv4.2 channels in the plasma membrane upon sympathetic stimulation in diabetic heart.

  15. In vivo differentiation of human amniotic epithelial cells into cardiomyocyte-like cells and cell transplantation effect on myocardial infarction in rats: comparison with cord blood and adipose tissue-derived mesenchymal stem cells.

    Science.gov (United States)

    Fang, Cheng-Hu; Jin, Jiyong; Joe, Jun-Ho; Song, Yi-Sun; So, Byung-Im; Lim, Sang Moo; Cheon, Gi Jeong; Woo, Sang-Keun; Ra, Jeong-Chan; Lee, Young-Yiul; Kim, Kyung-Soo

    2012-01-01

    Human amniotic epithelial cells (h-AECs), which have various merits as a cell source for cell therapy, are known to differentiate into cardiomyocytes in vitro. However, the ability of h-AECs to differentiate into cardiomyocytes in vivo and their cell transplantation effects on myocardial infarction are still unknown. In this study, we assessed whether h-AECs could differentiate into cardiomyocytes in vivo and whether h-AECs transplantation can decrease infarct size and improve cardiac function, in comparison to transplantation of cord blood-derived mesenchymal stem cells (MSCs) or adipose tissue-derived MSCs. For our study, we injected h-AECs, cord blood-derived MSCs, adipose tissue-derived MSCs, and saline into areas of myocardial infarction in athymic nude rats. After 4 weeks, 3% of the surviving h-AECs expressed myosin heavy chain, a marker specific to the myocardium. Compared with the saline group, all cell-implanted groups showed a higher ejection fraction, lower infarct area by positron emission tomography and histology, and more abundant myocardial gene and protein expression in the infarct area. We showed that h-AECs can differentiate into cardiomyocyte-like cells, decrease infarct size, and improve cardiac function in vivo. The beneficial effects of h-AECs were comparable to those of cord blood and adipose tissue-derived MSCs. These results support the need for further studies of h-AECs as a cell source for myocardial regeneration due to their plentiful availability, low immunity, and lack of ethical issues related to their use.

  16. The cardiomyocyte molecular clock, regulation of Scn5a, and arrhythmia susceptibility.

    Science.gov (United States)

    Schroder, Elizabeth A; Lefta, Mellani; Zhang, Xiping; Bartos, Daniel C; Feng, Han-Zhong; Zhao, Yihua; Patwardhan, Abhijit; Jin, Jian-Ping; Esser, Karyn A; Delisle, Brian P

    2013-05-15

    The molecular clock mechanism underlies circadian rhythms and is defined by a transcription-translation feedback loop. Bmal1 encodes a core molecular clock transcription factor. Germline Bmal1 knockout mice show a loss of circadian variation in heart rate and blood pressure, and they develop dilated cardiomyopathy. We tested the role of the molecular clock in adult cardiomyocytes by generating mice that allow for the inducible cardiomyocyte-specific deletion of Bmal1 (iCSΔBmal1). ECG telemetry showed that cardiomyocyte-specific deletion of Bmal1 (iCSΔBmal1(-/-)) in adult mice slowed heart rate, prolonged RR and QRS intervals, and increased episodes of arrhythmia. Moreover, isolated iCSΔBmal1(-/-) hearts were more susceptible to arrhythmia during electromechanical stimulation. Examination of candidate cardiac ion channel genes showed that Scn5a, which encodes the principle cardiac voltage-gated Na(+) channel (Na(V)1.5), was circadianly expressed in control mouse and rat hearts but not in iCSΔBmal1(-/-) hearts. In vitro studies confirmed circadian expression of a human Scn5a promoter-luciferase reporter construct and determined that overexpression of clock factors transactivated the Scn5a promoter. Loss of Scn5a circadian expression in iCSΔBmal1(-/-) hearts was associated with decreased levels of Na(V)1.5 and Na(+) current in ventricular myocytes. We conclude that disruption of the molecular clock in the adult heart slows heart rate, increases arrhythmias, and decreases the functional expression of Scn5a. These findings suggest a potential link between environmental factors that alter the cardiomyocyte molecular clock and factors that influence arrhythmia susceptibility in humans.

  17. Hyperprolactinemia affects spermiogenesis in adult male rats.

    Science.gov (United States)

    Aleem, M; Choudhari, J; Padwal, V; Balasinor, N; Parte, P; Gill-Sharma, M K

    2005-01-01

    The mechanisms underlying the antifertility effects of hyperprolactinemia have yet to be established in an appropriate experimental model. Hyperprolactinemia is a known side effect of fluphenazine, a broad spectrum, long-acting phenothiazine known to be dopamine type-D2 receptor antagonist. In our earlier study in adult male rats, we reported that fluphenazine at a dose of 3 mg/kg/day suppressed serum FSH but not testosterone (T) through increasing dopamine (DA) metabolism in the pituitary gland, within 60 days. Fluphenazine treatment affected sperm quality and male rats treated with fluphenazine sired fewer litters. The effects of fluphenazine-induced hyperprolactinemia on sperm quality appeared to be related to reduced FSH. We now report that FSH suppression enhanced the uptake of acridine orange (AO), a DNA intercalating, fluorescent dye by the fluphenazine-treated caput epididymal sperms with concomitant reduction in the uptake of thiol-specific monobromobimane (mBBr) fluorescent dye in vitro, suggesting greater accessibility of DNA intercalating dye to sperm chromatin and reduction in free sperm protein thiols. The concomitant increase in AO and decrease in mBBr fluorescence was suggestive of loose chromatin packaging in caput epididymal sperms after treatment with fluphenazine at 3 mg/kg/day for 60 days. The suppression in levels of protamine (P1) in caput epididymal sperms suggested that chromatin hypocompaction was due to reduced deposition of protamines in sperm chromatin. Reduction in testicular levels of cyclic adenosyl 3', 5' monophosphate response element modulator (CREMtau) and P1 further suggested that reduced deposition was indeed due to reduced synthesis. The concomitant reduction in testicular levels of transition protein 1 (TP1) and transition protein 2 (TP2) also suggested that hypoprotamination was due to reduced synthesis of these proteins crucial for facilitating P1 deposition. The effect appeared to have occurred at the level of translation

  18. Effects and mechanism of glucagon-like peptide-1 on injury of rats cardiomyocytes induced by hypoxia-reoxygenation

    Institute of Scientific and Technical Information of China (English)

    XIE Yun; WANG Shao-xin; SHA Wei-wei; ZHOU Xue; WANG Wei-lin; HAN Li-pin; LI Dai-qing; YU De-min

    2008-01-01

    Background Although the insulinotropic role of glucagon-like peptide-1 (GLP-1) in type 2 diabetes mellitus has been substantiated,its role in cardioprotection remains largely unknown.This study aimed to determine the effects of GLP-1 on injury of rats cardiac myocytes induced by hypoxia-reoxygenation (H/R) and the possible mechanisms.Methods The cultured neonatal rats cardiac myocytes were randomly divided into seven groups:the normal control group,the H/R group,the GLP-1+H/R group,the GLP-1+H/R+UO126 (the p42/44 mitogen-activated protein kinase (MAPK) inhibitor) group,the GLP-1+H/R+LY294002 (phosphatidylinositol 3-kinase (P13K) inhibitor) group,the H/R+UO126 group,and the H/R+LY294002 group.The lactate dehydrogenase (LDH) activity,apoptosis rate of cardiac myocytes,and caspase-3 activity were detected after the injury of H/R.Results Compared with the normal control group,the activity of LDH,cardiac myocyte apoptosis rate,and caspase-3 activity all increased significantly in the H/R group (P<0.01).Compared with the H/R group,these three indices all decreased in the H/R+GLP-1 group (P<0.01).However,the changes of LDH activity,apoptosis rate,and caspase-3 activity were inhibited by LY294002 and UO126 respectively.Conclusions GLP-1 can directly act on cardiac myocytes and protect them from H/R injury mainly by inhibiting their apoptosis.Its mechanism may be through the P13K-Akt pathway and the MAPK signaling pathway.

  19. 液态氟碳脂质微球靶向损伤心肌细胞的体外实验%In Vitro Experimental Study of Rat Cardiomyocyte Injury with Targeting of Perfluorocarbon Lipid Particles

    Institute of Scientific and Technical Information of China (English)

    何佰永; 李赵欢; 唐红; 李国华; 陈松; 王炼; 宋海波; 方华; 曾俊

    2011-01-01

    The present study was to investigate in vitro the rat cardiomyocyte injury with targeting of home-made per-fluorocarbon lipid particles with avidin-biotin interaction. Neonatal rat cardiomyocytes were cultured in vitro and divided into two groups: TNF-a activated group and non-activated group. Those in the TNF-α activated group were exposed to 200ng/ml TNF-a solution for 6 hours and then cardiomyocytes in both groups were pretargeted with bioti-nylated ICAM-1 monoclonal antibodies, and were exposed to streptavidin, and then to home-made green fluorescent-ly-labeled biotinylated perfluorocarbon lipid particles. Cardiomyocytes nucleus stained with Hoechst. The results were detected with fluorescence microscope. As a result, in TNF-a activated group, around blue fluorescent cardiomyocytes nucleus, a great amount of green fluorescent particles were found, while there were few green fluorescent particles in non-TNF activated group. It has been shown that ICAM-1 is expressed in the surface of cardiomyocytes when they are stimulated by TNF-a. Perfluorocarbon lipid particles associated with ICAM-1 monoclonal antibodies can be targeted to injured cardiomyocytes by avidin-biotin interaction.%采用生物素-亲和素作用实现自制液态氟碳脂质微球与损伤后心肌细胞的靶向结合.先体外培养大鼠原代心肌细胞,将培养出的心肌细胞分为TNF-α处理组和非处理组,TNF-α处理组的心肌细胞给予200 ng/ml TNF-α溶液刺激.6h后两组均先后加入等量的生物素化的抗大鼠细胞间黏附分子-1(ICAM-1)单克隆抗体、链酶亲和素和自制生物素化液态氟碳脂质微球,然后用Hoechst液对两组心肌细胞核染色,最后在荧光显微镜下观察.结果显示TNF-α处理组染成蓝色的心肌细胞核周围可见大量绿色荧光微球,但非处理组蓝色的心肌细胞核周围有极少许绿色荧光微球.研究表明心肌细胞在TNF-α刺激下可产生ICAM-1炎症细胞因子,液

  20. Dobutamine stress echocardiography in healthy adult male rats

    OpenAIRE

    Couet Jacques; Roussel Élise; Drolet Marie-Claude; Lachance Dominic; Plante Eric; Arsenault Marie

    2005-01-01

    Abstract Background Dobutamine stress echocardiography is used to investigate a wide variety of heart diseases in humans. Dobutamine stress echocardiography has also been used in animal models of heart disease despite the facts that the normal response of healthy rat hearts to this type of pharmacological stress testing is unknown. This study was performed to assess this normal response. Methods 15 normal adult male Wistar rats were evaluated. Increasing doses of dobutamine were infused intra...

  1. Hypertension after bilateral kidney irradiation in young and adult rats

    Energy Technology Data Exchange (ETDEWEB)

    Jongejan, H.T.; van der Kogel, A.J.; Provoost, A.P.; Molenaar, J.C.

    1987-09-01

    The mechanism of a rise in blood pressure after kidney irradiation is unclear but most likely of renal origin. We have investigated the role of the renin-angiotensin system and dietary salt restriction in the development of systolic hypertension after bilateral kidney irradiation in young and adult rats. Three to 12 months after a single X-ray dose of 7.5 or 12.5 Gy to both kidneys of young and adult rats, the systolic blood pressure (SBP) and plasma renin concentration (PRC) were measured regularly. A single X-ray dose of 12.5 Gy caused a moderate rise in SBP and a slight reduction in PRC in both young and adult rats. A dose of 7.5 Gy did not significantly alter the SBP or PRC during the follow-up period of 1 year. In a second experiment, the kidneys of young rats received an X-ray dose of 20 Gy. Subsequently, rats were kept on a standard diet (110 mmol sodium/kg) or a sodium-poor diet (10 mmol sodium/kg). On both diets, SBP started to rise rapidly 3 months after kidney irradiation. Sodium balance studies carried out at that time revealed an increased sodium retention in the irradiated rats compared to controls on the same diet. In rats on a low sodium intake, there was neither a delay nor an alleviation in the development of hypertension. Compared to controls, the PRC tended to be lower in irradiated rats up to 4 months after irradiation. Subsequently, malignant hypertension developed in all 20 Gy rats, resulting in pressure natriuresis, stimulating the renin-angiotensin system. Our findings indicated that hypertension after bilateral kidney irradiation was not primarily the result of an activation of the renin-angiotensin system. Although there were some indications that sodium retention played a role, dietary sodium restriction did not influence the development of hypertension.

  2. Rat tail tendon collagens protect cardiomyocytes against oxidative damage%鼠尾胶原在心肌细胞氧化损伤中的保护作用

    Institute of Scientific and Technical Information of China (English)

    包馨慧; 李晓梅; 陶静; 杨毅宁; 马依彤; 陈邦党

    2014-01-01

    背景:胶原蛋白具有抗氧化作用,但既往在实验室主要将鼠尾胶原用于促进细胞贴壁和支架构建,对于其抗氧化作用目前尚无相关研究。  目的:探讨鼠尾胶原对过氧化氢导致离体心肌细胞氧化损伤的保护作用。  方法:将原代培养的SD大鼠乳鼠心肌细胞随机接种到铺有鼠尾胶原的培养皿(实验组)和普通培养皿(对照组)中,并且均用0,10,100µmol/L H2O2诱导。24 h后,以电子显微镜观察各组乳鼠心肌细胞的形态,应用MTT 比色法检测心肌细胞存活率,TUNEL 法检测心肌细胞凋亡形态,流式细胞技术检测心肌细胞凋亡率,黄嘌呤氧化酶法检测超氧化物歧化酶活力,硫代巴比妥比色法检测丙二醛水平,Western-Blot 检测凋亡蛋白Bax、Bcl-2的表达。  结果与结论:两组培养皿中,随着过氧化氢浓度的增高,均可见细胞凋亡状态明显加重,细胞存活率及细胞内过氧化氢活力明显下降,细胞凋亡率及细胞内丙二醛水平明显增高,Bcl-2/Bax比值显著降低,呈剂量依赖性。而在相同浓度过氧化氢诱导下,与对照组相比,实验组细胞凋亡状态明显减弱,细胞存活率、超氧化物歧化酶活力及Bcl-2/Bax比值增高,细胞凋亡率和丙二醛水平明显减低。表明鼠尾胶原对过氧化氢所致的心肌细胞氧化损伤具有保护作用,其机制可能与提高超氧化物歧化酶活力,减少丙二醛产生及提高Bcl-2的表达有关。%BACKGROUND:Although colagen has been approved to have antioxidant effect, there is no relevant research at the cel level. Previous experimental studies have focused on the effect of rat tail tendon colagens to promote cel adhesion and scaffold construction. OBJECTIVE: To investigate the protective role of rat tail tendon colagen in oxidative stress of cardiomyocytes induced by hydrogen peroxide. METHODS: Primary neonatal rat cardiomyocytes

  3. Newborn hypoxia/anoxia inhibits cardiomyocyte proliferation and decreases cardiomyocyte endowment in the developing heart: role of endothelin-1.

    Directory of Open Access Journals (Sweden)

    Alexandra N Paradis

    Full Text Available In the developing heart, cardiomyocytes undergo terminal differentiation during a critical window around birth. Hypoxia is a major stress to preterm infants, yet its effect on the development and maturation of the heart remains unknown. We tested the hypothesis in a rat model that newborn anoxia accelerates cardiomyocyte terminal differentiation and results in reduced cardiomyocyte endowment in the developing heart via an endothelin-1-dependent mechanism. Newborn rats were exposed to anoxia twice daily from postnatal day 1 to 3, and hearts were isolated and studied at postnatal day 4 (P4, 7 (P7, and 14 (P14. Anoxia significantly increased HIF-1α protein expression and pre-proET-1 mRNA abundance in P4 neonatal hearts. Cardiomyocyte proliferation was significantly decreased by anoxia in P4 and P7, resulting in a significant reduction of cardiomyocyte number per heart weight in the P14 neonates. Furthermore, the expression of cyclin D2 was significantly decreased due to anoxia, while p27 expression was increased. Anoxia has no significant effect on cardiomyocyte binucleation or myocyte size. Consistently, prenatal hypoxia significantly decreased cardiomyocyte proliferation but had no effect on binucleation in the fetal heart. Newborn administration of PD156707, an ETA-receptor antagonist, significantly increased cardiomyocyte proliferation at P4 and cell size at P7, resulting in an increase in the heart to body weight ratio in P7 neonates. In addition, PD156707 abrogated the anoxia-mediated effects. The results suggest that hypoxia and anoxia via activation of endothelin-1 at the critical window of heart development inhibits cardiomyocyte proliferation and decreases myocyte endowment in the developing heart, which may negatively impact cardiac function later in life.

  4. Roles and Mechanisms of Interleukin-32 on Rat Cardiomyocytes with Hypoxia Injury%IL-32在大鼠心肌细胞缺氧损伤中的作用及其机制

    Institute of Scientific and Technical Information of China (English)

    方毅; 陈芷菱; 夏小杰

    2013-01-01

    Objective:To investigate the roles and mechanisms of interleukin-32 (IL-32) on rat cardiomyocytes with hypoxia injury. Methods; When cardiomyocytes with hypoxia injury was produced , mRNA and protein levels of IL-32, IL-1 β, IL-6, IL-18, TNF-α and IL-10 were compared between hypoxia group and control group. The relationships of IL-32 with other factors were also evaluated. Results: When compared with control group , number of apoptotic cardiomyocytes was significantly higher , accompanied with higher levels of mRNA and proteins of IL-32, IL-1β, IL-6, IL-18, TNF-α and IL-10. As indicated by the Pearson correlation analysis , IL-32 was positively correlated with IL-1β, IL-6, IL-18, TNF-α and IL-10. Conclusion: IL-32 was significantly increased after insulted by hypoxia injury in rat cardiomyocytes , and IL-32 was positively correlated with inflammatory factors such as IL-1β, IL-6, IL-18, TNF-α and IL-10.%目的:探讨IL-32在大鼠心肌细胞缺氧损伤中的作用及其机制.方法:构建乳鼠心肌细胞缺氧模型后,比较缺氧组与正常组IL-32、IL-1β、IL-6、IL-18、TNF-α和IL-10 mRNA及蛋白水平的表达情况,以及IL-32与各细胞因子间的相关性.结果:与正常组相比,缺氧组心肌细胞坏死明显;IL-32、IL-1β、IL-6、IL-18、TNF-α和IL-10基因及蛋白表达水平均明显升高;Pearson相关分析提示IL-32与IL-1β、IL-6、IL-18、TNF-α和IL-10水平呈正相关.结论:大鼠心肌细胞缺氧后,IL-32表达水平明显升高;IL-32与传统细胞因子IL-1β、IL-6、IL-18、TNF-α和IL-10表达水平呈正相关.

  5. Influx mechanisms in the embryonic and adult rat choroid plexus

    DEFF Research Database (Denmark)

    Saunders, Norman R; Dziegielewska, Katarzyna M; Møllgård, Kjeld

    2015-01-01

    The transcriptome of embryonic and adult rat lateral ventricular choroid plexus, using a combination of RNA-Sequencing and microarray data, was analyzed by functional groups of influx transporters, particularly solute carrier (SLC) transporters. RNA-Seq was performed at embryonic day (E) 15 and a...

  6. Influence of the availability of iron during hypoxia on the genes associated with apoptotic activity and local iron metabolism in rat H9C2 cardiomyocytes and L6G8C5 skeletal myocytes.

    Science.gov (United States)

    Dziegala, Magdalena; Kasztura, Monika; Kobak, Kamil; Bania, Jacek; Banasiak, Waldemar; Ponikowski, Piotr; Jankowska, Ewa A

    2016-10-01

    The differential availability of iron during hypoxia is presumed to affect the functioning of cardiac and skeletal myocytes. Rat H9C2 cardiomyocytes and L6G8C5 myocytes were cultured for 48 h in normoxic or hypoxic conditions at the optimal, reduced or increased iron concentration. The mRNA expression levels of markers of apoptosis [B‑cell lymphoma‑2 (Bcl2; inhibition) and Bcl‑2‑activated X protein (Bax; induction)], atrophy (Atrogin), glycolysis (pyruvate kinase 2; PKM2) and iron metabolism [transferrin receptor 1 (TfR1; iron importer), ferroportin 1 (FPN1; iron exporter), ferritin heavy chain (FTH; iron storage protein) and hepcidin (HAMP; iron regulator)] were determined using reverse transcription‑quantitative polymerase chain reaction, and cell viability was measured using an tetrazolium reduction assay. Cardiomyocytes and myocytes, when exposed to hypoxia, demonstrated an increased Bax/Bcl‑2 gene expression ratio (Pcell type (Pviability. The analogous alterations were observed in both cell types upon ammonium ferric citrate (AFC) treatment during hypoxia; however, the increased Bax/Bcl‑2 ratio and associated viability loss was lower compared with that in case of DFO treatment (Pcell types upon DFO during hypoxia demonstrated the increased expression of TfR1 and HAMP (all P0.6 and Pviability of cardiomyocytes and myocytes more severely compared with iron excess. In myocytes, during hypoxia iron may act in a protective manner, since the level of atrophy is decreased in the iron‑salt‑treated cells.

  7. Fractalkine depresses cardiomyocyte contractility.

    Directory of Open Access Journals (Sweden)

    David Taube

    Full Text Available BACKGROUND: Our laboratory reported that male mice with cardiomyocyte-selective knockout of the prostaglandin E2 EP4 receptor sub-type (EP4 KO exhibit reduced cardiac function. Gene array on left ventricles (LV showed increased fractalkine, a chemokine implicated in heart failure. We therefore hypothesized that fractalkine is regulated by PGE2 and contributes to depressed contractility via alterations in intracellular calcium. METHODS: Fractalkine was measured in LV of 28-32 week old male EP4 KO and wild type controls (WT by ELISA and the effect of PGE2 on fractalkine secretion was measured in cultured neonatal cardiomyocytes and fibroblasts. The effect of fractalkine on contractility and intracellular calcium was determined in Fura-2 AM-loaded, electrical field-paced cardiomyocytes. Cardiomyocytes (AVM from male C57Bl/6 mice were treated with fractalkine and responses measured under basal conditions and after isoproterenol (Iso stimulation. RESULTS: LV fractalkine was increased in EP4 KO mice but surprisingly, PGE2 regulated fractalkine secretion only in fibroblasts. Fractalkine treatment of AVM decreased both the speed of contraction and relaxation under basal conditions and after Iso stimulation. Despite reducing contractility after Iso stimulation, fractalkine increased the Ca(2+ transient amplitude but decreased phosphorylation of cardiac troponin I, suggesting direct effects on the contractile machinery. CONCLUSIONS: Fractalkine depresses myocyte contractility by mechanisms downstream of intracellular calcium.

  8. Ultrasonic Vocalizations by Adult Rats (Rattus norvegicus)

    Science.gov (United States)

    1991-12-01

    begun. Diazepam , chlordiazepoxide , morphine, or naloxone was administered I.P. prior to placing the rat in the tailshock apparatus. Four different...by chlordiazepoxide and diazepam . Drug Dev. Res., 5, 185-193 (1985). Gardner, C.R., and Budhram, P. Effects of agents which interact with central... diazepam , and chlorpromazine, attenuate these vocalizations. Recent work by Kaltwasser (1990) examined the occurrence of vocalizations in response to

  9. Diamide: positive inotropic effect in isolated atria and inhibition of Na+/Ca2+ exchange in cardiomyocytes.

    Science.gov (United States)

    Antolini, M; Debetto, P; Trevisi, L; Luciani, S

    1991-02-01

    The influence of frequency of stimulation and external calcium on the positive inotropic response of guinea-pig left atria to diamide and the inhibitory action on Na+/Ca2+ exchange activity of rat cardiomyocytes by this oxidant of sulphhydryl groups have been investigated. Diamide (50-500 microM) induces a concentration-dependent positive inotropic effect which is more pronounced when atria are driven at 1.0 Hz rather than at 0.5 and 0.1 Hz, and are bathed in 2.72 mM rather than in 1.36 mM external calcium. A decrease in the positive inotropic effect at 35 degrees C with respect to 29 degrees C is also observed. In addition, diamide in positive inotropic concentrations (100-300 microM) significantly reduces Na+/Ca2+ exchange activity and cytoplasmic glutathione levels in adult rat cardiomyocytes. The thiol reducing agent dithiothreitol either reverses or prevents diamide effects both in isolated atria and cardiomyocytes, suggesting that the actions of diamide are correlated to its property to oxidize sulphhydryl groups to disulphides. In view of the functional importance of Na+/Ca2+ exchange in myocardial contractility, it is proposed that diamide may increase the heart force of contraction by an inhibition of the sarcolemmal Na+/Ca2+ exchange activity.

  10. Morfologia e contratilidade em cardiomiócitos de ratos com baixo desempenho para o exercício físico Morphology and contractility in cardiomyocytes of rats with low exercise performance

    Directory of Open Access Journals (Sweden)

    Judson Fonseca Quintão Júnior

    2012-05-01

    Full Text Available FUNDAMENTO: A capacidade aeróbica é fundamental para o desempenho físico, e a baixa capacidade aeróbica está relacionada ao desencadeamento de diversas doenças cardiovasculares. OBJETIVO: Comparar a contratilidade e a morfologia de cardiomiócitos isolados de ratos com baixo desempenho e desempenho padrão para o exercício físico. MÉTODOS: Ratos Wistar, com 10 semanas de idade, foram submetidos a um protocolo de corrida em esteira até a fadiga, e foram divididos em dois grupos: Baixo Desempenho (BD e Desempenho Padrão (DP. Em seguida, após eutanásia, o coração foi removido rapidamente e, por meio de dissociação enzimática, os cardiomiócitos do ventrículo esquerdo foram isolados. O comprimento celular e dos sarcômeros e a largura dos cardiomiócitos foram medidos usando-se um sistema de detecção de bordas. Os cardiomiócitos isolados foram estimulados eletricamente a 1 e 3 Hz e a contração celular foi medida registrando-se a alteração do seu comprimento. RESULTADOS: O comprimento celular foi menor no grupo BD (157,2 ± 1,3µm; p BACKGROUND: Aerobic capacity is essential to physical performance, and low aerobic capacity is related to the triggering of various cardiovascular diseases. OBJECTIVE: To compare the morphology and contractility of isolated rat cardiomyocytes with low performance and standard performance for exercise. METHODS: Wistar rats with 10 weeks of age underwent a protocol of treadmill running to fatigue, and were divided into two groups: Low Performance (LP and Standard Performance (SP. Then, the animals were sacrificed, the heart was quickly removed and, by means of enzymatic dissociation, left ventricular cardiomyocytes were isolated. The cell and sarcomeres length and width of cardiomyocytes were measured using an edge detection system. The isolated cardiomyocytes were electrically stimulated at 1 and 3 Hz and cell contraction was measured by registering the change of their length. RESULTS: The cell

  11. Basal autophagy protects cardiomyocytes from doxorubicin-induced toxicity.

    Science.gov (United States)

    Pizarro, Marcela; Troncoso, Rodrigo; Martínez, Gonzalo J; Chiong, Mario; Castro, Pablo F; Lavandero, Sergio

    2016-08-31

    Doxorubicin (Doxo) is one of the most effective anti-neoplastic agents but its cardiotoxicity has been an important clinical limitation. The major mechanism of Doxo-induced cardiotoxicity is associated to its oxidative capacity. However, other processes are also involved with significant consequences for the cardiomyocyte. In recent years, a number of studies have investigated the role of autophagy on Doxo-induced cardiotoxicity but to date it is not clear how Doxo alters that process and its consequence on cardiomyocytes viability. Here we investigated the effect of Doxo 1uM for 24h of stimulation on cultured neonatal rat cardiomyocytes. We showed that Doxo inhibits basal autophagy. This inhibition is due to both Akt/mTOR signaling pathway activation and Beclin 1 level decrease. To assess the role of autophagy on Doxo-induced cardiomyocyte death, we evaluated the effects 3-methyladenine (3-MA), bafilomycin A1 (BafA), siRNA Beclin 1 (siBeclin 1) and rapamycin (Rapa) on cell viability. Inhibition of autophagy with 3-MA, BafA and siBeclin 1 increased lactate dehydrogenase (LDH) release but, when autophagy was induced by Rapa, Doxo-induced cardiomyocyte death was decreased. These results suggest that Doxo inhibits basal autophagy and contributes to cardiomyocyte death. Activation of autophagy could be used as a strategy to protect the heart against Doxo toxicity.

  12. Contextual fear conditioning differs for infant, adolescent, and adult rats.

    Science.gov (United States)

    Esmorís-Arranz, Francisco J; Méndez, Cástor; Spear, Norman E

    2008-07-01

    Contextual fear conditioning was tested in infant, adolescent, and adult rats in terms of Pavlovian-conditioned suppression. When a discrete auditory-conditioned stimulus (CS) was paired with footshock (unconditioned stimulus, US) within the largely olfactory context, infants and adolescents conditioned to the context with substantial effectiveness, but adult rats did not. When unpaired presentations of the CS and US occurred within the context, contextual fear conditioning was strong for adults, weak for infants, but about as strong for adolescents as when pairings of CS and US occurred in the context. Nonreinforced presentations of either the CS or context markedly reduced contextual fear conditioning in infants, but, in adolescents, CS extinction had no effect on contextual fear conditioning, although context extinction significantly reduced it. Neither CS extinction nor context extinction affected responding to the CS-context compound in infants, suggesting striking discrimination between the compound and its components. Female adolescents showed the same lack of effect of component extinction on response to the compound as infants, but CS extinction reduced responding to the compound in adolescent males, a sex difference seen also in adults. Theoretical implications are discussed for the development of perceptual-cognitive processing and hippocampus role.

  13. Immature rats show ovulatory defects similar to those in adult rats lacking prostaglandin and progesterone actions

    Directory of Open Access Journals (Sweden)

    Sanchez-Criado Jose E

    2004-09-01

    Full Text Available Abstract Gonadotropin-primed immature rats (GPIR constitute a widely used model for the study of ovulation. Although the equivalence between the ovulatory process in immature and adult rats is generally assumed, the morphological and functional characteristics of ovulation in immature rats have been scarcely considered. We describe herein the morphological aspects of the ovulatory process in GPIR and their response to classical ovulation inhibitors, such as the inhibitor of prostaglandin (PG synthesis indomethacin (INDO and a progesterone (P receptor (PR antagonist (RU486. Immature Wistar rats were primed with equine chorionic gonadotropin (eCG at 21, 23 or 25 days of age, injected with human chorionic gonadotropin (hCG 48 h later, and sacrificed 16 h after hCG treatment, to assess follicle rupture and ovulation. Surprisingly, GPIR showed age-related ovulatory defects close similar to those in adult rats lacking P and PG actions. Rats primed with eCG at 21 or 23 days of age showed abnormally ruptured corpora lutea in which the cumulus-oocyte complex (COC was trapped or had been released to the ovarian interstitum, invading the ovarian stroma and blood and lymphatic vessels. Supplementation of immature rats with exogenous P and/or PG of the E series did not significantly inhibit abnormal follicle rupture. Otherwise, ovulatory defects were practically absent in rats primed with eCG at 25 days of age. GPIR treated with INDO showed the same ovulatory alterations than vehicle-treated ones, although affecting to a higher proportion of follicles. Blocking P actions with RU486 increased the number of COC trapped inside corpora lutea and decreased ovulation. The presence of ovulatory defects in GPIR, suggests that the capacity of the immature ovary to undergo the coordinate changes leading to effective ovulation is not fully established in Wistar rats primed with eCG before 25 days of age.

  14. Comparative study on influence of fetal bovine serum and serum of adult rat on cultivation of newborn rat neural cells

    Directory of Open Access Journals (Sweden)

    Sukach A. N.

    2014-09-01

    Full Text Available Aim. To study the influence of fetal bovine serum and serum of adult rats on behavior of newborn rat isolated neural cells during their cultivation in vitro. Methods. The isolation of neural cells from neonatal rat brain. The determination of the dynamics of cellular monolayer formation. Immunocytochemical staining of cells for β-tubulin III, nestin and vimentin. Results. It has been determined that the addition of serum of adult rats to the cultivation medium creates more favorable conditions for survival, attachment and spread of differentiated, and proliferation of the stem/progenitor neural cells of newborn rats during cultivation in vitro compared with the fetal bovine serum. Conclusions. Using the serum of adult rats is preferable for the cultivation of isolated neural cells of newborn rats compared with the fetal bovine serum.

  15. 腹主动脉缩窄20周大鼠心肌细胞的自噬通量%Autophagic flux of cardiomyocytes from 20-week transverse abdominal aortic constriction rats

    Institute of Scientific and Technical Information of China (English)

    崔龙彪; 圣娟娟; 王云英; 余志斌

    2013-01-01

    Cardiac autophagy dramatically increases in heart failure induced by sustained pressure overload.However,it has not yet been addressed if enhanced autophagy plays a role in protecting myocardium or mediating progression from compensative hypertrophy to heart failure.The aim of the present study was to detect autophagic flux of cardiomyocytes from 20-week transverse abdominal aortic constriction (TAC) rats.Fasting rats were used as the positive control for detecting cardiac autophagy.Echocardiography was applied to find the changes of cardiac structure and function.Immunofluorescent histochemistry and Western blot were used to analyze the related biomolecular indexes reflecting cardiac autophagic flux.After the previous methods for detecting cardiac autophagy were confirmed,the autophagic flux in cardiomyocytes of rats subjected to 20-week TAC was examined.The results showed that fasting had no obvious influence on parameters of cardiac structure in rats,including interventricular septal wall thickness and left ventricle posterior wall thickness,but heart rate,diastolic left ventricle internal dimension,fractional shortening of left ventricle dimension,ejection fraction and mitral inflow velocity decreased in rats after fasting for 3 d.Meanwhile,positively stained particles of LC3 and cathepsin D,but not ubiquitin and complement 9,distributed within cardiomyocytes of 3-day fasting rats,indicating augmented autophagic flux.Compared with sham rats,20-week TAC rats did not show any changes ofLC3,cathepsin D,ubiquitin and complement 9 in myocardium detected by immunofluorescent histochemistry.In addition,protein levels of LC3,cathepsin D and p62 in myocardium of TAC rats did not changed.These results reveal the unchanged autophagic flux in cardiomyocytes at middle or late phase of cardiac hypertrophy in TAC rats,implying a balance between inhibition of hypertrophy and activation of pressure load stress on autophagy.%长期心脏压力超负荷致心衰心肌的自噬

  16. Actin-binding Rho activating protein is expressed in the central nervous system of normal adult rats

    Institute of Scientific and Technical Information of China (English)

    Lihua Liu; Jutta Schaper; Mingying Luo; Baolin Yang; Xiaoqiong Wu; Wu Zhu; Yinglu Guan; Weijun Cai; Kerstin Troidl; Wolfgang Schaper

    2012-01-01

    Previous studies show that actin-binding Rho activating protein (Abra) is expressed in cardiomyocytes and vascular smooth muscle cells. In this study, we investigated the expression profile of Abra in the central nervous system of normal adult rats by confocal immunofluorescence.Results show ed that Abra immunostaining was located in neuronal nuclei, cytoplasm and processes in the central nervous system, with the strongest staining in the nuclei; in the cerebral cortex, Abra positive neuronal bodies and processes were distributed in six cortical layers including molecular layer, external granular layer, external pyramidal layer, internal granular layer, internal pyramidal layer and polymorphic layer; in the hippocampus, the cell bodies of Abra positive neurons were distributed evenly in pyramidal layer and granular layer, with pos itive processes in molecular layer and orien layer; in the cerebellar cortex, Abra staining showed the positive neuronal cell bodies in Purkinje cell layer and granular layer and positive processes in molecular layer; in the spinal cord, Abra-immunopositive products covered the whole gray matter and w hite matter; co-localization studies showed that Abra was co-stained with F-actin in neuronal cytoplasm and processes, but weakly in the nuclei. In addition, in the hippocampus, Abra was co-stained with F-actin only in neuronal processes, but not in the cell body. This study for the first time presents a comprehensive overview of Abra expression in the central nervous system, providing insights for further investigating the role of Abra in the mature central nervous system.

  17. Functional protein expression of multiple sodium channel alpha- and beta-subunit isoforms in neonatal cardiomyocytes.

    Science.gov (United States)

    Kaufmann, Susann G; Westenbroek, Ruth E; Zechner, Christoph; Maass, Alexander H; Bischoff, Sebastian; Muck, Jenny; Wischmeyer, Erhard; Scheuer, Todd; Maier, Sebastian K G

    2010-01-01

    Voltage-gated sodium channels are composed of pore-forming alpha- and auxiliary beta-subunits and are responsible for the rapid depolarization of cardiac action potentials. Recent evidence indicates that neuronal tetrodotoxin (TTX) sensitive sodium channel alpha-subunits are expressed in the heart in addition to the predominant cardiac TTX-resistant Na(v)1.5 sodium channel alpha-subunit. These TTX-sensitive isoforms are preferentially localized in the transverse tubules of rodents. Since neonatal cardiomyocytes have yet to develop transverse tubules, we determined the complement of sodium channel subunits expressed in these cells. Neonatal rat ventricular cardiomyocytes were stained with antibodies specific for individual isoforms of sodium channel alpha- and beta-subunits. alpha-actinin, a component of the z-line, was used as an intracellular marker of sarcomere boundaries. TTX-sensitive sodium channel alpha-subunit isoforms Na(v)1.1, Na(v)1.2, Na(v)1.3, Na(v)1.4 and Na(v)1.6 were detected in neonatal rat heart but at levels reduced compared to the predominant cardiac alpha-subunit isoform, Na(v)1.5. Each of the beta-subunit isoforms (beta1-beta4) was also expressed in neonatal cardiac cells. In contrast to adult cardiomyocytes, the alpha-subunits are distributed in punctate clusters across the membrane surface of neonatal cardiomyocytes; no isoform-specific subcellular localization is observed. Voltage clamp recordings in the absence and presence of 20 nM TTX provided functional evidence for the presence of TTX-sensitive sodium current in neonatal ventricular myocardium which represents between 20 and 30% of the current, depending on membrane potential and experimental conditions. Thus, as in the adult heart, a range of sodium channel alpha-subunits are expressed in neonatal myocytes in addition to the predominant TTX-resistant Na(v)1.5 alpha-subunit and they contribute to the total sodium current.

  18. Effect of piperine on the epididymis of adult male rats

    Institute of Scientific and Technical Information of China (English)

    S. C. D'cruz; P. P. Mathur

    2005-01-01

    Aim: To study the effect of piperine on the epididymal antioxidant system of adult male rats. Methods: Adult male rats were orally administered piperine at doses of 1 mg/kg, 10 mg/kg and 100 mg/kg body weight each day for 30consecutive days. Twenty-four hours after the last treatment, the rats were weighed and killed with ether and the epididymis was dissected from the bodies. Sperm collected from the cauda region of the epididymis was used for the assessment of its count, motility and viability. Caput, corpus and cauda regions of the epididymis were separated and homogenized separately to obtain 10 % homogenates. The supernatants were used for the assays of sialic acid,superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, lipid peroxidation and hydrogen peroxide generation. Results: Body weight of the piperine-treated rats remained unchanged. The weights of the caput,corpus and cauda regions of the epididymis significantly decreased at dose of 100 mg/kg. Epididymal sperm count and motility decreased at 10 mg/kg and 100 mg/kg, and sperm viability decreased significantly at 100 mg/kg. Sialic acid levels in the epididymis decreased significantly at 100 mg/kg while significant decrease in the cauda region alone was observed at 10 mg/kg. A significant decline in the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, along with an increase in hydrogen peroxide generation and lipid peroxidation were observed at 10 mg/kg and 100 mg/kg. Conclusion: Piperine caused a decrease in the activity of antioxidant enzymes and sialic acid levels in the epididymis and thereby increased reactive oxygen species levels that could damage the epididymal environment and sperm function.

  19. Basement membrane chondroitin sulfate proteoglycans: localization in adult rat tissues

    DEFF Research Database (Denmark)

    McCarthy, K J; Couchman, J R

    1990-01-01

    Heparan sulfate proteoglycans have been described as the major proteoglycan component of basement membranes. However, previous investigators have also provided evidence for the presence of chondroitin sulfate glycosaminoglycan in these structures. Recently we described the production...... and characterization of core protein-specific monoclonal antibodies (MAb) against a chondroitin sulfate proteoglycan (CSPG) present in Reichert's membrane, a transient extra-embryonic structure of rodents. This CSPG was also demonstrated to be present in adult rat kidney. We report here the tissue distribution...... sulfate proteoglycans previously described....

  20. 大鼠心力衰竭细胞 microRNA 表达谱及生物信息学分析%Screening of specific microRNAs and bioinformatics analysis on cardiomyocytes in rat with heart failure

    Institute of Scientific and Technical Information of China (English)

    朱海娟; 何淑芳; 金世云; 胡军; 张野

    2016-01-01

    Objective To investigate microRNAs ( miRNAs) expression profiling of cardiomyocytes in rats with heart failure, and predict miRNAs-regulated target genes and their functions.Methods Total of 18 male SD rats weighing 200-220 g were randomly divided into 2 groups:the control group ( CON) and the heart failure group (HF).The rats in HF group were injected by adriamycin via tail vein to induce heart failure, meanwhile in CON group, rats were received an equal volume of 0.9% sodium chloride intravenously.The cardiomyocytes isolated from the rat hearts in two groups and cultured overnight.After that, total RNA was extracted and then subjected to miRNA microarray to screen differentially expressed miRNAs.The reults of microarray were further verified by quantitative real-time PCR ( qRT-PCR ) .The target genes regulated by differentially expressed miRNAs were predicted by the software of Targetscan and miRanda.Bioinformatics analysis was performed to predict the miRNAs-regulated target genes and analyze the enriched gene ontology ( GO) and signaling pathway ( KEGG Pathway) .Results The results of miRNA microarray showed that a total of 37 miRNAs were differentially expressed in HF group as compared to CON group, among which 22 miRNAs were up-regulated and 15 miRNAs were down-regulated (P<0.01, FDR<0.05).The expression of miR-133b-5p (t=14.56, P<0.01), miR-6216 (t=9.32, P<0.01) and let-7e-5p (t=13.92, P<0.01) which were detected by qRT-PCR exhibited the similar tendency of up or down regulation to those shown in microarray results.Bioinformatics analysis indicated that miRNAs-regulated target genes were significantly enriched in 31 GOs (P<0.01, FDR<0.05) and 12 signal pathways (P<0.05, FDR<0.05), among which ubiquitin-proteasome system, MAPK signaling pathway and Toll like siganling pathway exhibited a higher enrichment. Conclusion MiRNA expression profile on cardiomyocytes in rat with adriamycin-induced heart failure was significantly changed.These differentially expressed

  1. Protective effect of trigonelline on rat cardiomyocytes during hypoxia and reoxygenation%胡芦巴碱对缺氧/复氧乳鼠心肌细胞的保护作用

    Institute of Scientific and Technical Information of China (English)

    韩坤; 王丹萍; 袁磊

    2015-01-01

    目的:探究胡芦巴碱(T RG )对缺氧/复氧乳鼠心肌细胞的保护作用及其机制。方法原代培养SD乳鼠心肌细胞,随机分成3组:正常对照(Control组)、缺氧/复氧组(H/R组)和TRG加缺氧/复氧组(TRG+ H/R组);采用流式细胞术分别检测TRG对缺氧/复氧乳鼠心肌细胞凋亡和线粒体膜电位的影响;采用超氧化物歧化酶(SOD)和丙二醛(MDA)试剂盒检测SOD活性和MDA水平,蛋白免疫印迹法(Western blot)检测procaspase‐9、cleaved caspase‐9、procaspase‐3和cleaved caspase‐3蛋白水平。结果 TRG能够显著降低缺氧/复氧乳鼠心肌细胞凋亡率(P<0.05),增强SOD活性(P<0.05),减少MDA的生成(P<0.05),稳定线粒体膜电位( P<0.05),促进caspase‐9和caspase‐3的活化。结论 T RG可减轻缺氧/复氧对乳鼠心肌细胞的损伤,其机制可能与抗脂质过氧化和稳定线粒体膜电位有关。%Objective To investigate the protective effects of trigonelline in neonatal rat cardiomyocytes during hypoxia /reoxygenation and its mechanism .Methods The neonatal rat cardiomyocytes was randomly divided into the normal control group , the hypoxia/reoxygenation group and the trigonelline group .Flow cytometry was used to determine the apoptosis and mitochondrial membrane potential .The levels of SOD and MDA were measured in different groups .Western blot method was used to measure the procaspase‐9 ,cleaved caspase‐9 ,procaspase‐3 and cleaved caspase‐3 protein level .Results Trigonelline could inhibit apoptosis (P<0 .05) ,enhanced activity of SOD (P<0 .05) ,reduce production of MDA (P<0 .05) ,stabilize the mitochondrial membrane potential (P<0 .05) and activate caspase‐9 and caspase‐3 in neonatal rat cardiomyocytes during hypoxia/reoxygenation .Conclusion Trigo‐nelline could protect myocardial cells from injury caused by hypoxia and reoxygenation ,and the

  2. Effects of NOS inhibitor on dentate gyrus neurogenesis after diffuse brain injury in the adult rats

    Institute of Scientific and Technical Information of China (English)

    SunLi-Sha; XuJiang-ping

    2004-01-01

    Objective To investigate the effects of selective nitric oxide synthase (NOS) inhibitors on dentate gyrus neurogenesis after diffuse brain injury (DBI) in the adult rat brain. Methods Adult male SD rats were subjected to diffuse brain injury (DBI) model. By using systemic bromodeoxyuridine (BrdU) to label dividing cells, we compared the proliferation rate of

  3. AMPK and substrate availability regulate creatine transport in cultured cardiomyocytes.

    Science.gov (United States)

    Darrabie, Marcus D; Arciniegas, Antonio Jose Luis; Mishra, Rajashree; Bowles, Dawn E; Jacobs, Danny O; Santacruz, Lucia

    2011-05-01

    Profound alterations in myocellular creatine and phosphocreatine levels are observed during human heart failure. To maintain its intracellular creatine stores, cardiomyocytes depend upon a cell membrane creatine transporter whose regulation is not clearly understood. Creatine transport capacity in the intact heart is modulated by substrate availability, and it is reduced in the failing myocardium, likely adding to the energy imbalance that characterizes heart failure. AMPK, a key regulator of cellular energy homeostasis, acts by switching off energy-consuming pathways in favor of processes that generate energy. Our objective was to determine the effects of substrate availability and AMPK activation on creatine transport in cardiomyocytes. We studied creatine transport in rat neonatal cardiomyocytes and HL-1 cardiac cells expressing the human creatine transporter cultured in the presence of varying creatine concentrations and the AMPK activator 5-aminoimidazole-4-carboxamide-1-β-d-ribonucleoside (AICAR). Transport was enhanced in cardiomyocytes following incubation in creatine-depleted medium or AICAR. The changes in transport were due to alterations in V(max) that correlated with changes in total and cell surface creatine transporter protein content. Our results suggest a positive role for AMPK in creatine transport modulation for cardiomyocytes in culture.

  4. Dobutamine stress echocardiography in healthy adult male rats

    Directory of Open Access Journals (Sweden)

    Couet Jacques

    2005-10-01

    Full Text Available Abstract Background Dobutamine stress echocardiography is used to investigate a wide variety of heart diseases in humans. Dobutamine stress echocardiography has also been used in animal models of heart disease despite the facts that the normal response of healthy rat hearts to this type of pharmacological stress testing is unknown. This study was performed to assess this normal response. Methods 15 normal adult male Wistar rats were evaluated. Increasing doses of dobutamine were infused intravenously under continuous imaging of the heart by a 12 MHz ultrasound probe. Results Dobutamine stress echocardiography reduced gradually LV diastolic and systolic dimensions. Ejection fraction increased by a mean of +24% vs. baseline. Heart rate increased progressively without reaching a plateau. Changes in LV dimensions and ejection fraction reached a plateau after a mean of 4 minutes at a constant infusion rate. Conclusion DSE can be easily performed in rats. The normal response is an increase in heart rate and ejection fraction and a decrease in LV dimensions. A plateau in echocardiographic measurements is obtained after 4 minutes of a constant infusion rate in most animals.

  5. Lipoic acid attenuates Aroclor 1260-induced hepatotoxicity in adult rats.

    Science.gov (United States)

    Aly, Hamdy A A; Mansour, Ahmed M; Hassan, Memy H; Abd-Ellah, Mohamed F

    2016-08-01

    The present study was aimed to investigate the mechanistic aspect of Aroclor 1260-induced hepatotoxicity and its protection by lipoic acid. The adult male Albino rats were divided into six groups. Group I served as control. Group II received lipoic acid (35 mg/kg/day). Aroclor 1260 was given to rats by oral gavage at doses 20, 40, or 60 mg/kg/day (Groups III, IV, and V, respectively). Group VI was pretreated with lipoic acid (35 mg/kg/day) 24 h before Aroclor 1260 (40 mg/kg/day). Treatment in all groups was continued for further 15 consecutive days. Serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase activities and total bilirubin, total cholesterol, and triglycerides were significantly increased while total protein, total albumin, and high-density lipoprotein were significantly decreased. Hydrogen peroxide production and lipid peroxidation were significantly increased while superoxide dismutase and catalase activities and reduced glutathione (GSH) content was significantly decreased in liver. Caspase-3 & -9 activities were significantly increased in liver. Lipoic acid pretreatment significantly reverted all these abnormalities toward their normal levels. In conclusion, Aroclor 1260 induced liver dysfunction, at least in part, by induction of oxidative stress. Apoptotic effect of hepatic cells is involved in Aroclor 1260-induced liver injury. Lipoic acid could protect rats against Aroclor 1260-induced hepatotoxicity. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 913-922, 2016.

  6. Acute behavioral toxicity of carbaryl and propoxur in adult rats.

    Science.gov (United States)

    Ruppert, P H; Cook, L L; Dean, K F; Reiter, L W

    1983-04-01

    Motor activity and neuromotor function were examined in adult CD rats exposed to either carbaryl or propoxur, and behavioral effects were compared with the time course of cholinesterase inhibition. Rats received an IP injection of either 0, 2, 4, 6 or 8 mg/kg propoxur or 0, 4, 8, 16 or 28 mg/kg carbaryl in corn oil 20 min before testing. All doses of propoxur reduced 2 hr activity in a figure-eight maze, and crossovers and rears in an open field. For carbaryl, dosages of 8, 16 and 28 mg/kg decreased maze activity whereas 16 and 28 mg/kg reduced open field activity. In order to determine the time course of effects, rats received a single IP injection of either corn oil, 2 mg/kg propoxur or 16 mg/kg carbaryl, and were tested for 5 min in a figure-eight maze either 15, 30, 60, 120 or 240 min post-injection. Immediately after testing, animals were sacrificed and total cholinesterase was measured. Maximum effects of propoxur and carbaryl on blood and brain cholinesterase and motor activity were seen within 15 min. Maze activity had returned to control levels within 30 and 60 min whereas cholinesterase levels remained depressed for 120 and 240 min for propoxur and carbaryl, respectively. These results indicate that both carbamates decrease motor activity, but behavioral recovery occurs prior to that of cholinesterase following acute exposure.

  7. The role of mAKAPβ in the process of cardiomyocyte hypertrophy induced by angiotensin II.

    Science.gov (United States)

    Guo, Huixin; Liu, Baoxin; Hou, Lei; The, Erlinda; Li, Gang; Wang, Dongzhi; Jie, Qiqiang; Che, Wenliang; Wei, Yidong

    2015-05-01

    Angiotensin II (AngII) is the central product of the renin-angiotensin system (RAS) and this octapeptide contributes to the pathophysiology of cardiac hypertrophy and remodeling. mAKAPβ is an A-kinase anchoring protein (AKAP) that has the function of binding to the regulatory subunit of protein kinase A (PKA) and confining the holoenzyme to discrete locations within the cell. In this study, we aimed to investigate the role of mAKAPβ in AngII‑induced cardiomyocyte hypertrophy and the possible mechanisms involved. Cultured cardiomyocytes from neonatal rats were treated with AngII. Subsequently, the morphology of the cardiomyocytes was observed and the expression of mAKAPβ and cardiomyocyte hypertrophic markers was measured. mAKAPβ‑shRNA was constructed for RNA interference; the expression of mAKAPβ and hypertrophic markers, the cell surface area and the [3H]Leucine incorporation rate in the AngII‑treated rat cardiomyocytes were detected following RNA interference. Simultaneously, changes in the expression levels of phosphorylated extracellular signal-regulated kinase (p-ERK)2 in the cardiomyocytes were assessed. The cell size of the AngII-treated cardiaomyocytes was significantly larger than that of the untreated cardiomyocytes. The expression of hypertrophic markers and p-ERK2, the cell surface area and the [3H]Leucine incorporation rate were all significantly increased in the AngII‑treated cells. However, the expression of mAKAPβ remained unaltered in this process. RNA interference simultaneously inhibited the protein expression of mAKAPβ and p‑ERK2, and the hypertrophy of the cardiomyocytes induced by AngII was attenuated. These results demonstrate that AngII induces hypertrophy in cardiomyocytes, and mAKAPβ is possibly involved in this process. The effects of mAKAPβ on AngII‑induced cardiomyocyte hypertrophy may be associated with p-ERK2 expression.

  8. Effects of neonatal peripheral tissue injury on pain-related behaviors in adult rats

    Directory of Open Access Journals (Sweden)

    Meng-meng LI

    2013-09-01

    Full Text Available Objective To observe the effects of peripheraltissueinjury in the developmental stage of newborn rats on pain-related behaviors in adult rats. Methods SD rats 1,4,7,14,21 and 28days after birth were selected in thepresent study(4litters at each time point and 10 rats per litter.Each litter of rats was randomly divided intoinjury group(receiving subcutaneous injection of 20μl bee venomand control group(receiving subcutaneous injection of 20μl normal saline, with20 in each group, and then raised for 2 months to adulthood. The baseline pain threshold was observed by measuring spontaneous paw flinching reflex,paw withdrawal thermal latency(PWTLand paw withdrawal mechanical threshold(PWMT, then 50μl 0.4% bee venom was subcutaneously injected to each rat, and the changesinpa in reaction and pain threshold were determined. Results The baseline thermal pain threshold in adult rats receiving bee venom or normal saline at different time points after birth was similar,but baseline mechanical pain threshold in adult rats receiving bee venom at1,4,7and14 days after birth was decreased significantly compared with the adult rats receiving normal saline at corresponding time points(P0.05.Mechanical hyperalgesia was not induced in rats injected with bee venom but induced in adult ratsinjected with normal saline4-21days after birth.Injection of bee venom 21 and 28 days after birth could obviously enhance the bee venom-induced hyperalgesiain adult rats compared with control group(P<0.01. Conclusions Bee venom stimuli at different time points after birth could affect the baseline PWMT and mechanical pain hypersensitivityin adult rats but not the baseline PWTL and thermal pain hypersensitivity. The 21st day maybe a key time point of nervous system development in rats.

  9. Neonatal caffeine exposure and seizure susceptibility in adult rats.

    Science.gov (United States)

    Guillet, R; Dunham, L

    1995-08-01

    Early developmental exposure to caffeine in rats results in changes in brain excitability that persist to adulthood. The mechanism of these alterations is unknown. To identify potential neurotransmitter systems involved, we exposed neonatal rats to caffeine and determined seizure thresholds for chemoconvulsants active at different CNS receptors in the adult animal. Rats were unhandled (NH) or received by gavage (0.05 ml/10 g) either vehicle (water) or caffeine (15-20 mg/kg/day) for postnatal days 2-6. At age 70-90 days, each rat was infused intravenously (i.v.) with picrotoxin (PIC), bicuculline (BIC) [convulsants acting at the gamma-aminobutyric acid/benzodiazepine (GABA/BDZ) receptor], pentylenetetrazol [PTZ, possibly acting at both GABA/BDZ and N-methyl-D-aspartate (NMDA) receptors], caffeine (acting at adenosine receptors), strychnine (STR, acting at glycine receptors), or kainic acid (KA, acting at the NMDA receptor). Seizure thresholds were analyzed as a function of neonatal treatment and sex. Thresholds for caffeine, PTZ, PIC, and KA were increased as a function of neonatal caffeine exposure (p = 0.01, 0.02, 0.02, and 0.005, respectively). The thresholds for BIC and STR were not altered. There were also gender differences in seizure susceptibility. Thresholds for seizures produced by BIC, caffeine, PIC, and STR were higher in females (p = 0.005, 0.005, 0.001, and 0.0001, respectively), but were not different for seizures caused by PTZ. These results suggest that early developmental exposure to caffeine affects later seizure susceptibility. Moreover, some of these effects are gender specific.

  10. Contractile force measured in unskinned isolated adult rat heart fibres.

    Science.gov (United States)

    Brady, A J; Tan, S T; Ricchiuti, N V

    1979-12-13

    A number of investigators have succeeded in preparing isolated cardiac cells by enzymatic digestion which tolerate external [Ca2+] in the millimolar range. However, a persistent problem with these preparations is that, unlike in situ adult ventricular fibres, the isolated fibres usually beat spontaneously. This spontaneity suggests persistent ionic leakage not present in situ. A preferable preparation for mechanical and electrical studies would be one which is quiescent but excitable in response to electrical stimulation and which does not undergo contracture with repeated stimulation. We report here a modified method of cardiac fibre isolation and perfusion which leaves the fibre membrane electrically excitable and moderately resistant to mechanical stress so that the attachment of suction micropipettes to the fibre is possible for force measurement and length control. Force generation in single isolated adult rat heart fibres is consistent with in situ contractile force. The negative staircase effect (treppe) characteristic of adult not heart tissue is present with increased frequency of stimulation. Isometric developed tension increases with fibre length as in in situ ventricular tissue.

  11. Insulin improves cardiomyocyte contractile function through enhancement of SERCA2a activity in simulated ischemia/reperfusion

    Institute of Scientific and Technical Information of China (English)

    Jie YU; Hai-feng ZHANG; Feng WU; Qiu-xia LI; Heng MA; Wen-yi GUO; Hai-chang WANG; Feng GAO

    2006-01-01

    Aim: Insulin exerts anti-apoptotic effects in both cardiomyocytes and coronary endothelial cells following ischemia/reperfusion (I/R) via the Akt-endothelial nitric oxide synthase survival signal pathway. This important insulin signaling might further contribute to the improvement of cardiac function after reperfusion. In this study, we tested the hypothesis that sarcoplasmic reticulum calcium-AT-Pase (SERCA2a) is involved in the insulin-induced improvement of cardiac contractile function following I/R. Methods: Ventricular myocytes were enzymatically isolated from adult SD rats. Simulated I/R was induced by perfusing cells with chemical anoxic solution for 15 min followed by reperfusion with Tyrode's solution with or without insulin for 30 min. Myocyte shortening and intracellular calcium transients were assessed and underlying mechanisms were investigated. Results: Reperfusion with insulin (10-7 mol/L) significantly improved the recovery of contractile function (n=15-20 myocytes from 6-8 hearts, P<0.05), and increased calcium transients, as evidenced by the increased calcium (Ca2+) fluorescence ratio, shortened time to peak Ca2+ and time to 50% diastolic Ca2+, compared with those in cells reperfused with vehicle (P<0.05). In addition, Akt phosphorylation and SERCA2a activity were both increased in insulin-treated I/R cardiomyocytes, which were markedly inhibited by pretreatment of cells with a specific Akt inhibitor. Moreover, inhibition of Akt activity abolished insulin-induced positive contractile and calcium transients responses in I/R cardiomyocytes. Conclusion: These data demonstrated for the first time that insulin improves the recovery of contractile function in simulated I/R cardiomyocytes in an Akt-dependent and SERCA2a-mediated fashion.

  12. Inhibition of Receptor Interacting Protein Kinases Attenuates Cardiomyocyte Hypertrophy Induced by Palmitic Acid.

    Science.gov (United States)

    Zhao, Mingyue; Lu, Lihui; Lei, Song; Chai, Hua; Wu, Siyuan; Tang, Xiaoju; Bao, Qinxue; Chen, Li; Wu, Wenchao; Liu, Xiaojing

    2016-01-01

    Palmitic acid (PA) is known to cause cardiomyocyte dysfunction. Cardiac hypertrophy is one of the important pathological features of PA-induced lipotoxicity, but the mechanism by which PA induces cardiomyocyte hypertrophy is still unclear. Therefore, our study was to test whether necroptosis, a receptor interacting protein kinase 1 and 3 (RIPK1 and RIPK3-) dependent programmed necrosis, was involved in the PA-induced cardiomyocyte hypertrophy. We used the PA-treated primary neonatal rat cardiac myocytes (NCMs) or H9c2 cells to study lipotoxicity. Our results demonstrated that cardiomyocyte hypertrophy was induced by PA treatment, determined by upregulation of hypertrophic marker genes and cell surface area enlargement. Upon PA treatment, the expression of RIPK1 and RIPK3 was increased. Pretreatment with the RIPK1 inhibitor necrostatin-1 (Nec-1), the PA-induced cardiomyocyte hypertrophy, was attenuated. Knockdown of RIPK1 or RIPK3 by siRNA suppressed the PA-induced myocardial hypertrophy. Moreover, a crosstalk between necroptosis and endoplasmic reticulum (ER) stress was observed in PA-treated cardiomyocytes. Inhibition of RIPK1 with Nec-1, phosphorylation level of AKT (Ser473), and mTOR (Ser2481) was significantly reduced in PA-treated cardiomyocytes. In conclusion, RIPKs-dependent necroptosis might be crucial in PA-induced myocardial hypertrophy. Activation of mTOR may mediate the effect of necroptosis in cardiomyocyte hypertrophy induced by PA.

  13. MicroRNA-1 and-16 inhibit cardiomyocyte hypertrophy by targeting cyclins/Rb pathway

    Institute of Scientific and Technical Information of China (English)

    SHAN Zhi-xin; ZHU Jie-ning; TANG Chun-mei; ZHU Wen-si; LIN Qiu-xiong; HU Zhi-qin; FU Yong-heng; ZHANG Meng-zhen

    2016-01-01

    AIM:MicroRNAs ( miRNAs) were recognized to play significant roles in cardiac hypertrophy .But, it remains unknown whether cyclin/Rb pathway is modulated by miRNAs during cardiac hypertrophy .This study investigates the potential roles of microRNA-1 (miR-1) and microRNA-16 (miR-16) in modulating cyclin/Rb pathway during cardiomyocyte hypertrophy .METHODS:An animal model of hypertrophy was established in a rat with abdominal aortic constriction (AAC).In addition, a cell model of hypertrophy was also achieved based on PE-promoted neonatal rat ventricular cardiomyocyte .RESULTS:miR-1 and-16 expression were markedly de-creased in hypertrophic myocardium and hypertrophic cardiomyocytes in rats .Overexpression of miR-1 and -16 suppressed rat cardiac hypertrophy and hypertrophic phenotype of cultured cardiomyocytes .Expression of cyclins D1, D2 and E1, CDK6 and phosphorylated pRb was increased in hypertrophic myocardium and hypertrophic cardiomyocytes , but could be reversed by enforced expression of miR-1 and -16.CDK6 was validated to be modulated post-transcriptionally by miR-1, and cyclins D1, D2 and E1 were further validated to be modulated post-transcriptionally by miR-16.CONCLUSION: Attenuations of miR-1 and -16 provoke cardiomyocyte hypertrophy via derepressing the cyclins D1, D2, E1 and CDK6, and activating cyclin/Rb pathway.

  14. Cell Competition Promotes Phenotypically Silent Cardiomyocyte Replacement in the Mammalian Heart

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    Cristina Villa del Campo

    2014-09-01

    Full Text Available Heterogeneous anabolic capacity in cell populations can trigger a phenomenon known as cell competition, through which less active cells are eliminated. Cell competition has been induced experimentally in stem/precursor cell populations in insects and mammals and takes place endogenously in early mouse embryonic cells. Here, we show that cell competition can be efficiently induced in mouse cardiomyocytes by mosaic overexpression of Myc during both gestation and adult life. The expansion of the Myc-overexpressing cardiomyocyte population is driven by the elimination of wild-type cardiomyocytes. Importantly, this cardiomyocyte replacement is phenotypically silent and does not affect heart anatomy or function. These results show that the capacity for cell competition in mammals is not restricted to stem cell populations and suggest that stimulated cell competition has potential as a cardiomyocyte-replacement strategy.

  15. Dystrophin-deficient cardiomyocytes derived from human urine: New biologic reagents for drug discovery

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    Xuan Guan

    2014-03-01

    Full Text Available The ability to extract somatic cells from a patient and reprogram them to pluripotency opens up new possibilities for personalized medicine. Induced pluripotent stem cells (iPSCs have been employed to generate beating cardiomyocytes from a patient's skin or blood cells. Here, iPSC methods were used to generate cardiomyocytes starting from the urine of a patient with Duchenne muscular dystrophy (DMD. Urine was chosen as a starting material because it contains adult stem cells called urine-derived stem cells (USCs. USCs express the canonical reprogramming factors c-myc and klf4, and possess high telomerase activity. Pluripotency of urine-derived iPSC clones was confirmed by immunocytochemistry, RT-PCR and teratoma formation. Urine-derived iPSC clones generated from healthy volunteers and a DMD patient were differentiated into beating cardiomyocytes using a series of small molecules in monolayer culture. Results indicate that cardiomyocytes retain the DMD patient's dystrophin mutation. Physiological assays suggest that dystrophin-deficient cardiomyocytes possess phenotypic differences from normal cardiomyocytes. These results demonstrate the feasibility of generating cardiomyocytes from a urine sample and that urine-derived cardiomyocytes retain characteristic features that might be further exploited for mechanistic studies and drug discovery.

  16. The Anti-Apoptotic and Cardioprotective Effects of Salvianolic Acid A on Rat Cardiomyocytes following Ischemia/Reperfusion by DUSP-Mediated Regulation of the ERK1/2/JNK Pathway

    Science.gov (United States)

    Chen, Qiuping; Zhu, Shasha; Liu, Yang; Pan, Defeng; Chen, Xiaohu; Li, Dongye

    2014-01-01

    The purpose of this study was to observe the effects of salvianolic acid A (SAA) pretreatment on the myocardium during ischemia/reperfusion (I/R) and to illuminate the interrelationships among dual specificity protein phosphatase (DUSP) 2/4/16, ERK1/2 and JNK pathways during myocardial I/R, with the ultimate goal of elucidating how SAA exerts cardioprotection against I/R injury (IRI). Wistar rats were divided into the following six groups: control group (CON), I/R group, SAA+I/R group, ERK1/2 inhibitor PD098059+I/R group (PD+I/R), PD+SAA+I/R group, and JNK inhibitor SP600125+I/R group (SP+I/R). The cardioprotective effects of SAA on the myocardium during I/R were investigated with a Langendorff device. Heart rate (HR), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), maximum rate of ventricular pressure rise and fall (±dp/dtmax), myocardial infarction areas (MIA), lactate dehydrogenase (LDH), and cardiomyocytes apoptosis were monitored. To determine the crosstalk betwee JNK and ERK1/2 via DUSP2/4/16 with SAA pretreatment, siRNA-DUSP2/4/16 were performed. The expression levels of Bcl-2, Bax, caspase 3, p-JNK, p-ERK1/2 and DUSP2/4/16 in cardiomyocytes were assayed by Western blot. Our results showed that LDH, MIA and cell apoptosis were decreased, and various parameters of heart function were improved by SAA pretreatment and SP application. In the I/R group, the expression levels of p-ERK1/2 and DUSP4/16 were not significantly different compared with the CON group, however, the protein expression levels of p-ERK1/2, Bcl-2 and DUSP4/16 were higher, while p-JNK, Bax, caspase 3 and DUSP2 levels were reduced among the SAA+I/R, PD+SAA+I/R and SP+I/R groups. The above indices were not significantly different between the SAA+I/R and SP+I/R groups. Compared with the SAA+I/R group, p-ERK1/2 was increased and p-JNK was decreased in the SAA+si-DUSP2+I/R, however, p-ERK was downregulated and p-JNK was upregulated in SAA+si-DUSP4+I

  17. The anti-apoptotic and cardioprotective effects of salvianolic acid a on rat cardiomyocytes following ischemia/reperfusion by DUSP-mediated regulation of the ERK1/2/JNK pathway.

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    Tongda Xu

    Full Text Available The purpose of this study was to observe the effects of salvianolic acid A (SAA pretreatment on the myocardium during ischemia/reperfusion (I/R and to illuminate the interrelationships among dual specificity protein phosphatase (DUSP 2/4/16, ERK1/2 and JNK pathways during myocardial I/R, with the ultimate goal of elucidating how SAA exerts cardioprotection against I/R injury (IRI. Wistar rats were divided into the following six groups: control group (CON, I/R group, SAA+I/R group, ERK1/2 inhibitor PD098059+I/R group (PD+I/R, PD+SAA+I/R group, and JNK inhibitor SP600125+I/R group (SP+I/R. The cardioprotective effects of SAA on the myocardium during I/R were investigated with a Langendorff device. Heart rate (HR, left ventricular systolic pressure (LVSP, left ventricular end-diastolic pressure (LVEDP, maximum rate of ventricular pressure rise and fall (±dp/dtmax, myocardial infarction areas (MIA, lactate dehydrogenase (LDH, and cardiomyocytes apoptosis were monitored. To determine the crosstalk betwee JNK and ERK1/2 via DUSP2/4/16 with SAA pretreatment, siRNA-DUSP2/4/16 were performed. The expression levels of Bcl-2, Bax, caspase 3, p-JNK, p-ERK1/2 and DUSP2/4/16 in cardiomyocytes were assayed by Western blot. Our results showed that LDH, MIA and cell apoptosis were decreased, and various parameters of heart function were improved by SAA pretreatment and SP application. In the I/R group, the expression levels of p-ERK1/2 and DUSP4/16 were not significantly different compared with the CON group, however, the protein expression levels of p-ERK1/2, Bcl-2 and DUSP4/16 were higher, while p-JNK, Bax, caspase 3 and DUSP2 levels were reduced among the SAA+I/R, PD+SAA+I/R and SP+I/R groups. The above indices were not significantly different between the SAA+I/R and SP+I/R groups. Compared with the SAA+I/R group, p-ERK1/2 was increased and p-JNK was decreased in the SAA+si-DUSP2+I/R, however, p-ERK was downregulated and p-JNK was upregulated in SAA+si-DUSP4

  18. β-adrenergic response modulated by κ-opioid receptor stimulation is attenuated in the cardiomyocytes of rats following chronic hypoxia

    Institute of Scientific and Technical Information of China (English)

    裴建明; 毕辉; 王跃民; 朱妙章; 周京军; 朱运龙

    2003-01-01

    Objective: To study cross-talk between β-opioid receptor and β-adrenoceptor through determination of the intracellular calcium ([Ca2+]i) and cAMP responses in ventricular myocytes of rats subjected to chronic hypoxia for 4 weeks.Methods: Electrically-induced [Ca2+]i transient was measured in single right ventricular myocytes isolated from hearts of chronically hypoxic rats and the age-matched normoxic rats, by using a spectrofluorometric method.Results: β-adrenoceptor stimulation with isoproterenol increased the electrically-induced [Ca2+]i transient and cAMP in myocytes of normoxic rats.U50,488H, a selective β-opioid receptor agonist, at dose (1 μmol/L) which itself had no effect on the [Ca2+]i transient and cAMP, significantly inhibited the effect of isoproterenol.This inhibition was completely abolished in the presence of nor-BNI, a selective κ-opioid receptor antagonist.In the ventricular myocytes of chronically hypoxic rats, the inhibition of U50,488H on the increased [Ca2+]i transient and cAMP with isoproterenol was blunted.Conclusion: Results indicate that the cross-talk between the κ-opioid receptor and β-adrenoceptor is attenuated in the right ventricular myocytes of chronically hypoxic rat.This may be a self-protective mechanism of the heart following chronic hypoxia, which prevents the further decrease of the cardiac function.

  19. Behavioral effects of subchronic inhalation of toluene in adult rats.

    Science.gov (United States)

    Beasley, Tracey E; Evansky, Paul A; Gilbert, Mary E; Bushnell, Philip J

    2010-01-01

    Whereas the acute neurobehavioral effects of toluene are robust and well characterized, evidence for persistent effects of repeated exposure to this industrial solvent is less compelling. The present experiment sought to determine whether subchronic inhalation of toluene caused persistent behavioral changes in rats. Adult male Long-Evans rats inhaled toluene vapor (0, 10, 100, or 1000 ppm) for 6h/day, 5 days/week for 13 weeks and were evaluated on a series of behavioral tests beginning 3 days after the end of exposure. Toluene delayed appetitively-motivated acquisition of a lever-press response, but did not affect motor activity, anxiety-related behavior in the elevated plus maze, trace fear conditioning, acquisition of an appetitively-motivated visual discrimination, or performance of a visual signal detection task. Challenges with acute inhalation of toluene vapor (1200-2400 ppm for 1 h) and injections of quinpirole (0.01-0.03 mg/kg) and raclopride (0.03-0.10 mg/kg) revealed no toluene-induced latent impairments in visual signal detection. These results are consistent with a pattern of subtle and inconsistent long-term effects of daily exposure to toluene vapor, in contrast to robust and reliable effects of acute inhalation of the solvent.

  20. Neonatal injections of methoxychlor decrease adult rat female reproductive behavior.

    Science.gov (United States)

    Bertolasio, Jennifer; Fyfe, Susanne; Snyder, Ben W; Davis, Aline M

    2011-12-01

    Methoxychlor (MXC), a commonly used pesticide, has been labeled as an endocrine disruptor. To evaluate the impact of neonatal exposure to MXC on female reproduction, female Sprague-Dawley rats were given subcutaneous injections on postnatal days 1, 3, and 5. The injections contained 1.0mg MXC, 2.0mg MXC, 10 μg 17β-estradiol benzoate (positive control), or sesame oil (vehicle). The injections of MXC had no effect on anogenital distance or day of vaginal opening. Treatment with either 2.0mg MXC or estradiol significantly increased the total number of days with vaginal keratinization. Treatment with MXC had no effect on ability to exhibit a mating response as an adult female, although the high dose MXC (2.0) and the positive control (estradiol) animals demonstrated a decrease in degree of receptivity, a decrease in proceptive behavior and an increase in rejection behavior. These data suggest that higher doses of MXC given directly to pups during the neonatal period can act as an estrogen and alter aspects of the nervous system, impacting adult reproductive characteristics.

  1. The proteome of neural stem cells from adult rat hippocampus

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    Fütterer Carsten D

    2003-06-01

    Full Text Available Abstract Background Hippocampal neural stem cells (HNSC play an important role in cerebral plasticity in the adult brain and may contribute to tissue repair in neurological disease. To describe their biological potential with regard to plasticity, proliferation, or differentiation, it is important to know the cellular composition of their proteins, subsumed by the term proteome. Results Here, we present for the first time a proteomic database for HNSC isolated from the brains of adult rats and cultured for 10 weeks. Cytosolic proteins were extracted and subjected to two-dimensional gel electrophoresis followed by protein identification through mass spectrometry, database search, and gel matching. We could map about 1141 ± 209 (N = 5 protein spots for each gel, of which 266 could be identified. We could group the identified proteins into several functional categories including metabolism, protein folding, energy metabolism and cellular respiration, as well as cytoskeleton, Ca2+ signaling pathways, cell cycle regulation, proteasome and protein degradation. We also found proteins belonging to detoxification, neurotransmitter metabolism, intracellular signaling pathways, and regulation of DNA transcription and RNA processing. Conclusions The HNSC proteome database is a useful inventory which will allow to specify changes in the cellular protein expression pattern due to specific activated or suppressed pathways during differentiation or proliferation of neural stem cells. Several proteins could be identified in the HNSC proteome which are related to differentiation and plasticity, indicating activated functional pathways. Moreover, we found a protein for which no expression has been described in brain cells before.

  2. Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration.

    Science.gov (United States)

    Mahmoud, Ahmed I; O'Meara, Caitlin C; Gemberling, Matthew; Zhao, Long; Bryant, Donald M; Zheng, Ruimao; Gannon, Joseph B; Cai, Lei; Choi, Wen-Yee; Egnaczyk, Gregory F; Burns, Caroline E; Burns, C Geoffrey; MacRae, Calum A; Poss, Kenneth D; Lee, Richard T

    2015-08-24

    Some organisms, such as adult zebrafish and newborn mice, have the capacity to regenerate heart tissue following injury. Unraveling the mechanisms of heart regeneration is fundamental to understanding why regeneration fails in adult humans. Numerous studies have revealed that nerves are crucial for organ regeneration, thus we aimed to determine whether nerves guide heart regeneration. Here, we show using transgenic zebrafish that inhibition of cardiac innervation leads to reduction of myocyte proliferation following injury. Specifically, pharmacological inhibition of cholinergic nerve function reduces cardiomyocyte proliferation in the injured hearts of both zebrafish and neonatal mice. Direct mechanical denervation impairs heart regeneration in neonatal mice, which was rescued by the administration of neuregulin 1 (NRG1) and nerve growth factor (NGF) recombinant proteins. Transcriptional analysis of mechanically denervated hearts revealed a blunted inflammatory and immune response following injury. These findings demonstrate that nerve function is required for both zebrafish and mouse heart regeneration.

  3. Primary culture of adult rat liver cells. I. Preparation of isolated cells from trypsin-perfused liver of adult rat

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    Miyazaki,Masahiro

    1977-12-01

    Full Text Available Isolated hepatic cells from adult rats were prepared by perfusing the livers with trypsin. The highest yield of viable cells was obtained by perfusing the liver with 0.1% trypsin, pH 7.0, at 37 degrees C for 30 min. Following this treatment about 70% of cells excluded trypan blue. The isolated cells contained many binucleate cells. Between 60 and 70% of DNA present originally in the liver was recovered from the isolated hepatic cells, which had higher glucose 6-phosphatase activity than the liver. Thus the resulting cell population seems to be rich in hepatocytes. The isolated hepatic cells, however, lost some of their cellular proteins such as alanine and tyrosine amino-transferases. It was suggested that the membranes of isolated hepatic cells might be damaged by both enzymatic digestion and mechanical destruction.

  4. Cardiomyocyte proliferation in cardiac development and regeneration: a guide to methodologies and interpretations.

    Science.gov (United States)

    Leone, Marina; Magadum, Ajit; Engel, Felix B

    2015-10-01

    The newt and the zebrafish have the ability to regenerate many of their tissues and organs including the heart. Thus, a major goal in experimental medicine is to elucidate the molecular mechanisms underlying the regenerative capacity of these species. A wide variety of experiments have demonstrated that naturally occurring heart regeneration relies on cardiomyocyte proliferation. Thus, major efforts have been invested to induce proliferation of mammalian cardiomyocytes in order to improve cardiac function after injury or to protect the heart from further functional deterioration. In this review, we describe and analyze methods currently used to evaluate cardiomyocyte proliferation. In addition, we summarize the literature on naturally occurring heart regeneration. Our analysis highlights that newt and zebrafish heart regeneration relies on factors that are also utilized in cardiomyocyte proliferation during mammalian fetal development. Most of these factors have, however, failed to induce adult mammalian cardiomyocyte proliferation. Finally, our analysis of mammalian neonatal heart regeneration indicates experiments that could resolve conflicting results in the literature, such as binucleation assays and clonal analysis. Collectively, cardiac regeneration based on cardiomyocyte proliferation is a promising approach for improving adult human cardiac function after injury, but it is important to elucidate the mechanisms arresting mammalian cardiomyocyte proliferation after birth and to utilize better assays to determine formation of new muscle mass.

  5. Electrophysiological properties and calcium handling of embryonic stem cell-derived cardiomyocytes

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    Jae Boum Youm

    2016-03-01

    Full Text Available Embryonic stem cell-derived cardiomyocytes (ESC-CMs hold great interest in many fields of research including clinical applications such as stem cell and gene therapy for cardiac repair or regeneration. ESC-CMs are also used as a platform tool for pharmacological tests or for investigations of cardiac remodeling. ESC-CMs have many different aspects of morphology, electrophysiology, calcium handling, and bioenergetics compared with adult cardiomyocytes. They are immature in morphology, similar to sinus nodal-like in the electrophysiology, higher contribution of trans-sarcolemmal Ca2+ influx to Ca2+ handling, and higher dependence on anaerobic glycolysis. Here, I review a detailed electrophysiology and Ca2+ handling features of ESC-CMs during differentiation into adult cardiomyocytes to gain insights into how all the developmental changes are related to each other to display cardinal features of developing cardiomyocytes.

  6. 不同剂量辛伐他汀对多柔比星导致的乳鼠心肌细胞损伤的保护作用%Protective effect of different doses of simvastatin on neonate rat cardiomyocyte injury induced by doxorubicin

    Institute of Scientific and Technical Information of China (English)

    潘建业; 陈星; 顾琳; 王好; 张国辉

    2011-01-01

    目的 探讨辛伐他汀(SIM)对多柔比星(DOX)损伤乳鼠心肌细胞的保护作用.方法 新生SD大鼠(乳鼠)心肌细胞随机分为5组,对照组不予任何药物,正常培养;DOX组予1μmol/L DOX,SIM低、中、高剂量组分别在给予1 μmol/L DOX基础上予1、10、20 μmol/L SIM,继续培养24h后,倒置相差显微镜下测定各组心肌细胞搏动频率,流式细胞术检测凋亡率,Western blot法检测钙释放通道(RyR2)蛋白表达情况.结果 DOX组及SIM低、中、高剂量组的心肌细胞搏动频率、RyR2表达均明显低于对照组,凋亡率均明显高于对照组,P均<0.05;SIM低、中、高剂量组的心肌细胞搏动频率、RyR2表达均明显高于DOX组,凋亡率均明显低于DOX组,且呈剂量依赖性,P均<0.05.结论 SIM对DOX损伤乳鼠心肌细胞有保护作用,且呈剂量依赖性,其机制可能与提高RyR2表达有关.%Objective To investigate the protective effect of simvastatin(SIM) on neonate rat myocardium cell injury induced by doxorubicin( DOX). Methods The cardiomyocytes of renewal SD rats( neonate rat) were divided randomly into five groups, control group was only given cell culture medium; DOX group was given DOX with the final concentration of 1 μmol/L; SIM groups of low, moderate and high dosage were given SIM with the final concentration of 1, 10, 20 μnol/L at the base of DOX group. After 24 hours further cultivation, the cardiomyocytes beating rate was determined by inverted phase contrast microscope, the apoptosis ratio of cardiomyocytes was detected by flow cytometry, expression of RyR2 protein was evaluated using Western blot. Results Compared to the control group, the cardiomyocytes beating rate and the syn-thesis of RyR2 were descended significantly in the DOX and SIM (low, moderate, high dosage) groups, and the apoptosis ratio'of cardiomyocytes was increased significantly (all P <0.05). Compared to the DOX group, the cardiomyocytes beat-ing rate and the expression of Ry

  7. PREPUBERTAL EXPOSURES TO COMPOUNDS THAT INCREASE PROLACTIN SECRETION IN THE MALE RAT: EFFECTS ON ADULT PROSTATE

    Science.gov (United States)

    Prepubertal exposure to compounds that increase prolactin secretion in the male rat: effects on the adult prostate.Stoker TE, Robinette CL, Britt BH, Laws SC, Cooper RL.Endocrinology Branch, Reproductive Toxicology Division, National Health and Environmental Effec...

  8. Estudo histomorfométrico dos cardiomiócitos do ventrículo esquerdo das ratas albinas durante a prenhez Histomorphometrical study of cardiomyocytes of the left ventricular of albino rats during pregnancy

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    A.W. Liberatori Filho

    1999-07-01

    Full Text Available OBJETIVO. No presente estudo propusemo-nos a avaliar, por meio da microscopia de luz, os aspectos morfológicos e morfométricos dos cardiomiócitos do ventrículo esquerdo de ratas albinas durante a prenhez. MÉTODOS. Acasalamos doze ratas virgens que foram dividas ao acaso em quatro grupos, de acordo com a idade gestacional. Os animais correspondentes a cada grupo foram sacrificados ao 1o(G-A, 7o(G-B, 14o(G-C e 21o(G-D dias de prenhez, sendo coletados fragmentos do terço médio do ventrículo esquerdo, os quais após processamento apropriado, permitiram observação adequada à microscopia de luz. A cariometria foi realizada mensurando-se os diâmetros maiores e menores dos cardiomiócitos com o auxílio de um tambor rotativo modelo K 8 X adaptado a um microscópio de luz. RESULTADOS. O estudo em nível da microscopia de luz praticamente não mostrou alterações com o decorrer da prenhez. No entanto, a morfometria revelou que os volumes dos cardiomiócitos estão aumentados no 14o dia da prenhez, mostrando-se estatisticamente significante quando comparado aos demais grupos estudados. Assim, nossos resultados demonstraram haver hipertrofia ventricular esquerda durante a gestação. CONCLUSÃO. Durante a gestação há um processo dinâmico reversível de remodelação ventricular em conseqüência das alterações adaptativas gravídicas.PURPOSE. In the present study we evaluated, by light microscopy, and throughout morphometry, whether hypertrophy of cardiac striated muscular fibers of left ventricular occur in albino rat, during pregnancy. METHODS. After maiting, 12 nuliparous rats were divided into four groups with three animals for each group. The female rats corresponding to each group were killed at 1st, 7th, 14th and 21st days of pregnancy. RESULTS. Observation, on light microscopy (H.E had at one view, did not display any alterations during pregnancy. However, the morphometry revealed that nuclei of cardiomyocytes are augmented in

  9. Reduced function and disassembled microtubules of cultured cardiomyocytes in spaceflight

    Institute of Scientific and Technical Information of China (English)

    YANG Fen; DAI ZhongQuan; TAN YingJun; WAN YuMin; LI YingHui; DING Bai; NIE JieLin; WANG HongHui; ZHANG XiaoYou; WANG ChunYan; LING ShuKuan; NI ChengZhi

    2008-01-01

    Lack of gravity during spaceflight has profound effects on cardiovascular system, but little is known about how the cardiomyocytes respond to microgravity. In the present study, the effects of spaceflight on the structure and function of cultured cardiomyocytes were reported. The primary cultures of neo-natal rat cardiomyocytes were carried on Shenzhou-6 spacecraft and activated at 4 h in orbit. 8 samples were fixed respectively at 4, 48 and 96 h after launching for immunofluorescence of cytoskeleton, and 2 samples remained unfixed to analyze contractile and secretory functions of the cultures. Ground sam-ples were treated in our laboratory in parallel. After 115 h spaceflight, video recordings displayed that the number of spontaneous beating sites in flown samples decreased significantly, and the cells in the beating aggregate contracted in fast frequency without synchrony. Radioimmunoassay of the medium showed that the atrial natriuretic peptide secreted from flown cells reduced by 59.6%. Confocal images demonstrated the time-dependant disassembly of mirotubules versus unchanged distribution and or-ganization of microfilaments. In conclusion, above results indicate reduced function and disorganized cytoskeleton of cardiomyocytes in spaceflight, which might provide some cellular basis for further investigations to probe into the mechanisms underlying space cardiovascular dysfunction.

  10. Combinatorial MicroRNAs Suppress Hypoxia-Induced Cardiomyocytes Apoptosis

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    Yingqi Xu

    2015-09-01

    Full Text Available Background/Aims: Our previous in silico analysis revealed potential synergy in the activities of micro(miRNAs in myocardial infarction. The present study investigated whether miR-1 and -21 act synergistically to protect against cardiomyocytes apoptosis. Methods: Cell survival was analyzed with cell viability assay; apoptosis was detected by flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labeling, and the caspase-3 activity assay; and protein expression level was determined by western blotting. Results: MiR-1:miR-21 and several other miRNA pairs were evaluated for their potentially synergistic effects against myocardial hypoxia in neonatal rat ventricular cardiomyocytes. Lower combination indices suggested that miRNA pairs acted synergistically to inhibit apoptosis; miR-1 and -21 jointly blocked hypoxia-induced cardiomyocytes apoptosis. Moreover, combined application of miR-1 and -21 activated Akt and blocked hypoxia-induced upregulation of p53 in these cells. Conclusion: MiR-1 and -21 exert synergistic effects against hypoxia-induced cardiomyocytes apoptosis. These results provide a basis for the development of combined miRNA-based therapeutics to treat cardiovascular diseases.

  11. Effects of Substrate Mechanics on Contractility of Cardiomyocytes Generated from Human Pluripotent Stem Cells

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    Laurie B. Hazeltine

    2012-01-01

    Full Text Available Human pluripotent stem cell (hPSC- derived cardiomyocytes have potential applications in drug discovery, toxicity testing, developmental studies, and regenerative medicine. Before these cells can be reliably utilized, characterization of their functionality is required to establish their similarity to native cardiomyocytes. We tracked fluorescent beads embedded in 4.4–99.7 kPa polyacrylamide hydrogels beneath contracting neonatal rat cardiomyocytes and cardiomyocytes generated from hPSCs via growth-factor-induced directed differentiation to measure contractile output in response to changes in substrate mechanics. Contraction stress was determined using traction force microscopy, and morphology was characterized by immunocytochemistry for α-actinin and subsequent image analysis. We found that contraction stress of all types of cardiomyocytes increased with substrate stiffness. This effect was not linked to beating rate or morphology. We demonstrated that hPSC-derived cardiomyocyte contractility responded appropriately to isoprenaline and remained stable in culture over a period of 2 months. This study demonstrates that hPSC-derived cardiomyocytes have appropriate functional responses to substrate stiffness and to a pharmaceutical agent, which motivates their use in further applications such as drug evaluation and cardiac therapies.

  12. 人生长素对雌性大鼠心力衰竭心脏重塑及心肌细胞凋亡的影响%Effect of Human Ghrelin on the Cardiac Remodeling and Cardiomyocytes Apoptosis in Heart Failure Female Rats

    Institute of Scientific and Technical Information of China (English)

    孙宇泽; 李艳丽; 赵勇; 袁寰; 田国忠; 李梅秀

    2015-01-01

    Objective To study the effect of human ghrelin on morphosis and cardiomyocytes apoptosis in heart failure ( HF) rats derived from acute myocardial infarction ( AMI) , so as to explore the cardioprotective activity mechanism of growth hormone releasing-peptides( GHRPs) .Methods Under the monitoring of the electrocardiogram ( ECG) by the multichannel physiological signal collection management system to confirm successfully permanent ligation the left anterior descending coronary artery(LAD) to set up AMI model and then by ultrasound B system to rule out the rats without HF or to make the sham group rats which merely pass through the stylolite beneeth LAD;HF model group rats accept three weeks human ghrelin through tail vein injection, using HE stain technique to analyze the changes of morphosis , the cardiomyocytes apoptosis in HF rats were assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling( TUNEL) .Results TUNEL staining results showed that the cardiomyocytes in rats after permanent LAD ligation aligned ex-tremely irregularly, granular degeneration,swelling,much karyopyknosis and severe interstitial fibrosis,inflammatory cell infiltrate,while in human ghrelin intervention rats, cardiaomyocytes aligned irregularly,swelling and granular degeneration also could be found but without typical karyopyknosis or severe interstitial fibrosis.The cardiomyocytes apoptotic index in HF group rats is significantly higher than that in ghrelin intervention group rats(P<0.05).Conclusion Extrinsic human ghrelin exerted the cardioprotective activities by reducing the cardiomyocytes apoptosis and inhabitting the cardiac remodeling.%目的:研究人ghrelin对急性心肌梗死( acute myocardial infarction,AMI)致心力衰竭( heart failure,HF)大鼠心肌形态结构变化和心肌细胞凋亡的影响,探索生长素释放肽( growth hormone releasing-peptides,GHRPs)心脏保护活性机制。方法经心电图监测成功永久结

  13. Influences of olfactory ensheathing cells transplantation on axonal regeneration in spinal cord of adult rats

    Institute of Scientific and Technical Information of China (English)

    沈慧勇; 唐勇; 吴燕峰; 陈燕涛; 程志安

    2002-01-01

    To observe whether olfactory ensheathing cells could be used to promote axonal regeneration in a spontaneously nonregenerating system. Methods: After laminectomy at the lower thoracic level, the spinal cords of adult rats were exposed and completely transected at T10. A suspension of ensheathing cells was injected into the lesion site in 12 adult rats, and control D/F-12 (1∶1 mixture of DMEM and Hams F-12) was injected in 12 adult rats. Six weeks and ten weeks after cell transplantation, the rats were evaluated by climbing test and motor evoked potentials (MEPs) monitoring. The samples were procured and studied with histologicl and immunohistochemical methods. Results: At the 6th week after cell transplantation, all the rats in both the transplanted and control groups were paraplegic and the MEPs could not be recorded. At the 10th week after cell transplantation, of 7 rats in the control group, 2 rats had muscles contraction of the lower extremities, 2 rats had hips and/or knees active movement; and 5 rats MEPs could be recorded in the hind limbs in the transplanted group (n=7). None of the rats in the control group had functional improvement and no MEPs recorded (n=7). Numerous regenerating axons were observed through the transplantation and continued to regenerate into the denervated host tract. Cell labelling using anti-Myelin Basic Protein (MBP) and anti-Nerve Growth Factor Receptor (anti-NGFR) indicated that the regenerated axons were derived from the appropriate neuronal source and that donor cells migrated into the denervated host tract. But axonal degeneration existed and regenerating axons were not observed within the spinal cords of the adult rats with only D/F-12 injection. Conclusions: The axonal regeneration in the transected adult rat spinal cord is possible after ensheathing cells transplantation.

  14. Cardiomyocytic apoptosis and heart failure

    Institute of Scientific and Technical Information of China (English)

    Quanzhou Feng

    2008-01-01

    Heart failure is a major disease seriously threatening human health.Once left ventricular dysfunction develops,cardiac function usually deteriorates and progresses to congestive heart failure in several months or years even if no factors which accelerate the deterioration repeatedly exist.Mechanism through which cardiac function continually deteriorates is still unclear.Cardiomyocytic apoptosis can occur in acute stage of ischemic heart diseases and the compensated stage of cardiac dysfunction.In this review,we summarize recent advances in understanding the role of cardiomyocytic apoptosis in heart failure.

  15. Neonatal Transplantation Confers Maturation of PSC-Derived Cardiomyocytes Conducive to Modeling Cardiomyopathy

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    Gun-Sik Cho

    2017-01-01

    Full Text Available Pluripotent stem cells (PSCs offer unprecedented opportunities for disease modeling and personalized medicine. However, PSC-derived cells exhibit fetal-like characteristics and remain immature in a dish. This has emerged as a major obstacle for their application for late-onset diseases. We previously showed that there is a neonatal arrest of long-term cultured PSC-derived cardiomyocytes (PSC-CMs. Here, we demonstrate that PSC-CMs mature into adult CMs when transplanted into neonatal hearts. PSC-CMs became similar to adult CMs in morphology, structure, and function within a month of transplantation into rats. The similarity was further supported by single-cell RNA-sequencing analysis. Moreover, this in vivo maturation allowed patient-derived PSC-CMs to reveal the disease phenotype of arrhythmogenic right ventricular cardiomyopathy, which manifests predominantly in adults. This study lays a foundation for understanding human CM maturation and pathogenesis and can be instrumental in PSC-based modeling of adult heart diseases.

  16. Tooth movement characteristics in relation to root resorption in young and adult rats

    NARCIS (Netherlands)

    Ren, Yijin; Maltha, Jaap C.; Kuijpers-Jagtman, Anne Marie

    2007-01-01

    The aim of this study was to investigate tooth movement characteristics in relation to root resorption in young and adult rats. Two groups of 30 rats each (aged 6 wk and 9-12 months, respectively) were used. Standardized orthodontic appliances were placed to move the maxillary molars mesially. Anima

  17. Differential Expression Levels of Integrin α6 Enable the Selective Identification and Isolation of Atrial and Ventricular Cardiomyocytes.

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    Anne Maria Wiencierz

    Full Text Available Central questions such as cardiomyocyte subtype emergence during cardiogenesis or the availability of cardiomyocyte subtypes for cell replacement therapy require selective identification and purification of atrial and ventricular cardiomyocytes. However, current methodologies do not allow for a transgene-free selective isolation of atrial or ventricular cardiomyocytes due to the lack of subtype specific cell surface markers.In order to develop cell surface marker-based isolation procedures for cardiomyocyte subtypes, we performed an antibody-based screening on embryonic mouse hearts. Our data indicate that atrial and ventricular cardiomyocytes are characterized by differential expression of integrin α6 (ITGA6 throughout development and in the adult heart. We discovered that the expression level of this surface marker correlates with the intracellular subtype-specific expression of MLC-2a and MLC-2v on the single cell level and thereby enables the discrimination of cardiomyocyte subtypes by flow cytometry. Based on the differential expression of ITGA6 in atria and ventricles during cardiogenesis, we developed purification protocols for atrial and ventricular cardiomyocytes from mouse hearts. Atrial and ventricular identities of sorted cells were confirmed by expression profiling and patch clamp analysis.Here, we introduce a non-genetic, antibody-based approach to specifically isolate highly pure and viable atrial and ventricular cardiomyocytes from mouse hearts of various developmental stages. This will facilitate in-depth characterization of the individual cellular subsets and support translational research applications.

  18. Enhancement of cardiomyocyte differentiation from human embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Several approaches have been used to encourage the differentiation of cardiomyocytes from human embryonic stem cells.However,the differentiation efficiency is low,and appropriate culture protocols are needed to produce adequate numbers of cardiomyocytes for therapeutic cell transplantation.This study investigated the effects of serum on cardiomyocyte differentiation in suspension culture medium during embryoid body(EB) formation by human embryonic stem cells.The addition of ascorbic acid,dimethylsulfoxide and 5-aza-2’-deoxycytidine during days 5-7 at the EB-forming stage resulted in an increase in the numbers of rhythmically contracting clusters of derived cardiomyocytes.Treatment with 0.1 mmol L-1 ascorbic acid alone,or more notably in combination with 10 μmol L-1 5-aza-2’-deoxycytidine,induced the formation of beating cells within EBs.Most of the beating clusters had spontaneous contraction rates similar to those found in human adults,and their contractile ac-tivity lasted for up to 194 days.

  19. TGF-β1, released by myofibroblasts, differentially regulates transcription and function of sodium and potassium channels in adult rat ventricular myocytes.

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    Kuljeet Kaur

    Full Text Available Cardiac injury promotes fibroblasts activation and differentiation into myofibroblasts, which are hypersecretory of multiple cytokines. It is unknown whether any of such cytokines are involved in the electrophysiological remodeling of adult cardiomyocytes. We cultured adult cardiomyocytes for 3 days in cardiac fibroblast conditioned medium (FCM from adult rats. In whole-cell voltage-clamp experiments, FCM-treated myocytes had 41% more peak inward sodium current (I(Na density at -40 mV than myocytes in control medium (p3 fold greater in FCM than control, which suggested that FCM effects could be mediated by TGF-β1. This was confirmed by pre-treatment with TGF-β1 neutralizing antibody, which abolished the FCM-induced changes in both I(Na and I(to. In current-clamp experiments TGF-β1 (10 ng/ml prolonged the action potential duration at 30, 50, and 90 repolarization (p<0.05; at 50 ng/ml it gave rise to early afterdepolarizations. In voltage-clamp experiments, TGF-β1 increased I(Na density in a dose-dependent manner without affecting voltage dependence of activation or inactivation. I(Na density was -36.25±2.8 pA/pF in control, -59.17±6.2 pA/pF at 0.1 ng/ml (p<0.01, and -58.22±6.6 pA/pF at 1 ng/ml (p<0.01. In sharp contrast, I(to density decreased from 22.2±1.2 pA/pF to 12.7±0.98 pA/pF (p<0.001 at 10 ng/ml. At 1 ng/ml TGF-β1 significantly increased SCN5A (Na(V1.5 (+73%; p<0.01, while reducing KCNIP2 (Kchip2; -77%; p<0.01 and KCND2 (K(V4.2; -50% p<0.05 mRNA levels. Further, the TGF-β1-induced increase in I(Na was mediated through activation of the PI3K-AKT pathway via phosphorylation of FOXO1 (a negative regulator of SCN5A. TGF-β1 released by myofibroblasts differentially regulates transcription and function of the main cardiac sodium channel and of the channel responsible for the transient outward current. The results provide new mechanistic insight into the electrical remodeling associated with myocardial injury.

  20. TGF-β1, Released by Myofibroblasts, Differentially Regulates Transcription and Function of Sodium and Potassium Channels in Adult Rat Ventricular Myocytes

    Science.gov (United States)

    Kaur, Kuljeet; Zarzoso, Manuel; Ponce-Balbuena, Daniela; Guerrero-Serna, Guadalupe; Hou, Luqia; Musa, Hassan; Jalife, José

    2013-01-01

    Cardiac injury promotes fibroblasts activation and differentiation into myofibroblasts, which are hypersecretory of multiple cytokines. It is unknown whether any of such cytokines are involved in the electrophysiological remodeling of adult cardiomyocytes. We cultured adult cardiomyocytes for 3 days in cardiac fibroblast conditioned medium (FCM) from adult rats. In whole-cell voltage-clamp experiments, FCM-treated myocytes had 41% more peak inward sodium current (INa) density at −40 mV than myocytes in control medium (p3 fold greater in FCM than control, which suggested that FCM effects could be mediated by TGF-β1. This was confirmed by pre-treatment with TGF-β1 neutralizing antibody, which abolished the FCM-induced changes in both INa and Ito. In current-clamp experiments TGF-β1 (10 ng/ml) prolonged the action potential duration at 30, 50, and 90 repolarization (p<0.05); at 50 ng/ml it gave rise to early afterdepolarizations. In voltage-clamp experiments, TGF-β1 increased INa density in a dose-dependent manner without affecting voltage dependence of activation or inactivation. INa density was −36.25±2.8 pA/pF in control, −59.17±6.2 pA/pF at 0.1 ng/ml (p<0.01), and −58.22±6.6 pA/pF at 1 ng/ml (p<0.01). In sharp contrast, Ito density decreased from 22.2±1.2 pA/pF to 12.7±0.98 pA/pF (p<0.001) at 10 ng/ml. At 1 ng/ml TGF-β1 significantly increased SCN5A (NaV1.5) (+73%; p<0.01), while reducing KCNIP2 (Kchip2; −77%; p<0.01) and KCND2 (KV4.2; −50% p<0.05) mRNA levels. Further, the TGF-β1-induced increase in INa was mediated through activation of the PI3K-AKT pathway via phosphorylation of FOXO1 (a negative regulator of SCN5A). TGF-β1 released by myofibroblasts differentially regulates transcription and function of the main cardiac sodium channel and of the channel responsible for the transient outward current. The results provide new mechanistic insight into the electrical remodeling associated with myocardial injury. PMID:23393573

  1. Isolation and culture of neonatal mouse cardiomyocytes.

    Science.gov (United States)

    Ehler, Elisabeth; Moore-Morris, Thomas; Lange, Stephan

    2013-09-06

    Cultured neonatal cardiomyocytes have long been used to study myofibrillogenesis and myofibrillar functions. Cultured cardiomyocytes allow for easy investigation and manipulation of biochemical pathways, and their effect on the biomechanical properties of spontaneously beating cardiomyocytes. The following 2-day protocol describes the isolation and culture of neonatal mouse cardiomyocytes. We show how to easily dissect hearts from neonates, dissociate the cardiac tissue and enrich cardiomyocytes from the cardiac cell-population. We discuss the usage of different enzyme mixes for cell-dissociation, and their effects on cell-viability. The isolated cardiomyocytes can be subsequently used for a variety of morphological, electrophysiological, biochemical, cell-biological or biomechanical assays. We optimized the protocol for robustness and reproducibility, by using only commercially available solutions and enzyme mixes that show little lot-to-lot variability. We also address common problems associated with the isolation and culture of cardiomyocytes, and offer a variety of options for the optimization of isolation and culture conditions.

  2. Growth factor PDGF-BB stimulates cultured cardiomyocytes to synthesize the extracellular matrix component hyaluronan.

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    Urban Hellman

    Full Text Available BACKGROUND: Hyaluronan (HA is a glycosaminoglycan located in the interstitial space which is essential for both structural and cell regulatory functions in connective tissue. We have previously shown that HA synthesis is up-regulated in a rat model of experimental cardiac hypertrophy and that cardiac tissue utilizes two different HA synthases in the hypertrophic process. Cardiomyocytes and fibroblasts are two major cell types in heart tissue. The fibroblasts are known to produce HA, but it has been unclear if cardiomyocytes share the same feature, and whether or not the different HA synthases are activated in the different cell types. METHODOLOGY/PRINCIPAL FINDINGS: This study shows, for the first time that cardiomyocytes can produce HA. Cardiomyocytes (HL-1 and fibroblasts (NIH 3T3 were cultivated in absence or presence of the growth factors FGF2, PDGF-BB and TGFB2. HA concentration was quantified by ELISA, and the size of HA was estimated using dynamic light scattering. Cardiomyocytes synthesized HA but only when stimulated by PDGF-BB, whereas fibroblasts synthesized HA without addition of growth factors as well as when stimulated by any of the three growth factors. When fibroblasts were stimulated by the growth factors, reverse dose dependence was observed, where the highest dose induced the least amount of HA. With the exception of TGFB2, a trend of reverse dose dependence of HA size was also observed. CONCLUSIONS/SIGNIFICANCE: Co-cultivation of cardiomyocytes and fibroblasts (80%/20% increased HA concentration far more that can be explained by HA synthesis by the two cell types separately, revealing a crosstalk between cardiomyocytes and fibroblasts that induces HA synthesis. We conclude that dynamic changes of the myocardium, such as in cardiac hypertrophy, do not depend on the cardiomyocyte alone, but are achieved when both cardiomyocytes and fibroblasts are present.

  3. Determination of the human cardiomyocyte mRNA and miRNA differentiation network by fine-scale profiling.

    Science.gov (United States)

    Babiarz, Joshua E; Ravon, Morgane; Sridhar, Sriram; Ravindran, Palanikumar; Swanson, Brad; Bitter, Hans; Weiser, Thomas; Chiao, Eric; Certa, Ulrich; Kolaja, Kyle L

    2012-07-20

    To gain insight into the molecular regulation of human heart development, a detailed comparison of the mRNA and miRNA transcriptomes across differentiating human-induced pluripotent stem cell (hiPSC)-derived cardiomyocytes and biopsies from fetal, adult, and hypertensive human hearts was performed. Gene ontology analysis of the mRNA expression levels of the hiPSCs differentiating into cardiomyocytes revealed 3 distinct groups of genes: pluripotent specific, transitional cardiac specification, and mature cardiomyocyte specific. Hierarchical clustering of the mRNA data revealed that the transcriptome of hiPSC cardiomyocytes largely stabilizes 20 days after initiation of differentiation. Nevertheless, analysis of cells continuously cultured for 120 days indicated that the cardiomyocytes continued to mature toward a more adult-like gene expression pattern. Analysis of cardiomyocyte-specific miRNAs (miR-1, miR-133a/b, and miR-208a/b) revealed an miRNA pattern indicative of stem cell to cardiomyocyte specification. A biostatistitical approach integrated the miRNA and mRNA expression profiles revealing a cardiomyocyte differentiation miRNA network and identified putative mRNAs targeted by multiple miRNAs. Together, these data reveal the miRNA network in human heart development and support the notion that overlapping miRNA networks re-enforce transcriptional control during developmental specification.

  4. Adolescent and adult male spontaneous hyperactive rats (SHR) respond differently to acute and chronic methylphenidate (Ritalin).

    Science.gov (United States)

    Barron, Elyssa; Yang, Pamela B; Swann, Alan C; Dafny, Nachum

    2009-01-01

    Eight groups of male adolescent and adult spontaneous hyperactive rats (SHR) were used in a dose response (saline, 0.6, 2.5, and 10 mg/kg) experiment of methylphenidate (MPD). Four different locomotor indices were recorded for 2 hours postinjection using a computerized monitoring system. Acutely, the 0.6 mg/kg dose of MPD did not elicit an increase in locomotor activity in either the adolescent or in the adult male SHR. The 2.5 and the 10.0 mg/kg doses increased activity in the adolescent and the adult rats. Chronically, MPD treatment when comparing adolescent and adult gave the following results: the 0.6 mg/kg dose of MPD failed to cause sensitization in the adolescent group but caused sensitization in the adult group, while the 2.5 and 10 mg/kg both caused sensitization in the adolescent and adult groups.

  5. Prenatal exposure to ethanol causes partial diabetes insipidus in adult rats.

    Science.gov (United States)

    Knee, Daniel S; Sato, Aileen K; Uyehara, Catherine F T; Claybaugh, John R

    2004-08-01

    Chronic consumption of ethanol in adult rats and humans leads to reduced AVP-producing neurons, and prenatal ethanol (PE) exposure has been reported to cause changes in the morphology of AVP-producing cells in the suprachiasmatic nucleus of young rats. The present studies further characterize the effects of PE exposure on AVP in the young adult rat, its hypothalamic synthesis, pituitary storage, and osmotically stimulated release. Pregnant rats were fed a liquid diet with 35% of the calories from ethanol or a control liquid diet for days 7-22 of pregnancy. Water consumption and urine excretion rate were measured in the offspring at 60-68 days of age. Subsequently, the offspring were infused with 5% NaCl at 0.05 ml.kg(-1).min(-1) with plasma samples taken before and at three 40-min intervals during infusion for measurement of AVP and osmolality. Urine output and water intake were approximately 20% greater in PE-exposed rats than in rats with no PE exposure, and female rats had a greater water intake than males. The relationship between plasma osmolality and AVP in PE-exposed rats was parallel to, but shifted to the right of, the control rats, indicating an increase in osmotic threshold for AVP release. Pituitary AVP was reduced by 13% and hypothalamic AVP mRNA content was reduced by 35% in PE-exposed rats. Our data suggest that PE exposure can cause a permanent condition of a mild partial central diabetes insipidus.

  6. Group B streptococcal beta-hemolysin/cytolysin directly impairs cardiomyocyte viability and function.

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    Mary E Hensler

    Full Text Available BACKGROUND: Group B Streptococcus (GBS is a leading cause of neonatal sepsis where myocardial dysfunction is an important contributor to poor outcome. Here we study the effects of the GBS pore-forming beta-hemolysin/cytolysin (Bh/c exotoxin on cardiomyocyte viability, contractility, and calcium transients. METHODOLOGY/PRINCIPAL FINDINGS: HL-1 cardiomyocytes exposed to intact wild-type (WT or isogenic Deltabeta h/c mutant GBS, or to cell-free extracts from either strain, were assessed for viability by trypan blue exclusion and for apoptosis by TUNEL staining. Functionality of exposed cardiomyocytes was analyzed by visual quantitation of the rate and extent of contractility. Mitochondrial membrane polarization was measured in TMRE-loaded cells exposed to GBS beta h/c. Effects of GBS beta h/c on calcium transients were studied in fura-2AM-loaded primary rat ventricular cardiomyocytes. Exposure of HL-1 cardiomyocytes to either WT GBS or beta h/c extracts significantly reduced both rate and extent of contractility and later induced necrotic and apoptotic cell death. No effects on cardiomyocyte viability or function were observed after treatment with Deltabeta h/c mutant bacteria or extracts. The beta h/c toxin was associated with complete and rapid loss of detectable calcium transients in primary neonatal rat ventricular cardiomyocytes and induced a loss of mitochondrial membrane polarization. These effects on viability and function were abrogated by the beta h/c inhibitor, dipalmitoyl phosphatidylcholine (DPPC. CONCLUSIONS/SIGNIFICANCE: Our data show a rapid loss of cardiomyocyte viability and function induced by GBS beta h/c, and these deleterious effects are inhibited by DPPC, a normal constituent of human pulmonary surfactant.. These findings have clinical implications for the cardiac dysfunction observed in neonatal GBS infections.

  7. HAIR CELL-LIKE CELL GENERATION INDUCED BY NATURE CULTURE OF ADULT RAT AUDITORY EPITHELIUM

    Institute of Scientific and Technical Information of China (English)

    Liu Hui; Zhu Hongliang; Li Shengli; Yao Xiaobao; Wang Xiaoxia

    2006-01-01

    Objective To establish adult rat auditory epithelial cell culture and try to find precursor cells of auditory hair cells in vitro. Methods With refinement of culture media and techniques, cochlear sensory epithelial cells of adult rat were cultured. Immunocytochemistry and Bromodeoxyuridine (BrdU)labeling were used to detect properties and mitotic status of cultured cells. Results The cultured auditory epithelial cells showed a large, flat epithelial morphotype and expressed F-actin and cytokeratin, a subset of cells generated from auditory epithelium were labeled by calretinin, a specific marker of early hair cell. Conclusion Adult rat auditory epithelium can be induced to generate hair cell-like cells by nature culture, this phenomenon suggests that progenitor cells may exist in rat cochlea and they may give birth to new hair cells. Whether these progenitor cells are tissue specific stem cells is still need more study.

  8. Lycium barbarum polysaccharides promotes in vivo proliferation of adult rat retinal progenitor cells

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    Hua Wang

    2015-01-01

    Full Text Available Lycium barbarum is a widely used Chinese herbal medicine prescription for protection of optic nerve. However, it remains unclear regarding the effects of Lycium barbarum polysaccharides, the main component of Lycium barbarum, on in vivo proliferation of adult ciliary body cells. In this study, adult rats were intragastrically administered low- and high-dose Lycium barbarum polysaccharides (1 and 10 mg/kg for 35 days and those intragastrically administered phosphate buffered saline served as controls. The number of Ki-67-positive cells in rat ciliary body in the Lycium barbarum polysaccharides groups, in particular low-dose Lycium barbarum polysaccharides group, was significantly greater than that in the phosphate buffered saline group. Ki-67-positive rat ciliary body cells expressed nestin but they did not express glial fibrillary acidic protein. These findings suggest that Lycium barbarum polysaccharides can promote the proliferation of adult rat retinal progenitor cells and the proliferated cells present with neuronal phenotype.

  9. Effects of acute adult and early-in-life bladder inflammation on bladder neuropeptides in adult female rats

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    Ness Timothy J

    2011-08-01

    Full Text Available Abstract Background The purpose of the present study was to determine how acute adult and/or prior early-in life (EIL; P14-P16 exposure to bladder inflammation affects bladder content of calcitonin gene related peptide (CGRP and substance P (SP. Estrous cycle influences were also studied in the adult-treatment conditions. Methods In Experiment 1, intravesical zymosan or isoflurane anesthesia alone was administered to adult female rats. Bladders and serum were collected 24 hours later during each phase of the estrous cycle. In Experiment 2, zymosan or anesthesia alone was administered EIL and as adults, with bladder tissue collection 24 h later. Results In general, Experiment 1 showed that bladder content of both CGRP and SP was increased by inflammation. This effect was significant when data were collapsed across all phases of the estrous cycle, but was only significant during proestrus when individual comparisons were made during each phase of estrous. Also, adult bladder inflammation significantly reduced estradiol levels. In Experiment 2, bladder content of CGRP and SP was significantly increased in rats receiving EIL and/or adult inflammation. Bladder weights were also significantly increased by inflammation. Conclusions These data indicate that bladder CGRP and SP are maximally increased during the proestrus phase of the estrous cycle in inflamed adult female rats. EIL exposure to bladder inflammation alone can also produce an increase in CGRP and SP lasting into adulthood. Therefore, EIL experience with bladder inflammation may predispose an organism to experience a painful bladder disorder as an adult by increasing primary afferent content of CGRP and/or SP.

  10. Detection of Over-Expressed Integrin-Linked Kinase in DNA Synthesis of Cardiomyocytes in Newborn Rats by EDU Immunofluorescence Assay%EDU免疫荧光法检测整合素连接激酶(ILK)高表达对新生大鼠心肌细胞DNA合成的影响

    Institute of Scientific and Technical Information of China (English)

    王丙剑; 白剑; 孙静娴; 张娜; 徐标

    2011-01-01

    Objective: To investigate the effects of over-expressed integrin-linked kinase on rat neonatal DNA synthesis of cardiomyocytes by EDU immunofluorescence assay. Methods: Primary neonatal rat (1-3 days old) cardiomyocytes were cultured in vitro and randomly divided into two groups 72 h after isolation: infected by either adeno-GFP (control group) or adeno-GFP containing adeno-ILK (ILK group). 48h after infection, DNA synthesis of cardiomyecytes in two groups were determined by 5-ethynyl-2-deoxyuridinc(EdU) immunofiuorescence assay. Results: Compared with the control groups, DNA synthesis of cardiomyocytes increased dramatically in ILK groups (P <0.05). Conclusion: The over-expression of ILK could promote Rat Neonatal DNA synthesis of cardiomyocytes.%目的:通过EDU免疫荧光法观察整合素连接激酶(Integrin-Linked Kinase,ILK)在新生大鼠心肌细胞内高表达后对心肌细胞DNA合成的影响.方法:取新生(1-3天内)大鼠原代心肌细胞,培养72小时后随机分为正常对照组、ILK转染组.对照组转染重组腺病毒载体(adeno-GFP),ILK组转染重组腺病毒载体+ILK基因(adeno-ILK).转然成功后48小时将两组心肌细胞分别通过5-乙基-2'-脱氧尿嘧啶核苷(EDU)免疫荧光法测定心肌细胞DNA合成.结果:ILK转染组心肌细胞内DNA合成较对照组明显增加(P<0.05).结论:ILK高表达具有促进新生大鼠心肌细胞的DNA合成的能力.

  11. CstF-64 is necessary for endoderm differentiation resulting in cardiomyocyte defects

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    Bradford A. Youngblood

    2014-11-01

    Full Text Available Although adult cardiomyocytes have the capacity for cellular regeneration, they are unable to fully repair severely injured hearts. The use of embryonic stem cell (ESC-derived cardiomyocytes as transplantable heart muscle cells has been proposed as a solution, but is limited by the lack of understanding of the developmental pathways leading to specification of cardiac progenitors. Identification of these pathways will enhance the ability to differentiate cardiomyocytes into a clinical source of transplantable cells. Here, we show that the mRNA 3′ end processing protein, CstF-64, is essential for cardiomyocyte differentiation in mouse ESCs. Loss of CstF-64 in mouse ESCs results in loss of differentiation potential toward the endodermal lineage. However, CstF-64 knockout (Cstf2E6 cells were able to differentiate into neuronal progenitors, demonstrating that some differentiation pathways were still intact. Markers for mesodermal differentiation were also present, although Cstf2E6 cells were defective in forming beating cardiomyocytes and expressing cardiac specific markers. Since the extraembryonic endoderm is needed for cardiomyocyte differentiation and endodermal markers were decreased, we hypothesized that endodermal factors were required for efficient cardiomyocyte formation in the Cstf2E6 cells. Using conditioned medium from the extraembryonic endodermal (XEN stem cell line we were able to restore cardiomyocyte differentiation in Cstf2E6 cells, suggesting that CstF-64 has a role in regulating endoderm differentiation that is necessary for cardiac specification and that extraembryonic endoderm signaling is essential for cardiomyocyte development.

  12. Mild Thyroid Hormone Insufficiency During Development Compromises Activity-Dependent Neuroplasticity in the Hippocampus of Adult Male Rats

    Data.gov (United States)

    U.S. Environmental Protection Agency — behavioral measures of learning and memory in adult offspring of rats treated with thyroid hormone synthesis inhibitor, propylthiouracil. Electrophysiological...

  13. Influence of rat substrain and growth conditions on the characteristics of primary cultures of adult rat spinal cord astrocytes.

    Science.gov (United States)

    Codeluppi, Simone; Gregory, Ebba Norsted; Kjell, Jacob; Wigerblad, Gustaf; Olson, Lars; Svensson, Camilla I

    2011-04-15

    Primary astrocyte cell cultures have become a valuable tool for studies of signaling pathways that regulate astrocyte physiology, reactivity, and function; however, differences in culture preparation affect data reproducibility. The aim of this work was to define optimal conditions for obtaining primary astrocytes from adult rat spinal cord with an expression profile most similar to adult human spinal cord astrocytes. Hence, we examined whether different Sprague-Dawley substrains and culture conditions affect astrocyte culture quality. Medium supplemented with fetal bovine serum from three sources (Sigma, Gibco, Hyclone) or a medium with defined composition (AM medium) was used to culture astrocytes isolated from spinal cords of adult Harlan and Charles River Spraque-Dawley rats. Purity was significantly different between cultures established in media with different sera. No microglia were detected in AM or Hyclone cultures. Gene expression was also affected, with AM cultures expressing the highest level of glutamine synthetase, connexin-43, and glutamate transporter-1. Interestingly, cell response to starvation was substrain dependent. Charles River-derived cultures responded the least, while astrocytes derived from Harlan rats showed a greater decrease in Gfap and glutamine synthetase, suggesting a more quiescent phenotype. Human and Harlan astrocytes cultured in AM media responded similarly to starvation. Taken together, this study shows that rat substrain and growth medium composition affect purity, expression profile and response to starvation of primary astrocytes suggesting that cultures of Harlan rats in AM media have optimal astrocyte characteristics, purity, and similarity to human astrocytes.

  14. The effects of acute alcohol on motor impairments in adolescent, adult, and aged rats.

    Science.gov (United States)

    Ornelas, Laura C; Novier, Adelle; Van Skike, Candice E; Diaz-Granados, Jaime L; Matthews, Douglas B

    2015-03-01

    Acute alcohol exposure has been shown to produce differential motor impairments between aged and adult rats and between adolescent and adult rats. However, the effects of acute alcohol exposure among adolescent, adult, and aged rats have yet to be systematically investigated within the same project using a dose-dependent analysis. We sought to determine the age- and dose-dependent effects of acute alcohol exposure on gross and coordinated motor performance across the rodent lifespan. Adolescent (PD 30), adult (PD 70), and aged (approximately 18 months) male Sprague-Dawley rats were tested on 3 separate motor tasks: aerial righting reflex (ARR), accelerating rotarod (RR), and loss of righting reflex (LORR). In a separate group of animals, blood ethanol concentrations (BEC) were determined at multiple time points following a 3.0 g/kg ethanol injection. Behavioral tests were conducted with a Latin square repeated-measures design in which all animals received the following doses: 1.0 g/kg or 2.0 g/kg alcohol or saline over 3 separate sessions via intraperitoneal (i.p.) injection. During testing, motor impairments were assessed on the RR 10 min post-injection and on ARR 20 min post-injection. Aged animals spent significantly less time on the RR when administered 1.0 g/kg alcohol compared to adult rats. In addition, motor performance impairments significantly increased with age after 2.0 g/kg alcohol administration. On the ARR test, aged rats were more sensitive to the effects of 1.0 g/kg and 2.0 g/kg alcohol compared to adolescents and adults. Seven days after the last testing session, animals were given 3.0 g/kg alcohol and LORR was examined. During LORR, aged animals slept longer compared to adult and adolescent rats. This effect cannot be explained solely by BEC levels in aged rats. The present study suggests that acute alcohol exposure produces greater motor impairments in older rats when compared to adolescent and adult rats and begins to establish a

  15. Effects of neonatal overfeeding on juvenile and adult feeding and energy expenditure in the rat.

    Directory of Open Access Journals (Sweden)

    Aneta Stefanidis

    Full Text Available Overfeeding during perinatal life leads to an overweight phenotype that persists throughout the juvenile stage and into adulthood, however, the mechanism(s underlying this effect are poorly understood. We hypothesized that obesity due to neonatal overfeeding is maintained by changes in energy expenditure and that these changes differ between males and females. We investigated feeding, physical activity, hormonal and metabolic alterations that occur in adult rats made obese by having been nursed in small litters (SL compared with those from control litters (CL. There were no differences in absolute food intake between the groups, and juvenile and adult SL rats ate less chow per gram body weight than the CL did in the dark (active phase. Juvenile, but not adult SL rats did have reduced whole body energy expenditure, but there were no differences between the groups by the time they reached adulthood. Adult SL females (but not males had reduced brown adipose tissue (BAT temperatures compared with CL in the first half of the dark phase. Our results indicate a persistent overweight phenotype in rats overfed as neonates is not associated with hyperphagia at any stage, but is reflected in reduced energy expenditure into the juvenile phase. The reduced dark phase BAT activity in adult SL females is not sufficient to reduce total energy expenditure at this stage of life and there is an apparently compensatory effect that prevents SL and CL from continuing to diverge in weight that appears between the juvenile and adult stages.

  16. Differentiation of embryonic versus adult rat neural stem cells into dopaminergic neurons in vitro

    Institute of Scientific and Technical Information of China (English)

    Chunlong Ke; Baili Chen; Shaolei Guo; Chao Yang

    2008-01-01

    BACKGROUND: It has been reported that the conversion of neural stem cells into dopaminergic neurons in vitro can be increased through specific cytokine combinations. Such neural stem cell-derived dopaminergic neurons could be used for the treatment of Parkinson's disease. However, little is known about the differences in dopaminergic differentiation between neural stem cells derived from adult and embryonic rats.OBJECTIVE: To study the ability of rat adult and embryonic-derived neural stem cells to differentiate into dopaminergic neurons in vitro.DESIGN: Randomized grouping design.SETTING: Department of Neurosurgery in the First Affiliated Hospital of Sun Yat-sen University.MATERIALS: This experiment was performed at the Surgical Laboratory in the First Affiliated Hospital of Sun Yat-scn University (Guangzhou, Guangdong, China) from June to December 2007. Eight, adult, male,Sprague Dawley rats and eight, pregnant, Sprague Dawley rats (embryonic day 14 or 15) were provided by the Experimental Animal Center of Sun Yat-sen University.METHODS: Neural stem cells derived from adult and embryonic rats were respectively cultivated in serum-free culture medium containing epidermal growth factor and basic fibroblast growth factor. After passaging, neural stem cells were differentiated in medium containing interleukin-1 ct, interleukin-11, human leukemia inhibition factor, and glial cell line-derived neurotrophic factor. Six days later, cells were analyzed by immunocytochemistry and flow cytometry.MAIN OUTCOME MEASURES: Alterations in cellular morphology after differentiation of neural stem cells derived from adult and embryonic rats; and percentage of tyrosine hydroxylase-positive neurons in the differentiated cells.RESULTS: Neural stem cells derived from adult and embryonic rats were cultivated in differentiation medium. Six days later, differentiated cells were immunoreactive for tyrosine hydroxylasc. The percentage of tyrosine hydroxylase positive neurons was (5.6 ± 2

  17. Three-dimensional direct measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections.

    Science.gov (United States)

    Bensley, Jonathan Guy; De Matteo, Robert; Harding, Richard; Black, Mary Jane

    2016-01-01

    Quantitative assessment of myocardial development and disease requires accurate measurement of cardiomyocyte volume, nuclearity (nuclei per cell), and ploidy (genome copies per cell). Current methods require enzymatically isolating cells, which excludes the use of archived tissue, or serial sectioning. We describe a method of analysis that permits the direct simultaneous measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections. To demonstrate the utility of our technique, heart tissue was obtained from four species (rat, mouse, rabbit, sheep) at up to three life stages: prenatal, weaning and adulthood. Thick (40 μm) paraffin sections were stained with Wheat Germ Agglutinin-Alexa Fluor 488 to visualise cell membranes, and DAPI (4',6-diamidino-2-phenylindole) to visualise nuclei and measure ploidy. Previous methods have been restricted to thin sections (2-10 μm) and offer an incomplete picture of cardiomyocytes. Using confocal microscopy and three-dimensional image analysis software (Imaris Version 8.2, Bitplane AG, Switzerland), cardiomyocyte volume, nuclearity, and ploidy were measured. This method of staining and analysis of cardiomyocytes enables accurate morphometric measurements in thick histological sections, thus unlocking the potential of archived tissue. Our novel time-efficient method permits the entire cardiomyocyte to be visualised directly in 3D, eliminating the need for precise alignment of serial sections.

  18. Three-dimensional direct measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections

    Science.gov (United States)

    Bensley, Jonathan Guy; de Matteo, Robert; Harding, Richard; Black, Mary Jane

    2016-04-01

    Quantitative assessment of myocardial development and disease requires accurate measurement of cardiomyocyte volume, nuclearity (nuclei per cell), and ploidy (genome copies per cell). Current methods require enzymatically isolating cells, which excludes the use of archived tissue, or serial sectioning. We describe a method of analysis that permits the direct simultaneous measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections. To demonstrate the utility of our technique, heart tissue was obtained from four species (rat, mouse, rabbit, sheep) at up to three life stages: prenatal, weaning and adulthood. Thick (40 μm) paraffin sections were stained with Wheat Germ Agglutinin-Alexa Fluor 488 to visualise cell membranes, and DAPI (4‧,6-diamidino-2-phenylindole) to visualise nuclei and measure ploidy. Previous methods have been restricted to thin sections (2–10 μm) and offer an incomplete picture of cardiomyocytes. Using confocal microscopy and three-dimensional image analysis software (Imaris Version 8.2, Bitplane AG, Switzerland), cardiomyocyte volume, nuclearity, and ploidy were measured. This method of staining and analysis of cardiomyocytes enables accurate morphometric measurements in thick histological sections, thus unlocking the potential of archived tissue. Our novel time-efficient method permits the entire cardiomyocyte to be visualised directly in 3D, eliminating the need for precise alignment of serial sections.

  19. Ultrastructure of Cardiomyocytes and Blood Capillary Endotheliocytes in the Myocardium under Conditions of Experimental Mechanical Injury to the Heart.

    Science.gov (United States)

    Novoselov, V P; Savchenko, S V; Porvin, A N; Koshlyak, D A; Nadev, A P; Ageeva, T A; Chikinev, Yu V; Polyakevich, A S

    2016-05-01

    We studied ultrastructural changes in cardiomyocytes and blood capillary endotheliocytes in the ventricular myocardium in response to mechanical injury of the heart of varying severity in Wistar rats. Acute alterative changes in cardiomyocyte and endotheliocyte ultrastructure indicate impairment of the energy-producing, contractile, and protein-synthesizing functions of the cells after mechanical injury. These disorders play the key role in the development of acute contractile insufficiency of the myocardium in mechanical injury to the heart.

  20. Isoflavones prevent bone loss following ovariectomy in young adult rats

    Directory of Open Access Journals (Sweden)

    Chen Li-Ting

    2008-03-01

    Full Text Available Abstract Soy protein, a rich source of phytoestrogens, exhibit estrogen-type bioactivity. The purpose of this study was to determine if ingestion of isoflavones before ovariectomy can prevent bone loss following ovariectomy. Twenty-four nulliparous Wistar rats were randomly divided into four groups. In the normal diet groups, a sham operation was performed on Group A, while ovariectomy was performed on Group B. For Groups C and D, all rats were fed with an isoflavone-rich (25 mg/day diet for one month, then bilateral ovariectomy were performed. In the rats in Group C, a normal diet was begun following the ovariectomy. The rats in Groups D continued to receive the isoflavone-rich diet for two additional months postoperatively. All rats were sacrificed 60 days after surgery. The weight of bone ash of the long bones and whole lumbar spine were determined. A histological study of cancellous bone was done and biochemical indices of skeletal metabolism were performed and analyzed. The markers of bone metabolism exhibited no significant changes. When compared with the sham-operated rats fed a normal diet, the bone mass of ovariectomized rats decreased significantly; pre-ovariectomy ingestion of an isoflavone-rich diet did not prevent bone loss. The bone mass of rats treated with an isoflavone-rich diet for three months was higher than controls two months after ovariectomy. Dietary isoflavones did not prevent the development of post-ovariectomy bone loss, but long-term ingestion of an isoflavone-rich diet increased the bone mineral contents after ovariectomy in young rats.

  1. Morphine treatment during juvenile isolation increases social activity and opioid peptides release in the adult rat.

    Science.gov (United States)

    Van den Berg, C L; Kitchen, I; Gerrits, M A; Spruijt, B M; Van Ree, J M

    1999-05-29

    The consequences of juvenile isolation and morphine treatment on general activity, social activity and endogenous opioid release during a social interaction test were investigated in the adult rat. Rats were either isolated or socially housed during weeks 4 and 5 of age and treated daily during this isolation period subcutaneously with either saline or morphine. Directly after a social interaction test at 10 weeks of age, rats were injected with [3H]-diprenorphine and subsequently prepared for in vivo autoradiography. The autoradiographic technique was used to visualise neuroanatomical changes in opioid receptor occupancy, probably reflecting changes in opioid peptide release, as a result of social activity. Juvenile isolation increased general activity during the social interaction test, an effect which was accompanied by a reduction of opioid receptor occupancy in many brain areas, suggesting an increased opioid peptide release as a consequence of socially-induced general activity. Morphine treatment in isolated rats caused an increase in adult social activity and enhanced opioid peptide release in some cortical regions and the ventral tegmental area as compared to saline treated rats. Both social activity and opioid receptor occupancy were unaffected by morphine treatment in non-isolated rats. The present study underscores the role of opioid systems in adult social behaviors as a consequence of juvenile isolation. The results suggest a relationship between social activity and opioid peptide release during social contact. Increased social activity seems to be accompanied by elevated opioid peptide release in distinct brain areas after morphine treatment during juvenile isolation.

  2. Effect of lindane on antioxidant enzymes in epididymis and epididymal sperm of adult rats

    Institute of Scientific and Technical Information of China (English)

    K.C. Chitra; R. Sujatha; C. Latchoumycandane; P.P. Mathur

    2001-01-01

    Aim: To find out the changes induced by lindane on the antioxidant enzymes in epididymis and epididymal sperm of adult rats, Methods; Adult male rats were orally administered lindane at a dose of 5.0 mg/kg body weight per day for 30 days. At the end of the treatment, the rats were sacrificed. The epididymis was removed and weighed and sperm were collected for sperm count, motility and biochemical studies. A 1% homogenate of epididymis was prepared and used for biochemical estimations. Results: In lindane-treated rats, there were significant reductions in the epididymal weight, epididymal sperm count and motility compared with the controls. Significant decreases in the superoxide dismutase (SOD), catalase, glutathione reductase and glutathione peroxidase activities and significant increases in the H2O2 generation and lipid peroxidation were also observed in the epididymis and epididymal sperm of lindane-treated rats. Conclusion: Lindane decreases the levels of antioxidant enzymes in the epididymis and epididymal sperm of adult rats thereby inducing oxidative stress.

  3. Early treatment with metformin induces resistance against tumor growth in adult rats.

    Science.gov (United States)

    Trombini, Amanda B; Franco, Claudinéia Cs; Miranda, Rosiane A; de Oliveira, Júlio C; Barella, Luiz F; Prates, Kelly V; de Souza, Aline A; Pavanello, Audrei; Malta, Ananda; Almeida, Douglas L; Tófolo, Laize P; Rigo, Kesia P; Ribeiro, Tatiane As; Fabricio, Gabriel S; de Sant'Anna, Juliane R; Castro-Prado, Marialba Aa; de Souza, Helenir Medri; de Morais, Hely; Mathias, Paulo Cf

    2015-01-01

    It is known that antidiabetic drug metformin, which is used worldwide, has anti-cancer effects and can be used to prevent cancer growth. We tested the hypothesis that tumor cell growth can be inhibited by early treatment with metformin. For this purpose, adult rats chronically treated with metformin in adolescence or in adulthood were inoculated with Walker 256 carcinoma cells. Adult rats that were treated with metformin during adolescence presented inhibition of tumor growth, and animals that were treated during adult life did not demonstrate any changes in tumor growth. Although we do not have data to disclose a molecular mechanism to the preventive metformin effect, we present, for the first time, results showing that cancer growth in adult life is dependent on early life intervention, thus supporting a new therapeutic prevention for cancer.

  4. Early Administration of Glutamine Protects Cardiomyocytes from Post-Cardiac Arrest Acidosis

    Directory of Open Access Journals (Sweden)

    Yan-Ren Lin

    2016-01-01

    Full Text Available Postcardiac arrest acidosis can decrease survival. Effective medications without adverse side effects are still not well characterized. We aimed to analyze whether early administration of glutamine could improve survival and protect cardiomyocytes from postcardiac arrest acidosis using animal and cell models. Forty Wistar rats with postcardiac arrest acidosis (blood pH < 7.2 were included. They were divided into study (500 mg/kg L-alanyl-L-glutamine, n=20 and control (normal saline, n=20 groups. Each of the rats received resuscitation. The outcomes were compared between the two groups. In addition, cardiomyocytes derived from human induced pluripotent stem cells were exposed to HBSS with different pH levels (7.3 or 6.5 or to culture medium (control. Apoptosis-related markers and beating function were analyzed. We found that the duration of survival was significantly longer in the study group (p<0.05. In addition, in pH 6.5 or pH 7.3 HBSS buffer, the expression levels of cell stress (p53 and apoptosis (caspase-3, Bcl-xL markers were significantly lower in cardiomyocytes treated with 50 mM L-glutamine than those without L-glutamine (RT-PCR. L-glutamine also increased the beating function of cardiomyocytes, especially at the lower pH level (6.5. More importantly, glutamine decreased cardiomyocyte apoptosis and increased these cells’ beating function at a low pH level.

  5. Paradoxical effects of ginkgolide B on cardiomyocyte contractile function in normal and high-glucose environments

    Institute of Scientific and Technical Information of China (English)

    Jihye KIM; Qun LI; Cindy X FANG; Jun REN

    2006-01-01

    Aim: Ginkgo biloba extract is a natural product used widely for cerebral and cardiovascular diseases. It is mainly composed of terpene lactones (ginkgolide A and B) and flavone glycosides (eg quercetin and kaempferol).To better understand the cardiac electromechanical action of Ginkgo biloba extract in normal and diabetic states, this study was designed to examine the effect of ginkgolide B on cardiomyocyte contractile function under normal and high-glucose environments. Methods: Isolated adult rat ventricular myocytes were cultured for 6 h in a serum-free medium containing either normal (NG;5.5 mmol/L) or high (HG;25.5 mmol/L) glucose with or without ginkgolide B (0.5-2.0μg/mL). Mechanical properties were evaluated using the IonOptix MyoCam system. Contractile properties analyzed included peak shortening (PS),maximal velocity of shortening/relengthening (+dl/dt),time-to-PS (TPS) and time-to-90% relengthening (TR90). Levels of essential Ca2+ regulatory proteins sarco(endo)plasmic reticulum Ca2+ -ATPase (SERCA2a),phospholamban (PLB) and Na+-Ca2+ exchanger (NCX) were assessed by Western blotting. Results: Ginkgolide B nullified HG-induced prolongation in TR90. However, ginkgolide B depressed PS.±dl/dt and shortened TPS in NG and HG cells. Ginkgolide B also prolonged TR90 in NG cells. Western blot analysis revealed that HG upregulated SERCA2a and downregulated PLB expression without affecting that of NCX. Ginkgolide B disrupted the NG-HG response pattern in SERCA2a and NCX without affecting that of PLB. Conclusion: Ginkgolide B affects cardiomyocyte contractile function under NG or HG environments in a paradoxical manner, which may be attributed to uneven action on Ca2+ regulatory proteins under NG and HG conditions.

  6. [Disruption of latent inhibition in adult rats after prepubertal dopamine terminals lesions in the ventral hippocampus].

    Science.gov (United States)

    Loskutova, L V; Kostiunina, N V; Red'kina, A V

    2010-05-01

    Wistar rats were submitted to bilateral ventral hippocampal injection of 6-hydroxydopamine on 32nd day after birth. Latent inhibition was measured in passive or active avoidance tasks when the rats received 20 and 100 pre-exposures of conditioned stimulus. Prepubertal and adult lesioned rats showed a deficit in the latent inhibition but not in the capacity to avoidance learning in presence of the conditioned stimulus novelty. Possible mechanism of the involvement of hippocampal dopaminergic terminals in attention inhibition to irrelevant information is considered.

  7. Role of Histone Demethylases in Cardiomyocytes Induced to Hypertrophy

    Directory of Open Access Journals (Sweden)

    Wendy Rosales

    2016-01-01

    Full Text Available Epigenetic changes induced by histone demethylases play an important role in differentiation and pathological changes in cardiac cells. However, the role of the jumonji family of demethylases in the development of cardiac hypertrophy remains elusive. In this study, the presence of different histone demethylases in cardiac cells was evaluated after hypertrophy was induced with neurohormones. A cell line from rat cardiomyocytes was used as a biological model. The phenotypic profiles of the cells, as well as the expression of histone demethylases, were studied through immunofluorescence, transient transfection, western blot, and qRT-PCR analysis after inducing hypertrophy by angiotensin II and endothelin-1. An increase in fetal gene expression (ANP, BNP, and β-MHC was observed in cardiomyocytes after treatment with angiotensin II and endothelin-1. A significant increase in JMJD2A expression, but not in UTX or JMJD2C expression, was observed. When JMJD2A was overexpressed in cardiomyocytes through transient transfection, the effect of neurohormones on fetal cardiac gene expression was increased. We conclude that JMJD2A plays a principal role in the regulation of fetal cardiac genes, which increase in expression during the pathological hypertrophic process.

  8. Low maternal care exacerbates adult stress susceptibility in the chronic mild stress rat model of depression

    DEFF Research Database (Denmark)

    Henningsen, Kim; Dyrvig, Mads; Bouzinova, Elena V

    2012-01-01

    In the present study we report the finding that the quality of maternal care, in early life, increased the susceptibility to stress exposure in adulthood, when rats were exposed to the chronic mild stress paradigm. Our results indicate that high, as opposed to low maternal care, predisposed rats...... to a differential stress-coping ability. Thus rats fostered by low maternal care dams became more prone to adopt a stress-susceptible phenotype developing an anhedonic-like condition. Moreover, low maternal care offspring had lower weight gain and lower locomotion, with no additive effect of stress. Subchronic...... exposure to chronic mild stress induced an increase in faecal corticosterone metabolites, which was only significant in rats from low maternal care dams. Examination of glucocorticoid receptor exon 17 promoter methylation in unchallenged adult, maternally characterized rats, showed an insignificant...

  9. HISTOLOGICAL STUDIES OF THE EFFECTS OF RED PEPPER ON THE STOMACH OF ADULT WISTAR RATS

    Directory of Open Access Journals (Sweden)

    Josiah O. Adjene

    2007-01-01

    Full Text Available Histological effects of red pepper commonly used as spice in food on the stomach of adult wistar rats were carefully investigated. The rats of both sexes (n=24, average weight of 200g were randomly assigned into two treatments (n=16 and control (n=6 groups. The rats in the treatments groups received 1g and 2g of red pepper thoroughly mixed with 20g of their feeds for 7 and 14 days, while the control rats received equal amounts of feeds without the red pepper added. The rats were fed with grower's mash purchased from Edo feeds and flour mill Ltd, Ewu, Edo State and were given water liberally. The rats were sacrificed on day eight and fifteen of the experiment respectively.The stomach was carefully dissected out and quickly fixed in 10% formol saline for routine histological procedure after H & E method.The histological findings after H&E methods indicated that the treated sections of the stomach showed some level of cellular hypertrophy, congestion of blood vessels degenerative changes disruption and distortion of the cytoarchitecture of the stomach.These findings indicate that red pepper may have some deleterious effects on the microanatomy of the stomach of adult wistar rat at higher doses. It is recommended that further studies aimed at corroborating these findings be carried out.

  10. HISTOLOGICAL STUDIES OF THE EFFECTS OF MONOSODIUM GLUTAMATE ON THE INFERIOR COLLICULUS OF ADULT WISTAR RATS.

    Directory of Open Access Journals (Sweden)

    A.O. Eweka.

    2008-01-01

    Full Text Available Histological effects of Monosodium glutamate (MSG commonly used as food additive on the inferior colliculus (IC of adult Wistar rats were carefully studied. The rats of both sexes (n=24, average weight of 185g were randomly assigned into two treatments (n=16 and control (n=8 groups. The rats in the treatment groups received 3g and 6g of MSG thoroughly mixed with their feeds for fourteen days, while the control rats received equal amounts of feeds without MSG added. The rats were fed with growers' mash purchased from Edo Feeds and Flour Mill Ltd, Ewu, Edo State and were given water liberally. The rats were sacrificed on day fifteen of the experiment. The inferior colliculus was carefully dissected out and quickly fixed in 10% formal saline for routine histological study after H&E method.The histological findings after H&E methods indicated that the treated sections of the inferior colliculus showed some cellular degenerative changes, cellular hypertrophy, and autophagic vacuoles with some intercellular vacuolations appearing in the stroma, and some degree of neuronal hypertrophy when compared to the control sections.These findings indicate that MSG consumption may have a deleterious effect on the neurons of the inferior colliculus (IC. MSG may probably have adverse effects on the auditory sensibilities by its deleterious effects on the nerve cells of the IC of adult Wistar rats. It is recommended that further studies aimed at corroborating these observations be carried out.

  11. Histological effects of chronic consumption of soda pop drinks on kidney of adult Wister rats

    Directory of Open Access Journals (Sweden)

    Josiah Obaghwarhievwo Adjene

    2010-05-01

    Full Text Available Background: Health concerns over soda pop drinks have been severally report. However, histological perspectives are not very common. Aim: The objective of this study is to investigate histological effect of chronic consumption of soda pop drinks on the kidney of adult Wistar rats. Materials and methods: The rats of both sexes (n = 24, with average weight of 200g were randomly assigned into two treatment (A & B (n=16 and Control (c (n=8 groups. The rats in the treatment group (A received a brand of soda pop drink on a daily basis for thirty days. The rats in treatment group (B received another brand of soda drink, while the control group (C received equal amount of water for the same period. The rats were given the drinks as well as feeds liberally for thirty days, and sacrificed by cervical dislocation on the thirty-first day of the experiment. The kidney was carefully dissected out and quickly fixed in 10% formal saline for histological study. Results: The findings indicate that rats in the treated groups (A&B showed some varying degree of distortion and disruption of the renal structure. There are observable diffuse signs of glomerulonephritis with some congestion and tubular necrosis as compared to the control group. Conclusion: Chronic consumption of soda pop drinks may affect the microanatomy of the kidney of adult Wistar rats. Further study aimed at corroborating these observations in humans is warranted.

  12. Histological effects of chronic consumption of soda pop drinks on kidney of adult Wister rats

    Directory of Open Access Journals (Sweden)

    Josiah Obaghwarhievwo Adjene

    2010-01-01

    Full Text Available Background : Health concerns over soda pop drinks have been severally report. However, histological perspectives are not very common. Aim: The objective of this study is to investigate histological effect of chronic consumption of soda pop drinks on the kidney of adult Wistar rats. Materials and methods : The rats of both sexes (n = 24, with average weight of 200g were randomly assigned into two treatment (A & B (n=16 and Control (c (n=8 groups. The rats in the treatment group (A received a brand of soda pop drink on a daily basis for thirty days. The rats in treatment group (B received another brand of soda drink, while the control group (C received equal amount of water for the same period. The rats were given the drinks as well as feeds liberally for thirty days, and sacrificed by cervical dislocation on the thirty-first day of the experiment. The kidney was carefully dissected out and quickly fixed in 10% formal saline for histological study. Results : The findings indicate that rats in the treated groups (A&B showed some varying degree of distortion and disruption of the renal structure. There are observable diffuse signs of glomerulonephritis with some congestion and tubular necrosis as compared to the control group. Conclusion : Chronic consumption of soda pop drinks may affect the microanatomy of the kidney of adult Wistar rats. Further study aimed at corroborating these observations in humans is warranted.

  13. HISTOLOGICAL EFFECTS OF CHRONIC CONSUMPTION OF NUTMEG ON THE LATERAL GENICULATE BODY OF ADULT WISTAR RATS.

    Directory of Open Access Journals (Sweden)

    J.O. Adjene

    2010-01-01

    Full Text Available The effects of chronic consumption of nutmeg commonly used as a spice in various dishes, as components of teas and soft drinks or mixed in milk and alcohol on the lateral geniculate body of adult wistar rats was studied.The rats of both sexes, with average weight of 200g were randomly assigned into treatment and control groups. The rats in the treatment group (n=8 received 2g of nutmeg thoroughly mixed with the feeds on a daily basis for thirty-two days. The control group (n=8 received equal amount of feeds daily without nutmeg added for thirty-two days. The growers mash feeds was obtained from Edo Feeds and Flour Mill Limited, Ewu, Edo State, Nigeria and the rats were given water liberally. The rats were sacrificed on the thirty-three day of the experiment. The lateral geniculate body was carefully dissected out and quickly fixed in 10% formal saline for histological study.The findings indicate that rats in the treated group showed some cellular degenerative changes like sparse cellular population, pyknotic nuclei with some microcystic changes, edema and vacuolations in the stroma of the treated lateral geniculate body as compared to that of the control group.Chronic consumption of nutmeg may therefore have an adverse effect on the visual sensibilities by affecting the microanatomy of the lateral geniculate body of adult wistar rats. It is recommended for further studies aimed at corroborating these observations.

  14. Neonatal sensory deprivation promotes development of absence seizures in adult rats with genetic predisposition to epilepsy.

    Science.gov (United States)

    Sitnikova, Evgenia

    2011-03-04

    Absence epilepsy has age-related onset. In a WAG/Rij rat genetic model, absence seizures appear after puberty and they are increased with age. It is known that (1) epileptic activity in WAG/Rij rats is initiated at the perioral area in the somatosensory cortex; (2) sensory deprivation, i.e., whisker trimming during the critical period of development, could enhance excitatory activity in the somatosensory cortex. It is hypothesized that the cortex may become more excitable after neonatal vibrissae removal, and this may precipitate absence seizures in adult rats. We found that whisker trimming during the first postnatal weeks caused more rapid development of EEG seizure activity in adult WAG/Rij rats. Epileptic discharges in the trimmed rats were more numerous (vs control), showed longer duration and often appeared in desynchronized and drowsy EEG. The number of absence-like spindle-shaped EEG events (spike-wave spindles) in the whisker-trimmed rats was higher than in control, especially during the intermediate sleep state. An age-dependent increase of intermediate sleep state was found in the trimmed rats, but not in the intact animals. We discuss epigenetic factors that can modulate absence epilepsy in genetically prone subjects.

  15. The Effect of Exercise and Dietary Control on Cardiomyocyte Apoptosis in Type 2 Diabetic Rats%有氧运动和膳食控制对2型糖尿病大鼠心肌细胞凋亡的影响

    Institute of Scientific and Technical Information of China (English)

    金其贯; 刘霞; 李涛

    2012-01-01

    Objective To explore the effect of aerobic exercise and dietary control on the cardiomyocyte apoptosis in type 2 diabetic rats. Methods 8 of 62 6-week-old male SD rats were randomly selected as normal control group (C,fed with standard diet). The remaining 54 SD rats were used to establish animal models of type 2 diabetes (DM) through intraperitoneal injection of low-dose streptozotocin and feeding high-fat and high-carbohydrate diet. Then they were randomly divided into 4 groups: DM control group(DM,n = 9),DM+ aerobic exercise group(DME,n = 10),DM+ diet control group(DMD,n = 10), DM+ aerobic exercise + diet control group(DMED,n = 10). The rats in group DM were continuously fed with high-fat and high-carbohydrate diet without exercise. 60 min unloaded swimming 6 times per week was used as aerobic exercise. Rats in diet control groups were fed with the standard diet. 12 weeks later, fasting plasma glucose(FPG),cardiomyocyte apoptosis index,Bcl-2 and Fas content were examined. Results (l)As compared with group C, cardiomyocyte apoptosis index and Fas content increased, and Bcl-2 content decreased significantly (P < 0.01 and P < 0.05,respectively) in group DM; (2) cardiomyocyte apoptosis index and Fas content in groups DMED decreased significantly (P < 0.01),while there was a significant interaction on decreasing cardiomyocyte apoptosis index and Fas content,and increasing Bcl-2 content in group DMED(P < 0.01). Conclusion ①Increased cardiomyocyte apoptosis index in diabetic rats probably caused by the decreased Bcl-2 content or increased Fas content. ②Long term aerobic exercise or dietary control, especially the combination of them could significantly reduce the cardiomyocyte apoptosis in diabetic rats.%目的:探讨有氧运动联合膳食控制对2型糖尿病大鼠心肌细胞凋亡的影响及其机制.方法:选用6周龄雄性SD大鼠62只,随机抽取8只大鼠作为正常对照组(C组),喂以标准饲料;其余54只在喂饲高脂高糖膳食的基础

  16. Influence of superior cervical ganglionectomy on hippocampal neurogenesis and learning and memory in adult rats

    Institute of Scientific and Technical Information of China (English)

    Yanping Ding; Baoping Shao; Shiyuan Yu; Shanting Zhao; Jianlin Wang

    2009-01-01

    BACKGROUND: Studies have shown that neurogenesis in the dentate gyrus plays an important role in learning and memory. However, studies have not determined whether the superior cervical ganglion or the sympathetic nerve system influences hippocampal neurogenesis or learning and memory in adult rats. OBJECTIVE: To observe differences in dentate gyrus neurogenesis, as well as learning and memory, in adult rats following superior cervical ganglionectomy. DESIGN, TIME AND SETTING: A randomized, controlled, animal study was performed at the Immunohistochemistry Laboratory of the School of Life Sciences in Lanzhou University from July 2006 to July 2007.MATERIALS: Doublecortin polyclonal antibody was provided by Santa Cruz Biotechnology, USA;avidin-biotin-peroxidase complex was purchased from Zhongshan Goldenbride Biotechnology, China;Morris water maze was bought from Taimeng Technology, China. METHODS: A total of 20 adult, male, Wistar rats were randomly divided into surgery and control groups, with 10 rats in each group. In the surgery group, the bilateral superior cervical ganglions were transected. In the control group, the superior cervical ganglions were only exposed, but no ganglionectomy was performed. MAIN OUTCOME MEASURES: To examine distribution, morphology, and number of newborn neurons in the dentate gyrus using doublecortin immunohistochemistry at 36 days following surgical procedures. To examine ability of learning and memory in adult rats using the Morris water maze at 30 days following surgical procedures. RESULTS: Doublecortin immunohistochemical results showed that a reduction in the number of doublecortin-positive neurons in the surgery group compared to the control group (P<0.05), while the distribution of doublecortin-positive neurons was identical in the two groups. The surgery group exhibited significantly worse performance in learning and spatial memory tasks compared to the control group (P<0.05). CONCLUSION: Superior cervical ganglionectomy

  17. Herpesvirus-Mediated Delivery of a Genetically Encoded Fluorescent Ca2+ Sensor to Canine Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    János Prorok

    2009-01-01

    Full Text Available We report the development and application of a pseudorabies virus-based system for delivery of troponeon, a fluorescent Ca2+ sensor to adult canine cardiomyocytes. The efficacy of transduction was assessed by calculating the ratio of fluorescently labelled and nonlabelled cells in cell culture. Interaction of the virus vector with electrophysiological properties of cardiomyocytes was evaluated by the analysis of transient outward current (Ito, kinetics of the intracellular Ca2+ transients, and cell shortening. Functionality of transferred troponeon was verified by FRET analysis. We demonstrated that the transfer efficiency of troponeon to cultured adult cardiac myocytes was virtually 100%. We showed that even after four days neither the amplitude nor the kinetics of the Ito current was significantly changed and no major shifts occurred in parameters of [Ca2+]i transients. Furthermore, we demonstrated that infection of cardiomyocytes with the virus did not affect the morphology, viability, and physiological attributes of cells.

  18. Uterine phenotype of young adult rats exposed to dietary soy or genistein during development.

    Science.gov (United States)

    Eason, Renea R; Till, S Reneé; Velarde, Michael C; Geng, Yan; Chatman, Leon; Gu, Liwei; Badger, Thomas M; Simmen, Frank A; Simmen, Rosalia C M

    2005-10-01

    Dietary soy intake is associated with protection from breast cancer, but questions persist on the potential risks of the major soy isoflavone genistein (GEN) on female reproductive health. Here, we evaluated intermediate markers of cancer risk in uteri of cycling, young adult Sprague-Dawley rats lifetime exposed to one of three AIN-93G semipurified diets: casein (CAS), soy protein isolate (SPI+ with 276 mg GEN aglycone equivalents/kg) and CAS+GEN (GEN at 250 mg/kg). Postnatal day 50 (PND50) rats lifetime exposed to GEN or SPI+ had similar uterine luminal epithelium height, myometrial thickness, endometrial gland numbers, endometrial immunoreactive proliferating cell nuclear antigen (PCNA), and serum estrogen and progesterone, as CAS-fed rats. GEN-fed rats showed modestly increased apoptosis in uterine glandular epithelium, compared to those of CAS- or SPI+-fed groups. Diet had no effect on the uterine expression of genes for the tumor suppressors PTEN, p53 and p21, and the apoptotic-associated proteins Bcl2, Bax and progesterone receptor. Uterine tissue and serum concentrations of total GEN were higher in rats fed GEN than in those fed SPI+. Human Ishikawa endocarcinoma cells treated with GEN-fed rat serum tended to exhibit increased apoptotic status than those treated with CAS-fed rat serum. Exogenously added GEN (0.2 and 2 microM) increased, while estradiol-17beta (0.1 microM) decreased Ishikawa cell apoptosis, relative to untreated cells. Results suggest that lifetime dietary exposure to soy foods does not alter uterine cell phenotype in young adult rats, while GEN, by enhancing uterine endometrial glandular apoptosis in vivo and in vitro, may confer protection against uterine carcinoma. Given its limited influence on uterine phenotype of young adult females, GEN, when taken as part of soy foods or as supplement, should be favorably considered for other potential health benefits.

  19. Nickel Nanoparticles Exposure and Reproductive Toxicity in Healthy Adult Rats

    Directory of Open Access Journals (Sweden)

    Lu Kong

    2014-11-01

    Full Text Available Nickel is associated with reproductive toxicity. However, the reproductive toxicity of nickel nanoparticles (Ni NPs is unclear. Our goal was to determine the association between nickel nanoparticle exposure and reproductive toxicity. According to the one-generation reproductive toxicity standard, rats were exposed to nickel nanoparticles by gavage and we selected indicators including sex hormone levels, sperm motility, histopathology, and reproductive outcome etc. Experimental results showed nickel nanoparticles increased follicle stimulating hormone (FSH and luteinizing hormone (LH, and lowered etradiol (E2 serum levels at a dose of 15 and 45 mg/kg in female rats. Ovarian lymphocytosis, vascular dilatation and congestion, inflammatory cell infiltration, and increase in apoptotic cells were found in ovary tissues in exposure groups. For male rats, the weights decreased gradually, the ratio of epididymis weight over body weight increased, the motility of rat sperm changed, and the levels of FSH and testosterone (T diminished. Pathological results showed the shedding of epithelial cells of raw seminiferous tubule, disordered arrangement of cells in the tube, and the appearance of cell apoptosis and death in the exposure group. At the same time, Ni NPs resulted in a change of the reproductive index and the offspring development of rats. Further research is needed to elucidate exposure to human populations and mechanism of actions.

  20. EFFECTS OF CEREBRAL CORTICAL CONCIS ON CELL PROLIFERATION OF THE SUBVENTRICULAR ZONE IN ADULT RATS

    Institute of Scientific and Technical Information of China (English)

    Zhang Yuelin; Qiu Shudong; Zhang Pengbo; Shi Wei

    2006-01-01

    Objective To investigate the proliferative response and time course of endogenous neural stem/progenitor cells after cerebral cortical concis in the adult rats. Methods Eighty adult male Sprague-Dawley rats were used in this study. Cumulative BrdU labeling was employed to detect the proliferating cells. At 1 d, 3 d, 7 d, 14 d, and 21 d after cerebral cortical concis, the rats were killed for BrdU immunohistochemical staining and cell counting in the injured ipsilateral SVZ. Results Little BrdU immunoreactivity cells was present in SVZ of the control rats from day 7 to day 21 after sham operation. The number of BrdU immunoreactivity cells in the injured ipsilateral SVZ increased at day 1 and peaked at day 7 after cerebral cortical concis. Conclusion After cerebral cortical concis of the adult rats, neural stem/progenitor cells in the injured ipsilateral SVZ markedly proliferated with a peak at day 7. This finding may be important for manipulating SVZ cells to promote the recovery from cerebral cortical concis.

  1. Cocaine self-administration punished by intravenous histamine in adolescent and adult rats.

    Science.gov (United States)

    Holtz, Nathan A; Carroll, Marilyn E

    2015-06-01

    Adolescence is a transitional phase marked by a heightened vulnerability to substances of abuse. It has been hypothesized that both increased sensitivity to reward and decreased sensitivity to aversive events may drive drug-use liability during this phase. To investigate possible age-related differences in sensitivity to the aversive consequences of drug use, adolescent and adult rats were compared on self-administration of cocaine before, during, and after a 10-day period in which an aversive agent, histamine, was added to the cocaine solution. Adult and adolescent female rats were trained to self-administer intravenous cocaine (0.4 mg/kg/infusion) over 10 sessions (2 h/session; 2 sessions/day). Histamine (4 mg/kg/infusion) was then added directly into the cocaine solution for the next 10 sessions. Finally, the cocaine/histamine solution was replaced with a cocaine-only solution, and rats continued to self-administer cocaine (0.4 mg/kg) for 20 sessions. Compared with adolescent rats, adult rats showed a greater decrease in cocaine self-administration when it was punished with intravenous histamine compared with their baseline cocaine self-administration rates. These results suggest that differences in the sensitivity to negative consequences of drug use may partially explain developmental differences in drug use vulnerability.

  2. Effect of lindane on testicular antioxidant system and steroidogenic enzymes in adult rats

    Institute of Scientific and Technical Information of China (English)

    R. Sujatha; K.C. Chitin; C. Latchoumycandane; P.P. Mathur

    2001-01-01

    Aim: To find out the effect of lindane on testicular antioxidant system and testicular steroidogenesis in adult male rats. Methods: Adult male rats were orally administered with lindane at a dose of 5.0 mg/kg body weight per day for 30 days. Twenty-four hours after the last treatment the rats were killed using anesthetic ether. Testes, epididymis,seminal vesicles and ventral prostate were removed and weighed. A 10% testicular homogenate was prepared and cen trifuged at 4°C. The supematant was used for various biochemical estimations. Results: The body weight and the weights of testes, epididymis, seminal vesicles and ventral prostate were reduced in lindane-treated rars. There was asignificant decline in the activities of antioxidant enzymes superoxide dismutase (SOD), catalase and glutathione reduc tase while an increase in hydrogen peroxide (H2O2) generation was observed. The specific activities of testicular steroidogenic enzymes 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase were decreased. The levels of DNA, RNA and protein were also decreased in lindane-treated rats. Conclusion: Lindane induces oxida tive stress and decreases antioxidant enzymes in adult male rats.

  3. Prenatal Choline Availability Alters the Context Sensitivity of Pavlovian Conditioning in Adult Rats

    Science.gov (United States)

    Lamoureux, Jeffrey A.; Meck, Warren H.; Williams, Christina L.

    2008-01-01

    The effects of prenatal choline availability on Pavlovian conditioning were assessed in adult male rats (3-4 mo). Neither supplementation nor deprivation of prenatal choline affected the acquisition and extinction of simple Pavlovian conditioned excitation, or the acquisition and retardation of conditioned inhibition. However, prenatal choline…

  4. Positron emission tomography for serial imaging of the contused adult rat spinal cord.

    NARCIS (Netherlands)

    Nandoe, R.D.S.; Yu, J.; Seidel, J.; Rahiem, S.T.; Hurtado, A.; Tsui, B.M.; Grotenhuis, J.A.; Pomper, M.G.; Oudega, M.

    2010-01-01

    We investigated whether small-animal positron emission tomography (PET) could be used in combination with computed tomography (CT) imaging techniques for longitudinal monitoring of the injured spinal cord. In adult female Sprague-Dawley rats (n = 6), the ninth thoracic (T9) spinal cord segment was e

  5. Prenatal exposure to vapors of gasoline-ethanol blends causes few cognitive deficits in adult rats

    Science.gov (United States)

    Developmental exposure to inhaled ethanol-gasoline fuel blends is a potential public health concern. Here we assessed cognitive functions in adult offspring of pregnant rats that were exposed to vapors of gasoline blended with a range of ethanol concentrations, including gasoli...

  6. The effect of prenatal methamphetamine exposure on recognition memory in adult rats.

    Science.gov (United States)

    Fialová, Markéta; Šírová, Jana; Bubeníková-Valešová, Věra; Šlamberová, Romana

    2015-01-01

    The use of methamphetamine (MA) among pregnant women is an increasing world-wide health problem. Prenatal MA exposure may cause changes in foetus but the exact effects have remained unclear. The aim of this study is to present the effect of prenatal MA exposure on recognition memory in adult rats. Adult female Wistar rats were injected daily with D-methamphetamine HCl (MA; 5 mg/kg, s.c.) during the entire gestation period. Control females were treated with saline in the same regime. Adult male offspring was administrated acutely by MA (1 mg/kg i.p.) or saline 30 minutes before beginning of an experiment. For testing recognition memory two tasks were chosen: Novel Object Recognition Test (NORT) and Object Location Test (OLT). Our results demonstrate that prenatally MA-exposed animals were worse in NORT independently on an acute administration of MA in adulthood. Prenatally MA-exposed rats did not deteriorate in OLT, but after acute administration of MA in adulthood, there was significant worsening compared to appropriate control. Prenatally saline-exposed offspring did not deteriorate in any test even after acute administration of MA. Our data suggest that prenatal MA exposure in rats cause impairment in recognition memory in adult offspring, but not in spatial memory. In addition, acute administration of MA to controls did not deteriorate either recognition or spatial memory.

  7. Monitoring of intermittent PTH(1-34) treatment by serum PINP in adult ovariectomized osteopenic rats

    DEFF Research Database (Denmark)

    Halleen, Jussi; Peng, ZhiQi; Fagerlund, Katja

    , allowing measurement of serum PINP in preclinical rodent osteoporosis models. The purpose of this study was to evaluate the use of serum PINP for monitoring intermittent PTH(1-34) treatment in adult ovariectomized (OVX) osteopenic rats. Study groups included a sham-operated control group and an OVX...

  8. Reinnervation of muscles after transection of the sciatic nerve in adult rats

    NARCIS (Netherlands)

    Ijkema-Paassen, J; Meek, MF; Gramsbergen, A

    2002-01-01

    Functional recovery after transection of the sciatic nerve in adult rats is poor, probably because of abnormalities in reinnervation. Denervation and reinnervation patterns were studied morphologically in the lateral gastrocnemius (LGC), tibialis anterior (TA), and soleus (SOL) muscles for 21 weeks

  9. Peripheral effect of NMDA receptor antagonists on adult rats exposed to neonatal colon pain

    Institute of Scientific and Technical Information of China (English)

    ChunLin; ElieD.Al-Chaer

    2004-01-01

    AIM: Previous work done by Al-Chaer' s lab has shown that colon irritation (CI) in neonates can lead to chronic visceral hypersensitivity in adult rats, with characteristics of visceral allodynia and hyperalgesia, associated with central neuronal sensitization in the absence of identifiable peripheral pathology (Al-Chaer et al. 2000) . The pathogenesis of

  10. Strain differences in baroceptor reflex in adult Wistar Kyoto rats

    Directory of Open Access Journals (Sweden)

    Vitor E. Valenti

    2010-01-01

    Full Text Available OBJECTIVES: A subset of normotensive Sprague-Dawley rats show lower baroreflex sensitivity; however, no previous study investigated whether there are differences in baroreflex sensitivity within this subset. Our study compared baroreflex sensitivity among conscious rats of this specific subtype. METHODS: Male Wistar Kyoto (WKY rats (16 weeks old were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure (MAP and heart rate (HR. Baroreflex gain was calculated as the ratio between change in HR and MAP variation (ΔHR/ΔMAP in response to a depressor dose of sodium nitroprusside (SNP, 50 µg/kg, i.v. and a pressor dose of phenylephrine (PE, 8 µg/kg, i.v.. Rats were divided into four groups: 1 low bradycardic baroreflex (LB, baroreflex gain (BG between -1 and -2 bpm/mmHg tested with PE; 2 high bradycardic baroreflex (HB, BG < -2 bpm/mmHg tested with PE; 3 low tachycardic baroreflex (LT, BG between -1 and -2 bpm/mmHg tested with SNP and; 4 high tachycardic baroreflex (HT, BG < -2 bpm/mmHg tested with SNP. Significant differences were considered for p < 0.05. RESULTS: Approximately 37% of the rats showed a reduced bradycardic peak, bradycardic reflex and decreased bradycardic gain of baroreflex while roughly 23% had a decreased basal HR, tachycardic peak, tachycardic reflex and reduced sympathetic baroreflex gain. No significant alterations were noted with regard to basal MAP. CONCLUSION: There is variability regarding baroreflex sensitivity among WKY rats from the same laboratory.

  11. Trading new neurons for status: Adult hippocampal neurogenesis in eusocial Damaraland mole-rats.

    Science.gov (United States)

    Oosthuizen, M K; Amrein, I

    2016-06-02

    Diversity in social structures, from solitary to eusocial, is a prominent feature of subterranean African mole-rat species. Damaraland mole-rats are eusocial, they live in colonies that are characterized by a reproductive division of labor and a subdivision into castes based on physiology and behavior. Damaraland mole-rats are exceptionally long lived and reproductive animals show delayed aging compared to non-reproductive animals. In the present study, we described the hippocampal architecture and the rate of hippocampal neurogenesis of wild-derived, adult Damaraland mole-rats in relation to sex, relative age and social status or caste. Overall, Damaraland mole-rats were found to have a small hippocampus and low rates of neurogenesis. We found no correlation between neurogenesis and sex or relative age. Social status or caste was the most prominent modulator of neurogenesis. An inverse relationship between neurogenesis and social status was apparent, with queens displaying the lowest neurogenesis while the worker mole-rats had the most. As there is no natural progression from one caste to another, social status within a colony was relatively stable and is reflected in the level of neurogenesis. Our results correspond to those found in the naked mole-rat, and may reflect an evolutionary and environmentally conserved trait within social mole-rat species.

  12. Effects of neonatal treatment with the TRPV1 agonist, capsaicin, on adult rat brain and behaviour.

    Science.gov (United States)

    Newson, Penny N; van den Buuse, Maarten; Martin, Sally; Lynch-Frame, Ann; Chahl, Loris A

    2014-10-01

    Treatment of neonatal rats with the transient receptor potential vanilloid 1 (TRPV1) channel agonist, capsaicin, produces life-long loss of sensory neurons expressing TRPV1 channels. Previously it was shown that rats treated on day 2 of life with capsaicin had behavioural hyperactivity in a novel environment at 5-7 weeks of age and brain changes reminiscent of those found in subjects with schizophrenia. The objective of the present study was to investigate brain and behavioural responses of adult rats treated as neonates with capsaicin. It was found that the brain changes found at 5-7 weeks in rats treated as neonates with capsaicin persisted into adulthood (12 weeks) but were less in older rats (16-18 weeks). Increased prepulse inhibition (PPI) of acoustic startle was found in these rats at 8 and 12 weeks of age rather than the deficit commonly found in animal models of schizophrenia. Subjects with schizophrenia also have reduced flare responses to niacin and methylnicotinate proposed to be mediated by prostaglandin D2 (PGD2). Flare responses are accompanied by cutaneous plasma extravasation. It was found that the cutaneous plasma extravasation responses to methylnicotinate and PGD2 were reduced in capsaicin-treated rats. In conclusion, several neuroanatomical changes observed in capsaicin-treated rats, as well as the reduced cutaneous plasma extravasation responses, indicate that the role of TRPV1 channels in schizophrenia is worthy of investigation.

  13. The role of apelin in the modulation of gastric and pancreatic enzymes activity in adult rats.

    Science.gov (United States)

    Antuschevich, H; Kapica, M; Krawczynska, A; Herman, A; Kato, I; Kuwahara, A; Zabielski, R

    2016-06-01

    Apelin is considered as important gut regulatory peptide ligand of APJ receptor with a potential physiological role in gastrointestinal cytoprotection, regulation of food intake and drinking behavior. Circulating apelin inhibits secretion of pancreatic juice through vagal- cholecystokinin-dependent mechanism and reduces local blood flow. Our study was aimed to determine the effect of fundectomy and intraperitoneal or intragastric administration of apelin-13 on pancreatic and gastric enzymes activities in adult rats. Fundectomy is a surgical removal of stomach fundus - maine site apelin synthesis. Three independent experiments were carried out on Wistar rats. In the first and second experiment apelin-13 was given by intragastric or intraperitoneal way twice a day for 10 days (100 nmol/kg b.w.). Control groups received the physiological saline respectively. In the third experiment the group of rats after fundectomy were used. Fundectomized rats did not receive apelin and the rats from control group were 'sham operated'. At the end of experiment rats were sacrificed and blood from rats was withdrawn for apelin and CCK (cholecystokinin) radioimmunoassay analysis and pancreas and stomach tissues were collected for enzyme activity analyses. Intragastric and intraperitoneal administrations of apelin-13 increased basal plasma CCK level and stimulated gastric and pancreatic enzymes activity in rats. In animals after fundectomy decreased activity of studied enzymes was observed, as well as basal plasma apelin and CCK levels. In conclusion, apelin can effects on CCK release and stimulates some gastric and pancreatic enzymes activity in adult rats while fudectomy suppresses those processes. Changes in the level of pancreatic lipase activity point out that apelin may occurs as a regulator of lipase secretion.

  14. Excitation-contraction coupling of human induced pluripotent stem cell-derived cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Christopher eKane

    2015-09-01

    Full Text Available Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs hold enormous potential in many fields of cardiovascular research. Overcoming many of the limitations of their embryonic counterparts, the application of iPSC-CMs ranges from facilitating investigation of familial cardiac disease and pharmacological toxicity screening to personalized medicine and autologous cardiac cell therapies. The main factor preventing the full realization of this potential is the limited maturity of iPSC-CMs, which display a number of substantial differences in comparison to adult cardiomyocytes. Excitation-contraction coupling, a fundamental property of cardiomyocytes, is often described in iPSC-CMs as being more analogous to neonatal than adult cardiomyocytes. With calcium handling linked, directly or indirectly, to almost all other properties of cardiomyocytes, a solid understanding of this process will be crucial to fully realizing the potential of this technology.Here we discuss the implications of differences in excitation-contraction coupling when considering the potential applications of iPSC-CMs in a number of areas as well as detailing the current understanding of this fundamental process in these cells.

  15. Body and Testicular Weight Changes in Adult Wistar Rats Following Oral Administration of Artesunate

    Directory of Open Access Journals (Sweden)

    al-hassan m. izunya

    2010-05-01

    Full Text Available This experiment was designed to study the effects on the body and testicular weights of adult wistar rats that recieved an oral administration of normal and double normal doses of artesunate. The rats were divided into three groups (A, B and C of five rats each. A and B served as the treatment groups, while C served as the control group. Group A rats were given 4mg.kg-1 b.w of artesunate daily for 3 days followed by 2mg.kg-1 b.w daily for next for 4 days. Group B rats were given 8mg.kg-1 b.w of artesunate daily for 3 days followed by 4mg.kg-1 b.w daily for next 4 days, while group C rats were given only distilled water. The rats were fed with grower's mash purchased from Edo feeds and Flour Mill Ltd, Ewu, Edo state and were given w ater ad libitum. On day eight of the experiment, the rats were weighed and sacrificed. The testes w ere carefully dissected out, freed from adherent tissues and weighed to the nearest 0.001 g. The results showed no changes in body weight of rats in groups A, B and C. There was also no significant change in testicular weight of rats in group A. However a significant increase in testicular weight was observed in group C. Our results suggest that artesunate at normal and double normal doses, has no effect on body weight of rats but may be toxic to the testes at higher doses. It is uncertain however if these changes are reversible. It is recommended therefore, that further studies aimed at corroborating these observations be carried out.

  16. Desvenlafaxine may accelerate neuronal maturation in the dentate gyri of adult male rats.

    Directory of Open Access Journals (Sweden)

    Aditya Asokan

    Full Text Available Adult hippocampal neurogenesis has been linked to the effects of anti-depressant drugs on behavior in rodent models of depression. To explore this link further, we tested whether the serotonin-norepinephrine reuptake inhibitor (SNRI venlafaxine impacted adult hippocampal neurogenesis differently than its primary active SNRI metabolite desvenlafaxine. Adult male Long Evans rats (n = 5-6 per group were fed vehicle, venlafaxine (0.5 or 5 mg or desvenlafaxine (0.5 or 5 mg twice daily for 16 days. Beginning the third day of drug treatment, the rats were given a daily bromodeoxyuridine (BrdU; 50 mg/kg injection for 5 days to label dividing cells and then perfused 2 weeks after the first BrdU injection to confirm total new hippocampal cell numbers and their phenotypes. The high desvenlafaxine dose increased total new BrdU+ cell number and appeared to accelerate neuronal maturation because fewer BrdU+ cells expressed maturing neuronal phenotypes and more expressed mature neuronal phenotypes in the dentate gyri of these versus vehicle-treated rats. While net neurogenesis was not increased in the dentate gyri of rats treated with the high desvenlafaxine dose, significantly more mature neurons were detected. Our data expand the body of literature showing that antidepressants impact adult neurogenesis by stimulating NPC proliferation and perhaps the survival of neuronal progeny and by showing that a high dose of the SNRI antidepressant desvenlafaxine, but neither a high nor low venlafaxine dose, may also accelerate neuronal maturation in the adult rat hippocampus. These data support the hypothesis that hippocampal neurogenesis may indeed serve as a biomarker of depression and the effects of antidepressant treatment, and may be informative for developing novel fast-acting antidepressant strategies.

  17. Dermal penetration of [14C]captan in young and adult rats.

    Science.gov (United States)

    Fisher, H L; Hall, L L; Sumler, M R; Shah, P V

    1992-07-01

    Age dependence in dermal absorption has been a major concern in risk assessment. Captan, a chloroalkyl thio heterocyclic fungicide, was selected for study of age dependence as representative of this class of pesticides. Dermal penetration of [14C]captan applied at 0.286 mumol/cm2 was determined in young (33-d-old) and adult (82-d-old) female Fischer 344 rats in vivo and by two in vitro methods. Dermal penetration in vivo at 72 h was about 9% of the recovered dose in both young and adult rats. The percentage penetration was found to increase as dosage (0.1, 0.5, 2.7 mumol/cm2) decreased. Two in vitro methods gave variable dermal penetration values compared with in vivo results. A static system yielded twofold higher dermal penetration values compared with in vivo results for both young and adult rats. A flow system yielded higher dermal penetration values in young rats and lower penetration values in adults compared with in vivo results. Concentration in body, kidney, and liver was less in young than in adult rats given the same absorbed dosage. A physiological pharmacokinetic model was developed having a dual compartment for the treated skin and appeared to describe dermal absorption and disposition well. From this model, tissue/blood ratios of captan-derived radioactivity for organs were found to range from 0.35 to 3.4, indicating no large uptake or binding preferences by any organ. This preliminary pharmacokinetic model summarizes the experimental findings and could provide impetus for more complex and realistic models.

  18. Effect of prenatal programming and postnatal rearing on glomerular filtration rate in adult rats.

    Science.gov (United States)

    Lozano, German; Elmaghrabi, Ayah; Salley, Jordan; Siddique, Khurrum; Gattineni, Jyothsna; Baum, Michel

    2015-03-01

    The present study examined whether a prenatal low-protein diet programs a decrease in glomerular filtration rate (GFR) and an increase in systolic blood pressure (BP). In addition, we examined whether altering the postnatal nutritional environment of nursing neonatal rats affected GFR and BP when rats were studied as adults. Pregnant rats were fed a normal (20%) protein diet or a low-protein diet (6%) during the last half of pregnancy until birth, when rats were fed a 20% protein diet. Mature adult rats from the prenatal low-protein group had systolic hypertension and a GFR of 0.38 ± 0.03 versus 0.57 ± 0.05 ml·min(-1)·100 g body wt(-1) in the 20% group (P < 0.01). In cross-fostering experiments, mothers continued on the same prenatal diet until weaning. Prenatal 6% protein rats cross-fostered to a 20% mother on day 1 of life had a GFR of 0.53 ± 0.05 ml·min(-1)·100 g body wt(-1), which was not different than the 20% group cross-fostered to a different 20% mother (0.45 ± 0.04 ml·min(-1)·100 g body wt(-1)). BP in the 6% to 20% group was comparable with the 20% to 20% group. Offspring of rats fed either 20% or 6% protein diets during pregnancy and cross-fostered to a 6% mother had elevated BP but a comparable GFR normalized to body weight as the 20% to 20% control group. Thus, a prenatal low-protein diet causes hypertension and a reduction in GFR in mature adult offspring, which can be modified by postnatal rearing.

  19. Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

    Energy Technology Data Exchange (ETDEWEB)

    Zago, A. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Leão, R.M.; Carneiro-de-Oliveira, P.E. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Programa Interinstitucional de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos/Universidade Estadual de São Paulo, Araraquara, SP (Brazil); Marin, M.T.; Cruz, F.C. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Planeta, C.S. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Programa Interinstitucional de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos/Universidade Estadual de São Paulo, Araraquara, SP (Brazil)

    2011-11-18

    Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although crosssensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9% NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

  20. Abnormal Calcium "Sparks" in Cardiomyocytes of Post-myocardial Infarction Heart

    Institute of Scientific and Technical Information of China (English)

    Kai HUANG; Dan HUANG; Shengquan FU; Chongzhe YANG; Yuhua LIAO

    2008-01-01

    In ischemic hypertrophic myocardium, contractile dysfunction can be attributed to the decreased calcium induced calcium release (CICR) in cytoplasm. This study aimed to investigate the electrophysiological properties and the expression of L calcium channel subunits in post-MI myocardium. The ischemic heart remodeling model was established in SD rats. The expressions of calcium channel subunits were determined by realtime RT-PCR. Whole cell patch clamp was used to record the electrophysiological properties of L calcium channel. The results showed that the L calcium channel agonist Bayk 8644 induced the significantly decreased CICR in the rat cardiomyocyte 6weeks after myocardial infarction (MI). In the post-MI cardiomyocytes, the amplitude of ICaL decreased dramatically and the inactivation curve of the current shifted to more negative potential. At mRNA level, the expression of the calcium channel alphalc, beta2c subunits decreased dramatically in the ventricle of post-MI rats. The expression of alpha2/delta subunit, however, remained constant.It is concluded that the abnormal expression of the L calcium channel subunits in post-MI cardiomyocytes contributes to the ICaL decrease at early stage of the ischemic remodeling in cardiomyocytes,which leads to the decreased CICR in the cell and contractile dysfunction of myocardium.

  1. Mechanism of Forelimb Motor Function Restoration after Cervical Spinal Cord Hemisection in Rats: A Comparison of Juveniles and Adults

    Directory of Open Access Journals (Sweden)

    Atsushi Hasegawa

    2016-01-01

    Full Text Available The aim of this study was to investigate forelimb motor function after cervical spinal cord injury in juvenile and adult rats. Both rats received a left segmental hemisection of the spinal cord after C3-C4 laminectomy. Behavioral evaluation of motor function was monitored and assessed using the New Rating Scale (NRS and Forelimb Locomotor Scale (FLS and by measuring the range of motion (ROM of both the elbow and wrist. Complete left forelimb motor paralysis was observed in both rats. The NRS showed motor function recovery restored to 50.2±24.7% in juvenile rats and 34.0±19.8% in adult rats. FLS was 60.4±26.8% in juvenile rats and 46.5±26.9% in adult rats. ROM of the elbow and wrist were 88.9±20.6% and 44.4±24.1% in juvenile rats and 70.0±29.2% and 40.0±21.1% in adult rats. Thus, the NRS and ROM of the elbow showed a significant difference between age groups. These results indicate that left hemisection of the cervical spinal cord was not related to right-sided motor functions. Moreover, while motor paralysis of the left forelimb gradually recovered in both groups, the improvement was greater in juvenile rats.

  2. Monosodium Glutamate Dietary Consumption Decreases Pancreatic β-Cell Mass in Adult Wistar Rats.

    Directory of Open Access Journals (Sweden)

    Piyanard Boonnate

    Full Text Available The amount of dietary monosodium glutamate (MSG is increasing worldwide, in parallel with the epidemics of metabolic syndrome. Parenteral administration of MSG to rodents induces obesity, hyperglycemia, hyperlipidemia, insulin resistance, and type 2 diabetes. However, the impact of dietary MSG is still being debated. We investigated the morphological and functional effects of prolonged MSG consumption on rat glucose metabolism and on pancreatic islet histology.Eighty adult male Wistar rats were randomly subdivided into 4 groups, and test rats in each group were supplemented with MSG for a different duration (1, 3, 6, or 9 months, n=20 for each group. All rats were fed ad libitum with a standard rat chow and water. Ten test rats in each group were provided MSG 2 mg/g body weight/day in drinking water and the 10 remaining rats in each group served as non-MSG treated controls. Oral glucose tolerance tests (OGTT were performed and serum insulin measured at 9 months. Animals were sacrificed at 1, 3, 6, or 9 months to examine the histopathology of pancreatic islets.MSG-treated rats had significantly lower pancreatic β-cell mass at 1, 6 and 9 months of study. Islet hemorrhages increased with age in all groups and fibrosis was significantly more frequent in MSG-treated rats at 1 and 3 months. Serum insulin levels and glucose tolerance in MSG-treated and untreated rats were similar at all time points we investigated.Daily MSG dietary consumption was associated with reduced pancreatic β-cell mass and enhanced hemorrhages and fibrosis, but did not affect glucose homeostasis. We speculate that high dietary MSG intake may exert a negative effect on the pancreas and such effect might become functionally significant in the presence or susceptibility to diabetes or NaCl; future experiments will take these crucial cofactors into account.

  3. Human Stem Cell Derived Cardiomyocytes: An Alternative ...

    Science.gov (United States)

    Chemical spills and associated deaths in the US has increased 2.6-fold and 16-fold from 1983 to 2012, respectfully. In addition, the number of chemicals to which humans are exposed to in the environment has increased almost 10-fold from 2001 to 2013 within the US. Internationally, a WHO report on the global composite impact of chemicals on health reported that 16% of the total burden of cardiovascular disease was attributed to environmental chemical exposure with 2.5 million deaths per year. Clearly, the cardiovascular system, at all its various developmental and life stages, represents a critical target organ system that can be adversely affected by existing and emerging chemicals (e.g., engineered nanomaterials) in a variety of environmental media. The ability to assess chemical cardiac risk and safety is critically needed but extremely challenging due to the number and categories of chemicals in commerce, as indicated. This presentation\\session will evaluate the use of adult human stem cell derived cardiomyocytes, and existing platforms, as an alternative model to evaluate environmental chemical cardiac toxicity as well as provide key information for the development of predictive adverse outcomes pathways associated with environmental chemical exposures. (This abstract does not represent EPA policy) Rapid and translatable chemical safety screening models for cardiotoxicity current status for informing regulatory decisions, a workshop sponsored by the Society

  4. Effect of morphine, naloxone and histamine system on water intake in adult male rats.

    Science.gov (United States)

    Eidi, Maryam; Oryan, Shahrbanoo; Eidi, Akram; Sepehrara, Leili

    2003-10-08

    The present study investigated the interaction between histamine and opioid systems on water intake in adult male rats. Intracerebroventricular (i.c.v.) injections were carried out in all experiments. Water intake was measured 1 h after drug injections. Administration of histamine (40-80 microg/rat) and naloxone (0.5-1 microg/rat) increased, while morphine (2.5 microg/rat), pyrilamine (25-50 microg/rat), the histamine H1 receptor antagonist, and ranitidine (10-20 microg/rat), the histamine H2 receptor antagonist, decreased water intake in isolated rats. Blockade of histamine H1 and H2 receptors attenuated the histamine-induced response. Pyrilamine, but not ranitidine, increased the inhibitory effect induced by morphine. Also, pharmacological blockade of histamine H1 and H2 receptors decreased the naloxone-induced effect on water intake. It is concluded that the histaminergic system may have a close interaction with morphine and naloxone on drinking behavior.

  5. Hepatoprotective activity of bacoside A against N-nitrosodiethylamine-induced liver toxicity in adult rats.

    Science.gov (United States)

    Janani, Panneerselvam; Sivakumari, Kanakarajan; Parthasarathy, Chandrakesan

    2009-10-01

    N-Nitrosodiethylamine (DEN) is a notorious carcinogen, present in many environmental factors. DEN induces oxidative stress and cellular injury due to enhanced generation of reactive oxygen species; free radical scavengers protect the membranes from DEN-induced damage. The present study was designed to evaluate the protective effect of bacoside A (the active principle isolated from Bacopa monniera Linn.) on carcinogen-induced damage in rat liver. Adult male albino rats were pretreated with 15 mg/kg body weight/day of bacoside A orally (for 14 days) and then intoxicated with single necrogenic dose of N-nitrosodiethylamine (200 mg/kg bodyweight, intraperitonially) and maintained for 7 days. The liver weight, lipid peroxidation (LPO), and activity of serum marker enzymes (aspartate transaminases, alanine transaminases, lactate dehydrogenase, alkaline phosphatase, and gamma-glutamyl transpeptidase) were markedly increased in carcinogen-administered rats, whereas the activities of marker enzymes were near normal in bacoside A-pretreated rats. Activities of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutatione-S-transferase, and reduced glutathione) in liver also decreased in carcinogen-administered rats, which were significantly elevated in bacoside A-pretreated rats. It is concluded that pretreatment of bacoside A prevents the elevation of LPO and activity of serum marker enzymes and maintains the antioxidant system and thus protects the rats from DEN-induced hepatotoxicity.

  6. Effect of artemether on hematological parameters of healthy and uninfected adult Wistar rats

    Institute of Scientific and Technical Information of China (English)

    Osonuga IO; Osonuga OA; Osonuga A; Onadeko AA; Osonuga AA

    2012-01-01

    Objective: To evaluate the effect of short term artemether administration on some blood parameters in adult male Wistar rats. Methods: Sixty five albino rats with body weight of 190-220 g were used for the four-phased study. The animals were randomly divided into five groups. The first-four groups of 15 rats were further divided into 3 subgroups of 5 rats. The drug was administered orally at sub-optimal, therapeutic, and high doses of 25, 50 and 75 mg/kg bw, respectively to the rats for 1 day, 2 days and 3 days. Blood samples were collected by cardio-puncture from the rats for hematology at the end of each phase. The last group served as control, and they were given water ad libitum. Results:Artemether caused significant reduction (P<0.05) of the hematological profile of the animals in a dose dependent manner. Discontinuation of the drug use however showed gradual recovery of the depressed indices of the blood parameters. Conclusions:The results suggest that artemether can induce reversible changes in hematological profiles of rats by extension man. This can probably aggravate anemia when artemether is administered to malaria patients. Hence, the study supports the use of the drug with caution especially in patients prone to anemic tendencies.

  7. Influence of endogenous ciliary neurotrophic factor on neural differentiation of adult rat hippocampal progenitors

    Institute of Scientific and Technical Information of China (English)

    Jun Ding; Zhili He; Juan Ruan; Ying Liu; Chengxin Gong; Shenggang Sun; Honghui Chen

    2013-01-01

    Ciliary neurotrophic factor is the only known neurotrophic factor that can promote differentiation of hippocampal neural progenitor cells to glial cells and neurons in adult rats. This process is similar to spontaneous differentiation. Therefore, ciliary neurotrophic factor may be involved in spontaneous differentiation of neural stem cells. To verify this hypothesis, the present study isolated neural progenitor cells from adult male rats and cultured them in vitro. Results showed that when neural progenitor cells were cultured in the absence of mitogen fibroblast growth factor-2 or epidermal growth factor, they underwent spontaneous differentiation into neurons and glial cells. Western blot and immunocytochemical staining showed that exogenous ciliary neurotrophic factor strongly induced adult hippocampal progenitor cells to differentiate into neurons and glial cells. Moreover, passage 4 adult hippocampal progenitor cells expressed high levels of endogenous ciliary neurotrophic factor, and a neutralizing antibody against ciliary neurotrophic factor prevented the spontaneous neuronal and glial differentiation of adult hippocampal progenitor cells. These results suggest that the spontaneous differentiation of adult hippocampal progenitor cells is mediated partially by endogenous ciliary neurotrophic factor.

  8. Potential testicular toxicity of sodium nitrate in adult rats.

    Science.gov (United States)

    Aly, Hamdy A A; Mansour, Ahmed M; Abo-Salem, Osama M; Abd-Ellah, Hala F; Abdel-Naim, Ashraf B

    2010-02-01

    Nitrate is a common contaminant in groundwater aquifers. Current study aimed at evaluating the potential testicular toxicity of sodium nitrate in rats. Sodium nitrate was given orally to rats at doses of 50, 100 or 200 mg/kg/day for 60 consecutive days. Sperm count and motility, daily sperm production and testis weight were significantly decreased specially at high doses. Testicular activity of lactate dehydrogenase-X, glucose-6-phosphate dehydrogenase, and acid phosphatase were inhibited in a dose-related manner. Lipid peroxides and hydrogen peroxide production were significantly increased in all treated animals. This was accompanied by inhibition of testicular activities of superoxide dismutase and glutathione peroxidase. Fifty mg/kg of sodium nitrate did not significantly alter catalase or glutathione reductase activity. Glutathione was significantly decreased by sodium nitrate in a dose-related manner. The decrease in sperm count and motility and daily sperm production was confirmed by histopathological studies which indicated chromatolysis, pyknosis and necrosis in spermatocytes. In conclusion, subchronic exposure of rats to sodium nitrate results in testicular toxicity as evidenced by decreased sperm count and motility, daily sperm production and testis weight, inhibited activity of enzyme markers of spermatogenesis and induction of histopathological changes. These effects are attributed, at least partly, to testicular oxidative stress.

  9. Caffeine induces cardiomyocyte hypertrophy via p300 and CaMKII pathways.

    Science.gov (United States)

    Shi, Liang; Xu, Hao; Wei, Jinhong; Ma, Xingfeng; Zhang, Jianbao

    2014-09-25

    Caffeine is commonly utilized to trigger intracellular calcium in cardiomyocyte. It is well accepted that caffeine could induce cardiac arrhythmia, but it is not clear with regard of its impacts on the cardiac function. This article presents a recent study concerning the effects of caffeine on the cardiomyocyte hypertrophy and the associated signal pathway. The experimental results showed that the total protein contents, the surface area of cardiomyocyte and β-myosin heavy chain (β-MHC) expression increased in ventricular myocytes of neonatal Sprague-Dawley (SD) rats after 24h caffeine incubation. It is also observed that the basal intracellular calcium (Ca(2+)) level has increased, while the amplitude of Ca(2+) oscillation and Ca(2+) content have decreased in sarcoplasmic reticulum (SR). The caffeine-induced myocyte enhancer factor-2 (MEF2) expression and hypertrophy can be completely abolished by the inhibition of cardiac ryanodine receptor (RyR2), as well as KN93 and curcumin treatments. Meanwhile, the amplitude of Ca(2+) oscillation and the Ca(2+) content of SR in the completely-inhibited group have reached the physiological level. These results suggest that the caffeine-induced cardiomyocyte hypertrophy established the connection between Ca(2+) release from SR and cytosol that activates CaMKII and p300, which in turn enhances the expression of MEF2 that promotes cardiomyocyte hypertrophy.

  10. Repair of acutely injured spinal cord through constructing tissue-engineered neural complex in adult rats

    Institute of Scientific and Technical Information of China (English)

    PU Yu; GUO Qing-shan; WANG Ai-min; WU Si-yu; XING Shu-xing; ZHANG Zhong-rong

    2007-01-01

    Objective: To construct tissue-engineered neural complex in vitro and study its effect in repairing acutely injured spinal cord in adult rats. Methods: Neural stem cells were harvested from the spinal cord of embryo rats and propagated in vitro. Then the neural stem cells were seeded into polyglycolic acid scaffolds and co-cultured with extract of embryonic spinal cord in vitro. Immunofluorescence histochemistry and scanning electron microscope were used to observe the microstructure of this complex. Animal model of spine semi-transection was made and tissue-engineered neural complex was implanted by surgical intervention. Six weeks after transplantation, functional evaluation and histochemistry were applied to evaluate the functional recovery and anatomic reconstruction. Results: The tissue-engineered neural complex had a distinct structure, which contained neonatal neurons, oligodendrocytes and astrocytes. After tissue-engineered neural complex was implanted into the injured spinal cord, the cell components such as neurons, astrocytes and oligodendrocytes, could survive and keep on developing. The adult rats suffering from spinal cord injury got an obvious neurological recovery in motor skills. Conclusions: The tissue-engineered neural complex appears to have therapeutic effects on the functional recovery and anatomic reconstruction of the adult rats with spinal cord injury.

  11. Effects of Chronic 5-Bromo-2-Deoxyuridine Adminidtration on Spatial Memory in the Adult Rats

    Directory of Open Access Journals (Sweden)

    Mahmoud Hosseini

    2013-05-01

    Full Text Available Background: 5-Bromo-2-deoxyuridine (BrdU has been a principal marker for mitotic cells in studies of adult neurogenesis. The method consists of a pulse injection of BrdU into the intraperitoneal cavity followed by a variable survival time allowing for tracking the divided cells and their progeny. However, such exogenous markers may produce toxic effects. Aim of this study was determined the effects of Brdu on spatial memory in the adult rat. Materials and Methods: 16 Wistar rats were used in this experimental study. The rats were randomly divided into 2 groups (N=8 in each group, as follows: control and Brdu (50 mg/kg. Brdu was administered intraperitoneally for 6 weeks and then animals were used for behavioral testing in the Morris water maze. The data were analyzed with repeated measure’s ANOVA.Results: Our present findings show that there were no differences in the path length, escape latency and swim speed between control and Brdu-administrated groups.Conclusion: This study show that Brdu (exogenic proliferation marker did not has side effects on spatial memory in the adult rats.

  12. Regulation of cardiomyocyte autophagy by calcium.

    Science.gov (United States)

    Shaikh, Soni; Troncoso, Rodrigo; Criollo, Alfredo; Bravo-Sagua, Roberto; García, Lorena; Morselli, Eugenia; Cifuentes, Mariana; Quest, Andrew F G; Hill, Joseph A; Lavandero, Sergio

    2016-04-15

    Calcium signaling plays a crucial role in a multitude of events within the cardiomyocyte, including cell cycle control, growth, apoptosis, and autophagy. With respect to calcium-dependent regulation of autophagy, ion channels and exchangers, receptors, and intracellular mediators play fundamental roles. In this review, we discuss calcium-dependent regulation of cardiomyocyte autophagy, a lysosomal mechanism that is often cytoprotective, serving to defend against disease-related stress and nutrient insufficiency. We also highlight the importance of the subcellular distribution of calcium and related proteins, interorganelle communication, and other key signaling events that govern cardiomyocyte autophagy.

  13. Adiponectin Inhibited Calcification in Cultured Rat Neonatal Cardiomyocytes via Reducing Endoplasmic Reticulum Stress-mediated Apoptosis%脂联素通过减轻内质网应激介导的凋亡抑制心肌细胞钙化

    Institute of Scientific and Technical Information of China (English)

    赵旭静; 边云飞; 白瑞; 王敏; 肖传实

    2012-01-01

    目的 通过培养SD大鼠乳鼠心室肌细胞并建立细胞钙化模型,观察脂联素对心肌细胞钙化的影响及其机制.方法 采用Ⅱ型胶原酶消化法原代培养SD大鼠乳鼠心室肌细胞,α肌动蛋白免疫荧光法进行鉴定.选用培养72 h的单层心肌细胞,实验分为3组:对照组、钙化组、脂联素+钙化组.β-甘油磷酸钠和丙酮酸钠联合诱导制备心肌细胞钙化模型,茜素红和Von Kossa染色法对钙化心肌细胞进行鉴定,通过细胞钙含量、碱性磷酸酶活性和骨钙素的测定判断钙化程度.通过乳酸脱氢酶活性测定和流式细胞术检测心肌细胞凋亡.用定量实时聚合酶链反应测定骨保护素及内质网应激指标葡萄糖调节蛋白78、半胱氨酸天冬氨酸蛋白酶12的表达.结果 与对照组相比,单纯心肌细胞钙化后,钙含量、碱性磷酸酶活性和骨钙素分泌量显著增加(P<0.01),骨保护素及内质网应激指标葡萄糖调节蛋白78和半胱氨酸天冬氨酸蛋白酶12在mRNA水平表达明显增高,乳酸脱氢酶活性和细胞凋亡率显著增加(P<0.01).用脂联素进行干预后,可较大程度地逆转上述指标变化,与心肌细胞钙化组相比均具有显著差异(P<0.05),并且呈现一定的浓度依赖性.结论 钙化心肌细胞可以诱导心肌细胞内质网应激介导的凋亡;脂联素可促进血管保护因子骨保护素的表达,并通过减轻内质网应激来减轻心肌细胞钙化及凋亡,对心肌细胞有保护作用.%Aim To investigate the effects of adiponectin on calcification in cultured cardiomyocytes via reducing endoplasmic reticulum stress-mediated apoptosis in vitro. Methods Primary cultured cardiomyocytes were obtained from neonatal rats by collagenase II digestion method. The ot-actin expression as molecular marker of the cardiomyocytes was observed by immunocytochemistry. The cells cultured for 72 h were used in the experiment and divided into groups randomly

  14. Cross-sensitization between testosterone and cocaine in adolescent and adult rats.

    Science.gov (United States)

    Engi, Sheila A; Cruz, Fabio C; Crestani, Carlos C; Planeta, Cleopatra S

    2015-11-01

    Cocaine and anabolic-androgenic steroids are substances commonly co-abused. The use of anabolic steroids and cocaine has increased among adolescents. However, few studies investigated the consequences of the interaction between anabolic-androgenic steroids in animals' model of adolescence. We examined the effects of acute and repeated testosterone administration on cocaine-induced locomotor activity in adult and adolescent rats. Rats received ten once-daily subcutaneous (s.c.) injections of testosterone (10mg/kg) or vehicle. Three days after the last testosterone or vehicle injections rats received an intraperitoneal (i.p.) challenge injection of either saline or cocaine (10mg/kg). A different subset of rats was treated with a single injection of testosterone (10mg/kg) or vehicle and three days later was challenged with cocaine (10mg/kg, i.p.) or saline. Immediately after cocaine or saline injections the locomotor activity was recorded during forty minutes. Our results demonstrated that repeated testosterone induced locomotor sensitization to cocaine in adolescent but not adult rats.

  15. Effects of extremely low frequency magnetic field on anxiety level and spatial memory of adult rats

    Institute of Scientific and Technical Information of China (English)

    HE Li-hua; SHI Hong-mei; LIU Tong-tong; XUYing-chun; YE Kang-ping; WANG Sheng

    2011-01-01

    Background As the widespread use of electric devices in modern life,human are exposed to extremely low frequency magnetic fields (ELF MF) much more frequently than ever.Over the past decades,a substantial number of epidemiological and experimental studies have demonstrated that ELF MF (50 Hz) exposure is associated with increased risk of various health effects.The present study examined the effects of chronic exposure to ELF MF on anxiety level and spatial memory of adult rats.Methods The 50-Hz ELF MF was used during the whole experimental procedures and the value of magnetic field (MF)was set to 2 mT.Adult rats were divided randomly to control,MF 1 hour and MF 4 hours group.Anxiety-related behaviors were examined in the open field test and the elevated plus maze; changes in spatial learning and memory were determined in Morris water maze after 4 weeks of daily exposure.Results Rats in MF 4 hours group had increased anxiety-like behaviors with unaltered locomotor activity.In the Morris water maze test,rats had reduced latency to find the hidden platform and improved long-term memory of former location of platform without changes in short-term memory and locomotor activity.Conclusion Chronic ELF MF exposure has anxiogenic effect on rats,and the promoting effects on spatial learning and long-term retention of spatial memory.

  16. Enriched experience and recovery from amblyopia in adult rats: impact of motor, social and sensory components.

    Science.gov (United States)

    Baroncelli, Laura; Bonaccorsi, Joyce; Milanese, Marco; Bonifacino, Tiziana; Giribaldi, Francesco; Manno, Ilaria; Cenni, Maria Cristina; Berardi, Nicoletta; Bonanno, Giambattista; Maffei, Lamberto; Sale, Alessandro

    2012-06-01

    Amblyopia is one of the most common forms of visual impairment, arising from an early functional imbalance between the two eyes. It is currently accepted that, due to a lack of neural plasticity,amblyopia is an untreatable pathology in adults. Environmental enrichment (EE) emerged as a strategy highly effective in restoring plasticity in adult animals, eliciting recovery from amblyopia through a reduction of intracortical inhibition. It is unknown whether single EE components are able to promote plasticity in the adult brain, crucial information for designing new protocols of environmental stimulation suitable for amblyopic human subjects. Here, we assessed the effects of enhanced physical exercise,increased social interaction, visual enrichment or perceptual learning on visual function recovery in adult amblyopic rats. We report a complete rescue of both visual acuity and ocular dominance in exercised rats, in animals exposed to visual enrichment and in animals engaged in perceptual learning.These effects were accompanied by a reduced inhibition/excitation balance in the visual cortex. In contrast, we did not detect any sign of recovery in socially enriched rats or in animals practicing a purely associative visual task. These findings could have a bearing in orienting clinical research in the field of amblyopia therapy.

  17. Neonatal nociception elevated baseline blood pressure and attenuated cardiovascular responsiveness to noxious stress in adult rats.

    Science.gov (United States)

    Chu, Ya-Chun; Yang, Cheryl C H; Lin, Ho-Tien; Chen, Pin-Tarng; Chang, Kuang-Yi; Yang, Shun-Chin; Kuo, Terry B J

    2012-10-01

    Neonatal nociception has significant long-term effects on sensory perception in adult animals. Although neonatal adverse experience affect future responsiveness to stressors is documented, little is known about the involvement of early nociceptive experiences in the susceptibility to subsequent nociceptive stress exposure during adulthood. The aim of this study is to explore the developmental change in cardiovascular regulating activity in adult rats that had been subjected to neonatal nociceptive insults. To address this question, we treated neonatal rats with an intraplantar injection of saline (control) or carrageenan at postnatal day 1. The carrageenan-treated rats exhibited generalized hypoalgesia at basal state, and localized hyperalgesia after re-nociceptive challenge induced by intraplantar injections of complete Freund's adjuvant (CFA) as adults. Then we recorded baseline cardiovascular variables and 24-h responsiveness to an injection of CFA in the free-moving adult rats with telemetric technique. The carrageenan-treated rats showed significantly higher basal blood pressures (110.3±3.16 vs. control 97.0±4.28 mmHg). In control animals, baroreceptor reflex sensitivity (BRS) decreased, sympathetic vasomotor activity increased, and parasympathetic activity was inhibited after CFA injection. Blood pressure elevation was evident (107.0±2.75 vs. pre-injection 97.0±4.28 mmHg). Comparatively, the carrageenan-treated rats showed a higher BRS (BrrLF 1.03±0.09 vs. control 0.70±0.06 ms/mmHg) and higher parasympathetic activity [0.93±0.17 vs. control 0.32±0.02 ln(ms²)] after CFA injection. The change in blood pressure is negligible (111.9±4.05 vs. pre-injection 110.3±3.16 mmHg). Our research has shown that neonatal nociception alters future pain sensation, raises basal blood pressure level, and attenuates cardiovascular responsiveness to nociceptive stress in adult rats.

  18. Comparison of airway measurements during influenza-induced tachypnea in infant and adult cotton rats

    Directory of Open Access Journals (Sweden)

    Prince Gregory A

    2009-06-01

    Full Text Available Abstract Background Increased respiratory rate (tachypnea is frequently observed as a clinical sign of influenza pneumonia in pediatric patients admitted to the hospital. We previously demonstrated that influenza infection of adult cotton rats (Sigmodon hispidus also results in tachypnea and wanted to establish whether this clinical sign was observed in infected infant cotton rats. We hypothesized that age-dependent differences in lung mechanics result in differences in ventilatory characteristics following influenza infection. Methods Lung tidal volume, dynamic elastance, resistance, and pleural pressure were measured in a resistance and compliance system on mechanically-ventilated anesthestized young (14–28 day old and adult (6–12 week old cotton rats. Animals at the same age were infected with influenza virus, and breathing rates and other respiratory measurements were recorded using a whole body flow plethysmograph. Results Adult cotton rats had significantly greater tidal volume (TV, and lower resistance and elastance than young animals. To evaluate the impact of this increased lung capacity and stiffening on respiratory disease, young and adult animals were infected intra-nasally with influenza A/Wuhan/359/95. Both age groups had increased respiratory rate and enhanced pause (Penh during infection, suggesting lower airway obstruction. However, in spite of significant tachypnea, the infant (unlike the adult cotton rats maintained the same tidal volume, resulting in an increased minute volume. In addition, the parameters that contribute to Penh were different: while relaxation time between breaths and time of expiration was decreased in both age groups, a disproportionate increase in peak inspiratory and expiratory flow contributed to the increase in Penh in infant animals. Conclusion While respiratory rate is increased in both adult and infant influenza-infected cotton rats, the volume of air exchanged per minute (minute volume is

  19. Induction of abnormal oocyte division under the constant light in the young adult rat

    Institute of Scientific and Technical Information of China (English)

    Wei Wang; Fangxiong Shi

    2012-01-01

    In order to study the effect of constant light on the ovary, 12 young adult female rats were exposed to constant light for 37 days and their estrous cycles were recorded by daily examination and the ovaries were examined histologically. The results showed that constant light induced in an abnormal and uncontrolled division of oocytes. In these divided-oocyte follicles (DOFs), two or more divided-oocytes shared one zona pellucida and usually floated freely in the follicular antrum. This fantastic phenomenon was discovered for the first time, and it was different from multioocyte follicles (MOFs) and polyovular follicles (POFs) founded in rats, humans, rabbits, mice and dogs.

  20. Propolis attenuates cobalt induced-nephrotoxicity in adult rats and their progeny.

    Science.gov (United States)

    Garoui, El Mouldi; Troudi, Afef; Fetoui, Hamadi; Soudani, Nejla; Boudawara, Tahia; Zeghal, Najiba

    2012-11-01

    The aim of this study was to evaluate the biochemical changes in cobalt-exposed rats and to investigate the potential role of Tunisian propolis against the cobalt-induced renal damages. Twenty-four pregnant Wistar rats were divided into four groups and were treated as follows: group 1 (control) received distilled water; group 2 received 350 ppm of CoCl(2) in drinking water; group 3 received 350 ppm CoCl(2) in drinking water and a propolis-supplemented diet (1 g/100 g of diet); group 4 received a propolis-supplemented diet (1 g/100 g of diet) without cobalt. In the cobalt group, a significant decrease in body, absolute and relative weights was noted when compared to controls. The administration of cobalt to pregnant rats from the 14th day of pregnancy until day 14 after delivery resulted in an increased level of renal malondialdehyde, a decreased renal content of glutathione and antioxidant enzyme activities such as superoxide dismutase, catalase and glutathione peroxidase in lactating rats and their pups. A statistically significant increase in plasma urea and creatinine serum levels was seen in treated female rats and their pups. Histopathologically, the cobalt-administration induced degenerative changes in the kidney of lactating rats and their pups. When compared with cobalt-treated rats, those receiving the propolis supplementation (along with cobalt-treatment) had lower malondialdehyde levels, higher antioxidant activities and the cobalt-related histopathological changes in the kidneys were at lower severity. Our results suggested that the propolis might be a potential candidate agent against cobalt-induced nephrotoxicity in adult and juvenile rats when administered to female rats during the late pregnancy and the early postnatal period.

  1. Enhanced currents through L-type calcium channels in cardiomyocytes disturb the electrophysiology of the dystrophic heart.

    Science.gov (United States)

    Koenig, Xaver; Rubi, Lena; Obermair, Gerald J; Cervenka, Rene; Dang, Xuan B; Lukacs, Peter; Kummer, Stefan; Bittner, Reginald E; Kubista, Helmut; Todt, Hannes; Hilber, Karlheinz

    2014-02-15

    Duchenne muscular dystrophy (DMD), induced by mutations in the gene encoding for the cytoskeletal protein dystrophin, is an inherited disease characterized by progressive muscle weakness. Besides the relatively well characterized skeletal muscle degenerative processes, DMD is also associated with cardiac complications. These include cardiomyopathy development and cardiac arrhythmias. The current understanding of the pathomechanisms in the heart is very limited, but recent research indicates that dysfunctional ion channels in dystrophic cardiomyocytes play a role. The aim of the present study was to characterize abnormalities in L-type calcium channel function in adult dystrophic ventricular cardiomyocytes. By using the whole cell patch-clamp technique, the properties of currents through calcium channels in ventricular cardiomyocytes isolated from the hearts of normal and dystrophic adult mice were compared. Besides the commonly used dystrophin-deficient mdx mouse model for human DMD, we also used mdx-utr mice, which are both dystrophin- and utrophin-deficient. We found that calcium channel currents were significantly increased, and channel inactivation was reduced in dystrophic cardiomyocytes. Both effects enhance the calcium influx during an action potential (AP). Whereas the AP in dystrophic mouse cardiomyocytes was nearly normal, implementation of the enhanced dystrophic calcium conductance in a computer model of a human ventricular cardiomyocyte considerably prolonged the AP. Finally, the described dystrophic calcium channel abnormalities entailed alterations in the electrocardiograms of dystrophic mice. We conclude that gain of function in cardiac L-type calcium channels may disturb the electrophysiology of the dystrophic heart and thereby cause arrhythmias.

  2. ROCK1 and ROCK2 silencing by ShRNA in rat cardiomyocytes%ShRNA对大鼠心肌细胞ROCK1和ROCK2表达的沉默作用

    Institute of Scientific and Technical Information of China (English)

    丁浩; 李菊香; 孙国芳; 洪葵; 程晓曙

    2011-01-01

    (32.15± 7 53)% and (39.42± 5.31)%. Res pe ctwe ty (P <0.05). These fin dings show that the expressions ofROCKI andROCK2 in rat cardiomyocytes can be effectively inhibited by the trarEfection of ROCK1-shRHAand R 0 C K2-s hR H A An d theshRHA with the best silencing eff ici en cy w as selected among these shRHAs.

  3. Prolonged performance of a high repetition low force task induces bone adaptation in young adult rats, but loss in mature rats.

    Science.gov (United States)

    Massicotte, Vicky S; Frara, Nagat; Harris, Michele Y; Amin, Mamta; Wade, Christine K; Popoff, Steven N; Barbe, Mary F

    2015-12-01

    We have shown that prolonged repetitive reaching and grasping tasks lead to exposure-dependent changes in bone microarchitecture and inflammatory cytokines in young adult rats. Since aging mammals show increased tissue inflammatory cytokines, we sought here to determine if aging, combined with prolonged performance of a repetitive upper extremity task, enhances bone loss. We examined the radius, forearm flexor muscles, and serum from 16 mature (14-18 months of age) and 14 young adult (2.5-6.5 months of age) female rats after performance of a high repetition low force (HRLF) reaching and grasping task for 12 weeks. Young adult HRLF rats showed enhanced radial bone growth (e.g., increased trabecular bone volume, osteoblast numbers, bone formation rate, and mid-diaphyseal periosteal perimeter), compared to age-matched controls. Mature HRLF rats showed several indices of radial bone loss (e.g., decreased trabecular bone volume, and increased cortical bone thinning, porosity, resorptive spaces and woven bone formation), increased osteoclast numbers and inflammatory cytokines, compared to age-matched controls and young adult HRLF rats. Mature rats weighed more yet had lower maximum reflexive grip strength, than young adult rats, although each age group was able to pull at the required reach rate (4 reaches/min) and required submaximal pulling force (30 force-grams) for a food reward. Serum estrogen levels and flexor digitorum muscle size were similar in each age group. Thus, mature rats had increased bone degradative changes than in young adult rats performing the same repetitive task for 12 weeks, with increased inflammatory cytokine responses and osteoclast activity as possible causes.

  4. Prostaglandin E₂ promotes post-infarction cardiomyocyte replenishment by endogenous stem cells.

    Science.gov (United States)

    Hsueh, Ying-Chang; Wu, Jasmine M F; Yu, Chun-Keung; Wu, Kenneth K; Hsieh, Patrick C H

    2014-04-01

    Although self-renewal ability of adult mammalian heart has been reported, few pharmacological treatments are known to promote cardiomyocyte regeneration after injury. In this study, we demonstrate that the critical period of stem/progenitor cell-mediated cardiomyocyte replenishment is initiated within 7 days and saturates on day 10 post-infarction. Moreover, blocking the inflammatory reaction with COX-2 inhibitors may also reduce the capability of endogenous stem/progenitor cells to repopulate lost cells. Injection of the COX-2 product PGE2 enhances cardiomyocyte replenishment in young mice and recovers cell renewal through attenuating TGF-β1 signaling in aged mice. Further analyses suggest that cardiac stem cells are PGE2-responsive and that PGE2 may regulate stem cell activity directly through the EP2 receptor or indirectly by modulating its micro-environment in vivo. Our findings provide evidence that PGE2 holds great potential for cardiac regeneration.

  5. lncRNA H19/miR-675 axis regulates cardiomyocyte apoptosis by targeting VDAC1 in diabetic cardiomyopathy

    Science.gov (United States)

    Li, Xiangquan; Wang, Hao; Yao, Biao; Xu, Weiting; Chen, Jianchang; Zhou, Xiang

    2016-01-01

    We previously established a rat model of diabetic cardiomyopathy (DCM) and found that the expression of lncRNA H19 was significantly downregulated. The present study was designed to investigate the pathogenic role of H19 in the development of DCM. Overexpression of H19 in diabetic rats attenuated oxidative stress, inflammation and apoptosis, and consequently improved left ventricular function. High glucose was associated with reduced H19 expression and increased cardiomyocyte apoptosis. To explore the molecular mechanisms involved, we performed in vitro experiments using cultured neonatal rat cardiomyocytes. Our results showed that miR-675 expression was decreased in cardiomyocytes transfected with H19 siRNA. The 3′UTR of VDAC1 was cloned downstream of a luciferase reporter construct and cotransfected into HEK293 cells with miR-675 mimic. The results of luciferase assay indicated that VDAC1 might be a direct target of miR-675. The expression of VDAC1 was upregulated in cardiomyocytes transfected with miR-675 antagomir, which consequently promotes cellular apoptosis. Moreover, enforced expression of H19 was found to reduce VDAC1 expression and inhibit apoptosis in cardiomyocytes exposed to high glucose. In conclusion, our study demonstrates that H19/miR-675 axis is involved in the regulation of high glucose-induced apoptosis by targeting VDAC1, which may provide a novel therapeutic strategy for the treatment of DCM. PMID:27796346

  6. Resveratrol improves reproductive parameters of adult rats varicocelized in peripuberty.

    Science.gov (United States)

    Mendes, Talita Biude; Paccola, Camila Cicconi; de Oliveira Neves, Flávia Macedo; Simas, Joana Noguères; da Costa Vaz, André; Cabral, Regina Elisabeth L; Vendramini, Vanessa; Miraglia, Sandra Maria

    2016-07-01

    The aim of this study was to investigate the protective action of resveratrol against the reproductive damage caused by left-sided experimental varicocele. There was a reduction of testicular major axis in the varicocele group when compared with the other groups; the testicular volume was reduced in varicocele group in comparison to the sham-control and resveratrol groups. The frequency of morphologically abnormal sperm was higher in varicocele and varicocele treated with resveratrol groups than in sham-control and resveratrol groups. The frequency of sperm with 100% of mitochondrial activity and normal acrosome integrity were lower in varicocele group than in varicocele treated with resveratrol, sham-control and resveratrol groups. Sperm motility was also reduced in varicocele group than in other groups. The sperm DNA fragmentation was higher in varicocele group than in other groups. Testicular levels of malondialdehyde were higher in varicocele and varicocele treated with resveratrol groups. The varicocele and varicocele treated with resveratrol groups had a significantly higher frequency of TUNEL-positive cells than sham-control and resveratrol groups; however, immunolabeling of the testes from varicocele treated with resveratrol group showed a lower number of apoptotic germ cells in comparison with the left testis of rats of the varicocele group. Reproductive alterations produced by varicocele from peripuberty were reduced by resveratrol in adulthood. Resveratrol should be better investigated as an adjuvant in the treatment of varicocele. Daily administration of resveratrol to rats with varicocele from peripuberty improves sperm quality in the adulthood.

  7. Electrophysiology of embryonic, adult and aged rat hippocampal neurons in serum-free culture.

    Science.gov (United States)

    Evans, M S; Collings, M A; Brewer, G J

    1998-01-31

    Methods were recently developed for culturing neurons from adult rat hippocampus using the serum-free medium Neurobasal with B27 supplement. To determine whether adult cultured neurons have normal electrical properties, we studied cultures from rats of three age groups: (1) embryonic; (2) 10-11 months old and (3) 35-36 months old. Neurons had a polarized morphology with a large branching apical dendrite and small basal dendrites. Mean resting potentials were similar in the three age groups. All neurons had nonlinear current-voltage relationships, indicating the presence of voltage-sensitive ion channels. Most neurons had a voltage-sensitive inward current followed by a sustained voltage-sensitive outward current. Tetrodotoxin blocked the inward current, which is likely to be a sodium current. The sustained outward current, which is likely to be a potassium current, reversed at -71 mV. Most neurons exhibited anomalous rectification. Calcium currents were present in both embryonic and adult neurons. Embryonic neurons would sometimes fire multiple action potentials but adult neurons fired only single action potentials. Our results indicate that both embryonic and adult cultured neurons retain a clearly neuronal electrophysiological phenotype in Neurobasal/B27 serum-free medium.

  8. Effect of the antioxidant dibunol on adrenocortical, thyroid, and adenohypopyseal function in adult and old rats

    Energy Technology Data Exchange (ETDEWEB)

    Gorban' , E.N.

    1986-04-01

    This paper studies the effect of dibunol (4-methyl-2,6-di-tert-butylphenol) (D) on the function of the adrenal cortex, thyroid gland, and adenhypophysis, which produces trophic hormones for the other two glands. Experiments were carried out on adult rats. After injection of D concentrations of corticosterone (CS), triodothyronine (T/sub 3/), ACTH, and thyrotrophin (TSH) in the blood plasma and the CS concentration in tssue of the adenohypophysis were determined. It is shown that injection of D caused biphasic changes in the CS concentration in both tissues studied in adult and old animals.

  9. Temporal Expression of Mutant LRRK2 in Adult Rats Impairs Dopamine Reuptake

    Directory of Open Access Journals (Sweden)

    Hongxia Zhou, Cao Huang, Jianbin Tong, Weimin C Hong, Yong-Jian Liu, Xu-Gang Xia

    2011-01-01

    Full Text Available Parkinson's disease (PD results from progressive degeneration of dopaminergic neurons. Most PD cases are sporadic, but some have pathogenic mutation in the individual genes. Mutation of the leucine-rich repeat kinase-2 (LRRK2 gene is associated with familial and sporadic PD, as exemplified by G2019S substitution. While constitutive expression of mutant LRRK2 in transgenic mice fails to induce neuron death, transient expression of the disease gene by viral delivery causes a substantial loss of dopaminergic neurons in mice. To further assess LRRK2 pathogenesis, we created inducible transgenic rats expressing human LRRK2 with G2019S substitution. Temporal overexpression of LRRK2G2019S in adult rats impaired dopamine reuptake by dopamine transporter (DAT and thus enhanced locomotor activity, the phenotypes that were not observed in transgenic rats constitutively expressing the gene throughout life time. Reduced DAT binding activity is an early sign of dopaminergic dysfunction in asymptomatic subjects carrying pathogenic mutation in LRRK2. Our transgenic rats recapitulated the initiation process of dopaminergic dysfunction caused by pathogenic mutation in LRRK2. Inducible transgenic approach uncovered phenotypes that may be obscured by developmental compensation in constitutive transgenic rats. Finding in inducible LRRK2 transgenic rats would guide developing effective strategy in transgenic studies: Inducible expression of transgene may induce greater phenotypes than constitutive gene expression, particularly in rodents with short life time.

  10. Effects of cyclophosphamide on the kaolin consumption (pica behavior) in five strains of adult male rats.

    Science.gov (United States)

    Tohei, Atsushi; Kojima, Shu-ichi; Ikeda, Masashi; Hokao, Ryoji; Shinoda, Motoo

    2011-07-01

    It is known that pica, the consumption of non-nutritive substances such as kaolin, can be induced by administration of toxins or emetic agents in rats. In the present study, we examined the effects of intraperitoneal (i.p.) administration of cyclophosphamide on pica behavior and on the concentration of 5-hydroxyindoleacetic acids (5HIAA) in cerebrospinal fluid (CSF) in the following five strains of adult male rats: Sprague Dawley (SD), Wistar, Fischer 344 (F344), Wistar-Imamichi (WI) and Long Evans (LE). Cyclophosphamide (25 mg or 50 mg/kg) was injected (i.p.) into the rats and kaolin and food intake were measured at 24 hr after injection. The animals were anesthetized with urethane (1 g/kg) at 3 hr after injection of cyclophosphamide, and CSF was collected from the cisterna magna. WI and LE rats clearly showed pica behavior as compared with the other strains. In LE rats, the concentration of 5HIAA in CSF also increased in a dose-dependent manner of cyclophosphamide. The pretreatment with ondansetron (5-HT(3) antagonist) restored both changes (kaolin consumption and 5HIAA levels) induced by cyclophosphamide. These results suggest that the LE rat is sensitive to cyclophosphamide, that pica induced by cyclophosphamide mimics many aspects of emesis including the serotonergic response in the central nervous system and that use of the pica model would be a practical method for evaluating the effects of antiemetic drugs in addition to the mechanism of emesis.

  11. Impairment in Spatial Memory in adult Rats following developmental Low Lead Exposure

    Directory of Open Access Journals (Sweden)

    Rajashekar Rao Barkur

    2012-11-01

    Full Text Available The present study was aimed to investigate the effect of environmentally relevant levels of lead exposure during gestational and early postnatal period on hippocampal dependent spatial memory in rats during adulthood. The pregnant rats were allowed to drink either normal water (control group or 0.2% lead acetate solution (Leadtreated group during pregnancy and lactation. Thus rats pups of lead treated group where exposed to lead indirectly through their mothers during this period. At weaning pups of lead treated group were allowed to drink normal water till they attain the adult hood. Blood lead level was estimated on postnatal day 22 and 120. Birth weight and weight gain of the rat pups as they grew were measured at regular intervals. Both the control and lead treated groups of rats were subjected to water maze test on postnatal day 30 and 120. Results showed that lead treatment had no effect on birth weight or weight gain. Blood lead level on postnatal day 22 was significantly high in treated group compared to the control group and it was normalized by end of four months. The rats born to lead treated mothers showed impaired in spatial memory during water maze test both on postnatal day 36 and 126. These data suggests that exposure to environmentally relevant levels of lead during intrauterine and early postnatal period of brain development causes impairment in spatial memory not only during infancy but also lasts till adulthood.

  12. Adolescent social defeat disturbs adult aggression-related impulsivity in wild-type rats.

    Science.gov (United States)

    Coppens, Caroline M; Coolen, Alex; de Boer, Sietse F; Koolhaas, Jaap M

    2014-10-01

    Adolescence is generally considered as a developmental period during which adverse social experiences may have lasting consequences in terms of an increased vulnerability to affective disorders. This study aimed at determining the individual susceptibility to adolescent social stress using a rat model. We used rats of the Wild-type Groningen strain, which are characterized by a broad variation in adult levels of aggression and impulsivity. We hypothesized that experience of social defeat in adolescence results in heightened aggression and impulsivity levels in adulthood. In contrast to our expectation, adolescent social defeat did not lead to a difference in the average adult level of aggression and impulsivity, but the significant correlation between offensive aggression and impulsivity found in control animals was not present in animals defeated during adolescence.

  13. Retrograde Labeling of Adult Rat Retinal Ganglion Cells with the Flurogold

    Institute of Scientific and Technical Information of China (English)

    Wei Huang; Yannian Hui; Miaoli Zhang

    2000-01-01

    Purpose: To study the densities and distribution of retinal ganglion cells(RGC) in adult rat retinae with flurogold(FG) labeling retogradely.Methods: FG was injected to the superior colliculi(SC) and dorsal lateral geniculate nuclei (dLGN) in adult rats and the retinae were examined by fluorescence microscopy at various periods of time.Results: FG-labelled RGC were observed in the retina as early as 3 days after application of FG. The labelled cells gradually increased in density, reached 95% of the maximal number on days 7 and the maximal number on days 30. The density of labelled cells was higher in the posterior pole than in the peripheral area. The fluorescence intensity in labelled cells maintained up to 60 days.Conclusion: The FG retrograde labeling method is reliable and effective for quantity of RGC. Eye Science 2000; 16:29 ~ 33.

  14. Retrograde Labeling of Adult Rat Retinal Ganglion Cells with the Flurogold

    Institute of Scientific and Technical Information of China (English)

    WeiHuang; YannianHui; 等

    2002-01-01

    Purpose:To study the densities and distribution of retinal ganglion cells(RGC) in adult rat retinae with flurogold(FG) labeling retogradely.Methods:FG was injected to the superior colliculid(SC) and dorsal lateral geniculate nuclei(dLGN) in adult rats and the retinae were examined by fluorescence microscopy at various periods of time.Results:FG-labelled RGC were observed in the retina as early as 3 days after application of FG.The labeled cells gradually increased in density,reached 95% of the maximal number on days 7 and the maximal nuber on days 30.The density of labeled cells was higher in the posterior pole than in the peripheral area.The fluorescence intensity in labeled cells maintained up to 60 days.Conclusion:The FG retrograde labeling method is reliable and effective for quantity of RGC.Eye Science 2000;46:29-33.

  15. Immunohistochemical localization of glutamate transporter EAAC1 in the brainstem of adult rat

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fu-xing; LIU Tao; ZHAO Jing-wei; LI Jin-lian; DONG Yu-lin; LI Ji-shuo

    2001-01-01

    Objective: To observe the distribution of EAAC1, a subtype of glutamate transporters, in the brainstem of adult rat. Methods: Immunocytochemical staining with avidin-biotin complex (ABC) method was employed. Results:EAAC1 was widely distributed throughout the brainstem. In many regions, the EAAC1-like immunoreactivity was primarily distributed in the neuropil. Cell body staining was observed in the prepositus hypoglossal nucleus, external cortex of the inferior colliculus, red nucleus, substantia nigra, mesencephalic raphe nuclei, ventral tegmental nucleus, superior olivary complex, nucleus of the trapezoid body, cochlear nucleus, sensory trigeminal complex, Barrington's nucleus,trigeminal motor nucleus, parabrachial nuclei, dorsal nucleus of vagus, hypoglossal nucleus, locus coeruleus, lateral and superior vestibular nuclei, lateral paragigantocellular nucleus and dorsal paragigantocellular nucleus. Conclusion: Glutamate transporter EAAC 1 is widely distributed throughout the brainstem of adult rat, which may play an important role in excitatory activities of the neurons induced by glutamate.

  16. Organotypic explant culture of adult rat retina for in vitro investigations of neurodegeneration, neuroprotection and cell transplantation

    OpenAIRE

    sprotocols

    2015-01-01

    This protocol details a method for isolating retinal tissue from adult rats as an organotypic culture to study neurobiological processes in mature tissue. It combines the efficiency and control common to in vitro techniques with close imitation of the in vivo environment. Eyes from adult rats are enucleated and the neural retina is isolated. Tissue is cut into quarters, yielding eight retinal explants per animal, and cultured at a fluid/air interface on organotypic culture membranes. Explanta...

  17. Toxicity Induced after Subchronic Administration of the Synthetic Food Dye Tartrazine in Adult Rats, Role of Oxidative Stress

    OpenAIRE

    Narges El Golli; Ines Bini-Dhouib; Aicha Jrad; Imene Boudali; Basma Nasri; Nadia Belhadjhmida; Saloua El Fazaa

    2016-01-01

    The present study was conducted to evaluate the toxic potential of tartrazine, a food color, in different tissues in adult rat: blood, liver, kidneys, and spleen. Tartrazine was administered orally at a dose of 300 mg/kg of body weight to adult male Wistar rats during a period of 30 days. Tartrazine treatment led to an increase in platelets count, a reduction in peripheral lymphocytes and in spleen T CD8-lymphocytes. Furthermore, tartrazine increased the activities of hepatocellular enzymes a...

  18. 成年大鼠心肌细胞分离方法的改良%A modified method for isolation of adult rat cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    廖华; 糜涛; 涂志业; 陈莉莉; 郭小梅

    2009-01-01

    背景:目前多采用酶解法分离成年大鼠心肌细胞,但在灌流装置、灌流液体和灌流方法等方面的差异较大,且多以单个细胞的急性分离为目的,仅适于进行电生理研究.目的:建立稳定的改良成年SD大鼠心肌细胞分离方法,使之适于进行原代培养和研究.设计、时间及地点:细胞学体外实验,于2008-03/09在华中科技大学同济医学院附属同济医院分子心脏病中心完成.材料:8~10周龄雄性SD大鼠30只,由同济医学院实验动物中心提供,Ⅱ型胶原酶、蛋白酶和不含脂肪酸的牛血清白蛋白分别为美国Worthington公司、美国Sigma公司和德国Merck公司产品.方法:SD大鼠麻醉后,快速取出心脏,采用改良的Langendorff灌流装置行主动脉逆行灌注,无钙Krebs-Henseleit缓冲液(KH液)非循环灌流4 min,0.6 g/L Worthington 2型胶原酶联合0.03 g/L蛋白酶消化约15 min,剪下心室组织于消化液和10 g/L牛血清白蛋白的混合液中,剪碎后于37℃振摇孵育10min,200 μm尼龙网过滤,500 g离心1 min,梯度复钙,自然沉降.主要观察指标:心肌细胞的形态、活力和产量.结果:复钙后的杆状存活心肌细胞得率为(73±5.6)%(n=30),其中90%以上的杆状心肌无明显搏动,横纹清晰.每只大鼠心脏的平均存活心肌细胞产量为(4.2±0.4)×106.结论:经过改良的Langendorff逆行主动脉灌流酶解法分离成年大鼠心肌细胞,可稳定获得高比例的存活心肌细胞并用于原代培养和细胞,分子生物学研究.

  19. Differentiation of endogenous neural precursors following spinal cord injury in adult rats

    Institute of Scientific and Technical Information of China (English)

    Bin Zhao; Hua Han; Shuanke Wang; Bingren Gao; Zhengyi Sun

    2008-01-01

    BACKGROUND:Studies have shown that cell death can activate proliferation of endogenous neural stem cells and promote newly generated cells to migrate to a lesion site.OBJECTIVE:To observe regeneration and differentiation of neural cells following spinal cord injury in adult rats and to quantitatively analyze the newly differentiated cells.DESIGN,TIME AND SETTING:A cell biology experiment was performed at the Institute of Orthopedics and Medical Experimental Center,Lanzhou University.between August 2005 and October 2007.MATERIALS:Fifty adult,Wistar rats of both sexes;5-bromodeoxyuridine(BrdU,Sigma,USA);antibodies against neuron-specific enolase,glial fibrillary acidic protein,and myelin basic protein(Chemicon,USA).METHODS:Twenty-five rats were assigned to the spinal cord injury group and received a spinal cord contusion injury.Materials were obtained at day 1,3,7,15,and 29 after injury,with 5 rats for each time point.Twenty-five rats were sham-treated by removing the lamina of the vertebral arch without performing a contusion.MAIN OUTCOME MEASURES:The phenotype of BrdU-labeled cells,i.e.,expression and distribution of surface markers for neurons(neuron-specific enolase),astrocytes(glial fibrillary acidic protein),and oligodendrocytes(myelin basic protein),were identified with immunofluorescence double-labeling.Confocal microscopy was used to detect double-labeled cells by immunofluorescence.Quantitative analysis of newly generated cells was performed with stereological counting methods.RESULTS:There was significant cell production and differentiation after adult rat spinal cord injury.The quantity of newly-generated BrdU-labeled cells in the spinal cord lesion was 75-fold greater than in the corresponding area of control animals.Endogenous neural precursor cells differentiated into astrocytes and oligodendrocytes,however spontaneous neuronal difierentiation was not detected.Between 7 and 29 d after spinal cord injury,newly generated cells expressed increasingly more

  20. Neurones in the adult rat anterior medullary velum.

    Science.gov (United States)

    Ibrahim, M; Menoud, P A; Celio, M R

    2000-03-27

    The presence of neurones in the rat anterior medullary velum (AMV) has been investigated by using antibodies to the calcium-binding proteins, parvalbumin (PV), calretinin (CR), and calbindin-D28k (CB). Disparate populations of mainly GABAergic neurones were located in the rostral and caudal regions of the AMV. The rostral region of the AMV was characterised by GABAergic CR-labelled or PV-labelled neurones. CR-labelled neurones were bipolar or multipolar with round to ovoid somata (diameters between 8 and 12 microm), and rostrocaudally running dendrites forming a network. PV-labelled neurones had round somata (diameters between 6 and 10 microm) and were bi-tufted, with beaded dendrites. Both CR-labelled and PV-labelled dendrites formed punctate pericellular associations with unlabelled somatic profiles. In the caudal region of the AMV, PV-labelled neurones were GABAergic, multipolar cells, having round somata (diameters between 9 and 12 microm), with either beaded or nonbeaded dendrites forming a network of interconnecting dendrites. PV-labelled pericellular associations were made around both PV-labelled and unlabelled somatic profiles. CR labelled unipolar brush cells (UBCs) were not GABAergic. UBCs were characterised by a round to oval somata (10-15 microm in diameter) from which a single primary dendrite emerged to form a distal expansion having small terminal dendrites. From the distal expansion, there also appeared to be CR-labelled processes emanating and extending for up to 250 microm. CB occasionally labelled "Purkinje-like cells" (PLCs). The rat AMV is a more complex structure than first envisaged with the presence of predominantly inhibitory neurones expressing different calcium-binding proteins. Functional and anatomic aspects of this circuitry are further discussed.

  1. Effect of Camphor on Pituitary-Gonadal Hormonal Axis and Oogenesis in Adult Female Rats

    OpenAIRE

    Habibollah Johari; Amir Ashkan Mahjoor; Siyamak Fallahi; Hossein Kargar Jahromi; Maryam Abedini; Mohammad Ali Poor Danesh; Zahra Zamani

    2013-01-01

    Background & Objective: Camphor stimulates the nervous system and the circulatory system, reduces lactation, and prevents conception and embryo embedding. We investigated the effects of camphor on the pituitary-gonadal hormonal axis and concentration of steroidal hormones.   Materials & Methods: The parameters investigated were concentrations of LH, FSH, estrogen, progesterone, and testosterone. Forty adult female rats at a mean weight of 180 ± 20 grams were divided into five groups. Camphor ...

  2. Selection of medium for serum-free primary culture of adult rat hepatocytes.

    Directory of Open Access Journals (Sweden)

    Miyazaki,Masahiro

    1990-02-01

    Full Text Available To select a suitable medium for serum-free primary culture of adult rat hepatocytes, ten commercially-available synthetic media were compared for their ability to maintain the cells under serum-free and serum-supplemented conditions with special reference to attachment, survival and albumin secretion. It was found that Williams' medium E and DM-160 medium were the best among the ten media for maintaining hepatocytes under serum-free conditions in primary culture.

  3. Use of the light/dark test for anxiety in adult and adolescent male rats.

    Science.gov (United States)

    Arrant, Andrew E; Schramm-Sapyta, Nicole L; Kuhn, Cynthia M

    2013-11-01

    The light/dark (LD) test is a commonly used rodent test of unconditioned anxiety-like behavior that is based on an approach/avoidance conflict between the drive to explore novel areas and an aversion to brightly lit, open spaces. We used the LD test to investigate developmental differences in behavior between adolescent (postnatal day (PN) 28-34) and adult (PN67-74) male rats. We investigated whether LD behavioral measures reflect anxiety-like behavior similarly in each age group using factor analysis and multiple regression. These analyses showed that time in the light compartment, percent distance in the light, rearing, and latency to emerge into the light compartment were measures of anxiety-like behavior in each age group, while total distance traveled and distance in the dark compartment provided indices of locomotor activity. We then used these measures to assess developmental differences in baseline LD behavior and the response to anxiogenic drugs. Adolescent rats emerged into the light compartment more quickly than adults and made fewer pokes into the light compartment. These age differences could reflect greater risk taking and less risk assessment in adolescent rats than adults. Adolescent rats were less sensitive than adults to the anxiogenic effects of the benzodiazepine inverse agonist N-methyl-β-carboline-3-carboxamide (FG-7142) and the α₂ adrenergic antagonist yohimbine on anxiety-like behaviors validated by factor analysis, but locomotor variables were similarly affected. These data support the results of the factor analysis and indicate that GABAergic and noradrenergic modulation of LD anxiety-like behavior may be immature during adolescence.

  4. Methylmercury chloride damage to the adult rat hippocampus cannot be detected by proton magnetic resonance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Zhiyan Lu; Jinwei Wu; Guangyuan Cheng; Jianying Tian; Zeqing Lu; Yongyi Bi

    2014-01-01

    Previous studies have found that methylmercury can damage hippocampal neurons and accord-ingly cause cognitive dysfunction. However, a non-invasive, safe and accurate detection method for detecting hippocampal injury has yet to be developed. This study aimed to detect methylmer-cury-induced damage on hippocampal tissue using proton magnetic resonance spectroscopy. Rats were given a subcutaneous injection of 4 and 2 mg/kg methylmercury into the neck for 50 consecutive days. Water maze and pathology tests confirmed that cognitive function had been impaired and that the ultrastructure of hippocampal tissue was altered after injection. The results of proton magnetic resonance spectroscopy revealed that the nitrogen-acetyl aspartate/creatine, choline complex/creatine and myoinositol/creatine ratio in rat hippocampal tissue were unchanged. Therefore, proton magnetic resonance spectroscopy can not be used to determine structural damage in the adult rat hippocampus caused by methylmercury chloride.

  5. Localization of Sonic hedgehog secreting and receiving cells in the developing and adult rat adrenal cortex.

    Science.gov (United States)

    Guasti, Leonardo; Paul, Alex; Laufer, Ed; King, Peter

    2011-04-10

    Sonic hedgehog signaling was recently demonstrated to play an important role in murine adrenal cortex development. The organization of the rat adrenal differs from that of the mouse, with the zona glomerulosa and zona fasciculata separated by an undifferentiated zone in the rat, but not in the mouse. In the present study we aimed to determine the mRNA expression patterns of Sonic hedgehog and the hedgehog signaling pathway components Patched-1 and Gli1 in the developing and adult rat adrenal. Sonic hedgehog expression was detected at the periphery of the cortex in cells lacking CYP11B1 and CYP11B2 expression, while signal-receiving cells were localized in the overlying capsule mesenchyme. Using combined in situ hybridization and immunohistochemistry we found that the cells expressing Sonic hedgehog lie between the CYP11B2 and CYP11B1 layers, and thus Sonic hedgehog expression defines one cell population of the undifferentiated zone.

  6. Low-intensity treadmill exercise and/or bright light promote neurogenesis in adult rat brain

    Institute of Scientific and Technical Information of China (English)

    Sung Jin Kwon; Jeongsook Park; So Yun Park; Kwang Seop Song; Sun Tae Jung; So Bong Jung; Ik Ryeul Park; Wan Sung Choi; Sun Ok Kwon

    2013-01-01

    The hippocampus is a brain region responsible for learning and memory functions. The purpose of this study was to investigate the effects of low-intensity exercise and bright light exposure on neurogenesis and brain-derived neurotrophic factor expression in adult rat hippocampus. Male Sprague-Dawley rats were randomly assigned to control, exercise, light, or exercise + light groups (n = 9 per group). The rats in the exercise group were subjected to treadmill exercise (5 days per week, 30 minutes per day, over a 4-week period), the light group rats were irradiated (5 days per week, 30 minutes per day, 10 000 lx, over a 4-week period), the exercise + light group rats were subjected to treadmill exercise in combination with bright light exposure, and the control group rats remained sedentary over a 4-week period. Compared with the control group, there was a significant increase in neurogenesis in the hippocampal dentate gyrus of rats in the exercise, light, and exercise + light groups. Moreover, the expression level of brain-derived neurotrophic factor in the rat hippocampal dentate gyrus was significantly higher in the exercise group and light group than that in the control group. Interestingly, there was no significant difference in brain-derived neurotrophic factor expression between the control group and exercise + light group. These results indicate that low-intensity treadmill exercise (first 5 minutes at a speed of 2 m/min, second 5 minutes at a speed of 5 m/min, and the last 20 minutes at a speed of 8 m/min) or bright-light exposure therapy induces positive biochemical changes in the brain. In view of these findings, we propose that moderate exercise or exposure to sunlight during childhood can be beneficial for neural development.

  7. Qualitative and quantitative analysis of bones in adult rats by repeated intraperitoneal administration of paclitaxel (taxol) using radioisotope EDXRF technique

    Energy Technology Data Exchange (ETDEWEB)

    Oezdemir, Y. E-mail: yozdemir25@yahoo.com; Iyiguen, Ibrahim; Durak, Ridvan

    2003-05-15

    Energy dispersive X-ray fluorescence analysis of right back leg bone samples taken from adult female rats administered paclitaxel (taxol) was carried out using standard addition method. Because qualitative and quantitative data analysis of rat bone samples is not found in the literature, comparison was not made with other experimental results. Our experimental results are presented and discussed in this study.

  8. Methods to evaluate functional nerve recovery in adult rats : walking track analysis, video analysis and the withdrawal reflex

    NARCIS (Netherlands)

    Dijkstra, [No Value; Meek, MF; Robinson, PH; Gramsbergen, A

    2000-01-01

    The aim of this study was to compare different methods for the evaluation of functional nerve recovery. Three groups of adult male Wistar rats were studied. In group A, a 12-mm gap between nerve ends was bridged by an autologous nerve graft; in rats of group B we performed a crush lesion of the scia

  9. A method for unit recording in the lumbar spinal cord during locomotion of the conscious adult rat

    DEFF Research Database (Denmark)

    Berg, Rune W; Chen, Ming-Teh; Huang, Hsueh-Chen;

    2009-01-01

    Extracellular recordings from single units in the brain, for example the neocortex, have proven feasible in moving, awake rats, but have not yet been possible in the spinal cord. Single-unit activity during locomotor-like activity in reduced preparations from adult cats and rats have provided...

  10. Identification and characterization of calcium sparks in cardiomyocytes derived from human induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Guang Qin Zhang

    Full Text Available INTRODUCTION: Ca2+ spark constitutes the elementary units of cardiac excitation-contraction (E-C coupling in mature cardiomyocytes. Human induced pluripotent stem cell (hiPSC-derived cardiomyocytes are known to have electrophysiological properties similar to mature adult cardiomyocytes. However, it is unclear if they share similar calcium handling property. We hypothesized that Ca2+ sparks in human induced pluripotent stem cell (hiPSCs-derived cardiomyocytes (hiPSC-CMs may display unique structural and functional properties than mature adult cardiomyocytes. METHODS AND RESULTS: Ca2+ sparks in hiPSC-CMs were recorded with Ca2+ imaging assay with confocal laser scanning microscopy. Those sparks were stochastic with a tendency of repetitive occurrence at the same site. Nevertheless, the spatial-temporal properties of Ca2+ spark were analogous to that of adult CMs. Inhibition of L-type Ca2+ channels by nifedipine caused a 61% reduction in calcium spark frequency without affecting amplitude of those sparks and magnitude of caffeine releasable sarcoplasmic reticulum (SR Ca2+ content. In contrast, high extracellular Ca2+ and ryanodine increased the frequency, full width at half maximum (FWHM and full duration at half maximum (FDHM of spontaneous Ca2+ sparks. CONCLUSIONS: For the first time, spontaneous Ca2+ sparks were detected in hiPSC-CMs. The Ca2+ sparks are predominately triggered by L-type Ca2+ channels mediated Ca2+ influx, which is comparable to sparks detected in adult ventricular myocytes in which cardiac E-C coupling was governed by a Ca2+-induced Ca2+ release (CICR mechanism. However, focal repetitive sparks originated from the same intracellular organelle could reflect an immature status of the hiPSC-CMs.

  11. Behavioral Differences Between Late Preweanling and Adult Female Sprague-Dawley Rat Exploration of Animate and Inanimate Stimuli and Food

    OpenAIRE

    Smith, Kiersten S.; Morrell, Joan I.

    2010-01-01

    The late preweanling rat has potential as a preclinical model for disorders initially manifested in early childhood that are characterized by dysfunctional interactions with specific stimuli (e.g., obsessive-compulsive disorder and autism). No reports, however, of specific-stimulus exploration in the late preweanling rat are found in the literature. We examined the behavioral responses of normal late preweanling (PND 18-19) and adult rats when presented with exemplars of categorically-varied ...

  12. Cardiac and plasma lipid profiles in response to acute hypoxia in neonatal and young adult rats

    Directory of Open Access Journals (Sweden)

    Raff Hershel

    2010-01-01

    Full Text Available Abstract Background The physiological and biochemical responses to acute hypoxia have not been fully characterized in neonates. Fatty acids and lipids play an important role in most aspects of cardiac function. Methods We performed comprehensive lipid profiling analysis to survey the changes that occur in heart tissue and plasma of neonatal and young adult rats exposed to hypoxia for 2 h, and following 2 h of recovery from hypoxia. Results Cardiac and plasma concentrations of short-chain acylcarnitines, and most plasma long-chain fatty acids, were decreased in hypoxic neonates. Following recovery from hypoxia, concentrations of propionylcarnitine, palmitoylcarnitine, stearoylcarnitine were increased in neonatal hearts, while oleylcarnitine and linoleylcarnitine concentrations were increased in neonatal plasma. The concentrations of long-chain fatty acids and long-chain acylcarnitines were increased in the hearts and plasma of hypoxic young adult rats; these metabolites returned to baseline values following recovery from hypoxia. Conclusion There are differential effects of acute hypoxia on cardiac and plasma lipid profiles with maturation from the neonate to the young adult rat. Changes to neonatal cardiac and plasma lipid profiles during hypoxia likely allowed for greater metabolic and physiologic flexibility and increased chances for survival. Persistent alterations in the neonatal cardiac lipid profile following recovery from hypoxia may play a role in the development of rhythm disturbances.

  13. Effects of estradiol and methoxychlor on Leydig cell regeneration in the adult rat testis.

    Science.gov (United States)

    Chen, Bingbing; Chen, Dongxin; Jiang, Zheli; Li, Jingyang; Liu, Shiwen; Dong, Yaoyao; Yao, Wenwen; Akingbemi, Benson; Ge, Renshan; Li, Xiaokun

    2014-05-06

    The objective of the present study is to determine whether methoxychlor (MXC) exposure in adulthood affects rat Leydig cell regeneration and to compare its effects with estradiol (E2). Adult 90-day-old male Sprague-Dawley rats received ethane dimethane sulfonate (EDS) to eliminate the adult Leydig cell population. Subsequently, rats were randomly assigned to four groups and gavaged with corn oil (control), 0.25 mg/kg E2 and 10 or 100 mg/kg MXC daily from days 5 to 30 post-EDS treatment. The results showed that MXC and E2 reduced serum testosterone levels on day 58 post-EDS treatment. qPCR showed Hsd17b3 mRNA levels were downregulated 7-15 fold by E2 and MXC, indicating that development of the new population of Leydig cells was arrested at the earlier stage. This observation was supported by the results of histochemical staining, which demonstrated that Leydig cells in MXC-treated testis on day 58 post-EDS treatment were mostly progenitor Leydig cells. However, Pdgfb mRNA levels were downregulated, while Lif transcript levels were increased by MXC. In contrast, E2 did not affect gene expression for these growth factors. In conclusion, our findings indicated that both MXC and E2 delayed rat Leydig cell regeneration in the EDS-treated model, presumably acting by different mechanisms.

  14. Effects of Estradiol and Methoxychlor on Leydig Cell Regeneration in the Adult Rat Testis

    Directory of Open Access Journals (Sweden)

    Bingbing Chen

    2014-05-01

    Full Text Available The objective of the present study is to determine whether methoxychlor (MXC exposure in adulthood affects rat Leydig cell regeneration and to compare its effects with estradiol (E2. Adult 90-day-old male Sprague-Dawley rats received ethane dimethane sulfonate (EDS to eliminate the adult Leydig cell population. Subsequently, rats were randomly assigned to four groups and gavaged with corn oil (control, 0.25 mg/kg E2 and 10 or 100 mg/kg MXC daily from days 5 to 30 post-EDS treatment. The results showed that MXC and E2 reduced serum testosterone levels on day 58 post-EDS treatment. qPCR showed Hsd17b3 mRNA levels were downregulated 7–15 fold by E2 and MXC, indicating that development of the new population of Leydig cells was arrested at the earlier stage. This observation was supported by the results of histochemical staining, which demonstrated that Leydig cells in MXC-treated testis on day 58 post-EDS treatment were mostly progenitor Leydig cells. However, Pdgfb mRNA levels were downregulated, while Lif transcript levels were increased by MXC. In contrast, E2 did not affect gene expression for these growth factors. In conclusion, our findings indicated that both MXC and E2 delayed rat Leydig cell regeneration in the EDS-treated model, presumably acting by different mechanisms.

  15. Imipramine reverses alterations in cytokines and BDNF levels induced by maternal deprivation in adult rats.

    Science.gov (United States)

    Réus, Gislaine Z; Dos Santos, Maria Augusta B; Abelaira, Helena M; Ribeiro, Karine F; Petronilho, Fabrícia; Vuolo, Francieli; Colpo, Gabriela D; Pfaffenseller, Bianca; Kapczinski, Flávio; Dal-Pizzol, Felipe; Quevedo, João

    2013-04-01

    A growing body of evidence is pointing toward an association between immune molecules, as well brain-derived neurotrophic factor (BDNF) and the depression. The present study was aimed to evaluate the behavioral and molecular effects of the antidepressant imipramine in maternally deprived adult rats. To this aim, maternally deprived and non-deprived (control group) male rats were treated with imipramine (30mg/kg) once a day for 14 days during their adult phase. Their behavior was then assessed using the forced swimming test. In addition to this, IL-10, TNF-α and IL-1β cytokines were assessed in the serum and cerebrospinal fluid (CSF). In addition, BDNF protein levels were assessed in the prefrontal cortex, hippocampus and amygdala. In deprived rats treated with saline was observed an increase on immobility time, compared with non-deprived rats treated with imipramine (pimipramine treatment reversed the effects of maternal deprivation on BDNF and cytokines levels (pimipramine, it is suggested that classic antidepressants could exert their effects by modulating the immune system.

  16. Repeated-dose liver micronucleus test of 4,4'-methylenedianiline using young adult rats.

    Science.gov (United States)

    Sanada, Hisakazu; Koyama, Naomi; Wako, Yumi; Kawasako, Kazufumi; Hamada, Shuichi

    2015-03-01

    Liver micronucleus (MN) tests using partial hepatectomized rats or juvenile rats have been shown to be useful for the detection of hepatic carcinogens. Moreover, Narumi et al. established the repeated-dose liver MN test using young adult rats for integration into general toxicity. In the present study, in order to examine the usefulness of the repeated-dose liver MN test, we investigated MN induction with a 14 or 28 day treatment protocol using young adult rats treated with 4,4′-methylenedianiline (MDA), a known hepatic carcinogen. MDA dose-dependently induced micronuclei in hepatocytes in 14- and 28-day repeated-dose tests. However, although statistically significant increases in micronuclei were observed in bone marrow cells at two dose levels in the 14-day study, there was no dose response and no increases in micronuclei in the 28-day study. These results indicate that the evaluation of genotoxic effects using hepatocytes is effective in cases where chromosomal aberrations are not clearly detectable in bone marrow cells. Moreover, the repeated-dose liver MN test allows evaluation at a dose below the maximum tolerable dose, which is required for the conventional MN test because micronucleated hepatocytes accumulate. The repeated-dose liver MN test employed in the present study can be integrated into the spectrum of general toxicity tests without further procedural modifications.

  17. Neonatal Maternal Separation Augments Carotid Body Response to Hypoxia in Adult Males but Not Female Rats

    Science.gov (United States)

    Soliz, Jorge; Tam, Rose; Kinkead, Richard

    2016-01-01

    Perinatal exposure to adverse experiences disrupts brain development, including the brainstem network that regulates breathing. At adulthood, rats previously subjected to stress (in the form of neonatal maternal separation; NMS) display features reported in patients suffering from sleep disordered breathing, including an increased hypoxic ventilatory response and hypertension. This effect is also sex-specific (males only). Based on these observations, we hypothesized that NMS augments the carotid body's O2-chemosensitivity. Using an isolated and perfused ex vivo carotid body preparation from adult rats we compared carotid sinus nerve (CSN) responses to hypoxia and hypercapnia in carotid bodies harvested from adult rats that either experienced control conditions (no experimental manipulation) or were subjected to NMS (3 h/day from postnatal days 3 to 12). In males, the CSN response to hypoxia measured in preparations from NMS males was 1.5 fold higher than controls. In control rats, the female's response was similar to that of males; however, the increase in CSN activity measured in NMS females was 3.0 times lower than controls. The CSN response to hypercapnia was not influenced by stress or sex. We conclude that NMS is sufficient to have persistent and sex-specific effects on the carotid body's response to hypoxia. Because NMS also has sex-specific effects on the neuroendocrine response to stress, we propose that carotid body function is influenced by stress hormones. This, in turn, leads to a predisposition toward cardio-respiratory disorders. PMID:27729873

  18. Basic fibroblast growth factor protects against excitotoxicity and chemical hypoxia in both neonatal and adult rats.

    Science.gov (United States)

    Kirschner, P B; Henshaw, R; Weise, J; Trubetskoy, V; Finklestein, S; Schulz, J B; Beal, M F

    1995-07-01

    Basic fibroblast growth factor (bFGF) is a polypeptide growth factor that promotes neuronal survival. We recently found that systemic administration of bFGF protects against both excitotoxicity and hypoxia-ischemia in neonatal animals. In the present study, we examined whether systemically administered bFGF could prevent neuronal death induced by intrastriatal injection of N-methyl-D-aspartate (NMDA) or chemical hypoxia induced by intrastriatal injection of malonate in adult rats and 1-methyl-4-phenylpyridinium (MPP+) in neonatal rats. Systemic administration of bFGF (100 micrograms/kg) for three doses both before and after intrastriatal injection of either NMDA or malonate in adult rats produced a significant neuroprotective effect. In neonatal rats, bFGF produced dose-dependent significant neuroprotective effects against MPP+ neurotoxicity, with a maximal protection of approximately 50% seen with either a single dose of bFGF of 300 micrograms/kg or three doses of 100 micrograms/kg. These results show that systemic administration of bFGF is effective in preventing neuronal injury under circumstances in which the blood-brain barrier may be compromised, raising the possibility that this strategy could be effective in stroke.

  19. R59022调节心肌细胞自噬促进ET-1诱导的乳鼠心肌细胞肥大%R59022 promotes ET-1-induced cardiac hypertrophy in neonatal rat cardiomyocytes via regulating autophagy

    Institute of Scientific and Technical Information of China (English)

    柳玉梅; 尹园; 张贵平; 张海宁

    2016-01-01

    Aim To investigate the effects of DGK in-hibitor R59022 on ET-1-induced myocardial hypertro-phy and autophagy, and explore the possible mecha-nisms. Methods Myocardial hypertrophy was in-duced by ET-1 in cultured rat neonatal cardiomyo-cytes. Western blot was used to detect the expression of microtubule-associate protein 1 light chain 3 ( LC3 ) , beclin-1, p62, p-Akt and Akt. mRNA expression of brain natriuretic peptide ( BNP) and beta mysion heav-y chain (β-MHC) and the cell size of cardiomyocytes were detected by RT-PCR and immunofluorescence, respectively. Results Treatment cardiomyocytes with ET-1(10 -7 mol·L-1 ) for 24 h induced the myocardi-al hypertrophy in cultured neonatal rat cardiomyocytes with the activation of autophagy as evidenced by the in-creased expression of autophagy-related proteins LC3-II/I and beclin-1 , as well as the increased p62 degra-dation. While, myocardial hypertrophy induced by ET-1 , including the increased myocardial cell size and the mRNA expression of fetal gene BNP and β-MHC, could be reversed by autophagy inhibitor 3-methyl ade-nine (3-MA) and chloroquine ( CQ) ,but promoted by autophagy agonist rapamycin ( RAPA ) . Pretreatment cardiomyocytes with R59022, an inhibitor of DGK, en-hanced ET-1-induced myocardial hypertrophy by en-hancing autophagy in cardiomyocytes. Furthermore,ET-1 treatment inhibited the activation of Akt by the down-regulation of the Akt phosphorylation, and R59022 en-hanced the effect of ET-1 on the activation of Akt. Conclusions Enhanced autophagy contributes to car-diomyocyte hypertrophy. R59022 deteriorate ET-1-in-duced myocardial hypertrophy by activating autophagy. The possible mechanism may be related to the inhibi-tion of activation of mTOR signaling pathway by inhibi-ting the activation of Akt.%目的:研究甘油二酯激酶( DGK)的抑制剂R59022对心肌细胞自噬及内皮素1(ET-1)诱导的心肌肥大的影响,并探讨其可能机制。方法原代培养乳鼠心肌细胞, ET-1诱导

  20. 西洋参茎叶总皂苷通过抑制过度内质网应激减轻大鼠心肌细胞缺氧/复氧损伤%Panax quinquefolium saponin attenuates hypoxia/reoxygenation injury in rat cardiomyocytes by inhibiting excessive endoplasmic reticulum stress

    Institute of Scientific and Technical Information of China (English)

    王琛; 李玉珍; 王晓礽; 吕振嵘; 史大卓; 刘秀华

    2012-01-01

    目的:观察西洋参茎叶总皂苷 (PQS) 对缺氧/复氧 (H/R) 心肌细胞的保护作用,并从内质网应激 (ERS)的角度探讨其分子机制.方法:建立心肌细胞缺氧/复氧 (H/R) 损伤模型,以台盼蓝染色法、乳酸脱氢酶活性以及流式细胞术检测细胞损伤及凋亡情况;以RT-PCR和Western blotting方法,检测ERS标志分子葡萄糖调节蛋白78 (GRP78)、钙网蛋白 (CRT)、C/EBP同源蛋白 (CHOP)、caspase-12及凋亡相关蛋白Bcl-2、Bax的表达.结果:和H/R组心肌细胞相比,PQS+H/R组:(1) 细胞凋亡率降低4.19% (P<0.05),存活率升高21.2% (P<0.05),LDH活性降低66.58% (P<0.05);(2) Bcl-2 mRNA和蛋白表达分别升高30.9%和48.0% (P<0.05),Bax mRNA和蛋白表达分别降低39.7%和48.4% (P<0.05);(3) GRP78 mRNA和蛋白表达分别降低61.6%和37.7% (P<0.05),CRT mRNA和蛋白表达分别降低35.7%和52.2% (P<0.05); CHOP mRNA和蛋白表达分别降低57.0%和51.7% (P<0.05);剪切后的caspase-12蛋白表达降低34.9% (P<0.05).结论:PQS可减轻H/R诱导的心肌细胞损伤,其机制是降低H/R诱导的GRP78、CRT mRNA和蛋白表达,抑制CHOP、caspase-12等内质网凋亡通路激活,从而抑制过度ERS介导的细胞凋亡.%AIM:To investigate the effect of Panax quinquefolium saponin ( PQS ) on hypoxia/reoxygenation injury and excessive endoplasmic reticulum stress ( ERS) in rat cardiomyocytes. METHODS:Cultured cardiomyocytes of neonatal Sprague - Dawley rats were used to establish hypoxia/reoxygenation ( H/R ) model. The cardioprotective effects of PQS were observed. The morphological changes, the activity of lactate dehydrogenase ( LDH ) and cell apoptosis were assessed. The mRNA and protein expression levels of glucose - regulated protein 78 ( GRP78 ), calreticulin ( CRT ), C/EBP homologous protein ( CHOP ), caspase - 12 and apoptosis - associated protein Bax and Bcl - 2 were determined by RT - PCR and Western blotting. RESULTS: Compared with H/R cardiomyocytes, PQS decreased the

  1. Histological effects of oral administration of nutmeg on the kidneys of adult Wister rats

    Directory of Open Access Journals (Sweden)

    Andrew Osayame Eweka

    2010-01-01

    Full Text Available Aims: The effects of oral administration of nutmeg commonly used as spice in various dishes, as components of teas and soft drinks or mixed in milk and alcohol on the kidneys of adult Wistar rats were carefully studied. Material and Methods: Rats of both sexes (n = 24, with average weight of 220g were randomly assigned into two treatments (A & B of (n=16 and Control (c (n=8 groups. The rats in the treatment groups (A & B received 0.1g (500mg/kg body weight and 0.2g (1000mg/kg body weight of nutmeg thoroughly mixed with the feeds respectively on a daily basis for forty-two days. The control group (c received equal amount of feeds daily without nutmeg added for forty-two days. The growers′ mash feeds was obtained from Edo Feeds and Flour Mill Limited, Ewu, Edo state, Nigeria and the rats were given water liberally. The rats were sacrificed by cervical dislocation on the forty-third day of the experiment. The kidneys were carefully dissected out and quickly fixed in 10% buffered formaldehyde for routine histological study after hematoxylin and eosin method. Result: The histological findings in the treated sections of the kidneys showed distortion of the renal cortical structures, vacuolations appearing in the stroma and some degree of cellular necrosis, with degenerative and atrophic changes when compared to the control group. Conclusion: These findings indicate that oral administration of nutmeg may have some deleterious effects on the kidneys of adult Wistar rats at higher doses and by extension may affect its excretory and other metabolic functions. It is recommended that caution should therefore be advocated in the intake of this product and further studies be carried out to examine these findings.

  2. Histological effects of oral administration of nutmeg on the kidneys of adult Wister rats

    Directory of Open Access Journals (Sweden)

    Andrew Osayame Eweka

    2010-04-01

    Full Text Available Aims: The effects of oral administration of nutmeg commonly used as spice in various dishes, as components of teas and soft drinks or mixed in milk and alcohol on the kidneys of adult Wistar rats were carefully studied. Material and Methods: Rats of both sexes (n = 24, with average weight of 220g were randomly assigned into two treatments (A & B of (n=16 and Control (c (n=8 groups. The rats in the treatment groups (A & B received 0.1g (500mg/kg body weight and 0.2g (1000mg/kg body weight of nutmeg thoroughly mixed with the feeds respectively on a daily basis for forty-two days. The control group (c received equal amount of feeds daily without nutmeg added for forty-two days. The growers’ mash feeds was obtained from Edo Feeds and Flour Mill Limited, Ewu, Edo state, Nigeria and the rats were given water liberally. The rats were sacrificed by cervical dislocation on the forty-third day of the experiment. The kidneys were carefully dissected out and quickly fixed in 10% buffered formaldehyde for routine histological study after hematoxylin and eosin method. Result: The histological findings in the treated sections of the kidneys showed distortion of the renal cortical structures, vacuolations appearing in the stroma and some degree of cellular necrosis, with degenerative and atrophic changes when compared to the control group. Conclusion: These findings indicate that oral administration of nutmeg may have some deleterious effects on the kidneys of adult Wistar rats at higher doses and by extension may affect its excretory and other metabolic functions. It is recommended that caution should therefore be advocated in the intake of this product and further studies be carried out to examine these findings.

  3. Avaliação ecocardiográfica evolutiva do infarto do miocárdio em ratos jovens e adultos Echocardiographic assessment of myocardial infarction evolution in young and adult rats

    Directory of Open Access Journals (Sweden)

    Francisco Cesar Pabis

    2008-11-01

    Full Text Available FUNDAMENTO: A regeneração dos cardiomiócitos após o infarto do miocárdio (IM é mais evidente em animais jovens; entretanto, não se sabe se é acompanhada de melhora funcional. OBJETIVO: Realizar a análise funcional pela ecocardiografia (eco de ratos jovens e adultos submetidos a IM. MÉTODOS: Setenta e dois animais foram incluídos no estudo: 35 ratos jovens (grupo J com 28 dias, e 37 ratos adultos (grupo A com 153 dias. Os ratos foram subdivididos em dois subgrupos: infartado (JI e AI e controle (JC e AC. Os animais foram avaliados por meio de ecocardiograma no 7º e 30º dias de pós-operatório para análise da fração de ejeção (FE e dos volumes sistólico (VSF e diastólico (VDF finais do ventrículo esquerdo. Foram incluídos no grupo de estudo somente animais com FE menor que 40%. RESULTADOS: Na comparação dos VDF e VSF entre infartados e controles, observou-se aumento significativo nos animais adultos infartados nas duas fases analisadas. Nos animais jovens, apenas o VSF, no 7º dia, foi significativamente maior. Na evolução intragrupo, observou-se aumento do VDF e do VSF nos dois subgrupos jovens, proporcional ao crescimento, e somente aumento do VDF no grupo adulto infartado. Houve melhora da FE nos ratos jovens, enquanto nos ratos adultos a FE permaneceu diminuída em relação aos controles. CONCLUSÃO: Os ratos jovens infartados apresentaram melhora da função sistólica e dos volumes ventriculares após 30 dias do infarto, enquanto nos ratos adultos houve aumento do VDF sem melhora da função sistólica.BACKGROUND: The regeneration of cardiomyocytes after a myocardial infarction (MI is more evident in young animals; however, it is not known whether it is associated with functional improvement. OBJECTIVE: To perform the functional analysis by echocardiography (echo of young adult rats submitted to MI. METHODS: Seventy-two animals were included in the study: 35 young rats (group Y that were 28 days old and 37 adult

  4. Caffeine in the neonatal period induces long-lasting changes in sleep and breathing in adult rats.

    Science.gov (United States)

    Montandon, Gaspard; Horner, Richard L; Kinkead, Richard; Bairam, Aida

    2009-11-15

    Caffeine is commonly used clinically to treat apnoeas and unstable breathing associated with premature birth. Caffeine antagonizes adenosine receptors and acts as an efficient respiratory stimulant in neonates. Owing to its persistent effects on adenosine receptor expression in the brain, neonatal caffeine administration also has significant effects on maturation of the respiratory control system. However, since adenosine receptors are critically involved in sleep regulation, and sleep also modulates breathing, we tested the hypothesis that neonatal caffeine treatment disrupts regulation of sleep and breathing in the adult rat. Neonatal caffeine treatment (15 mg kg(-1) day(-1)) was administered from postnatal days 3-12. At adulthood (8-10 weeks old), sleep and breathing were measured with a telemetry system and whole-body plethysmography respectively. In adult rats treated with caffeine during the neonatal period, sleep time was reduced, sleep onset latency was increased, and non-rapid eye movement (non-REM) sleep was fragmented compared to controls. Ventilation at rest was higher in caffeine-treated adult rats compared to controls across sleep/wake states. Hypercapnic ventilatory responses were significantly reduced in caffeine-treated rats compared to control rats across sleep/wake states. Additional experiments in adult anaesthetized rats showed that at similar levels of arterial blood gases, phrenic nerve activity was enhanced in caffeine-treated rats. This study demonstrates that administration of caffeine in the neonatal period alters respiratory control system activity in awake and sleeping rats, as well as in the anaesthetized rats, and also has persistent disrupting effects on sleep that are apparent in adult rats.

  5. Thymosin beta 4 protects cardiomyocytes from oxidative stress by targeting anti-oxidative enzymes and anti-apoptotic genes.

    Directory of Open Access Journals (Sweden)

    Chuanyu Wei

    Full Text Available BACKGROUND: Thymosin beta-4 (Tβ4 is a ubiquitous protein with many properties relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory mediators. The mechanism by which Tβ4 modulates cardiac protection under oxidative stress is not known. The purpose of this study is to dissect the cardioprotective mechanism of Tβ4 on H(2O(2 induced cardiac damage. METHODS: Rat neonatal cardiomyocytes with or without Tβ4 pretreatment were exposed to H(2O(2 and expression of antioxidant, apoptotic, and anti-inflammatory genes was evaluated by quantitative real-time PCR and western blotting. ROS levels were estimated by DCF-DA using fluorescent microscopy and fluorimetry. Selected antioxidant, anti-inflammatory and antiapoptotic genes were silenced by siRNA transfections in neonatal cardiomyocytes and effect of Tβ4 on H(2O(2-induced cardiac damage was evaluated. RESULTS: Pre-treatment of Tβ4 resulted in reduction of the intracellular ROS levels induced by H(2O(2 in cardiomyocytes. Tβ4 pretreatment also resulted in an increase in the expression of antiapoptotic proteins and reduction of Bax/BCl(2 ratio in the cardiomyocytes. Pretreatment with Tβ4 resulted in stimulating the expression of antioxidant enzymes copper/zinc SOD and catalase in cardiomyocytes at both transcription and translation levels. Tβ4 treatment resulted in the increased expression of anti-apoptotic and anti-inflammatory genes. Silencing of Cu/Zn SOD and catalase gene resulted in apoptotic cell death in the cardiomyocytes which was prevented by treatment with Tβ4. CONCLUSION: This is the first report that demonstrates the effect of Tβ4 on cardiomyocytes and its capability to selectively upregulate anti-oxidative enzymes, anti-inflammatory genes, and antiapoptotic enzymes in the neonatal cardiomyocytes thus preventing cell death thereby protecting the myocardium. Tβ4 treatment resulted in decreased oxidative stress and inflammation in the

  6. Urotensin II induction of neonatal cardiomyocyte hypertrophy involves the CaMKII/PLN/SERCA 2a signaling pathway.

    Science.gov (United States)

    Shi, Hongtao; Han, Qinghua; Xu, Jianrong; Liu, Wenyuan; Chu, Tingting; Zhao, Li

    2016-05-25

    Although studies have shown that Urotensin II (UII) can induce cardiomyocyte hypertrophy and UII-induced cardiomyocyte hypertrophy model has been widely used for hypertrophy research, but its precise mechanism remains unknown. Recent researches have demonstrated that UII-induced cardiomyocyte hypertrophy has a relationship with the changes of intracellular Ca(2+) concentration. Therefore, the aim of this study was to investigate the mechanisms of cardiomyocyte hypertrophy induced by UII and to explore whether the calcium/calmodulin-dependent protein kinase II (CaMKII)-mediated up-regulating of phospholamban (PLN) Thr17-phosphorylation signaling pathway contributed to UII-induced cardiomyocyte hypertrophy. Primary cultures of neonatal rat cardiomyocytes were stimulated for 48h with UII. Cell size, protein/DNA contents and intracellular Ca(2+) were determined. Phosphorylated and total forms of CaMKII, PLN and the total amount of serco/endo-plasmic reticulum ATPases (SERCA 2a) were quantified by western blot. The responses of cardiomyocytes to UII were also evaluated after pretreatment with the CaMKII inhibitor, KN-93. These results showed that UII increased cell size, protein/DNA ratio and intracellular Ca(2+), consistent with a hypertrophic response. Furthermore, the phosphorylation of CaMKII and its downstream target PLN (Thr17), SERCA 2a levels were up-regulated by UII treatment. Conversely, treatment with KN-93 reversed all those effects of UII. Taken together, the results suggest that UII can induce cardiomyocyte hypertrophy through CaMKII-mediated up-regulating of PLN Thr17-phosphorylation signaling pathway.

  7. Adolescent TBI-induced hypopituitarism causes sexual dysfunction in adult male rats.

    Science.gov (United States)

    Greco, Tiffany; Hovda, David A; Prins, Mayumi L

    2015-02-01

    Adolescents are at greatest risk for traumatic brain injury (TBI) and repeat TBI (RTBI). TBI-induced hypopituitarism has been documented in both adults and juveniles and despite the necessity of pituitary function for normal physical and brain development, it is still unrecognized and untreated in adolescents following TBI. TBI induced hormonal dysfunction during a critical developmental window has the potential to cause long-term cognitive and behavioral deficits and the topic currently remains unaddressed. The purpose of this study was to determine if four mild TBIs delivered to adolescent male rats disrupts testosterone production and adult behavioral outcomes. Plasma testosterone was quantified from 72 hrs preinjury to 3 months postinjury and pubertal onset, reproductive organ growth, erectile function and reproductive behaviors were assessed at 1 and 2 months postinjury. RTBI resulted in both acute and chronic decreases in testosterone production and delayed onset of puberty. Significant deficits were observed in reproductive organ growth, erectile function and reproductive behaviors in adult rats at both 1 and 2 months postinjury. These data suggest adolescent RTBI-induced hypopituitarism underlies abnormal behavioral changes observed during adulthood. The impact of undiagnosed hypopituitarism following RTBI in adolescence has significance not only for growth and puberty, but also for brain development and neurobehavioral function as adults.

  8. Nitroxyl (HNO stimulates soluble guanylyl cyclase to suppress cardiomyocyte hypertrophy and superoxide generation.

    Directory of Open Access Journals (Sweden)

    Eliane Q Lin

    Full Text Available BACKGROUND: New therapeutic targets for cardiac hypertrophy, an independent risk factor for heart failure and death, are essential. HNO is a novel redox sibling of NO• attracting considerable attention for the treatment of cardiovascular disorders, eliciting cGMP-dependent vasodilatation yet cGMP-independent positive inotropy. The impact of HNO on cardiac hypertrophy (which is negatively regulated by cGMP however has not been investigated. METHODS: Neonatal rat cardiomyocytes were incubated with angiotensin II (Ang II in the presence and absence of the HNO donor Angeli's salt (sodium trioxodinitrate or B-type natriuretic peptide, BNP (all 1 µmol/L. Hypertrophic responses and its triggers, as well as cGMP signaling, were determined. RESULTS: We now demonstrate that Angeli's salt inhibits Ang II-induced hypertrophic responses in cardiomyocytes, including increases in cardiomyocyte size, de novo protein synthesis and β-myosin heavy chain expression. Angeli's salt also suppresses Ang II induction of key triggers of the cardiomyocyte hypertrophic response, including NADPH oxidase (on both Nox2 expression and superoxide generation, as well as p38 mitogen-activated protein kinase (p38MAPK. The antihypertrophic, superoxide-suppressing and cGMP-elevating effects of Angeli's salt were mimicked by BNP. We also demonstrate that the effects of Angeli's salt are specifically mediated by HNO (with no role for NO• or nitrite, with subsequent activation of cardiomyocyte soluble guanylyl cyclase (sGC and cGMP signaling (on both cGMP-dependent protein kinase, cGK-I and phosphorylation of vasodilator-stimulated phosphoprotein, VASP. CONCLUSIONS: Our results demonstrate that HNO prevents cardiomyocyte hypertrophy, and that cGMP-dependent NADPH oxidase suppression contributes to these antihypertrophic actions. HNO donors may thus represent innovative pharmacotherapy for cardiac hypertrophy.

  9. The time course of denervation-induced changes is similar in soleus muscles of adult and old rats.

    NARCIS (Netherlands)

    Degens, H.; Kosar, S.N.; Hopman, M.T.E.; Haan, A. de

    2008-01-01

    Muscle denervation is accompanied by atrophy and a decline in oxidative capacity. We investigated whether the time course of adaptations following denervation of the soleus muscle differs in adult (5 months old) and older adult (25 months old) rats. We denervated the soleus muscle of the left leg, w

  10. A SELF-PRIMING EFFECT OF LHRH ON LH SECRETION IN DISPERSED ANTERIOR PITUITARY CELLS OF ADULT MALE RAT

    Institute of Scientific and Technical Information of China (English)

    QUZhi-Chao; GUOJing; GUOJian

    1989-01-01

    LHRH self-priming effect is simply defmed as an enhancement of LH response to LHRH, i. e., a second challenge with LHRH elicits more LH secretion as compared to the first challenge. The present study is to observe whether this phenomenon exists in perfused anterior pituitary (AP) cells of adult male rat. Dispersed AP cells of adult SD

  11. ZP2307, a novel cyclic PTH(1-17) analog, reversed established osteopenia in adult ovariectomized rats

    DEFF Research Database (Denmark)

    Vääräniemi, Jukka; Morko, Jukka; Peng, ZhiQi

    -17) analog, ZP2307, with a high efficacy and potency on the human PTH receptor in vitro. This study characterized the effects of intermittent treatment with ZP2307 on established osteopenia in adult ovariectomized (OVX) rats. Female Sprague-Dawley rats were ovariectomized at 6 months of age. After 6 weeks......-34). This study demonstrated that the intermittent treatment with ZP2307, the novel cyclic PTH(1-17) analog, is effective in reversing the established osteopenia in adult OVX rats to normal conditions. Due to its broad dose response relationship, ZP2307 may have a wider therapeutic window and a better safety...

  12. Influence of APS on the Calcium Channel Gene Expression in Cardiomyocyte of Type 2 Diabetes Rats%黄芪多糖对2型糖尿病大鼠心肌细胞钙通道基因表达的影响研究

    Institute of Scientific and Technical Information of China (English)

    刘洪凤; 王桂云; 张杰; 韩智学

    2012-01-01

    目的:研究黄芪多糖(astragaluspolysaccharide,APS)对2型糖尿病(2-DM)大鼠心肌细胞L型ca^2+通道蛋白mRNA表达的影响,探讨APS对2-DM的治疗作用。方法:将Wistar大鼠随机分为正常对照组、模型组、APS治疗组。治疗8周后采用RT—PcR检测3组大鼠心肌细胞L型Ca2+通道蛋白mRNA表达量。结果:糖尿病组、治疗组大鼠心肌组织L型Ca2+通道蛋白mRNA表达量均显著高于正常组,差异有统计学意义(P〈0.01)。结论:APS可以降低2DM大鼠心肌细胞L型Ca外通道蛋白mRNA的表达,对2-DM有一定的治疗作用。%[Objective] To investigate the influence of APS on the L-type calcium channel protein mRNA expression of the cardiomyocyte in the type 2 diabetes rats. [Method] Wistar rats were randomly divided into the control group, model group and APS groups. The mRNA expression of L-type calcium channelprotein was metered by RT-PCR at the end of 8 weeks. [Result] The expressions of the L-type calcium protein mRNA of diabetes group and therapy group were significantly higher than that of the control group, while the therapy group was significantly lower than the model group (P〈0.01). [Conclusion] APS can decrease the L-type calcium channel protein mRNA expression in the cardiomyocyte of the type 2 diabetes rats. APS have therapeutic effect on type 2 diabetes.

  13. Effect of glial cell line-derived neurotrophic factor on peripheral nerve regeneration in adult rat

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhe-yu; LI Jian-hong; ZHENG Xing-dong; LU Chang-lin; HE Cheng

    2001-01-01

    Objective: To study the effect of glial cell line-derived neurotrophic (GDNF) on adult peripheral nerve regeneration. Methods: Transectioned sciatic nerve in adult rats was sutured into silicone channel. GDNF or SAL solution was injected into the silicone channels during operation. Four weeks later, the effect of GDNF on axonal regeneration was evaluated by degenerative neurofiber staining and HRP retrograde tracing. Results: Compared with SAL group, the percentage of degenerative neurofiber areas decreased from 17.3% to 1.9% ( P<0.01 ) and the ratio of labeled spinal somas number was significantly increased from 43.5% to 68.3% ( P<0.01 ) in GDNF group. Conclusion: The results suggest that exogenous GDNF can obviously enhance adult peripheral nerve regeneration.

  14. Effects of Infantile Repeated Hyperglycemia on Behavioral Alterations in Adult Rats

    Directory of Open Access Journals (Sweden)

    Malihe Moghadami

    2012-09-01

    Full Text Available Anxiety symptoms have been reported to be present in many patients with diabetes mellitus. However, little is known about the effects of hyperglycemia in critical periods of the central nervous system development. We assessed locomotive, exploratory, and anxiety behaviors in adult rats that remained from infantile repeated hyperglycemia by the open field and elevated plus maze tests. Our findings showed significant hypo activity, reduced locomotive/exploratory activities, increased fear related behaviors, and anxiety state between hyperglycemic and control adult males and the same differences were observed among females. In addition, no significant behavioral alterations between male and female animals were observed. This study determined that repeated increments in daily blood sugar levels in newborns may affect neuronal functions and provide behavioral abnormalities in adults.

  15. Arrested neuronal proliferation and impaired hippocampal function following fractionated brain irradiation in the adult rat

    DEFF Research Database (Denmark)

    Madsen, Torsten Meldgaard; Kristjansen, P.E.G.; Bolwig, Tom Gert

    2003-01-01

    The generation of new neurons in the adult mammalian brain has been documented in numerous recent reports. Studies undertaken so far indicate that adult hippocampal neurogenesis is related in a number of ways to hippocampal function.Here, we report that subjecting adult rats to fractionated brain...... days after irradiation, the animals with blocked neurogenesis performed poorer than controls in a hippocampus-dependent place-recognition task, indicating that the presence of newly generated neurons may be necessary for the normal function of this brain area. The animals were never impaired...... irradiation blocked the formation of new neurons in the dentate gyrus of the hippocampus. At different time points after the termination of the irradiation procedure, the animals were tested in two tests of short-term memory that differ with respect to their dependence on hippocampal function. Eight and 21...

  16. Effect of maternal obesity on diabetes development in adult rat offspring.

    Science.gov (United States)

    de Campos, Kleber Eduardo; Sinzato, Yuri Karen; Pimenta, Walkyria de Paula; Rudge, Marilza Vieira Cunha; Damasceno, Débora Cristina

    2007-10-27

    This study aimed to evaluate whether maternal obesity leads to the onset of diabetes in adult Wistar rats offspring. MSG solution neonatally administration induced obesity in rats (F(1)MSG group, n=30); and saline solution was also administrated to control rats (F(1)CON group, n=13). In 3rd month of age, both control and MSG groups were mated for offspring (generation F(2)), named as F(2)CON, n=28 and F(2)MSG groups, n=15; and so both generations were studied until 7th month of life. Lee Index was measured for experimental obesity validation from 5th to 7th month. Glycemia was weekly determined during pregnancy and monthly from 3rd to 7th month. In the end of experimental period all rats were submitted to oral glucose tolerance test (OGTT), with estimation of total area under the curve (AUC); and insulin tolerance test (ITT). Rats were then anesthetized and killed. Data were statistically analyzed with significance level of pgenerations showed significant maternal interference in control and MSG groups. OGTT analysis showed higher glycemia in obese rats (F(1)MSG) and their offspring (F(2)MSG) as compared to their respective controls; and MSG groups increased AUC from OGTT. As regards ITT, F(2)MSG showed higher glycemia at 30 and 120 min, suggesting a delay of insulin action decreasing. Although glucose intolerance and insulin resistance clinical conditions represent as a factors for type 2 Diabetes mellitus development, this experimental model proposal was not efficient to induce type 2 Diabetes mellitus, but for obesity developing, glucose intolerance and insulin resistance in successive generations of rats.

  17. Alterations in cytochrome P-450 levels in adult rats following neonatal exposure to xenobiotics

    Energy Technology Data Exchange (ETDEWEB)

    Zangar, R.C. (Oregon State Univ., Corvallis (United States) Pacific Northwest Laboratories, Richland, WA (United States)); Springer, D.L. (Pacific Northwest Laboratories, Richland, WA (United States)); Buhler, D.R. (Oregon State Univ., Corvallis (United States))

    1993-01-01

    Neonatal exposure to certain xenobiotics has been shown to alter hepatic metabolism in adult rats in a manner that indicates long-term changes in enzyme regulation. Previously, the authors have observed changes in adult testosterone metabolism and in cytochrome P-450 (P-450) mRNA levels in animals neonatally exposed to phenobarbital (PB) or diethylstilbestrol (DES). In order to test for other enzyme alterations, they used Western blot procedures for specific P-450s to analyze hepatic microsomes from adult rats (24 wk old) that had been exposed neonatally to DES, PB, 7,12-dimethylbenz[a]anthracene (DMBA), or pregnenolone 16[alpha]-carbonitrile (PCN). The most striking effects were observed in the DES-treated males: P-4502C6 and an immunologically similar protein were increased 60 and 90%, respectively, relative to control values, but P-4503A2 was decreased by 44%. No changes were observed in the DES-treated males in levels of P-4502E1, P-4502B, or the male-specific P-4502C13. Adult males neonatally treated with PB had 150% increase in levels of anti-P4502B-reactive protein without significant changes in the other enzymes. The DES- and DMBA-treated females had increased levels of the female-specific P-4502C12 of 38 and 48%, respectively, but no other observed alterations. The results confirm that neonatal exposure to DES or PB can cause alterations in adult hepatic cytochrome P-450 levels but show that these chemicals act on different enzymes. Neonatal DMBA resulted in changes in adult females similar to those produced by the synthetic estrogen DES, but did so at about two-thirds lower dose. 37 refs., 5 figs.

  18. Environmental enrichment potentiates thalamocortical transmission and plasticity in the adult rat visual cortex.

    Science.gov (United States)

    Mainardi, Marco; Landi, Silvia; Gianfranceschi, Laura; Baldini, Sara; De Pasquale, Roberto; Berardi, Nicoletta; Maffei, Lamberto; Caleo, Matteo

    2010-11-01

    It has been demonstrated that the complex sensorimotor and social stimulation achieved by rearing animals in an enriched environment (EE) can reinstate juvenile-like plasticity in the adult cortex. However, it is not known whether EE can affect thalamocortical transmission. Here, we recorded in vivo field potentials from the visual cortex evoked by electrical stimulation of the dorsal lateral geniculate nucleus (dLGN) in anesthetized rats. We found that a period of EE during adulthood shifted the input-output curves and increased paired-pulse depression, suggesting an enhanced synaptic strength at thalamocortical terminals. Accordingly, EE animals showed an increased expression of the vesicular glutamate transporter 2 (vGluT-2) in geniculocortical afferents to layer IV. Rats reared in EE also showed an enhancement of thalamocortical long-term potentiation (LTP) triggered by theta-burst stimulation (TBS) of the dLGN. To monitor the functional consequences of increased LTP in EE rats, we recorded visual evoked potentials (VEPs) before and after application of TBS to the geniculocortical pathway. We found that responses to visual stimulation were enhanced across a range of contrasts in EE animals. This was accompanied by an up-regulation of the intracortical excitatory synaptic marker vGluT-1 and a decrease in the expression of the vesicular GABA transporter (vGAT), indicating a shift in the excitation/inhibition ratio. Thus, in the adult rat, EE enhances synaptic strength and plasticity of the thalamocortical pathway associated with specific changes in glutamatergic and GABAergic neurotransmission. These data provide novel insights into the mechanisms by which EE shapes the adult brain.

  19. Distinct Testicular Steroidogenic Response Mechanisms Between Neonatal and Adult Heat-Acclimated Male Rats

    Directory of Open Access Journals (Sweden)

    Beata Kurowicka

    2015-03-01

    Full Text Available Background: In comparison to short-term gonad heat exposure, little is known about the molecular mechanisms that regulate testicular steroidogenesis during long-term whole body heat acclimation. Material and Methods: Testicular slices from neonatal (NHA and adult (AHA heat-acclimated Wistar rats were analysed in vitro to assess the mRNA expression and enzymatic activity of steroidogenic enzymes under basal and luteinising hormone (LH or prolactin (PRL stimulated conditions compared with control rats (CR. Furthermore, a de-acclimated group (DA was created by transferring adult NHA rats to control conditions. Results: Heat acclimation significantly increased plasma LH levels in the AHA group and LH and PRL in the NHA group compared with the CR group; however, after heat acclimation, the T and E2 levels did not differ from the control levels. All heat-acclimated groups showed high basal intra-testicular steroid production in vitro. Moreover, basal Cyp11a1 and Hsd3b1 levels were upregulated in vitro in the NHA and DA groups versus the CR group. LH in vitro stimulation upregulated Cyp11a1 expression in the NHA and AHA groups and PRL stimulation upregulated Cyp17a1 levels in the NHA and DA groups compared with the basal expression levels. In the AHA group, decreased basal Star and CYP11A activities but increased HSD3B1 and CYP17A1 activities were found. Conclusion: Our data revealed that despite the similar steroid levels in plasma and secreted in vitro by neonatal and adult heat-acclimated rat testicular slices, the molecular mechanisms underlying the steroidogenic response to heat acclimation during these different developmental stages were distinct.

  20. shRNA沉默ROCK1和ROCK2表达对缺氧诱导的大鼠心肌细胞凋亡的影响%Effect of ROCK1 and ROCK2 silencing by shRNA on hypoxia-induced apoptosis of rat cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    孙国芳; 丁浩; 李菊香; 洪葵; 董家龙; 吴清华; 程晓曙

    2011-01-01

    ) and R0CK2 on apoptosis induced by hypoxia in rat cardiomyocytes. METHODS: Rat cardiomyocytes were cultured primarily and identified using an antibody targeting a. - actin of striated muscle. R0CK1 - shRNA and R0CK2 - shRNA were transiently transfected into the cells by liposome. After 48 h, these cells were subject to hypoxia for 6 h. The cells were divided into 5 groups: blank control group, hypoxia group, hypoxia + negative control shRNA group, hypoxia + R0CK1 - shRNA group and hypoxia + R0CK2 - shRNA group. The beating frequency and rhythm of the cardiomyocytes were assessed by microscopy. The activity of lactate dehydrogenase ( LDH ) in the cell culture supernatants was detected by automatic biochem-ical analyzer. The cell survival rate was analyzed by the method of MTT. The cell apoptotic rate was assessed by flow cy-tometry. Western blotting was used to determine the expression of R0CK1, R0CK2, caspase - 3 and p - PDK. RESULTS : The primary culture of the cardiomyocytes was successful. Western blotting results showed that the transfection of R0CK1 - shRNA or R0CK2 - shRNA decreased the expression of R0CK1 or R0CK2 in the cardiomyocytes. Hypoxia slowed down the beat frequency of the cardiomyocytes, also made the rhythm disorder. Hypoxia increased the release of LDH and decreased the cell survival rate. Flow cytometry results showed that hypoxia increased the cell apoptotic rate. Hypoxia increased the expression of caspase - 3 and decreased the expression of p - PDK. Transfection of R0CK1 - shRNA and R0CK2 - shRNA into the cardiomyocytes reduced all the effects of hypoxia mentioned above. CONCLUSION: Down - regulation of R0CK1 and R0CK2 expression suppresses the apoptosis of rat cardiomyocytes induced by hypoxia. The mechanism is associated with the inhibition of caspase - 3 activation and the up - regulation of p - PDK expression.

  1. FGF1-mediated cardiomyocyte cell cycle reentry depends on the interaction of FGFR-1 and Fn14.

    Science.gov (United States)

    Novoyatleva, Tatyana; Sajjad, Amna; Pogoryelov, Denys; Patra, Chinmoy; Schermuly, Ralph T; Engel, Felix B

    2014-06-01

    Fibroblast growth factors (FGFs) signal through FGF receptors (FGFRs) mediating a broad range of cellular functions during embryonic development, as well as disease and regeneration during adulthood. Thus, it is important to understand the underlying molecular mechanisms that modulate this system. Here, we show that FGFR-1 can interact with the TNF receptor superfamily member fibroblast growth factor-inducible molecule 14 (Fn14) resulting in cardiomyocyte cell cycle reentry. FGF1-induced cell cycle reentry in neonatal cardiomyocytes could be blocked by Fn14 inhibition, while TWEAK-induced cell cycle activation was inhibited by blocking FGFR-1 signaling. In addition, costimulation experiments revealed a synergistic effect of FGF1 and TWEAK in regard to cardiomyocyte cell cycle induction via PI3K/Akt signaling. Overexpression of Fn14 with either FGFR-1 long [FGFR-1(L)] or FGFR-1 short [FGFR-1(S)] isoforms resulted after FGF1/TWEAK stimulation in cell cycle reentry of >40% adult cardiomyocytes. Finally, coimmunoprecipitation and proximity ligation assays indicated that endogenous FGFR-1 and Fn14 interact with each other in cardiomyocytes. This interaction was strongly enhanced in the presence of their corresponding ligands, FGF1 and TWEAK. Taken together, our data suggest that FGFR-1/Fn14 interaction may represent a novel endogenous mechanism to modulate the action of these receptors and their ligands and to control cardiomyocyte cell cycle reentry.

  2. Impact of chronic nicotine administration on bone mineral content in young and adult rats: a comparative study.

    Science.gov (United States)

    Farag, Mahmoud M; Selima, Eman A; Salama, Mona A

    2013-11-15

    The aim of this study was to evaluate the effects of chronic nicotine administration on bone mineral homeostasis in rapidly growing young rats in comparison to effects in adult male rats. Two doses of nicotine (3 and 4.5mg/kg/day, as nicotine hydrogen tartrate) were used and rat treatment was continued for 6 months. In this study, all nicotine-treated rats weighed less than control rats and the effect was dose-dependent. Also, rats treated with nicotine had lower femoral wet weight and showed a significant reduction in femoral mid-shaft cortical width and femoral and lumbar vertebral ash weights. These effects were associated with a significant reduction of ash calcium and phosphorus contents of the femora and lumbar vertebrae. The bone mineral-lowering effects of nicotine were more severe in the lumbar vertebral spongy bone than in the femoral compact bone and these changes were more marked in adult rats than in young rats. An additional interesting observation was that the femora of young rats treated with nicotine were significantly shorter than those of control young rats. Also, the values of the femoral ash weight per unit length were significantly decreased in nicotine-treated adult rats but not in nicotine-treated young rats. Thus, these results show that nicotine-induced changes in bone vary with age. The clinical relevance of this study is that it may provide justification to insist that all people in general and the risky young group in particular should be warned against the hazards of the negative effects of nicotine on bone.

  3. Acute and Chronic Effects of Dietary Lactose in Adult Rats Are not Explained by Residual Intestinal Lactase Activity.

    Science.gov (United States)

    van de Heijning, Bert J M; Kegler, Diane; Schipper, Lidewij; Voogd, Eline; Oosting, Annemarie; van der Beek, Eline M

    2015-07-08

    Neonatal rats have a high intestinal lactase activity, which declines around weaning. Yet, the effects of lactose-containing products are often studied in adult animals. This report is on the residual, post-weaning lactase activity and on the short- and long-term effects of lactose exposure in adult rats. Acutely, the postprandial plasma response to increasing doses of lactose was studied, and chronically, the effects of a 30% lactose diet fed from postnatal (PN) Day 15 onwards were evaluated. Intestinal lactase activity, as assessed both in vivo and in vitro, was compared between both test methods and diet groups (lactose vs. control). A 50%-75% decreased digestive capability towards lactose was observed from weaning into adulthood. Instillation of lactose in adult rats showed disproportionally low increases in plasma glucose levels and did not elicit an insulin response. However, gavages comprising maltodextrin gave rise to significant plasma glucose and insulin responses, indicative of a bias of the adult GI tract to digest glucose polymers. Despite the residual intestinal lactase activity shown, a 30% lactose diet was poorly digested by adult rats: the lactose diet rendered the animals less heavy and virtually devoid of body fat, whereas their cecum tripled in size, suggesting an increased bacterial fermentation. The observed acute and chronic effects of lactose exposure in adult rats cannot be explained by the residual intestinal lactase activity assessed.

  4. Acute and Chronic Effects of Dietary Lactose in Adult Rats Are not Explained by Residual Intestinal Lactase Activity

    Directory of Open Access Journals (Sweden)

    Bert J. M. van de Heijning

    2015-07-01

    Full Text Available Neonatal rats have a high intestinal lactase activity, which declines around weaning. Yet, the effects of lactose-containing products are often studied in adult animals. This report is on the residual, post-weaning lactase activity and on the short- and long-term effects of lactose exposure in adult rats. Acutely, the postprandial plasma response to increasing doses of lactose was studied, and chronically, the effects of a 30% lactose diet fed from postnatal (PN Day 15 onwards were evaluated. Intestinal lactase activity, as assessed both in vivo and in vitro, was compared between both test methods and diet groups (lactose vs. control. A 50%–75% decreased digestive capability towards lactose was observed from weaning into adulthood. Instillation of lactose in adult rats showed disproportionally low increases in plasma glucose levels and did not elicit an insulin response. However, gavages comprising maltodextrin gave rise to significant plasma glucose and insulin responses, indicative of a bias of the adult GI tract to digest glucose polymers. Despite the residual intestinal lactase activity shown, a 30% lactose diet was poorly digested by adult rats: the lactose diet rendered the animals less heavy and virtually devoid of body fat, whereas their cecum tripled in size, suggesting an increased bacterial fermentation. The observed acute and chronic effects of lactose exposure in adult rats cannot be explained by the residual intestinal lactase activity assessed.

  5. Sexual interactions with unfamiliar females reduce hippocampal neurogenesis among adult male rats.

    Science.gov (United States)

    Spritzer, M D; Curtis, M G; DeLoach, J P; Maher, J; Shulman, L M

    2016-03-24

    Recent experiments have shown that sexual interactions prior to cell proliferation cause an increase in neurogenesis in adult male rats. Because adult neurogenesis is critical for some forms of memory, we hypothesized that sexually induced changes in neurogenesis may be involved in mate recognition. Sexually naive adult male rats were either exposed repeatedly to the same sexual partner (familiar group) or to a series of novel sexual partners (unfamiliar group), while control males never engaged in sexual interactions. Ovariectomized female rats were induced into estrus every four days. Males were given two injections of 5-bromo-2'-deoxyuridine (BrdU) (200mg/kg) to label proliferating cells, and the first sexual interactions occurred three days later. Males in the familiar and unfamiliar groups engaged in four, 30-min sexual interactions at four-day intervals, and brain tissue was collected the day after the last sexual interaction. Immunohistochemistry followed by microscopy was used to quantify BrdU-labeled cells. Sexual interactions with unfamiliar females caused a significant reduction in neurogenesis in the dentate gyrus compared to males that interacted with familiar females and compared to the control group. The familiar group showed no difference in neurogenesis compared to the control group. Males in the familiar group engaged in significantly more sexual behavior (ejaculations and intromissions) than did males in the unfamiliar group, suggesting that level of sexual activity may influence neurogenesis levels. In a second experiment, we tested whether this effect was unique to sexual interactions by replicating the entire procedure using anestrus females. We found that interactions with unfamiliar anestrus females reduced neurogenesis relative to the other groups, but this effect was not statistically significant. In combination, these results indicate that interactions with unfamiliar females reduce adult neurogenesis and the effect is stronger for sexual

  6. Effect of microRNA-21-transfected cardiomyocyte transplantation on heart failure rats under low-temperature condition%microRNA-21转染的心肌细胞移植对低温条件下心力衰竭大鼠的影响

    Institute of Scientific and Technical Information of China (English)

    唐艳; 王梦洪

    2013-01-01

    . METHODS: The rat model of heart failure was constructed by injection of adriamycin and the rats were placed in a climate box. The cardiac functions, the apoptotic index and pathological changes of the myocardium were determined. The expression of microRNA-21 in the myocardium of the rats was detected by qRT-PCR. Neonatal cardiomyocytes were cultured in vitro, labeled with BrdU and transferred with lenti-microRNA-21 by DNA transfection. The heart failure rats in the cold environment were randomly divided into 3 groups; the rats in group Ⅰ were transplanted with lenti-microRNA-21-transfected neonatal cardiomyocytes, the rats in group Ⅱ were transplanted with untransfected cardiomyocytes and the rats in group Ⅲ were transplanted with culture medium into the failure myocardium. The echocardiography was applied to evaluate the heart functions. The rats were then executed and the hearts were harvested for histological ( HE staining) and immuno-histological (anti-BrdU staining) examinations. RESULTS: The cardiac functions of the heart failure rats in the cold environraent (group d) were significantly worse than those in the normal environment (group c). The cardiac functions in group c were significantly worse than those in the normal rats in the normal environment ( group a). No obvious difference of the cardiac functions between group a and group b (the normal rats in the cold environment) was observed. The apoptot-ic index of the myocardium in group d was significantly higher than that in group c, and that in group c was significantly higher than that in group a. No obvious difference of the apoptotic index of myocardium between group a and group b was found. The expression level of microRNA-21 in the myocardium in group c was significantly lower than that in group a, that in group d was lower than that in group c, and that in group b was also lower than that in group A. The expression of mi-croRNA-21 in the transfected groups was higher than that in untransfected

  7. Cultured human embryonic neocortical cells survive and grow in infarcted cavities of adult rat brains and interconnect with host brain

    Institute of Scientific and Technical Information of China (English)

    ZENG Jin-sheng; YU Jian; CUI Chun-mei; ZHAO Zhan; HONG Hua; SHENG Wen-li; TAO Yu-qian; LI Ling; HUANG Ru-xun

    2005-01-01

    Background There are no reports on exnografting cultured human fetal neocortical cells in this infracted cavities of adult rat brains. This study was undertaken to observe whether cultured human cortical neurons and astrocytes can survive and grow in the infarcted cavities of adult rat brains and whether they interconnect with host brains.Methods The right middle cerebral artery was ligated distal to the striatal branches in 16 adult stroke-prone renovascular hypertensive rats. One week later, cultured cells from human embryonic cerebral cortexes were stereotaxically transferred to the infarcted cavity of 11 rats. The other 5 rats receiving sham transplants served as controls. For immunosuppression, all transplanted rats received intraperitoneal injection of cyclosporine A daily starting on the day of grafting. Immunohistochemistry for glial fibrillary acidic protein (GFAP), synaptophysin, neurofilament, and microtubule associated protein-2 (MAP-2) was performed on brain sections perfused in situ 8 weeks after transplantation.Results Grafts in the infarcted cavities of 6 of 10 surviving rats consisted of bands of neurons with an immature appearance, bundles of fibers, and GFAP-immunopositive astrocytes, which were unevenly distributed. The grafts were rich in synaptophysin, neurofilament, and MAP2-positive neurons with long processes. The graft/host border was diffuse with dendrites apparently bridging over to the host brain, into which neurofilament immunopositive fibers protruded. Conclusion Cultured human fetal brain cells can survive and grow in the infarcted cavities of immunodepressed rats and integrate with the host brain.

  8. Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

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    A. Zago

    2012-01-01

    Full Text Available Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although cross-sensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P 28-37 and adult (P60-67 rats received nicotine (0.4 mg/kg, sc or saline (0.9% NaCl, sc and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

  9. Impact of stirred suspension bioreactor culture on the differentiation of murine embryonic stem cells into cardiomyocytes

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    Shafa Mehdi

    2011-12-01

    Full Text Available Abstract Background Embryonic stem cells (ESCs can proliferate endlessly and are able to differentiate into all cell lineages that make up the adult organism. Under particular in vitro culture conditions, ESCs can be expanded and induced to differentiate into cardiomyocytes in stirred suspension bioreactors (SSBs. However, in using these systems we must be cognizant of the mechanical forces acting upon the cells. The effect of mechanical forces and shear stress on ESC pluripotency and differentiation has yet to be clarified. The purpose of this study was to investigate the impact of the suspension culture environment on ESC pluripotency during cardiomyocyte differentiation. Results Murine D3-MHC-neor ESCs formed embyroid bodies (EBs and differentiated into cardiomyocytes over 25 days in static culture and suspension bioreactors. G418 (Geneticin was used in both systems from day 10 to enrich for cardiomyocytes by eliminating non-resistant, undifferentiated cells. Treatment of EBs with 1 mM ascorbic acid and 0.5% dimethyl sulfoxide from day 3 markedly increased the number of beating EBs, which displayed spontaneous and cadenced contractile beating on day 11 in the bioreactor. Our results showed that the bioreactor differentiated cells displayed the characteristics of fully functional cardiomyocytes. Remarkably, however, our results demonstrated that the bioreactor differentiated ESCs retained their ability to express pluripotency markers, to form ESC-like colonies, and to generate teratomas upon transplantation, whereas the cells differentiated in adherent culture lost these characteristics. Conclusions This study demonstrates that although cardiomyocyte differentiation can be achieved in stirred suspension bioreactors, the addition of medium enhancers is not adequate to force complete differentiation as fluid shear forces appear to maintain a subpopulation of cells in a transient pluripotent state. The development of successful ESC

  10. Application of Luxol Fast Blue staining in locating the corticospinal tract in adult rats

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    Su Liu; Guangyu Shen; Guangming Lü; Xiaosong Gu

    2006-01-01

    BACKGROUND: There are many methods for myelin staining,mordant,or the special reaction of osmic acid with lipoid is used according to different principles.The commonly used methods are classic Well staining ,classic lithium carbonate-haematine staining,fast green staining,silver staining ,etc.Luxol Fast Blue can brightly stain myelin sheath,and has certain specificity .The background can be very clean if there is proper differentiation,whereas Luxol Fast Blue is cheap and convenient to operate,thus it is an ideal staining reagent for routine myelin sheath.OBJECTIVE: To show the coricospinal tract of normal adult rats with Luxol Fast Blue shaining method.DESIGN:A repetitive measurement design.SETTINGS: Institute of Nuerobiology,Nantong University;Department of Rehabilitation Medicine,Affiliated Hospital of Nantong University.MATERIALS: Six healthy adult male SD rats of clean dergree,weighing averagely 300 g.were provided by the experimental animal center of Nantong University.1 g/L Luxol Fast Blue solution was provided by Sigma Company;Leica CM1900 cryostat microtome by Leica Company;Leica DMR microscope by Leica Company.METHODS:The experiment was carried out in the Staff Room of Human Anatomy,Nantong University in May 2005.The rats were given intraperitoneal injection of combined anesthetic(2 mL/kg),then the chest was open for perfusing saline and phosphate buffer containing formamint via heart. Brain and spinal cord were removed after 1 hour then fixed,then changed to phosphate buffer(pH 7.4)containing 300 g/L saccharu at 4 ℃.and stayed overnight,tissue blocks at pyramid,decussation of pyramid and cervical,thoracic,lumbar and sacral segments of spinal cord were removed to prepare continuous horizontal frozen sections(30 μm) after sedimentation,the sections were dried at room temperature.The corticospinal tract of normal adult rats were shown with Luxol Fast Blue staining method,and observed under Leica DMR microscope.MAIN OUTCOME MEASURES:Positive fibers in

  11. Ghrelin modulates testicular germ cells apoptosis and proliferation in adult normal rats

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    Kheradmand, Arash, E-mail: arashkheradmand@yahoo.com [Department of Clinical Sciences, School of Veterinary Medicine, Lorestan University, P.O. Box: 465, Khorram Abad (Iran, Islamic Republic of); Dezfoulian, Omid [Department of Pathobiology, School of Veterinary Medicine, Lorestan University, Khorram Abad (Iran, Islamic Republic of); Alirezaei, Masoud [Division of Biochemistry, School of Veterinary Medicine, Lorestan University, P.O. Box: 465, Khorram Abad (Iran, Islamic Republic of); Rasoulian, Bahram [Razi Herbal Medicine Research Center, Lorestan University of Medical Sciences, Khorram Abad (Iran, Islamic Republic of)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer Spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. Black-Right-Pointing-Pointer Numerous studies have documented the direct action of ghrelin in the modulation of apoptosis in different cell types. Black-Right-Pointing-Pointer Ghrelin may be considered as a modulator of spermatogenesis in normal adult rats. Black-Right-Pointing-Pointer Ghrelin may be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors. -- Abstract: Under normal condition in the most mammals, spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. The present study was designed to determine the effects of ghrelin treatment on in vivo quality and quantity expression of apoptosis and proliferation specific indices in rat testicular germ cells. Twenty eight adult normal rats were subdivided into equal control and treatment groups. Treatment group received 3 nmol of ghrelin as subcutaneous injection for 30 consecutive days or vehicle to the control animals. The rats from each group (n = 7) were killed on days 10 and 30 and their testes were taken for immunocytochemical evaluation and caspase-3 assay. Immunohistochemical analysis indicated that the accumulations of Bax and PCNA peptides are generally more prominent in spermatocytes and spermatogonia of both groups. Likewise, the mean percentage of immunoreactive spermatocytes against Bax increased (P < 0.01) in the ghrelin-treated group on day 10, while despite of 30% increment in the Bax level of spermatocytes in the treated rats on day 30, however, it was not statistically significant. During the experimental period, only a few spermatogonia represented Bax expression and the changes of Bax immunolabling cells were negligible upon ghrelin treatment. Likewise, there were immunostaining cells against Bcl-2 in each germ cell neither in the control nor in the treated animals. In fact

  12. Construction and effect of recombinant adenovirus vector containing siRNA targeting Raf-1 on cardiomyocyte hypertrophy in neonatal rats%Raf-1基因重组腺病毒 siRNA 载体构建及其对大鼠心肌细胞肥大的影响

    Institute of Scientific and Technical Information of China (English)

    郑亚萍; 刘春杰

    2016-01-01

    Objective To construct an adenovirus vector expressing small interfering RNA ( siRNA) targeting to rat Raf-1 gene and identify its function in cardiomyocytes.Methods The siRNA containing DNA sequence targeting to Raf-1 and its negative control sequence were designed, synthesized, annealed and subcloned into adenoviral shuttle vector pAdTrack-CMV.The recombinant adenovirus vector pAd-siRaf-1 was obtained by homologous recombination with pAdTrack-siRaf-1 linearized by PmeI and pAdeasy-1 in bacteria BJ5183, then transfected into HEK293 cells to package the adenovirus.Cardiomyocytes were infected with the adenovirus pAd-siRaf-1, and the expressions of Raf-1 and NF-κB protein were detected by Western blotting.[ 3 H ]-leu incorporation was evaluated by scintillation.The surface area of cardiomyocytes was measured using a HJ2000 image analysis system.Results The adenovirus vectors were verified by enzyme digestion and DNA sequencing.Compared with the Ang II group, Raf-1 and NF-κB expression, the surface area and [ 3 H]-leu incorporation of cardiomyocytes were significantly decreased in cardiomyocytes infected with the adenovirus PAd-siRaf-1.Conclusions A recombinant adenovirus vector containing rat siRaf-1 gene is successfully constructed.It can effectively reduce Raf-1 and NF-κB expression and cardiomyocyte hypertrophy induced by Ang II.%目的:构建特异性抑制大鼠Raf-1基因的重组腺病毒载体,并将其体外转导大鼠心肌细胞中进行功能鉴定。方法合成针对大鼠Raf-1的靶序列及阴性对照序列,经退火形成的DNA双链定向克隆到穿梭质粒pAdTrackCMV中获得pAdTrack-siRaf-1质粒,PmeI线性化后在BJ5183细菌中与pAdEasy-1骨架质粒进行同源重组获得pAd-siRaf-1质粒,后转染HEK293细胞,包装获得pAd-siRaf-1腺病毒颗粒,继而感染原代培养的心肌细胞,通过Western blot方法检测siRNA对Raf-1、NF-κB基因的抑制效率,液体闪烁计数仪测定3 H-亮氨酸([3 H

  13. Impacts of prenatal nanomaterial exposure on male adult Sprague-Dawley rat behavior and cognition.

    Science.gov (United States)

    Engler-Chiurazzi, Elizabeth B; Stapleton, Phoebe A; Stalnaker, Jessica J; Ren, Xuefang; Hu, Heng; Nurkiewicz, Timothy R; McBride, Carroll R; Yi, Jinghai; Engels, Kevin; Simpkins, James W

    2016-01-01

    It is generally accepted that gestational xenobiotic exposures result in systemic consequences in the adult F1 generation. However, data on detailed behavioral and cognitive consequences remain limited. Using our whole-body nanoparticle inhalation facility, pregnant Sprague-Dawley rats (gestational day [GD] 7) were exposed 4 d/wk to either filtered air (control) or nano-titanium dioxide aerosols (nano-TiO2; count median aerodynamic diameter of 170.9 ± 6.4 nm, 10.4 ± 0.4 mg/m(3), 5 h/d) for 7.8 ± 0.5 d of the remaining gestational period. All rats received their final exposure on GD 20 prior to delivery. The calculated daily maternal deposition was 13.9 ± 0.5 µg. Subsequently, at 5 mo of age, behavior and cognitive functions of these pups were evaluated employing a standard battery of locomotion, learning, and anxiety tests. These assessments revealed significant working impairments, especially under maximal mnemonic challenge, and possible deficits in initial motivation in male F1 adults. Evidence indicates that maternal engineered nanomaterial exposure during gestation produces psychological deficits that persist into adulthood in male rats.

  14. Effect of pinealectomy, adrenalectomy, pinealectomy plus adrenalectomy upon the quantification of spermatogenic cells of adult rats

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    Castro A.C.S.

    2002-01-01

    Full Text Available The objectives of this study were to evaluate the effects of pinealectomy, adrenalectomy and pinealectomy-adrenalectomy upon the quantification of spermatogenic cells of rats. As such, 32 adult Wistar rats with a mean body weight of 331.7± 15.5g were assigned into one of the following treatments: (a a sham-operated control group, consisting of nine animals; (b ten pinealectomized animals; (c seven adrenalectomized animals and (d six pinealectomized plus adrenalectomized animals. No significant differences were observed between groups for the following parameters: body, testes, prostate and seminal vesicle weights, seminiferous tubular diameter, number of cells per seminiferous tubular cross sections (primary spermatocytes at pachytene, round spermatids, Sertoli cells and numbers of germ cells per Sertoli cell (primary spermatocytes at pachytene and round spermatids . Although no increase in testicular weight was observed following pinealectomy, a significant (P<0.05 increase of approximately 11.5% in the number of round spermatids per Sertoli cell (Sertoli cell ratio occurred thus suggesting that short-term pinealectomy abolishes the antigonadal effect of the pineal gland upon adult Wistar rat testes.

  15. Variability in the distribution of callosal projection neurons in the adult rat parietal cortex.

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    Ivy, G O; Gould, H J; Killackey, H P

    1984-07-23

    Previous reports have shown that the barrel field area of the parietal cortex of the adult rat contains relatively few callosal projection neurons, even though callosal projection neurons are abundant in this cortical region in the neonatal rat. Furthermore, it has been shown that many of the callosal neurons which seem to disappear as the animal matures do not die, but project to ipsilateral cortical areas. These findings rely on the ability of retrograde transport techniques which utilize injections of horseradish peroxidase (HRP) or of fluorescent dyes into one hemisphere. We now show that several technical modifications of the HRP technique yield a wider distribution of HRP-containing neurons in the contralateral barrel field area of the adult rat than previously reported. These include implants of HRP pellets into transected axons of the corpus callosum, the addition of DMSO and nonidet P40 to Sigma VI HRP, wheat germ agglutinin HRP and the use of tetramethyl benzidine as the chromogen in the reaction procedure. Our findings have implications for transport studies in general and for the development of the cortical barrel field in particular.

  16. Effects of moderate zinc deficiency on cognitive performance in young adult rats.

    Science.gov (United States)

    Massaro, T F; Mohs, M; Fosmire, G

    1982-07-01

    Two experiments were conducted to establish a dietary zinc level which approximates a moderate deficiency in the young adult rat and to determine if a concurrent zinc deficiency affects cognitive performance. Male rats were fed varying levels of zinc in diet throughout a 17-day period. The lowest dietary level that depressed serum and bone zinc without influencing food consumption or body weight gains was observed to be 5.8 microgram Zn/g diet. Young adult rats maintained on either a zinc adequate (24.4 microgram Zn/g) or low-zinc (5.3 microgram Zn/g) diet were tested in a modified Skinner Box involving tests of visual, auditory, association, and discrimination learning. No differences were observed in the visual discrimination performance of the zinc deficient animals when compared with control counterparts. Deficits in the ability to transfer a learned association between visual and auditory stimuli were observed, however, in the deficient group during the transfer test phase. The latter performed better during the final auditory discrimination task in transferring a learned food-relevant cue.

  17. Early life stress enhancement of limbic epileptogenesis in adult rats: mechanistic insights.

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    Gaurav Kumar

    Full Text Available BACKGROUND: Exposure to early postnatal stress is known to hasten the progression of kindling epileptogenesis in adult rats. Despite the significance of this for understanding mesial temporal lobe epilepsy (MTLE and its associated psychopathology, research findings regarding underlying mechanisms are sparse. Of several possibilities, one important candidate mechanism is early life 'programming' of the hypothalamic-pituitary-adrenal (HPA axis by postnatal stress. Elevated corticosterone (CORT in turn has consequences for neurogenesis and cell death relevant to epileptogenesis. Here we tested the hypotheses that MS would augment seizure-related corticosterone (CORT release and enhance neuroplastic changes in the hippocampus. METHODOLOGY/PRINCIPAL FINDINGS: Eight-week old Wistar rats, previously exposed on postnatal days 2-14 to either maternal separation stress (MS or control brief early handling (EH, underwent rapid amygdala kindling. We measured seizure-induced serum CORT levels and post-kindling neurogenesis (using BrdU. Three weeks post-kindling, rats were euthanized for histology of the hippocampal CA3c region (pyramidal cell counts and dentate gyrus (DG (to count BrdU-labelled cells and measure mossy fibre sprouting. As in our previous studies, rats exposed to MS had accelerated kindling rates in adulthood. Female MS rats had heightened CORT responses during and after kindling (p<0.05, with a similar trend in males. In both sexes total CA3c pyramidal cell numbers were reduced in MS vs. EH rats post-kindling (p = 0.002. Dentate granule cell neurogenesis in female rats was significantly increased post-kindling in MS vs. EH rats. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that early life stress results in enduring enhancement of HPA axis responses to limbic seizures, with increased hippocampal CA3c cell loss and augmented neurogenesis, in a sex-dependent pattern. This implicates important candidate mechanisms through which early life

  18. Impaired contextual fear extinction and hippocampal synaptic plasticity in adult rats induced by prenatal morphine exposure.

    Science.gov (United States)

    Tan, Ji-Wei; Duan, Ting-Ting; Zhou, Qi-Xin; Ding, Ze-Yang; Jing, Liang; Cao, Jun; Wang, Li-Ping; Mao, Rong-Rong; Xu, Lin

    2015-07-01

    Prenatal opiate exposure causes a series of neurobehavioral disturbances by affecting brain development. However, the question of whether prenatal opiate exposure increases vulnerability to memory-related neuropsychiatric disorders in adult offspring remains largely unknown. Here, we found that rats prenatally exposed to morphine (PM) showed impaired acquisition but enhanced maintenance of contextual fear memory compared with control animals that were prenatally exposed to saline (PS). The impairment of acquisition was rescued by increasing the intensity of footshocks (1.2 mA rather than 0.8 mA). Meanwhile, we also found that PM rats exhibited impaired extinction of contextual fear, which is associated with enhanced maintenance of fear memory. The impaired extinction lasted for 1 week following extinction training. Furthermore, PM rats exhibited reduced anxiety-like behavior in the elevated plus-maze and light/dark box test without differences in locomotor activity. These alterations in PM rats were mirrored by abnormalities in synaptic plasticity in the Schaffer collateral-CA1 synapses of the hippocampus in vivo. PS rats showed blocked long-term potentiation and enabled long-term depression in CA1 synapses following contextual fear conditioning, while prenatal morphine exposure restricted synaptic plasticity in CA1 synapses. The smaller long-term potentiation in PM rats was not further blocked by contextual fear conditioning, and the long-term depression enabled by contextual fear conditioning was abolished. Taken together, our results provide the first evidence suggesting that prenatal morphine exposure may increase vulnerability to fear memory-related neuropsychiatric disorders in adulthood.

  19. Protective effects of vitamin E and selenium on spermatogenesis in adult male rat insulin-resistant

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    Alireza Zakerabasali

    2013-03-01

    Full Text Available Background & Objective: Diabetes mellitus is a metabolic disease and is a multifactorial disorder characterized by chronic hyperglycemia resulting from impaired insulin secretion and insulin factional or both. In this study, the protective role of vitamin E and sodium selenite in preventing the harmful effects of insulin resistance (diabetes type 2 on spermatogenesis was studied.   Materials & Methods: Male adults (180-200 g of Wistar rats were divided into five groups, each containing 7 rats (control, sham, and three experimental groups. The rats were fed daily with water-soluble fructose (10%, mg/kg 200 of vitamin E (gavage, and 5/0 mg/kg of sodium selenite (intraperitoneal injection or both for 110 days. Subsequently, sperm parameters, levels of testosterone, LH, and daily sperm production (DSP were checked. Additionally, testicular histopathology and malondialdehyde (MDA in the testis were examined.   Results: Sperm count, sperm motility and viability, and insulin resistance in the rats decreased DSP. A significant decrease was observed in the number of Leydig cells, spermatogonia, spermatogenesis, and spermatozoa in the testis of the insulin-resistant animals, whereas MDA and testosterone rose in the insulin-resistant rats. Vitamin E and sodium selenite intake reduced the levels of MDA and harmful effects of fructose on testicles, as well as sperm parameters and testicular pathology. A simultaneous intake of vitamin E and sodium selenite conferred the highest level of protection.   Conclusion: These findings suggest that vitamin E and sodium selenite can have a protective role in the testes of rats against oxidative stress induced by diabetes type 2.

  20. Moderate and severe perinatal asphyxia induces differential effects on cocaine sensitization in adult rats.

    Science.gov (United States)

    Galeano, Pablo; Romero, Juan Ignacio; Luque-Rojas, María Jesús; Suárez, Juan; Holubiec, Mariana Inés; Bisagno, Verónica; Santín, Luis Javier; De Fonseca, Fernando Rodríguez; Capani, Francisco; Blanco, Eduardo

    2013-09-01

    Perinatal asphyxia (PA) increases the likelihood of suffering from dopamine-related disorders, such as ADHD and schizophrenia. Since dopaminergic transmission plays a major role in cocaine sensitization, the purpose of this study was to determine whether PA could be associated with altered behavioral sensitization to cocaine. To this end, adult rats born vaginally (CTL), by caesarean section (C+), or by C+ with 15 min (PA15, moderate PA) or 19 min (PA19, severe PA) of global anoxia were repeatedly administered with cocaine (i.p., 15 mg/kg) and then challenged with cocaine (i.p., 15 mg/kg) after a 5-day withdrawal period. In addition, c-Fos, FosB/ΔFosB, DAT, and TH expression were assessed in dorsal (CPu) and ventral (NAcc) striatum. Results indicated that PA15 rats exhibited an increased locomotor sensitization to cocaine, while PA19 rats displayed an abnormal acquisition of locomotor sensitization and did not express a sensitized response to cocaine. c-Fos expression in NAcc, but not in CPu, was associated with these alterations in cocaine sensitization. FosB/ΔFosB expression was increased in all groups and regions after repeated cocaine administration, although it reached lower expression levels in PA19 rats. In CTL, C+, and PA15, but not in PA19 rats, the expression of TH in NAcc was reduced in groups repeatedly treated with cocaine, independently of the challenge test. Furthermore, this reduction was more pronounced in PA15 rats. DAT expression remained unaltered in all groups and regions studied. These results suggest that moderate PA may increase the vulnerability to drug abuse and in particular to cocaine addiction.

  1. Ependymal cell proliferation and apoptosis following acute spinal cord injury in the adult rat

    Institute of Scientific and Technical Information of China (English)

    Xu Wang; Jun Qian; Yanchao Ma; Guoxin Nan; Shuanke Wang; Yayi Xia; Youcheng Zhang

    2008-01-01

    BACKGROUND: Studies have reported that spinal cord injury can induce the reactive proliferation of ependymal cells and secondarily cause the apoptosis of nerve cells. However, there is no generally accepted theory on the apoptotic characteristics of ependymal cells in the injured spinal cord.OBJECTIVE: To observe the reactive proliferation and apoptosis of ependymal cells in adult rats following acute spinal cord injury.DESIGN, TIME AND SETTING: A randomized control study based on neuropathology was performed in the Third Military Medical University of Chinese PLA between 2005 and 2007.MATERIALS: Forty healthy, adult, Wistar rats were included in the present study.METHODS: Moderate spinal cord injury was established in twenty rats using Feeney's method, while the remaining 20 rats served as controls and were only treated with laminectomy. All rats were injected intraperitoneally with 1.25 mL of BrdU solution (10 mg BrdU/mL saline) 3 times at 4 hours intervals during the 12 hours prior to sacrifice.MAIN OUTCOME MEASURES: Ependymal cell proliferation and apoptosis in the rat spinal cord were determined by BrdU and nestin immunofluorescence double-labeling, as well as the TUNEL method, at 1, 3, 7, and 14 days after operation.RESULTS: In the moderate spinal cord injury rats, nestin expression was observed in the cytoplasm of ependymal cells. One day immediately following surgery, ependymal cells were BrdU-labeled. The number of BrdU-positive cells increased at 3 days, reached a peak at 7 days, and gradually reduced thereafter. The ependyma developed ti'om a constitutive monolayer cells to a multi-layer cell complex. Some BrdU/Nestin double-positive ependymal cells migrated out from the ependyma. TUNEL-positive cells were also detected in the ependyma in the central region, as well as ischemic regions of the injured spinal cord. In addition, TUNEL-positive cells were visible in the ependyma. No TUNEL-positive ependymal cells were observed in the normal spinal cord

  2. Anti-Nogo-A Immunotherapy Does Not Alter Hippocampal Neurogenesis after Stroke in Adult Rats

    Science.gov (United States)

    Shepherd, Daniel J.; Tsai, Shih-Yen; O'Brien, Timothy E.; Farrer, Robert G.; Kartje, Gwendolyn L.

    2016-01-01

    Ischemic stroke is a leading cause of adult disability, including cognitive impairment. Our laboratory has previously shown that treatment with function-blocking antibodies against the neurite growth inhibitory protein Nogo-A promotes functional recovery after stroke in adult and aged rats, including enhancing spatial memory performance, for which the hippocampus is critically important. Since spatial memory has been linked to hippocampal neurogenesis, we investigated whether anti-Nogo-A treatment increases hippocampal neurogenesis after stroke. Adult rats were subject to permanent middle cerebral artery occlusion followed 1 week later by 2 weeks of antibody treatment. Cellular proliferation in the dentate gyrus was quantified at the end of treatment, and the number of newborn neurons was determined at 8 weeks post-stroke. Treatment with both anti-Nogo-A and control antibodies stimulated the accumulation of new microglia/macrophages in the dentate granule cell layer, but neither treatment increased cellular proliferation or the number of newborn neurons above stroke-only levels. These results suggest that anti-Nogo-A immunotherapy does not increase post-stroke hippocampal neurogenesis. PMID:27803646

  3. Negative elongation factor controls energy homeostasis in cardiomyocytes.

    Science.gov (United States)

    Pan, Haihui; Qin, Kunhua; Guo, Zhanyong; Ma, Yonggang; April, Craig; Gao, Xiaoli; Andrews, Thomas G; Bokov, Alex; Zhang, Jianhua; Chen, Yidong; Weintraub, Susan T; Fan, Jian-Bing; Wang, Degeng; Hu, Yanfen; Aune, Gregory J; Lindsey, Merry L; Li, Rong

    2014-04-10

    Negative elongation factor (NELF) is known to enforce promoter-proximal pausing of RNA polymerase II (Pol II), a pervasive phenomenon observed across multicellular genomes. However, the physiological impact of NELF on tissue homeostasis remains unclear. Here, we show that whole-body conditional deletion of the B subunit of NELF (NELF-B) in adult mice results in cardiomyopathy and impaired response to cardiac stress. Tissue-specific knockout of NELF-B confirms its cell-autonomous function in cardiomyocytes. NELF directly supports transcription of those genes encoding rate-limiting enzymes in fatty acid oxidation (FAO) and the tricarboxylic acid (TCA) cycle. NELF also shares extensively transcriptional target genes with peroxisome proliferator-activated receptor α (PPARα), a master regulator of energy metabolism in the myocardium. Mechanistically, NELF helps stabilize the transcription initiation complex at the metabolism-related genes. Our findings strongly indicate that NELF is part of the PPARα-mediated transcription regulatory network that maintains metabolic homeostasis in cardiomyocytes.

  4. Effect of Three Statins on Glucose Uptake of Cardiomyocytes and its Mechanism.

    Science.gov (United States)

    Jiang, Zhenhuan; Yu, Bo; Li, Yang

    2016-08-11

    BACKGROUND The aim of this study was to investigate the effects of different statins on glucose uptake and to confirm its mechanism in primary cultured rat cardiomyocytes after administration of atorvastatin, pravastatin, and rosuvastatin. MATERIAL AND METHODS Primary cultured rat cardiomyocytes were randomly assigned to 5 groups: normal control group (OB), insulin group (S1), statin 1-μM (S2), 5-μM (S3), and 10-μM (S4) groups for 3 different statins. The 2-[3H]-DG uptake of each group was determined and the mRNA and protein expression levels of glucose transporter type 4 (GLUT4), insulin receptor substrate (IRs), and RhoA were assessed. RESULTS After treatment with different concentrations of statins and insulin, the 2-[3H]-DG uptake showed a significant negative correlation with the concentration of atorvastatin (Pstatins. CONCLUSIONS These results confirm that atorvastatin can inhibit insulin-induced glucose uptake in primary cultured rat cardiomyocytes by regulating the PI3K/Akt insulin signal transduction pathway.

  5. Cardiac regenerative potential of cardiosphere-derived cells from adult dog hearts.

    Science.gov (United States)

    Hensley, Michael Taylor; de Andrade, James; Keene, Bruce; Meurs, Kathryn; Tang, Junnan; Wang, Zegen; Caranasos, Thomas G; Piedrahita, Jorge; Li, Tao-Sheng; Cheng, Ke

    2015-08-01

    The regenerative potential of cardiosphere-derived cells (CDCs) for ischaemic heart disease has been demonstrated in mice, rats, pigs and a recently completed clinical trial. The regenerative potential of CDCs from dog hearts has yet to be tested. Here, we show that canine CDCs can be produced from adult dog hearts. These cells display similar phenotypes in comparison to previously studied CDCs derived from rodents and human beings. Canine CDCs can differentiate into cardiomyocytes, smooth muscle cells and endothelial cells in vitro. In addition, conditioned media from canine CDCs promote angiogenesis but inhibit cardiomyocyte death. In a doxorubicin-induced mouse model of dilated cardiomyopathy (DCM), intravenous infusion of canine CDCs improves cardiac function and decreases cardiac fibrosis. Histology revealed that injected canine CDCs engraft in the mouse heart and increase capillary density. Out study demonstrates the regenerative potential of canine CDCs in a mouse model of DCM.

  6. Sodium metabisulfite-induced changes on testes, spermatogenesis and epididymal morphometric values in adult rats

    Directory of Open Access Journals (Sweden)

    Shahnaz Shekarforoush

    2015-12-01

    Full Text Available Background: Sulphites are widely used as a preservative and antioxidant additives in the food and pharmaceutical industries. Many types of biological and toxicological effects of sulphites in multiple organs of mammals have been shown in previous studies. Objective: The aim of this study was to investigate the effects of sodium metabisulfite (SMB on testicular function and morphometric values of epididymis in adult male Wistar rats. Materials and Methods: A total of 32 rats were randomly divided into four groups. The experimental groups received SMB at doses of 10 mg/kg (S10, 100mg/kg (S100, and 260 mg/kg (S260 while an equal volume of normal saline was administered to the control group via gavage. The rats were anaesthetized after 28 days and the left testis with the head of epididimis was excised following abdominal incision for histological observation using hematoxylin and eosin staining. Serum samples were collected for assay of testosterone level. The initial epididymis was analyzed for motility, morphology, and the number of sperms. Result: The results of this study showed that normal morphology, count, and motility of sperms and testosterone level were decreased in the SMB treated groups. In comparison with the control group, SMB resulted in a lower total number of spermatogonia, primary spermatocyte, spermatids, and Leydig cells. Conclusion: It is suggested that SMB decreases the sperm production and has the potential to affect the fertility adversely in male rats.

  7. Sugar overconsumption during adolescence selectively alters motivation and reward function in adult rats.

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    Leandro F Vendruscolo

    Full Text Available BACKGROUND: There has been a dramatic escalation in sugar intake in the last few decades, most strikingly observed in the adolescent population. Sugar overconsumption has been associated with several adverse health consequences, including obesity and diabetes. Very little is known, however, about the impact of sugar overconsumption on mental health in general, and on reward-related behavioral disorders in particular. This study examined in rats the effects of unlimited access to sucrose during adolescence on the motivation for natural and pharmacological rewards in adulthood. METHODOLOGY/PRINCIPAL FINDINGS: Adolescent rats had free access to 5% sucrose or water from postnatal day 30 to 46. The control group had access to water only. In adulthood, rats were tested for self-administration of saccharin (sweet, maltodextrin (non-sweet, and cocaine (a potent drug of abuse using fixed- and progressive-ratio schedules, and a concentration-response curve for each substance. Adult rats, exposed or not exposed to sucrose, were tested for saccharin self-administration later in life to verify the specificity of adolescence for the sugar effects. Sugar overconsumption during adolescence, but not during adulthood, reduced the subsequent motivation for saccharin and maltodextrin, but not cocaine. This selective decrease in motivation is more likely due to changes in brain reward processing than changes in gustatory perception. CONCLUSIONS/SIGNIFICANCE: Sugar overconsumption induces a developmental stage-specific chronic depression in reward processing that may contribute to an increase in the vulnerability to reward-related psychiatric disorders.

  8. Influx mechanisms in the embryonic and adult rat choroid plexus: a transcriptome study

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    Norman Ruthven Saunders

    2015-04-01

    Full Text Available The transcriptome of embryonic and adult rat lateral ventricular choroid plexus, using a combination of RNA-Sequencing and microarray data, was analysed by functional groups of influx transporters, particularly solute carrier (SLC transporters. RNA-Seq was performed at embryonic day (E 15 and adult with additional data obtained at intermediate ages from microarray analysis. The largest represented functional group in the embryo was amino acid transporters (twelve with expression levels 2-98 times greater than in the adult. In contrast, in the adult only six amino acid transporters were up-regulated compared to the embryo and at more modest enrichment levels (<5-fold enrichment above E15. In E15 plexus five glucose transporters, in particular Glut-1, and only one monocarboxylate transporter were enriched compared to the adult, whereas only two glucose transporters but six monocarboxylate transporters in the adult plexus were expressed at higher levels than in embryos. These results are compared with earlier published physiological studies of amino acid and monocarboxylate transport in developing rodents. This comparison shows correlation of high expression of some transporters in the developing brain with higher amino acid transport activity reported previously. Data for divalent metal transporters are also considered. Immunohistochemistry of several transporters (e.g. Slc16a10, a thyroid hormone transporter gene products was carried out to confirm translational activity and to define cellular distribution of the proteins. Overall the results show that there is substantial expression of numerous influx transporters in the embryonic choroid plexus, many at higher levels than in the adult. This, together with immunohistochemical evidence and data from published physiological transport studies suggests that the choroid plexus in embryonic brain plays a major role in supplying the developing brain with essential nutrients.

  9. Spermine ameliorates ischemia/reperfusion injury in cardiomyocytes via regulation of autophagy

    Science.gov (United States)

    Duan, Qunjun; Yang, Weijun; Jiang, Daming; Tao, Kaiyu; Dong, Aiqiang; Cheng, Haifeng

    2016-01-01

    Myocardial infarction could result in high morbidity and mortality and heart diseases of children have becoming prevalent. Functions of spermine administration on cardiomyocytes remain unknown. The present study was designed to investigate the role of spermine pretreatment on myocardial ischemia/reperfusion injury (IRI). A cell model of simulated ischemia/reperfusion injury was established by incubating neonatal Sprague-Dawley rat cardiomyocytes in ischemia medium and re-cultured in normal medium. Of note, spermine pretreatment significantly reduced apoptosis and increased viability of immature cardiomyocytes. Spermine pretreatment enhanced autophagic flux as determined by confocal microscopy and transmission electron microscopy. Furthermore, proteins of mammalian target of rapamycin (mTOR) pathway were significantly reduced in response to spermine pretreatment during IRI, while proteins related to autophagy were up-regulated. The cell viability was enhanced and apoptosis decreased by rapamycin after spermine pretreatment, while these were reversed by 3-methyladenine. However, when immature cardiomyocytes were pretreated with rapamycin or 3-methyladenine, followed by IRI and spermine administration, no significant changes of viability and apoptosis were observed. In conclusion, this study suggests that spermine is a potential novel approach for preventing IRI, especially in children. PMID:27725878

  10. Constituent ratio of motor fibers from the C5-C7 spinal nerves in the radial nerve is greater in pup rats than in adult rats.

    Science.gov (United States)

    Nie, Mingbo; Chen, Liang; Gu, Yudong

    2012-06-01

    Clinically, injuries of C5-C7 of the brachial plexus cause falling of the wrist and fingers in infants but not in adults unless 4 consecutive spinal nerves are injured. The purpose of this study was to compare the constituent difference of spinal nerves in the radial nerve between pup and adult rats.A group of 16 pup rats and a group of 16 adult rats were each divided into 2 groups of 8 (P1 and A1 groups, C5-C6 were divided; P2 and A2 groups, C5-C7 were divided]). A nerve conduction study and histological examination were performed to evaluate radial nerve innervation to the extensor digitorum communis muscle after dividing the spinal nerves. Retrograde tracing with 5% cholera toxin B for anterior horn motoneurons of the spinal cord innervating the radial nerve was performed in 8 pup rats and 8 adult rats. Results showed that the division of C5-C7 caused more significant damage to radial nerve innervation to the extensor digitorum communis in pups than in adults, although the division of C5-C6 did not. In pups, the percentages (median with interquartile) of anterior horn motoneurons of the spinal cord innervating the radial nerve were 36.4 (28.3-38.5) in C5-C6, 28.1 (24.5-32.5) in C7, and 37.5 (36.5-39.3) in C8-T1. In adults, they were 24.2 (23.6-27.8) in C5-C6, 21.8 (19.5-26.3) in C7, and 50.7 (48.7-55.5) C8-T1.This study implies that C7 innervation in the radial nerve in humans may be more critical to the function of this nerve in infants than in adults.

  11. The 14-day repeated dose liver micronucleus test with methapyrilene hydrochloride using young adult rats.

    Science.gov (United States)

    Inoue, Kenji; Ochi, Akimu; Koda, Akira; Wako, Yumi; Kawasako, Kazufumi; Doi, Takaaki

    2015-03-01

    The repeated dose liver micronucleus (RDLMN) assay using young adult rats has the potential to detect genotoxic hepatocarcinogens that can be integrated into a general toxicity study. The assay methods were thoroughly validated by 19 Japanese facilities. Methapyrilene hydrochloride (MP), known to be a non-genotoxic hepatocarcinogen, was examined in the present study. MP was dosed orally at 10, 30 and 100mg/kg/day to 6-week-old male Crl:CD (SD) rats daily for 14 days. Treatment with MP resulted in an increase in micronucleated hepatocytes (MNHEPs) with a dosage of only 100mg/kg/day. At this dose level, cytotoxicity followed by regenerative cell growth was noted in the liver. These findings suggest that MP may induce clastogenic effects indirectly on the liver or hepatotoxicity of MP followed by regeneration may cause increase in spontaneous incidence of MNHEPs.

  12. Long-term effects of repeated maternal separation and ethanol intake on HPA axis responsiveness in adult rats.

    Science.gov (United States)

    Odeon, María Mercedes; Yamauchi, Laura; Grosman, Mauricio; Acosta, Gabriela Beatriz

    2017-02-15

    It has been shown that early life manipulations produce behavioral, neural, and hormonal effects. The long term consequences of repeated maternal separation (RMS) plus cold stress and ethanol intake were evaluated during adolescence and adult rats on hypothalamic-pituitary-adrenal (HPA) axis in male adult Wistar rats. RMS+ cold stress was applied from postnatal day (PD) 2 in which the pups were separated from their mothers and exposed to cold stress (4°C) 1h per day for 20days; controls remained with their mothers. Then they were exposed to either voluntary ethanol (6%) or dextrose (1%) intake for 7days: PD22-29 and PD59-66. Half of the animals were sacrificed, while the others were exposed to acute stress (AS) for 2h and then they were killed. RMS+ cold stress: a) increased voluntary ethanol intake in adolescent and adult rats; b) reduced protein expression (Western measurements) in corticotropin-releasing hormone (CRH) in hypothalamus (Hyp) and mineralocorticoid receptor (MR) in hippocampus (Hic) while increased glucocorticoid receptor (GR) in Hic; c) decreased plasmatic levels of adrenocorticotropic hormone (ACTH) and increased corticosterone (COR) levels in HPA axis, d) adult rats exposure a new AS incremented ACTH and COR levels. However, this modification did not alter the HPA axis capacity to respond to a new type of stressor. These results demonstrate the consequences of early life stress on the vulnerability of ethanol consumption and HPA axis responsiveness to a stressor in adult rats.

  13. Histological changes in kidneys of adult rats treated with Monosodium glutamate: A light microscopic study

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    Singh BR, Ujwal Gajbe, Anil Kumar Reddy, Vandana Kumbhare

    2015-01-01

    Full Text Available Introduction: Monosodium Glutamate (MSG, which is chemically known as AJI-NO-MOTO also familiar as MSG in routine life. MSG is always considered to be a controversial food additive used in the world. It is a natural excitatory neurotransmitter, helps in transmitting the fast synaptic signals in one third of CNS. Liver and kidney play a crucial role in metabolism as well as elimination of MSG from the body. Present study is to detect structural changes in adult rat kidney tissue treated with MSG; observations are done with a light microscope. Materials & Methods: The study was conducted in the department of Anatomy, J.N.M.C, Sawangi (M Wardha. Thirty (30 adult Wistar rats (2-3 months old weighing about (200 ± 20g were used in the current study, animals were divided into three groups (Group – A, B, C. Group A: Control, Group B: 3 mg /gm body weight, Group C: 6 mg /gm body weight, MSG were administered orally daily for 45 days along with the regular diet. Observations & Results: The Mean values of animals weight at the end of experiment (46th day respectively were 251.2 ± 13, 244.4 ± 19.9 and 320 ± 31.1. Early degenerative changes like, Glomerular shrinkage (GSr, loss of brush border in proximal convoluted tubules and Cloudy degeneration was observed in sections of kidney treated with 3 mg/gm body weight of MSG. Animals treated with 6 mg/gm body weight of MSG showed rare changes like interstitial chronic inflammatory infiltrate with vacuolation in some of the glomeruli, and much glomerular shrinkage invaginated by fatty lobules. Conclusion: The effects of MSG on kidney tissues of adult rats revealed that the revelatory changes are directly proportional to the doses of MSG.

  14. Neonatal stress tempers vulnerability of acute stress response in adult socially isolated rats

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    Mariangela Serra

    2014-06-01

    Full Text Available Adverse experiences occurred in early life and especially during childhood and adolescence can have negative impact on behavior later in life and the quality of maternal care is considered a critical moment that can considerably influence the development and the stress responsiveness in offspring. This review will assess how the association between neonatal and adolescence stressful experiences such as maternal separation and social isolation, at weaning, may influence the stress responsiveness and brain plasticity in adult rats. Three hours of separation from the pups (3-14 postnatal days significantly increased frequencies of maternal arched-back nursing and licking-grooming by dams across the first 14 days postpartum and induced a long-lasting increase in their blood levels of corticosterone. Maternal separation, which per sedid not modified brain and plasma allopregnanolone and corticosterone levels in adult rats, significantly reduced social isolation-induced decrease of the levels of these hormones. Moreover, the enhancement of corticosterone and allopregnanolone levels induced by foot shock stress in socially isolated animals that were exposed to maternal separation was markedly reduced respect to that observed in socially isolated animals. Our results suggest that in rats a daily brief separation from the mother during the first weeks of life, which per se did not substantially alter adult function and reactivity of hypothalamic-pituitary-adrenal (HPA axis, elicited a significant protection versus the subsequent long-term stressful experience such that induced by social isolation from weaning. Proceedings of the 10th International Workshop on Neonatology · Cagliari (Italy · October 22nd-25th, 2014 · The last ten years, the next ten years in NeonatologyGuest Editors: Vassilios Fanos, Michele Mussap, Gavino Faa, Apostolos Papageorgiou

  15. Increased astrocytic expression of metallothioneins I + II in brainstem of adult rats treated with 6-aminonicotinamide

    DEFF Research Database (Denmark)

    Penkowa, Milena; Hidalgo, Juan; Moos, Torben

    1997-01-01

    The cerebral distribution of metallothioneins I and II (MT-I + II) was studied in adult rats subjected to i.p. injection with the gliotoxin 6-aminonicotinamide (6-AN). Grey matter regions of the brainstem heralded numerous OX-42-positive macrophages and microglia, indicating that 6-AN primarily...... caused damage to this part of the brain. In the grey matter regions infiltrated with OX-42-positive cells, astrocytes identified by anti-GFAP and MT-I + II antibodies were almost absent. By contrast, in the peripheral zone of the lesioned regions numerous reactive GFAP- and MT-I + II-positive astrocytes...

  16. Combination Therapy for the Cardiovascular Effects of Perinatal Lead Exposure in Young and Adult Rats

    Energy Technology Data Exchange (ETDEWEB)

    Gaspar, Andréia Fresneda [Departamento de Farmacologia, Instituto de Biociências - Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil); Faculdade da Alta Paulista (FAP), Tupã, SP (Brazil); Cordellini, Sandra, E-mail: cordelli@ibb.unesp.br [Departamento de Farmacologia, Instituto de Biociências - Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil)

    2014-09-15

    Combination therapy can play a significant role in the amelioration of several toxic effects of lead (Pb) and recovery from associated cardiovascular changes. To investigate the effects of combination therapy on the cardiovascular effects of perinatal lead exposure in young and adult rats Female Wistar rats received drinking water with or without 500 ppm of Pb during pregnancy and lactation. Twenty-two- and 70-day-old rat offspring who were or were not exposed to Pb in the perinatal period received meso-dimercaptosuccinic acid (DMSA), L-arginine, or enalapril and a combination of these compounds for 30 additional days. Noradrenaline response curves were plotted for intact and denuded aortas from 23-, 52-, 70-, and 100-day-old rats stratified by perinatal Pb exposure (exposed/unexposed) and treatment received (treated/untreated). Systolic blood pressure was evaluated and shown to be higher in the 23-, 52-, 70-, and 100-day age groups with Pb exposure than in the corresponding control age groups: 117.8 ± 3.9*, 135.2 ± 1.3*, 139.6 ± 1.6*, and 131.7 ± 2.8*, respectively and 107.1 ± 1.8, 118.8 ± 2.1, 126.1 ± 1.1, and 120.5 ± 2.2, respectively (p < 0.05). Increased reactivity to noradrenaline was observed in intact, but not denuded, aortas from 52-, 70-, and 100-day-old exposed rats, and the maximum responses (g of tension) in the respective Pb-exposed and control age groups were as follows: 3.43 ± 0.16*, 4.32 ± 0.18*, and 4.21 ± 0.23*, respectively and 2.38 ± 0.33, 3.37 ± 0.13, and 3.22 ± 0.21, respectively (p < 0.05). All treatments reversed the changes in vascular reactivity to noradrenaline in rats perinatally exposed to Pb. The combination therapy resulted in an earlier restoration of blood pressure in Pb-exposed rats compared with the monotherapies, except for enalapril therapy in young rats. These findings represent a new approach to the development of therapeutic protocols for the treatment of Pb-induced hypertension.

  17. Impairment on sperm quality and fertility of adult rats after antiandrogen exposure during prepuberty.

    Science.gov (United States)

    Perobelli, Juliana Elaine; Alves, Thaís Regina; de Toledo, Fabíola Choqueta; Fernandez, Carla Dal Bianco; Anselmo-Franci, Janete A; Klinefelter, Gary R; Kempinas, Wilma De Grava

    2012-06-01

    This study evaluated the effects of antiandrogen exposure during the prepubertal period on reproductive development and reproductive competence in adults. Male rats were divided into two groups: flutamide, receiving 25 mg/kg/day of flutamide by oral gavage and control, receiving vehicle daily. Dosing continued from PND 21 to 44, and animals were killed on PND 50 or PND 75-80. The epididymis, prostate, vas deferens and seminal vesicle weights were lower in Flutamide group on PND 50, while on PND 80 only seminal vesicle weight was reduced. Fertility assessed by IUI revealed a decrease in the fertility potential in the flutamide-treated adults. Flutamide accelerated sperm transit time through the epididymis, impairing sperm motility and storage. A quantitative analysis of the cauda sperm membrane proteome revealed a few significant changes in protein expression. Thus, exposure to flutamide during the prepubertal period compromises the function of the epididymis along with epididymal sperm quality at adulthood.

  18. The cortical response to sensory deprivation in adult rats is affected by gonadectomy.

    Science.gov (United States)

    Mowery, Todd M; Elliott, Kevin S; Garraghty, Preston E

    2009-05-01

    The present study investigated the effects of adult-onset sensory deprivation and gonadectomy. Adult male and female rats underwent unilateral transection of the infraorbital nerve. Half of the subjects had been gonadectomized 1 week prior to the nerve injury. We found that the areas of deprived barrels were significantly reduced when compared to barrels in the contralateral control hemisphere, and that this shrinkage was independent of sex and gonadectomy. We also found significant reductions in cytochrome oxidase staining intensity in the deprived barrels. While there were no differences in the magnitude of this effect between males and females, this effect was substantially more pronounced in the gonadectomized subjects. That is, gonadal hormones appeared to play a significant neuroprotective role in the metabolic response of the barrel cortex to deprivation. Thus, either males and females have a common neuroprotective hormonal pathway, or each has a sex-specific hormone pathway that serves an equivalent neuroprotective function.

  19. Reproducible isolation of type II pneumocytes from fetal and adult rat lung using nycodenz density gradients.

    Science.gov (United States)

    Viscardi, R M; Ullsperger, S; Resau, J H

    1992-01-01

    Isolating fresh, relatively pure type II pneumocytes from the lung, particularly of fetal origin, is a difficult process. Separation by buoyant density gradient centrifugation has been used successfully to isolate adult type II cells. There is concern, however, that Percoll, a gradient medium that is commonly used for type II cell isolation, may be toxic to cells. We evaluated a new gradient medium, Nycodenz, that is (1) a true solution, (2) transparent, (3) not metabolized by cells, and (4) nontoxic to cells. Type II pneumocytes were isolated from 19- and 21-day gestation fetal and adult rat lung by elastase digestion and separated on preformed isotonic Nycodenz gradients (2 mL each of 27.6, 20.7, 13.8, and 4.6 (w/v) solutions). Type II pneumocytes were recovered from the density range 1.057-1.061 and identified by binding of FITC-conjugated and gold-complexed Maclura pomifera lectin. Cells derived from 19-day fetal lung contained abundant glycogen and reacted with a monoclonal antibody to the cytokeratins 8 and 18, which are markers of the fetal type II cell. Adult type II cells reacted with antibodies to cytokeratins 8, 18, and 19. Type II cell purity was 79.7 +/- 2.4%, 83.8 +/- 2.8%, and 82.6 +/- 1.8% (means +/- SEM) for 19- and 21-day gestation fetal and adult lung preparations, respectively. Cell viability was greater than 95%. The final cell yield for adult preparations was 17.8 +/- 2.7 x 10(6)/rat (means +/- SEM). To determine if the freshly isolated type II pneumocytes were functionally active, the incorporation of [3H]choline into phosphatidylcholine was measured. The percent saturation of phosphatidylcholine was high for both populations of freshly isolated cells. However, adult type II pneumocytes incorporated [3H]choline into phosphatidylcholine more rapidly than 21-day gestation fetal cells (5.97 x 10(-3) dpm/10(6) cells/h vs. 0.32 x 10(-3) dpm/10(6) cells/h, P less than .005). We have demonstrated that, using the Nycodenz isolation method, it is

  20. The protective effect of dioscin-containing serum on hydrogen Peroxide injured cardiomyocytes of neonate rats%薯蓣皂苷含药血清对乳鼠心肌细胞过氧化损伤的保护作用

    Institute of Scientific and Technical Information of China (English)

    郭春宏; 李欣; 康毅

    2012-01-01

    目的:采用血清药理学方法研究薯蓣皂苷对过氧化氢(H2O2)致心肌细胞过氧化损伤的保护作用.方法:采用血清药理学方法制备薯蓣皂苷含药血清(600mg·kg-1).体外培养原代乳鼠心肌细胞,随机分为DMEM对照组、过氧化损伤模型组、正常血清对照组、薯蓣皂苷低、中、高剂量干预组,分别加入不同处理因素干预2h.除DMEM对照组外,其余细胞均以终浓度为100 μmol·L -1的H2O2进行损伤2h,MTT法测定细胞存活率,并检测各组心肌细胞培养上清液中乳酸脱氢酶(LDH)、丙二醛(MDA)的含量及总超氧化物歧化酶(T-SOD)及过氧化氢酶(CAT)的活性.结果:与DMEM对照组相比,损伤模型组细胞经100μmol·L-1 H2O2处理2h后,活力降至(33.2±5.0)%(P<0.01);与损伤模型组及正常血清组比较,薯蓣皂苷低、中、高剂量干预组的心肌细胞存活率分别升至(42.3±2.5)%,(62.8±3.2)%,(74.3±2.8)%(P<0.01),呈现一定的剂量依赖性;与DMEM对照组相比,H2O2损伤后MDA、LDH含量明显升高,T-SOD、CAT活性降低(P<0.01),而薯蓣皂苷含药血清可剂量依赖性的降低损伤细胞MDA、1LDH含量(P<0.01),升高CAT、T-SOD活性(P<0.01).结论:薯蓣皂苷对H2O2诱导的心肌细胞损伤具有保护作用,机制与增强细胞抗氧化作用、减轻自由基和脂质过氧化物导致的细胞膜损伤有关.%OBJECTIVE To study the effects and mechanism of dioscin on hydrogen peroxide( H2O2) injured cardiomyocytes with a serum pharmacological method. METHODS Prepared the serum containing dioscin (600 mg·kg-1) with serum pharmacological method. Cardiomyocytes derived from neonatal rats were cultured in Dulbecco Modified Eagle Medium ( DMEM ) . The cardiomyocytes were injured with hydrogen peroxide (H2O2), and treated with the serum containing different conccrntra-tions of dioscin. The survival rates of cardiomyocytes were measured with MTT method. The contents of malondialdehyde (MDA) and

  1. Neuroprotective Effect of Melatonin Against PCBs Induced Behavioural, Molecular and Histological Changes in Cerebral Cortex of Adult Male Wistar Rats.

    Science.gov (United States)

    Bavithra, S; Selvakumar, K; Sundareswaran, L; Arunakaran, J

    2017-02-01

    There is ample evidence stating Polychlorinated biphenyls (PCBs) as neurotoxins. In the current study, we have analyzed the behavioural impact of PCBs exposure in adult rats and assessed the simultaneous effect of antioxidant melatonin against the PCBs action. The rats were grouped into four and treated intraperitoneally with vehicle, PCBs, PCBs + melatonin and melatonin alone for 30 days, respectively. After the treatment period the rats were tested for locomotor activity and anxiety behaviour analysis. We confirmed the neuronal damage in the cerebral cortex by molecular and histological analysis. Our data indicates that there is impairment in locomotor activity and behaviour of PCBs treated rats compared to control. The simultaneous melatonin treated rat shows increased motor coordination and less anxiety like behaviour compared to PCBs treated rats. Molecular and histological analysis supports that, the impaired motor coordination in PCBs treated rats is due to neurodegeneration in motor cortex region. The results proved that melatonin treatment improved the motor co-ordination and reduced anxiety behaviour, prevented neurodegeneration in the cerebral cortex of PCBs-exposed adult male rats.

  2. Ovariectomy results in variable changes in nociception, mood and depression in adult female rats.

    Directory of Open Access Journals (Sweden)

    Li-Hong Li

    Full Text Available Decline in the ovarian hormones with menopause may influence somatosensory, cognitive, and affective processing. The present study investigated whether hormonal depletion alters the nociceptive, depressive-like and learning behaviors in experimental rats after ovariectomy (OVX, a common method to deplete animals of their gonadal hormones. OVX rats developed thermal hyperalgesia in proximal and distal tail that was established 2 weeks after OVX and lasted the 7 weeks of the experiment. A robust mechanical allodynia was also occurred at 5 weeks after OVX. In the 5th week after OVX, dilute formalin (5%-induced nociceptive responses (such as elevating and licking or biting during the second phase were significantly increased as compared to intact and sham-OVX females. However, chronic constriction injury (CCI of the sciatic nerve-induced mechanical allodynia did not differ as hormonal status (e.g. OVX and ovarian intact. Using formalin-induced conditioned place avoidance (F-CPA, which is believed to reflect the pain-related negative emotion, we further found that OVX significantly attenuated F-CPA scores but did not alter electric foot-shock-induced CPA (S-CPA. In the open field and forced swimming test, there was an increase in depressive-like behaviors in OVX rats. There was no detectable impairment of spatial performance by Morris water maze task in OVX rats up to 5 weeks after surgery. Estrogen replacement retrieved OVX-induced nociceptive hypersensitivity and depressive-like behaviors. This is the first study to investigate the impacts of ovarian removal on nociceptive perception, negative emotion, depressive-like behaviors and spatial learning in adult female rats in a uniform and standard way.

  3. Ethidium bromide-induced demyelination of the sciatic nerve of adult Wistar rats

    Directory of Open Access Journals (Sweden)

    Riet-Correa G.

    2002-01-01

    Full Text Available Peripheral nerve ultrastructure was assessed after single or multiple local injections of the intercalating dye ethidium bromide. Thirty-four adult Wistar rats of both sexes were divided into five groups and maintained in a controlled environment with rat chow and water ad libitum throughout the experiment. The experimental animals were injected with 1 µl of 0.1% ethidium bromide in 0.9% saline into the central third of the left sciatic nerve 1 (group 1, 2 (group 2, 4 (group 3, 6 (group 4 or 8 (group 5 times. In groups 2 to 5 the injections were made at 28-day intervals. Control animals received the same amount of 0.9% saline. The animals were killed at different times after injection: group 1 at 7 days (2 rats and 15 days (2 rats; for groups 2, 3, 4 and 5, all rats were killed 10 days after the last injection and the lesions were investigated by light and transmission electron microscopy. In the acute lesions, intoxicated Schwann cells showed a vacuolated cytoplasm and separation of the sheaths from the axon. Myelin sheaths underwent progressive vesiculation and subsequent segmental demyelination. Myelin debris were withdrawn by macrophages and remyelination by Schwann cells was prominent. With the increase in the number of injections collagen fibers also increased in number and progressively enveloped smaller numbers of remyelinated axons composing new fascicles. Wallerian degeneration of fibers apparently not affected by ethidium bromide was more intense in the nerves from groups 4 and 5. The peripheral nerve repairs itself after demyelinating challenges with a profusion of collagen fibers and new fasciculations. This experimental model is valid to mimic recurrent demyelinating neuropathies.

  4. The social behavior of male rats administered an adult-onset calorie restriction regimen.

    Science.gov (United States)

    Govic, Antonina; Levay, Elizabeth A; Kent, Stephen; Paolini, Antonio G

    2009-03-23

    The behavioral outcomes of a calorie restricted diet are often neglected in favour of a more physiological examination of the consequences of calorie restriction (CR). This is especially the case with social behavior. A few findings within the maternal CR literature suggest that adult male social behavior is altered by this regimen. Despite the paucity of findings within the maternal CR literature, a systematic investigation of the behavioral phenotype of males administered an adult-onset CR is completely lacking and was the focus of the current study. Adult male hooded Wistar rats were administered a three week CR, with one group receiving a 25% CR and another group receiving a 50% CR before male-to-male social behavior was examined and compared with ad libitium fed males. Various behavioral elements were modulated by CR, both the CR25% and 50% group initiated contact sooner and engaged in greater social activity compared to the ad libitum fed controls. The CR25% group also demonstrated less non-social (self-grooming) behavior and a greater frequency of walkovers compared to all groups, indicating a propensity towards dominance. The CR50% group demonstrated greater environmental assessment/exploration, as measured by the frequency of rearing. As with the maternal CR literature, an adult-onset chronic CR induces a more socially active behavioral phenotype and reduces interest in non-social behavior in the moderately CR group. Taken together, the social behavioral phenotype can be modulated by a CR initiated and maintained during adulthood.

  5. Immunohistochemical distribution of Plexin A4 in the adult rat central nervous system

    Directory of Open Access Journals (Sweden)

    Claire-Anne Gutekunst

    2010-07-01

    Full Text Available PlexinA4 is the latest member to be identified of the plexin A subfamily, critical transducers of class 3 semaphorin signaling as co-receptors to neuropilins 1 and 2. Despite functional information regarding the role of PlexinA4 in development and guidance of specific neuronal pathways, little is known about its distribution in the adult central nervous system (CNS. Here we report an in depth immunohistochemical analysis of PlexinA4 expression in the adult rat CNS. PlexinA4 staining was present in neurons and fibers throughout the brain and spinal cord, including neocortex, hippocampus, lateral hypothalamus, red nucleus, facial nucleus and the mesencephalic trigeminal nucleus. PlexinA4 antibodies labeled fibers in the lateral septum, nucleus accumbens, several thalamic nuclei, substantia nigra pars reticulata, zona incerta, pontine reticular region, as well as in several cranial nerve nuclei. This constitutes the first detailed description of the topographic distribution of PlexinA4 in the adult CNS and will set the basis for future studies on the functional implications of PlexinA4 in adult brain physiology.

  6. Embryonic template-based generation and purification of pluripotent stem cell-derived cardiomyocytes for heart repair

    NARCIS (Netherlands)

    Dierickx, P.; Doevendans, P.A.; Geijsen, N.; van Laake, L.W.

    2012-01-01

    Cardiovascular disease remains a leading cause of death in Western countries. Many types of cardiovascular diseases are due to a loss of functional cardiomyocytes, which can result in irreversible cardiac failure. Since the adult human heart has limited regenerative potential, cardiac transplantatio

  7. Cardiomyocyte Marker Expression in Mouse Embryonic Fibroblasts by Cell-Free Cardiomyocyte Extract and Epigenetic Manipulation

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    Tahereh Talaei-Khozani

    2014-03-01

    Full Text Available Background: The regenerative capacity of the mammalian heart is quite limited. Recent reports have focused on reprogramming mesenchymal stem cells into cardiomyocytes. We investigated whether fibroblasts could transdifferentiate into myocardium. Methods: Mouse embryonic fibroblasts were treated with Trichostatin A (TSA and 5-Aza-2-Deoxycytidine (5-aza-dC. The treated cells were permeabilized with streptolysin O and exposed to the mouse cardiomyocyte extract and cultured for 1, 10, and 21 days. Cardiomyocyte markers were detected by immunohistochemistry. Alkaline phosphatase activity and OCT4 were also detected in cells treated by chromatin-modifying agents. Results: The cells exposed to a combination of 5-aza-dC and TSA and permeabilized in the presence of the cardiomyocyte extract showed morphological changes. The cells were unable to express cardiomyocyte markers after 24 h. Immunocytochemical assays showed a notable degree of myosin heavy chain and α-actinin expressions after 10 days. The expression of the natriuretic factor and troponin T occurred after 21 days in these cells. The cells exposed to chromatin-modifying agents also expressed cardiomyocyte markers; however, the proportion of reprogrammed cells was clearly smaller than that in the cultures exposed to 5-aza-dC , TSA, and extract. Conclusion: It seems that the fibroblasts were able to eliminate the previous epigenetic markers and form new ones according to the factors existing in the extract. Since no beating was observed, at least up to 21 days, the cells may need an appropriate extracellular matrix for their function.

  8. Resveratrol increases antioxidant defenses and decreases proinflammatory cytokines in hippocampal astrocyte cultures from newborn, adult and aged Wistar rats.

    Science.gov (United States)

    Bellaver, Bruna; Souza, Débora Guerini; Souza, Diogo Onofre; Quincozes-Santos, André

    2014-06-01

    Astrocytes are responsible for modulating neurotransmitter systems and synaptic information processing, ionic homeostasis, energy metabolism, maintenance of the blood-brain barrier, and antioxidant and inflammatory responses. Our group recently published a culture model of cortical astrocytes obtained from adult Wistar rats. In this study, we established an in vitro model for hippocampal astrocyte cultures from adult (90 days old) and aged (180 days old) Wistar rats. Resveratrol, a polyphenol found in grapes and red wine, exhibits antioxidant, anti-inflammatory, anti-aging and neuroprotective effects that modulate glial functions. Here, we evaluated the effects of resveratrol on GSH content, GS activity, TNF-α and IL-1β levels in hippocampal astrocytes from newborn, adult and aged Wistar rats. We observed a decrease in antioxidant defenses and an increase in the inflammatory response in hippocampal astrocytes from adult and aged rats compared to classical astrocyte cultures from newborn rats. Resveratrol prevented these effects. These findings reinforce the neuroprotective effects of resveratrol, which are mainly associated with antioxidant and anti-inflammatory activities.

  9. Hepatotrophic activity of benzodiazepine drugs in adult rats of either sex.

    Science.gov (United States)

    Gershbein, L L

    1994-07-01

    Adult rats with two-thirds of the liver removed were administered diets supplemented with benzodiazepine drugs over a period of 10 days and the mass of organ regenerated or the liver increment ascertained. For a number of the drugs, liver regeneration was stimulated; the effect was more consistent and reproducible in the adult female. On the basis of the lower sensitivity of the male, such animals provided an approach toward rating the hepatotrophic efficacy of the agents and in relation to structure. According to the current classification, hepatotrophic activity was higher with lorazepam, loprazolam, oxazepam and chlordiazepoxide; intermediate with nitrazepam, temazepam, quazepam, halazepam and triazepam and lower with diazepam, clorazepate dipotassium, clobazam and alprazolam. More reproducible responses in terms of g wet and dry liver per 100 g body weight were obtained with sham-operated or intact males. The antagonist, flumazenil, fed at 0.080% was not effective as such nor modified the responses in admixture with several drugs in partially hepatectomized or intact males. In vivo hepatic microsomal changes in protein, cytochrome P-450 or the enzymes, aminopyrine demethylase and benzo[a]pyrene hydroxylase with the various series were not remarkable or sporadic. Among other factors, the liver incremental changes noted currently are dependent on the metabolic intermediate benzodiazepines of varying elimination half-lives which may be distinct from that of the parent drug coupled with the alterations induced by partial ablation of the organ in rats of either sex.

  10. Stem cells in the adult rat spinal cord: plasticity after injury and treadmill training exercise.

    Science.gov (United States)

    Foret, Ariane; Quertainmont, Renaud; Botman, Olivier; Bouhy, Delphine; Amabili, Philippe; Brook, Gary; Schoenen, Jean; Franzen, Rachelle

    2010-02-01

    Ependymal cells located around the central canal of the adult spinal cord are considered as a source of neural stem cells (NSCs) and represent an interesting pool of endogenous stem cells for repair strategies. Physical exercise is known to increase ependymal cell proliferation, while improving functional recovery. In this work, we further characterized those endogenous NSCs within the normal and injured adult rat spinal cord and investigated the effects of treadmill training using immunohistochemical and behavioral studies. In uninjured untrained rats, Sox-2, a NSC marker, was detected in all ependymal cells of the central canal, and also scattered throughout the parenchyma of the spinal cord. Within the lesion, Sox-2 expression increased transiently, while the number of nestin-positive ependymal cells increased with a concomitant enhancement of proliferation, as indicated by the mitotic markers Ki67 and bromo-deoxyuridine. Exercise, which improved functional recovery and autonomous micturition, maintained nestin expression in both injured and uninjured spinal cords, with a positive correlation between locomotor recovery and the number of nestin-positive cells.

  11. Cortical neurogenesis in adult rats after ischemic brain injury:most new neurons fail to mature

    Institute of Scientific and Technical Information of China (English)

    Qing-quan Li; Guan-qun Qiao; Jun Ma; Hong-wei Fan; Ying-bin Li

    2015-01-01

    The present study examines the hypothesis that endogenous neural progenitor cells isolated from the neocortex of ischemic brain can differentiate into neurons or glial cells and contribute to neural regeneration. We performed middle cerebral artery occlusion to establish a model of cerebral ischemia/reperfusion injury in adult rats. Immunohistochemical staining of the cortex 1, 3, 7, 14 or 28 days after injury revealed that neural progenitor cells double-positive for nestin and sox-2 appeared in the injured cortex 1 and 3 days post-injury, and were also positive for glial ifbrillary acidic protein. New neurons were labeled using bromodeoxyuridine and different stages of maturity were identiifed using doublecortin, microtubule-associated protein 2 and neuronal nuclei antigen immunohistochemistry. Immature new neurons coexpressing doublecortin and bromodeoxyuridine were observed in the cortex at 3 and 7 days post-injury, and semi-mature and mature new neurons double-positive for microtubule-associated protein 2 and bromode-oxyuridine were found at 14 days post-injury. A few mature new neurons coexpressing neuronal nuclei antigen and bromodeoxyuridine were observed in the injured cortex 28 days post-injury. Glial ifbrillary acidic protein/bromodeoxyuridine double-positive astrocytes were also found in the injured cortex. Our ifndings suggest that neural progenitor cells are present in the damaged cortex of adult rats with cerebral ischemic brain injury, and that they differentiate into astrocytes and immature neurons, but most neurons fail to reach the mature stage.

  12. Subacute toxicity assessment of diflubenzuron, an insect growth regulator, in adult male rats.

    Science.gov (United States)

    de Barros, Aline Lima; Cavalheiro, Gabriela Finoto; de Souza, Alexsandra Vila Maior; Traesel, Giseli Karenina; Anselmo-Franci, Janete A; Kassuya, Cândida Aparecida Leite; Arena, Arielle Cristina

    2016-04-01

    Diflubenzuron (DFB), an insecticide and acaricide insect growth regulator, can be used in agriculture against insect predators and in public health programs, to control insects and vectors, mainly Aedes aegypti larvae. Due to the lack of toxicological assessments of this compound, the objective of the present study was to evaluate the toxicological effects of subacute exposure to the DFB insecticide in adult male rats. Adult male rats were exposed (gavage) to 0, 2, 4, or 8 mg/kg of DFB for 28 days. No clinical signs of toxicity were observed in the DFB-treated animals of the experimental groups. However, there was an increase in serum levels of alanine aminotransferase in the group that received 8 mg/kg/DFB/day and urea at doses of 4 and 8 mg/kg/DFB/day, without altering other biochemical or hematological parameters. The subacute exposure to the lowest dose of DFB caused significant decrease in testis weight, daily sperm production, and in number of sperm in the epididymis in relation to the control group. However, no alterations were observed in the sperm morphology, testicular, epididymis, liver and kidney histology, or testosterone levels. These findings unveiled the hazardous effects of DFB on male reproduction after the subacute exposure and special attention should be addressed to the effects of low doses of this pesticide.

  13. Fluoxetine Dose and Administration Method Differentially Affect Hippocampal Plasticity in Adult Female Rats

    Directory of Open Access Journals (Sweden)

    Jodi L. Pawluski

    2014-01-01

    Full Text Available Selective serotonin reuptake inhibitor medications are one of the most common treatments for mood disorders. In humans, these medications are taken orally, usually once per day. Unfortunately, administration of antidepressant medications in rodent models is often through injection, oral gavage, or minipump implant, all relatively stressful procedures. The aim of the present study was to investigate how administration of the commonly used SSRI, fluoxetine, via a wafer cookie, compares to fluoxetine administration using an osmotic minipump, with regards to serum drug levels and hippocampal plasticity. For this experiment, adult female Sprague-Dawley rats were divided over the two administration methods: (1 cookie and (2 osmotic minipump and three fluoxetine treatment doses: 0, 5, or 10 mg/kg/day. Results show that a fluoxetine dose of 5 mg/kg/day, but not 10 mg/kg/day, results in comparable serum levels of fluoxetine and its active metabolite norfluoxetine between the two administration methods. Furthermore, minipump administration of fluoxetine resulted in higher levels of cell proliferation in the granule cell layer (GCL at a 5 mg dose compared to a 10 mg dose. Synaptophysin expression in the GCL, but not CA3, was significantly lower after fluoxetine treatment, regardless of administration method. These data suggest that the administration method and dose of fluoxetine can differentially affect hippocampal plasticity in the adult female rat.

  14. Impact of neonatal anoxia on adult rat hippocampal volume, neurogenesis and behavior.

    Science.gov (United States)

    Takada, Silvia Honda; Motta-Teixeira, Lívia Clemente; Machado-Nils, Aline Vilar; Lee, Vitor Yonamine; Sampaio, Carlos Alberto; Polli, Roberson Saraiva; Malheiros, Jackeline Moraes; Takase, Luiz Fernando; Kihara, Alexandre Hiroaki; Covolan, Luciene; Xavier, Gilberto Fernando; Nogueira, Maria Inês

    2016-01-01

    Neonates that suffer oxygen deprivation during birth can have long lasting cognitive deficits, such as memory and learning impairments. Hippocampus, one of the main structures that participate in memory and learning processes, is a plastic and dynamic structure that conserves during life span the property of generating new cells which can become neurons, the so-called neurogenesis. The present study investigated whether a model of rat neonatal anoxia, that causes only respiratory distress, is able to alter the hippocampal volume, the neurogenesis rate and has functional implications in adult life. MRI analysis revealed significant hippocampal volume decrease in adult rats who had experienced neonatal anoxia compared to control animals for rostral, caudal and total hippocampus. In addition, these animals also had 55.7% decrease of double-labelled cells to BrdU and NeuN, reflecting a decrease in neurogenesis rate. Finally, behavioral analysis indicated that neonatal anoxia resulted in disruption of spatial working memory, similar to human condition, accompanied by an anxiogenic effect. The observed behavioral alterations caused by oxygen deprivation at birth might represent an outcome of the decreased hippocampal neurogenesis and volume, evidenced by immunohistochemistry and MRI analysis. Therefore, based on current findings we propose this model as suitable to explore new therapeutic approaches.

  15. Renoprotective effects of moringa oleifera leaf extract on the kidneys of adult wistar rats

    Directory of Open Access Journals (Sweden)

    Ezejindu D. N

    2016-07-01

    Full Text Available Moringa oleifera is one of several nutritional supplements giving wide spread popularity in Nigeria and many other countries of the world. The leaves and flowers are being used by the population with great dietary importance. The aim of this study is to investigate the effects of oral administration of Moringa oleifera leaf extract on the kidneys of adult wistar rats. 24 apparently healthy adult wistar rats weighing between190- 230kg were divided into four groups of six animals each. Group A served as the control and received 0.3ml of distilled water orally. The experimental groups B, C & D received 0.5ml, 0.6ml &0.7ml of Moringa oleifera extract orally respectively. The administration lasted for twenty one days. The animals were weighed, sacrificed using chloroform vapour. The kidney tissue were removed, weighed and trimmed down for histological studies. Result of this study showed non-distortion of the kidney cells. The findings of this study suggest that chronic Moringa oleifera consumption may not put the kidneys at risk of adverse histopathological conditions.

  16. Bisphenol A exposure at an environmentally relevant dose induces meiotic abnormalities in adult male rats.

    Science.gov (United States)

    Liu, Chuan; Duan, Weixia; Zhang, Lei; Xu, Shangcheng; Li, Renyan; Chen, Chunhai; He, Mindi; Lu, Yonghui; Wu, Hongjuan; Yu, Zhengping; Zhou, Zhou

    2014-01-01

    Whether environmental exposure to bisphenol A (BPA) may induce reproductive disorders is still controversial but certain studies have reported that BPA may cause meiotic abnormalities in C. elegans and female mice. However, little is known about the effect of BPA on meiosis in adult males. To determine whether BPA exposure at an environmentally relevant dose could induce meiotic abnormalities in adult male rats, we exposed 9-week-old male Wistar rats to BPA by gavage at 20 μg/kg body weight (bw)/day for 60 consecutive days. We found that BPA significantly increased the proportion of stage VII seminiferous epithelium and decreased the proportion of stage VIII. Consequently, spermiation was inhibited and spermatogenesis was disrupted. Further investigation revealed that BPA exposure delayed meiosis initiation in the early meiotic stage and induced the accumulation of chromosomal abnormalities and meiotic DNA double-strand breaks (DSBs) in the late meiotic stage. The latter event subsequently activated the phosphatidylinositol 3-kinase-related protein kinase (ATM). Our results suggest that long-term exposure to BPA may lead to continuous meiotic abnormalities and ultimately put mammalian reproductive health at risk.

  17. Effects of Extremely Low Frequency Electromagnetic Fields on Vascular Permeability of Circumventricular Organs in the Adult Rat

    Science.gov (United States)

    Gutiérrez-Mercado, Y. K.; Cañedo-Dorantes, L.; Bañuelos-Pineda, J.; Serrano-Luna, G.; Feria-Velasco, A.

    2008-08-01

    The present work deals with the effects of extremely low frequency electromagnetic fields (ELF-EMF) on blood vessels permeability to non liposoluble substances of the circumventricular organs (CVO) of adult rats. Male Wistar adult rats were exposed to ELF-EMF and vascular permeability to colloidal carbon was investigated with the use of histological techniques. Results were compared to corresponding data from sham-exposed and control groups of animals. Exposure to ELF-EMF increased the CVO vascular permeability to colloidal carbon intravascularly injected, particularly in the subfornical organ, the median eminence, the pineal gland and the area postrema.

  18. Increased adult hippocampal brain-derived neurotrophic factor and normal levels of neurogenesis in maternal separation rats.

    Science.gov (United States)

    Greisen, Mia H; Altar, C Anthony; Bolwig, Tom G; Whitehead, Richard; Wörtwein, Gitta

    2005-03-15

    Repeated maternal separation of rat pups during the early postnatal period may affect brain-derived neurotrophic factor (BDNF) or neurons in brain areas that are compromised by chronic stress. In the present study, a highly significant increase in hippocampal BDNF protein concentration was found in adult rats that as neonates had been subjected to 180 min of daily separation compared with handled rats separated for 15 min daily. BDNF protein was unchanged in the frontal cortex and hypothalamus/paraventricular nucleus. Expression of BDNF mRNA in the CA1, CA3, or dentate gyrus of the hippocampus or in the paraventricular hypothalamic nucleus was not affected by maternal separation. All animals displayed similar behavioral patterns in a forced-swim paradigm, which did not affect BDNF protein concentration in the hippocampus or hypothalamus. Repeated administration of bromodeoxyuridine revealed equal numbers of surviving, newly generated granule cells in the dentate gyrus of adult rats from the 15 min or 180 min groups. The age-dependent decline in neurogenesis from 3 months to 7 months of age did not differ between the groups. Insofar as BDNF can stimulate neurogenesis and repair, we propose that the elevated hippocampal protein concentration found in maternally deprived rats might be a compensatory reaction to separation during the neonatal period, maintaining adult neurogenesis at levels equal to those of the handled rats.

  19. Loss of mitochondrial exo/endonuclease EXOG affects mitochondrial respiration and induces ROS-mediated cardiomyocyte hypertrophy.

    Science.gov (United States)

    Tigchelaar, Wardit; Yu, Hongjuan; de Jong, Anne Margreet; van Gilst, Wiek H; van der Harst, Pim; Westenbrink, B Daan; de Boer, Rudolf A; Silljé, Herman H W

    2015-01-15

    Recently, a locus at the mitochondrial exo/endonuclease EXOG gene, which has been implicated in mitochondrial DNA repair, was associated with cardiac function. The function of EXOG in cardiomyocytes is still elusive. Here we investigated the role of EXOG in mitochondrial function and hypertrophy in cardiomyocytes. Depletion of EXOG in primary neonatal rat ventricular cardiomyocytes (NRVCs) induced a marked increase in cardiomyocyte hypertrophy. Depletion of EXOG, however, did not result in loss of mitochondrial DNA integrity. Although EXOG depletion did not induce fetal gene expression and common hypertrophy pathways were not activated, a clear increase in ribosomal S6 phosphorylation was observed, which readily explains increased protein synthesis. With the use of a Seahorse flux analyzer, it was shown that the mitochondrial oxidative consumption rate (OCR) was increased 2.4-fold in EXOG-depleted NRVCs. Moreover, ATP-linked OCR was 5.2-fold higher. This increase was not explained by mitochondrial biogenesis or alterations in mitochondrial membrane potential. Western blotting confirmed normal levels of the oxidative phosphorylation (OXPHOS) complexes. The increased OCR was accompanied by a 5.4-fold increase in mitochondrial ROS levels. These increased ROS levels could be normalized with specific mitochondrial ROS scavengers (MitoTEMPO, mnSOD). Remarkably, scavenging of excess ROS strongly attenuated the hypertrophic response. In conclusion, loss of EXOG affects normal mitochondrial function resulting in increased mitochondrial respiration, excess ROS production, and cardiomyocyte hypertrophy.

  20. SarcOptiM for ImageJ: high-frequency online sarcomere length computing on stimulated cardiomyocytes.

    Science.gov (United States)

    Pasqualin, Côme; Gannier, François; Yu, Angèle; Malécot, Claire O; Bredeloux, Pierre; Maupoil, Véronique

    2016-08-01

    Accurate measurement of cardiomyocyte contraction is a critical issue for scientists working on cardiac physiology and physiopathology of diseases implying contraction impairment. Cardiomyocytes contraction can be quantified by measuring sarcomere length, but few tools are available for this, and none is freely distributed. We developed a plug-in (SarcOptiM) for the ImageJ/Fiji image analysis platform developed by the National Institutes of Health. SarcOptiM computes sarcomere length via fast Fourier transform analysis of video frames captured or displayed in ImageJ and thus is not tied to a dedicated video camera. It can work in real time or offline, the latter overcoming rotating motion or displacement-related artifacts. SarcOptiM includes a simulator and video generator of cardiomyocyte contraction. Acquisition parameters, such as pixel size and camera frame rate, were tested with both experimental recordings of rat ventricular cardiomyocytes and synthetic videos. It is freely distributed, and its source code is available. It works under Windows, Mac, or Linux operating systems. The camera speed is the limiting factor, since the algorithm can compute online sarcomere shortening at frame rates >10 kHz. In conclusion, SarcOptiM is a free and validated user-friendly tool for studying cardiomyocyte contraction in all species, including human.

  1. SOX6 and PDCD4 enhance cardiomyocyte apoptosis through LPS-induced miR-499 inhibition.

    Science.gov (United States)

    Jia, Zhuqing; Wang, Jiaji; Shi, Qiong; Liu, Siyu; Wang, Weiping; Tian, Yuyao; Lu, Qin; Chen, Ping; Ma, Kangtao; Zhou, Chunyan

    2016-02-01

    Sepsis-induced cardiac apoptosis is one of the major pathogenic factors in myocardial dysfunction. As it enhances numerous proinflammatory factors, lipopolysaccharide (LPS) is considered the principal mediator in this pathological process. However, the detailed mechanisms involved are unclear. In this study, we attempted to explore the mechanisms involved in LPS-induced cardiomyocyte apoptosis. We found that LPS stimulation inhibited microRNA (miR)-499 expression and thereby upregulated the expression of SOX6 and PDCD4 in neonatal rat cardiomyocytes. We demonstrate that SOX6 and PDCD4 are target genes of miR-499, and they enhance LPS-induced cardiomyocyte apoptosis by activating the BCL-2 family pathway. The apoptosis process enhanced by overexpression of SOX6 or PDCD4, was rescued by the cardiac-abundant miR-499. Overexpression of miR-499 protected the cardiomyocytes against LPS-induced apoptosis. In brief, our results demonstrate the existence of a miR-499-SOX6/PDCD4-BCL-2 family pathway in cardiomyocytes in response to LPS stimulation.

  2. Magnetic resonance imaging of the normal and chronically injured adult rat spinal cord in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Guizar-Sahagun, G. (Centro de Investigacion del Proyecto Camina, Mexico City (Mexico) Dept. of Clinical Research in Neurology and Neurosurgery, Hospital de Especialidades, Centro Medico Nacional Siglo XXI, Inst. Mexicano del Seguro Social, Mexico City (Mexico)); Rivera, F. (Centro de Investigacion del Proyecto Camina, Mexico City (Mexico)); Babinski, E. (Centro de Investigacion del Proyecto Camina, Mexico City (Mexico)); Berlanga, E. (Dept. of Magnetic Resonance Imaging, Hospital Angeles del Pedregal, Mexico City (Mexico)); Madrazo, M. (Dept. of Magnetic Resonance Imaging, Hospital Angeles del Pedregal, Mexico City (Mexico)); Franco-Bourland, R. (Centro de Investigacion del Proyecto Camina, Mexico City (Mexico) Dept. of Biochemistry, Inst. Nacional de la Nutricion, Mexico City (Mexico)); Grijalva, I. (Centro de Investigacion del Proyecto Camina, Mexico City (Mexico) Dept. of Clinical Research in Neurology and Neurosurgery, Hospital de Especialidades, Centro Medico Nacional Siglo

    1994-08-01

    We assessed the capacity of MRI to show and characterise the spinal cord (SC) in vivo in normal and chronically injured adult rats. In the chronically injured animals the SC was studied by MRI and histological examination. MRI was performed at 1.5 T, using gradient-echo and spin-echo (SE) sequences, the latter with and without gadolinium-DTPA (Gd-DTPA). Several positions were tried for good alignment and to diminish interference by respiratory movements. Images of the SC were obtained in sagittal, coronal, and axial planes. Normal SC was observed as a continuous intensity in both sequences, although contrast resolution was better using SE; it was not possible to differentiate the grey and white matter. Low signal was seen in the damaged area in chronically injured rats, which corresponded to cysts, trabeculae, mononuclear infiltrate, and fibroglial wall on histological examination. Gd-DTPA failed to enhance the SC in normal or chronically injured rats. It did, however, cause enhancement of the lesion after acute SC injury. (orig.)

  3. PROLIFERATION AND DIFFERENTIATION OF NEURAL STEM CELLS IN ADULT RATS AFTER CEREBRAL INFARCTION

    Institute of Scientific and Technical Information of China (English)

    Bo Zhang; Ren-zhi Wang; Yong Yao; Zhi-hai Liu; Zhi-gang Lian; Yu-jie Zou; Yu-kui Wei

    2004-01-01

    Objective To investigate proliferation and differentiation of neural stem cells in adult rats after cerebral infarction.Methods Models of cerebral infarction in rats were made and the time-course expression of bromodeoxyuridine (BrdU), Musashil, glial fibrillary acidic protein (GFAP), and neuronal nuclear antigen (NeuN) were determined by immunohistochemistry and immunofluorescence staining. BrdU and Musashil were used to mark dividing neural stem cells. GFAP and NeuN were used to mark differentiating neural stem cells.Results Compared with controls, the number of BrdU-labeled and BrdU-labeled with Musashil-positive cells increased strikingly 1 day after cerebral infarction; approximately 6 fold with a peak 7 days later; markedly decreased 14 days later, but was still elevated compared with that of controls; decling to the control level 28 days later. The number of BrdU-labeled with GFAP-positive cells nearly remained unchanged in the hippocampus after cerebral infarction. The number of BrdU-labeled with NeuN-positive cells increased strikingly 14 days after cerebral infarction, reached maximum peak in the hippocampus 28 days after cerebral infarction in rats.Conclusion Cerebral infarction stimulate proliferation of inherent neural stem cells and most proliferated neural stem cells differentiate into neurons.

  4. Adrenal steroidogenesis disruption caused by HDL/cholesterol suppression in diethylstilbestrol-treated adult male rat.

    Science.gov (United States)

    Haeno, Satoko; Maeda, Naoyuki; Yamaguchi, Kousuke; Sato, Michiko; Uto, Aika; Yokota, Hiroshi

    2016-04-01

    The synthetic estrogen diethylstilbestrol is used to prevent miscarriages and as a therapeutic treatment for prostate cancer, but it has been reported to have adverse effects on endocrine homeostasis. However, the toxicity mechanism is poorly understood. Recently, we reported that diethylstilbestrol impairs adrenal steroidogenesis via cholesterol insufficiency in adult male rats. In the present study, we found that the adrenal cholesterol level was significantly reduced without of the decrease in other precursors in the adrenal steroidogenesis 24 h after a single dose of diethylstilbestrol (0.33 μg/g body mass). The serum HDL/cholesterol level was also reduced only 12 h after the diethylstilbestrol exposure. The level of Apo E, which is indispensable for HDL/cholesterol maturation, was decreased in both the HDL and VLDL/LDL fractions, whereas the level of Apo A1, which is an essential constituent of HDL, was not altered in the HDL fraction. Because the liver is a major source of Apo E and Apo A1, the secretion rates of these proteins were examined using a liver perfusion experiment. The secretion rate of Apo A1 from the liver was consistent between DES-treated and control rats, but that of Apo E was comparatively suppressed in the DES-treated rats. The disruption of adrenal steroidogenesis by diethylstilbestrol was caused by a decrease in serum HDL/cholesterol, which is the main source of adrenal steroidogenesis, due to the inhibition of Apo E secretion from the liver.

  5. Circadian variations in expression of the trkB receptor in adult rat hippocampus.

    Science.gov (United States)

    Dolci, Claudia; Montaruli, Angela; Roveda, Eliana; Barajon, Isabella; Vizzotto, Laura; Grassi Zucconi, Gigliola; Carandente, Franca

    2003-12-19

    The expression of brain-derived neurotrophic factor (BDNF) in the central nervous system (CNS) and the expression of its high-affinity trkB receptor on neuron surfaces are known to depend on neuron activity. The expression of BDNF (mRNA and protein) and trkB mRNA shows circadian oscillations in rat hippocampal homogenates. We investigated circadian variations in trkB expression in specific areas of the adult rat hippocampal formation by immunohistochemistry. In sets of two experiments performed in the spring, 39 2-month-old male Wistar rats were accustomed to a 12-h light-12-h dark cycle for 2 weeks. Three animals were then sacrificed every 4 h. Forty-micrometer-thick coronal sections of hippocampal formation were obtained and processed for trkB immunohistochemistry. Cell staining intensity was assessed by image analysis of different hippocampal areas on five sections per animal. Circadian rhythmicity was evaluated by the cosinor method. Statistically significant circadian variations in trkB expression were found in dentate gyrus, entorhinal cortex, and the CA3 and hilar regions of the hippocampus, with highest expression during the first half of the dark (activity) period. These findings suggest a relationship between trkB expression and the physiological neuronal activation of wakefulness. TrkB receptor expression in the hippocampal regions studied was continuous and changes were gradual over the 24-h cycle, suggesting that more complex regulatory mechanisms also intervened.

  6. Behavioral and neuroendocrine consequences of juvenile stress combined with adult immobilization in male rats.

    Science.gov (United States)

    Fuentes, Silvia; Carrasco, Javier; Armario, Antonio; Nadal, Roser

    2014-08-01

    Exposure to stress during childhood and adolescence increases vulnerability to developing several psychopathologies in adulthood and alters the activity of the hypothalamic-pituitary-adrenal (HPA) axis, the prototypical stress system. Rodent models of juvenile stress appear to support this hypothesis because juvenile stress can result in reduced activity/exploration and enhanced anxiety, although results are not always consistent. Moreover, an in-depth characterization of changes in the HPA axis is lacking. In the present study, the long-lasting effects of juvenile stress on adult behavior and HPA function were evaluated in male rats. The juvenile stress consisted of a combination of stressors (cat odor, forced swim and footshock) during postnatal days 23-28. Juvenile stress reduced the maximum amplitude of the adrenocorticotropic hormone (ACTH) levels (reduced peak at lights off), without affecting the circadian corticosterone rhythm, but other aspects of the HPA function (negative glucocorticoid feedback, responsiveness to further stressors and brain gene expression of corticotrophin-releasing hormone and corticosteroid receptors) remained unaltered. The behavioral effects of juvenile stress itself at adulthood were modest (decreased activity in the circular corridor) with no evidence of enhanced anxiety. Imposition of an acute severe stressor (immobilization on boards, IMO) did not increase anxiety in control animals, as evaluated one week later in the elevated-plus maze (EPM), but it potentiated the acoustic startle response (ASR). However, acute IMO did enhance anxiety in the EPM, in juvenile stressed rats, thereby suggesting that juvenile stress sensitizes rats to the effects of additional stressors.

  7. Effects of morphine on thermal sensitivity in adult and aged rats.

    Science.gov (United States)

    Morgan, Drake; Mitzelfelt, Jeremiah D; Koerper, Lorraine M; Carter, Christy S

    2012-06-01

    There are contradictory data regarding older individuals' sensitivity to pain stimulation and opioid administration. Adult (12-16 months; n = 10) and aged (27-31 months; n = 7) male F344xBN rats were tested in a thermal sensitivity procedure where the animal chooses to remain in one of two compartments with floors maintained at various temperatures ranging from hot (45°C) through neutral (30°C) to cold (15°C). Effects of morphine were determined for three temperature comparisons (ie, hot/neutral, cold/neutral, and hot/cold). Aged rats were more sensitive to cold stimulation during baseline. Morphine produced antinociception during hot thermal stimulation, but had no effect on cold stimulation. The antinociceptive (and locomotor-altering) effects of morphine were attenuated in aged rats. These data demonstrate age-related differences in baseline thermal sensitivity and responsiveness to opioids. Based on behavioral and physiological requirements of this procedure, it is suggested that thermal sensitivity may provide a relevant animal model for the assessment of pain and antinociception.

  8. Neonatal local noxious insult affects gene expression in the spinal dorsal horn of adult rats

    Directory of Open Access Journals (Sweden)

    Dubner Ronald

    2005-09-01

    Full Text Available Abstract Neonatal noxious insult produces a long-term effect on pain processing in adults. Rats subjected to carrageenan (CAR injection in one hindpaw within the sensitive period develop bilateral hypoalgesia as adults. In the same rats, inflammation of the hindpaw, which was the site of the neonatal injury, induces a localized enhanced hyperalgesia limited to this paw. To gain an insight into the long-term molecular changes involved in the above-described long-term nociceptive effects of neonatal noxious insult at the spinal level, we performed DNA microarray analysis (using microarrays containing oligo-probes for 205 genes encoding receptors and transporters for glutamate, GABA, and amine neurotransmitters, precursors and receptors for neuropeptides, and neurotrophins, cytokines and their receptors to compare gene expression profiles in the lumbar spinal dorsal horn (LDH of adult (P60 male rats that received neonatal CAR treatment within (at postnatal day 3; P3 and outside (at postnatal 12; P12 of the sensitive period. The data were obtained both without inflammation (at baseline and during complete Freund's adjuvant induced inflammation of the neonatally injured paw. The observed changes were verified by real-time RT-PCR. This study revealed significant basal and inflammation-associated aberrations in the expression of multiple genes in the LDH of adult animals receiving CAR injection at P3 as compared to their expression levels in the LDH of animals receiving either no injections or CAR injection at P12. In particular, at baseline, twelve genes (representing GABA, serotonin, adenosine, neuropeptide Y, cholecystokinin, opioid, tachykinin and interleukin systems were up-regulated in the bilateral LDH of the former animals. The baseline condition in these animals was also characterized by up-regulation of seven genes (encoding members of GABA, cholecystokinin, histamine, serotonin, and neurotensin systems in the LDH ipsilateral to the

  9. Neonatal local noxious insult affects gene expression in the spinal dorsal horn of adult rats.

    Science.gov (United States)

    Ren, Ke; Novikova, Svetlana I; He, Fang; Dubner, Ronald; Lidow, Michael S

    2005-09-22

    Neonatal noxious insult produces a long-term effect on pain processing in adults. Rats subjected to carrageenan (CAR) injection in one hindpaw within the sensitive period develop bilateral hypoalgesia as adults. In the same rats, inflammation of the hindpaw, which was the site of the neonatal injury, induces a localized enhanced hyperalgesia limited to this paw. To gain an insight into the long-term molecular changes involved in the above-described long-term nociceptive effects of neonatal noxious insult at the spinal level, we performed DNA microarray analysis (using microarrays containing oligo-probes for 205 genes encoding receptors and transporters for glutamate, GABA, and amine neurotransmitters, precursors and receptors for neuropeptides, and neurotrophins, cytokines and their receptors) to compare gene expression profiles in the lumbar spinal dorsal horn (LDH) of adult (P60) male rats that received neonatal CAR treatment within (at postnatal day 3; P3) and outside (at postnatal 12; P12) of the sensitive period. The data were obtained both without inflammation (at baseline) and during complete Freund's adjuvant induced inflammation of the neonatally injured paw. The observed changes were verified by real-time RT-PCR. This study revealed significant basal and inflammation-associated aberrations in the expression of multiple genes in the LDH of adult animals receiving CAR injection at P3 as compared to their expression levels in the LDH of animals receiving either no injections or CAR injection at P12. In particular, at baseline, twelve genes (representing GABA, serotonin, adenosine, neuropeptide Y, cholecystokinin, opioid, tachykinin and interleukin systems) were up-regulated in the bilateral LDH of the former animals. The baseline condition in these animals was also characterized by up-regulation of seven genes (encoding members of GABA, cholecystokinin, histamine, serotonin, and neurotensin systems) in the LDH ipsilateral to the neonatally-injured paw. The

  10. Perinatal Nicotine Exposure Increases Obesity Susceptibility in Adult Male Rat Offspring by Altering Early Adipogenesis.

    Science.gov (United States)

    Fan, Jie; Zhang, Wan-Xia; Rao, Yi-Song; Xue, Jing-Ling; Wang, Fei-Fei; Zhang, Li; Yan, You-E

    2016-11-01

    The present study aims to evaluate whether perinatal nicotine (NIC) exposure increases obesity susceptibility in adult male rat offspring by altering early adipogenesis. NIC was sc administered (2.0 mg/kg per day) to pregnant rats from gestational day 9 to the time of weaning (postnatal day 28). At weaning, NIC-exposed male pups had an increased body weight and inguinal sc fat mass and a decreased average cell area of adipocyte, which was accompanied by an overexpression of adipogenic and lipogenic genes in the epididymal white adipose tissue. Additionally, the hepatic lipogenic gene levels from NIC-exposed male pups were also affected. At 12 and 26 weeks of age, body weight and fat mass were increased, whereas there was no change in food intake in NIC-exposed male offspring. Adipogenic and lipogenic genes, glucose transporter 4, and leptin mRNA levels were increased, whereas adiponectin mRNA levels were decreased in the epididymal white adipose tissue of NIC-exposed males. The hepatic lipogenic gene expression of NIC-exposed males was increased. NIC-exposed male offspring showed normal glycemia and a higher serum insulin level, homeostasis model assessment of insulin resistance, and homeostasis model assessment of β-cell function. Furthermore, the NIC-exposed male offspring showed higher serum lipids and Castelli index I and lower nonesterified fatty acid. At 26 weeks, in the ip glucose and insulin tolerance tests, the glucose clearance was delayed, and the area under the curve was higher in the NIC-exposed male offspring. In conclusion, perinatal NIC exposure increased obesity susceptibility in adult male rat offspring by altering early adipogenesis.

  11. Subculture of proliferating adult rat hepatocytes in medium supplemented with nicotinamide and EGF.

    Science.gov (United States)

    Mitaka, T; Kojima, T; Mizuguchi, T; Mochizuki, Y

    1996-09-01

    To establish parenchymal hepatocyte cell lines, we tried to subculture the primary hepatocytes isolated from adult rats. The hepatocytes were cultured in serum-free modified Dulbecco's modified Eagle's medium supplemented with 10 mM nicotinamide and 10 ng/ml epidermal growth factor. When 6 x 10(5) cells were plated on 35-mm dishes coated with rat tail collagen, the cells proliferated and reached confluence at Day 6 to Day 8. The first subculture was carried out at Day 8 using 0.005% collagenase and gentle pipettings. Most cells were recovered and plated on the new dishes coated with the collagen (first passage). The attached cells could proliferate and reached near confluence when the cells occupied more than two-thirds of the dish surface. About a week after the first subculture, the second one was conducted. Although the number of the recovered cells was smaller than at the first passage, the cells could attach and proliferate to a certain extent. Thereafter, they were maintained for more than 2 mo, but they never overgrew. Albumin secretion into the culture medium was confirmed in the subcultured cells. Ultrastructurally, these subcultured cells possessed hepatic characteristics such as peroxisomes with a crystalline nucleiod and bile-canaliculus structures. When 10% fetal bovine serum and ascorbic acid 2-phosphate were added to the cells of the second passage, they began to proliferate very slowly. These proliferating cells were mainly mononucleate and had a small cytoplasm. In addition, some of them could differentitate into typical mature hepatocytes by forming a three-dimensional structure interacting with nonparenchymal cells. In this experiment, we showed the successful subculturing of parenchymal hepatocytes isolated from adult rats and provided evidence that the subcultured cells still have the potential to proliferate and to differentiate.

  12. The Histopathological Effect of Sildenafil Citrate on Superior Colliculus of Adult Male Rat

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    Amany Shams

    2013-08-01

    Full Text Available Objective: Preclinical and very limited clinical studies suggest that sildenafil may have therapeutic potential in selected neurological disorders. However, many neurological side effects of sildenafil have been reported. This work aimed to clarify the histopathological effect of sildenafil citrate on the superior colliculus (SC of adult male albino rat. Material and methods: 24 adult male albino rats were used and divided into 4 groups. The first 3 groups were received respectively sildenafil citrate orally at doses 0.25, 0.70 and 1.43mg/kg body weight daily for 30 days while the 4th group was used as control. At end of the treatment, the superior colliculi were undergone light and electron microscopic investigation. Results: In the control group, superficial part of the SC has neural cells and myelinated nerve fibers. With least dose of sildenafil, the superficial part of SC revealed disturbance in neural tissue with dilated capillaries and vacuoles. Some neurons showed deeply stained nuclei shrunken cytoplasm. Some cells showed enlarged mitochondria and dilated endoplasmic reticulum. With medium dose of sildenafil, SC showed more disturbances; stripped myelin sheaths or widely separated myelin lamellae, dilated blood vessels with large vacuoles around them and many neurons with apoptotic criteria. However, maximum dose of sildenafil induced massive destruction of edematous neural tissue; invasion of the surface with massive blood vessels, marked decrease in thickness of myelin sheaths and the neural cells revealed degenerative and apoptotic changes. The mean number and size of cells revealed significantly progressive decrease in all treated rats with increasing doses of the drug. Conclusion: Long-term, daily use of sildenafil can lead to pathological effect in the superior colliculus which may be implicated in visual disturbance and this effect is dose dependent, so neurological effect of sildenafil necessitates further investigations. [J

  13. Identification of interneurons activated at different inclines during treadmill locomotion in adult rats.

    Science.gov (United States)

    Tillakaratne, Niranjala J K; Duru, Paul; Fujino, Hidemi; Zhong, Hui; Xiao, Mei Si; Edgerton, V Reggie; Roy, Roland R

    2014-12-01

    By using c-fos as an activity-dependent marker, we identified the cholinergic interneurons around the central canal and lumbar interneurons throughout the gray matter that were activated after a 30-min bout of quadrupedal treadmill stepping at a 0° or 25° incline in adult rats. Increased loading (elevated treadmill incline) imposed during treadmill stepping activated more cholinergic interneurons in the proximity of the central canal, i.e., central canal cluster cells and partition neurons. Since cholinergic central canal cells are thought to modulate motoneuron excitability, these data suggest that increased load during stepping may increase motoneuronal activity through activating more cholinergic central canal cells. We identified the muscle-specific motoneurons and afferent terminals in the spinal cord by injecting cholera toxin subunit B in the soleus and tibialis anterior muscles. The number of interneurons in lumbar segments L4 (tibialis anterior) and L5 (soleus) was higher in both groups that stepped on the treadmill compared with control and was highest in rats that stepped at a 25° incline. In a majority of laminae, the distribution of total and muscle-specific activated interneurons was highest in the 25° incline group and lowest in the control group for both muscles. These data could reflect increased peripheral (proprioceptive) input as well as supraspinal drive associated with stepping and demonstrate the differences in 1) the activation of cholinergic interneurons near the central canal and 2) the laminar and segmental location of interneurons throughout the gray matter that play a role in generating stepping under different loading conditions in adult rats.

  14. Effects of H2S on the central regulation of respiration in adult rats.

    Science.gov (United States)

    Li, Hui; Hou, Xuefei; Ding, Yan; Nie, Lihong; Zhou, Hua; Nie, Zheng; Tang, Yuhong; Chen, Li; Zheng, Yu

    2014-04-16

    Hydrogen sulfide (H2S) is a gasotransmitter synthesized from cysteine (Cys) by pyridoxal-5'-phosphate-dependent enzymes. We investigated the potential roles of H2S in the regulation of central rhythmic respiration in adult rats in vivo. Sodium hydrosulfide (NaHS: 2.5 mM, 10 mM, and 5 mM) as a source of exogenous H2S, Cys (2.5 mM, 10 mM and 5 mM) as a source of endogenous H2S, 2.5 mM Cys+10 mM hydroxylamine (NH2OH), and 10 mM NH2OH, respectively, were intracerebroventricularly injected into rats. The rhythmic discharge of the diaphragm, including burst duration (BD), burst interval (BI), burst frequency (BF), and integrated amplitude (IA), and arterial blood pressure (BP) were measured at different time points. The results were analyzed by analysis of variance. A total of 2.5 mM NaHS did not significantly affect changes in BD, BI, BF, IA, or BP (P>0.05), whereas 2.5 mM Cys significantly altered BD, BI, and BF (P0.05). A concentration of 5 mM Cys had effects similar to those of 5 mM NaHS; both induced biphasic respiratory responses and changed the BF (P0.05) except for BD was temporarily decreased (P<0.05) in the 2.5 mM Cys+10 mM NH2OH group. These results suggest that exogenous and endogenous H2S may participate in the regulation of respiratory activity in adult rats.

  15. The soluble guanylyl cyclase activator bay 58-2667 selectively limits cardiomyocyte hypertrophy.

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    Jennifer C Irvine

    Full Text Available BACKGROUND: Although evidence now suggests cGMP is a negative regulator of cardiac hypertrophy, the direct consequences of the soluble guanylyl cyclase (sGC activator BAY 58-2667 on cardiac remodeling, independent of changes in hemodynamic load, has not been investigated. In the present study, we tested the hypothesis that the NO(•-independent sGC activator BAY 58-2667 inhibits cardiomyocyte hypertrophy in vitro. Concomitant impact of BAY 58-2667 on cardiac fibroblast proliferation, and insights into potential mechanisms of action, were also sought. Results were compared to the sGC stimulator BAY 41-2272. METHODS: Neonatal rat cardiomyocytes were incubated with endothelin-1 (ET(1, 60nmol/L in the presence and absence of BAY 41-2272 and BAY 58-2667 (0.01-0.3 µmol/L. Hypertrophic responses and its triggers, as well as cGMP signaling, were determined. The impact of both sGC ligands on basal and stimulated cardiac fibroblast proliferation in vitro was also determined. RESULTS: We now demonstrate that BAY 58-2667 (0.01-0.3 µmol/L elicited concentration-dependent antihypertrophic actions, inhibiting ET(1-mediated increases in cardiomyocyte 2D area and de novo protein synthesis, as well as suppressing ET(1-induced cardiomyocyte superoxide generation. This was accompanied by potent increases in cardiomyocyte cGMP accumulation and activity of its downstream signal, vasodilator-stimulated phosphoprotein (VASP, without elevating cardiomyocyte cAMP. In contrast, submicromolar concentrations of BAY 58-2667 had no effect on basal or stimulated cardiac fibroblast proliferation. Indeed, only at concentrations ≥10 µmol/L was inhibition of cardiac fibrosis seen in vitro. The effects of BAY 58-2667 in both cell types were mimicked by BAY 41-2272. CONCLUSIONS: Our results demonstrate that BAY 58-2667 elicits protective, cardiomyocyte-selective effects in vitro. These actions are associated with sGC activation and are evident in the absence of confounding

  16. Role of microRNA-195 in cardiomyocyte apoptosis induced by myocardial ischaemia–reperfusion injury

    Indian Academy of Sciences (India)

    Chang-Kui Gao; Hui Liu; Cheng-Ji Cui; Zhao-Guang Liang; Hong Yao; Ye Tian

    2016-03-01

    This study aims to investigate microRNA-195 (miR-195) expression in myocardial ischaemia–reperfusion (I/R) injury and the roles of miR-195 in cardiomyocyte apoptosis though targeting Bcl-2. A mouse model of I/R injury was established. MiR-195 expression levels were detected by real-time quantitative PCR (qPCR), and the cardiomyocyte apoptosis was detected by TUNEL assay. After cardiomyocytes isolated from neonatal rats and transfected with miR-195 mimic or inhibitor, the hypoxia/reoxygenation (H/R) injury model was established. Cardiomyocyte apoptosis and mitochondrial membrane potential were evaluated using flow cytometry. Bcl-2 and Bax mRNA expressions were detected by RT-PCR. Bcl-2, Bax and cytochrome c (Cyt-c) protein levels were determined by Western blot. Caspase-3 and caspase-9 activities were assessed by luciferase assay. Compared with the sham group, miR-195 expression levels and rate of cardiomyocyte apoptosis increased significantly in I/R group (both < 0.05). Compared to H/R + negative control (NC) group, rate of cardiomyocyte apoptosis increased in H/R + miR-195 mimic group while decreased in H/R + miR-195 inhibitor group (both < 0.05). MiR-195 knockdown alleviated the loss of mitochondrial membrane potential ( < 0.05). MiR-195 overexpression decreased Bcl-2 mRNA and protein expression, increased BaxmRNA and protein expression, Cyt-c protein expression and caspase-3 and caspase-9 activities (all < 0.05). While, downregulated MiR-195 increased Bcl-2 mRNA and protein expression, decreased Bax mRNA and protein expression, Cyt-c protein expression and caspase-3 and caspase-9 activities (all < 0.05). Our study identified that miR-195 expression was upregulated in myocardial I/R injury, and miR-195 overexpression may promote cardiomyocyte apoptosis by targeting Bcl-2 and inducing mitochondrial apoptotic pathway.

  17. High Throughput Screening Identifies a Novel Compound Protecting Cardiomyocytes from Doxorubicin-Induced Damage

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    Szabolcs Gergely

    2015-01-01

    Full Text Available Antracyclines are effective antitumor agents. One of the most commonly used antracyclines is doxorubicin, which can be successfully used to treat a diverse spectrum of tumors. Application of these drugs is limited by their cardiotoxic effect, which is determined by a lifetime cumulative dose. We set out to identify by high throughput screening cardioprotective compounds protecting cardiomyocytes from doxorubicin-induced injury. Ten thousand compounds of ChemBridge’s DIVERSet compound library were screened to identify compounds that can protect H9C2 rat cardiomyocytes against doxorubicin-induced cell death. The most effective compound proved protective in doxorubicin-treated primary rat cardiomyocytes and was further characterized to demonstrate that it significantly decreased doxorubicin-induced apoptotic and necrotic cell death and inhibited doxorubicin-induced activation of JNK MAP kinase without having considerable radical scavenging effect or interfering with the antitumor effect of doxorubicin. In fact the compound identified as 3-[2-(4-ethylphenyl-2-oxoethyl]-1,2-dimethyl-1H-3,1-benzimidazol-3-ium bromide was toxic to all tumor cell lines tested even without doxorubicine treatment. This benzimidazole compound may lead, through further optimalization, to the development of a drug candidate protecting the heart from doxorubicin-induced injury.

  18. HISTOLOGICAL STUDIES OF THE EFFECTS OF MONOSODIUM GLUTAMATE ON THE MEDIAL GENICULATE BODY OF ADULT WISTAR RATS

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    A.O.Eweka

    2007-01-01

    Full Text Available Histological effects of Monosodium glutamate (MSG commonly used as food additive on the medial geniculate body (MGB of adult wistar rats were carefully studied. The rats of both sexes (n=24, average weight of 185g were randomly assigned into two treatments (n=16 and control (n=8 groups.The rats in the treatment groups received 3g and 6g of MSG thoroughly mixed with their feeds for fourteen days, while the control rats received equal amounts of feeds without MSG added. The rats were fed with grower's mash purchased from Edo Feeds and Flour Mill Ltd, Ewu, Edo State and were given water liberally. The rats were sacrificed on day fifteen of the experiment. The medial geniculate body was carefully dissected out and quickly fixed in 10% formal saline for routine histological study after H&E method.The histological findings after H&E methods indicated that the treated sections of the medial geniculate body showed some cellular degenerative changes, autophagic vacuoles with some vacuolations appearing in the stroma, and some degree of neuronal hypertrophy when compared to the control sections. These findings indicate that MSG consumption may have a deleterious effect on the neurons of the medial geniculate body (MGB. MSG may probably have adverse effects on the auditory sensibilities by its deleterious effects on the nerve cells of the MGB of adult wistar rats. It is recommended that further studies aimed at corroborating these observations be carried out.

  19. Dissociation enzyme effects on the biophysical properties of calcium current in acutely isolated rat ventricular myocytes

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    Julio Álvarez

    2013-04-01

    Full Text Available Proteolytic enzymes such as collagenase, trypsin and pronase E are widely used to acutely dissociate adult cardiomyocytes. There is some evidence that enzyme treatment can alter ionic channels. The aim of the present investigation was to compare the characteristics of the L-type Ca2+ current (ICaL of rat ventricular cardiomyocytes dissociated with two enzyme combinations: collagenase + trypsin (C+T and collagenase + pronase E (C+P. ICaL density (pA/pF was significantly lower (~ 2 pA/pF in myocytes isolated with the C+P combination. However, its inactivation time course was barely affected. As well, the voltage dependency of ICaL kinetics was not affected by the C+P treatment. Our results suggest that, compared to the C+T, treatment with the C+P enzyme combination could decrease the number of functional (expressed channels in the sarcolemma.

  20. Perinatal Resveratrol Supplementation to Spontaneously Hypertensive Rat Dams Mitigates the Development of Hypertension in Adult Offspring.

    Science.gov (United States)

    Care, Alison S; Sung, Miranda M; Panahi, Sareh; Gragasin, Ferrante S; Dyck, Jason R B; Davidge, Sandra T; Bourque, Stephane L

    2016-05-01

    This study was undertaken to determine whether perinatal maternal resveratrol (Resv)--a phytoalexin known to confer cardiovascular protection--could prevent the development of hypertension and improve vascular function in adult spontaneously hypertensive rat offspring. Dams were fed either a control or Resv-supplemented diet (4 g/kg diet) from gestational day 0.5 until postnatal day 21. Indwelling catheters were used to assess blood pressure and vascular function in vivo; wire myography was used to assess vascular reactivity ex vivo. Perinatal Resv supplementation in dams had no effect on fetal body weights, albeit continued maternal treatment postnatally resulted in growth restriction in offspring by postnatal day 21; growth restriction was no longer evident after 5 weeks of age. Maternal perinatal Resv supplementation prevented the onset of hypertension in adult offspring (-18 mm Hg; P=0.007), and nitric oxide synthase inhibition (with L-NG-nitroarginine methyl ester) normalized these blood pressure differences, suggesting improved nitric oxide bioavailability underlies the hemodynamic alterations in the Resv-treated offspring. In vivo and ex vivo, vascular responses to methylcholine were not different between treatment groups, but prior treatment with L-NG-nitroarginine methyl ester attenuated the vasodilation in untreated, but not Resv-treated adult offspring, suggesting a shift toward nitric oxide-independent vascular control mechanisms in the treated group. Finally, bioconversion of the inactive precursor big endothelin-1 to active endothelin-1 in isolated mesenteric arteries was reduced in Resv-treated offspring (-28%; Phypertension and causes persistent alterations in vascular responsiveness in spontaneously hypertensive rats.

  1. Characterization and enrichment of hepatic progenitor cells in adult rat liver

    Institute of Scientific and Technical Information of China (English)

    Ai-Lan Qin; Xia-Qiu Zhou; Wei Zhang; Hong Yu; Qin Xie

    2004-01-01

    AIM: To detect the markers of oval cells in adult rat liver and to enrich them for further analysis of characterization in vitro.METHODS: Rat model for hepatic oval cell proliferation was established with 2-acetylaminofluorene and two third partial hepatectomy (2-AAF/PH). Paraffin embedded rat liver sections from model (11 d after hepatectomy) and control groups were stained with HE and OV6, cytokeratin19 (CK19),albumin, alpha fetoprotein (AFP), connexin43, and c-kit antibodies by immunohistochemistry. Oval cell proliferation was measured with BrdU incorporation test. C-kit positive oval cells were enriched by using magnetic activated cell sorting (MACS) .The sorted oval cells were cultured in a low density to observe colony formation and to examine their characterization in vitroby immunocytochemistry and RT-PCR. RESULTS: A 2-AAF/PH model was successfully established to activate the oval cell compartment in rat liver. BrdU incorporation test of oval cell was positive. The hepatic oval cells coexpressed oval cell specific marker OV6, hepatocytemarker albumin and cholangiocyte-marker CK19. They also expressed AFP and connexin 43. C-kit, one hematopoietic stem cell receptor, was expressed in hepatic oval cells at high levels. By using c-kit antibody in conjunction with MACS,we developed a rapid oval cell isolation protocol. The sorted cells formed colony when cultured in vitro. Cells in the colony expressed albumin or CK19 or coexpressed both and BrdU incorporation test was positive. RT-PCR on colony showed expression of albumin and CK19 gene.CONCLUSION: Hepatic oval cells in the 2-AAF/PH model had the properties of hepatic stem/progenitor cells. Using MACS, we established a method to isolate oval cells. The sorted hepatic oval cells can form colony in vitro which expresses different combinations of phenotypic markers and genes from both hepatocytes and cholangiocyte lineage.

  2. AVPV neurons containing estrogen receptor-beta in adult male rats are influenced by soy isoflavones

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    Bu Lihong

    2007-02-01

    Full Text Available Abstract Background Isoflavones, the most abundant phytoestrogens in soy foods, are structurally similar to 17beta-estradiol. It is known that 17beta-estradiol induces apoptosis in anteroventral periventricular nucleus (AVPV in rat brain. Also, there is evidence that consumption of soy isoflavones reduces the volume of AVPV in male rats. Therefore, in this study, we examined the influence of dietary soy isoflavones on apoptosis in AVPV of 150 day-old male rats fed either a soy isoflavone-free diet (Phyto-free or a soy isoflavone-rich diet (Phyto-600. Results The occurrence of apoptosis in AVPV was examined by TUNEL staining. The incidence of apoptosis was about 10 times higher in the Phyto-600 group (33.1 ± 1.7% than in the Phyto-free group (3.6 ± 1.0%. Furthermore, these apoptotic cells were identified as neurons by dual immunofluorescent staining of GFAP and NeuN as markers of astrocytes and neurons, respectively. Then the dopaminergic neurons in AVPV were detected by immunohistochemistry staining of tyrosine hydroxylase (TH. No significant difference in the number of TH neurons was observed between the diet treatment groups. When estrogen receptor (ER alpha and beta were examined by immunohistochemistry, we observed a 22% reduction of ERbeta-positive cell numbers in AVPV with consumption of soy isoflavones, whereas no significant change in ERalpha-positive cell numbers was detected. Furthermore, almost all the apoptotic cells were ERbeta-immunoreactive (ir, but not ERalpha-ir. Last, subcutaneous injections of equol (a major isoflavone metabolite that accounts for approximately 70–90% of the total circulating plasma isoflavone levels did not alter the volume of AVPV in adult male rats. Conclusion In summary, these findings provide direct evidence that consumption of soy isoflavones, but not the exposure to equol, influences the loss of ERbeta-containing neurons in male AVPV.

  3. The effects of biological sex and gonadal hormones on learning strategy in adult rats.

    Science.gov (United States)

    Hawley, Wayne R; Grissom, Elin M; Barratt, Harriet E; Conrad, Taylor S; Dohanich, Gary P

    2012-02-28

    When learning to navigate toward a goal in a spatial environment, rodents employ distinct learning strategies that are governed by specific regions of the brain. In the early stages of learning, adult male rats prefer a hippocampus-dependent place strategy over a striatum-dependent response strategy. Alternatively, female rats exhibit a preference for a place strategy only when circulating levels of estradiol are elevated. Notably, male rodents typically perform better than females on a variety of spatial learning tasks, which are mediated by the hippocampus. However, limited research has been done to determine if the previously reported male spatial advantage corresponds with a greater reliance on a place strategy, and, if the male preference for a place strategy is impacted by removal of testicular hormones. A dual-solution water T-maze task, which can be solved by adopting either a place or a response strategy, was employed to determine the effects of biological sex and hormonal status on learning strategy. In the first experiment, male rats made more correct arm choices than female rats during training and exhibited a bias for a place strategy on a probe trial. The results of the second experiment indicated that testicular hormones modulated arm choice accuracy during training, but not the preference for a place strategy. Together, these findings suggest that the previously reported male spatial advantage is associated with a greater reliance on a place strategy, and that only performance during the training phase of a dual-solution learning task is impacted by removal of testicular hormones.

  4. 高温预处理对过氧化氢诱导大鼠心肌细胞线粒体金属硫蛋白表达的影响%Effect of high temperature preconditioning on hydrogen peroxide-induced expression of mitochondrial metallothionein in rat cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    胡艳; 周建美; 冉珂; 刘健平

    2013-01-01

    Objective To investigate the effects of high temperature preconditioning on hydrogen peroxide (H2 O2)-induced expression of mitochondrial metallothionein (MT) in rat cardiomyocytes.Methods The rat cardiomyocytes H9C2 cultured in vitro were randomly divided into 3 groups (n =6 each):control group (group C) ;H2O2 group (group H2O2); high temperature preconditioning group (group HTP).The cells were continuously cultured for 3 h in group C.The cells were cultured for 3 h in serum-free DMEM liquid culture medium containing H2O2 0.5 mmol/L in an incubator filled with 5% CO2 at 37 ℃ in group H2O2.In group HTP,the cells were cultured in serum-containing DMEM liquid culture medium,then placed in a warm bath of 42 ℃ for 1 h,cultured for 12 h in an incubator filled with 5% CO2 at 37 ℃,DMEM liquid culture medium was then removed,and the other procedures were similar to those previously described in group H2 O2.Myocardial cell apoptosis was observed by flow cytometry.The apoptotic rate was calculated.The ultrastructure of myocardial mitochondria was examined with electron microscope.The expression of mitochondrial MT in cardiomyocytes was determined using Western blot.Results Compared with group C,the apoptotic rate was significantly increased,and the expression of mitochondrial MT was up-regulated in groups H2O2 and HTP (P < 0.01).The apoptotic rate was significantly lower,and the expression of mitochondrial MT was higher in group HTP than in group H2O2 (P < 0.01).The mitochondrial injury was attenuated in group HTP as compared with group H2 O2.Conclusion The mechanism by which high temperature preconditioning reduces H2 O2-induced myocardial damage may be related to up-regulation of expression of mitochondrial MT in cardiomyocytes and endogenous myocardium-protective mechanism in rats.%目的 探讨高温预处理对过氧化氢(H2O2)诱导大鼠心肌细胞线粒体金属硫蛋白(MT)表达的影响.方法 采用随机数字表法,将体外培养的H9C2

  5. Neonatal Androgen Exposure Causes Persistent Gut Microbiota Dysbiosis Related to Metabolic Disease in Adult Female Rats.

    Science.gov (United States)

    Moreno-Indias, Isabel; Sánchez-Alcoholado, Lidia; Sánchez-Garrido, Miguel Ángel; Martín-Núñez, Gracia María; Pérez-Jiménez, Francisco; Tena-Sempere, Manuel; Tinahones, Francisco J; Queipo-Ortuño, María Isabel

    2016-12-01

    Alterations of gut microbiome have been proposed to play a role in metabolic disease, but the major determinants of microbiota composition remain ill defined. Nutritional and sex hormone challenges, especially during early development, have been shown to permanently alter adult female phenotype and contribute to metabolic disturbances. In this study, we implemented large-scale microbiome analyses to fecal samples from groups of female rats sequentially subjected to various obesogenic manipulations, including sex hormone perturbations by means of neonatal androgenization or adult ovariectomy (OVX), as a model of menopause, to establish whether these phenomena are related to changes in gut microbiota. Basic metabolic profiles concerning glucose/insulin homeostasis were also explored. The effects of the sex hormonal perturbations, either developmentally (androgenization) or in adulthood (OVX), clearly outshone the impact of nutritional interventions, especially concerning the gut microbiota profile. Notably, we observed a lower diversity in the androgenized group, with the highest Firmicutes to Bacteroidetes ratio, supporting the occurrence of durable alterations in gut microbiota composition, even in adulthood. Moreover, the elimination of adult ovarian secretions by OVX affected the richness of gut microbiota. Our data are the first to document the durable impact of sex steroid manipulations, and particularly early androgenization, on gut microbiota composition. Such dysbiosis is likely to contribute to the metabolic perturbations of conditions of obesity linked to gonadal dysfunction in the female.

  6. Persistent sodium current properties in hippocampal CA1 pyramidal neurons of young and adult rats.

    Science.gov (United States)

    Lunko, Oleksii; Isaev, Dmytro; Maximyuk, Oleksandr; Ivanchick, Gleb; Sydorenko, Vadym; Krishtal, Oleg; Isaeva, Elena

    2014-01-24

    Persistent tetrodotoxin-sensitive sodium current (INaP) plays an important role in cellular and neuronal network excitability in physiological conditions and under different pathological circumstances. However, developmental changes in INaP properties remain largely unclear. In the present study using whole cell patch clamp technique we evaluated INaP properties in CA1 hippocampal pyramidal neurons isolated from young (postnatal day (P) 12-16) and adult (P60-75) rats. We show that the INaP density is substantially larger in the adult group. Although INaP inactivation characteristics were found to be similar in both groups, voltage dependence of INaP activation is shifted to more negative membrane potentials (young: -48.6±0.5mV vs. adult: -52.4±0.2mV, p<0.01). Our data indicates the increase of INaP contribution in the basal membrane sodium conductivity in the mature hippocampus.

  7. Expression of alpha-synuclein in different brain parts of adult and aged rats.

    Science.gov (United States)

    Adamczyk, A; Solecka, J; Strosznajder, J B

    2005-03-01

    The synucleins are a family of presynaptic proteins that are abundant in neurons and include alpha-, beta, and gamma-synuclein. Alpha-synuclein (ASN) is involved in several neurodegenerative age-related disorders but its relevance in physiological aging is unknown. In the present study we investigated the expression of ASN mRNA and protein in the different brain parts of the adult (4-month-old) and aged (24-month-old) rats by using RT-PCR technique and Western blot, respectively. Our results indicated that mRNA expression and immunoreactivity of ASN is similar in brain cortex, hippocampus and striatum but markedly lower in cerebellum comparing to the other brain parts. Aging lowers ASN mRNA expression in striatum and cerebellum by about 40%. The immunoreactivity of ASN in synaptic plasma membranes (SPM) from aged brain cortex, hippocampus and cerebellum is significantly lower comparing to adult by 39%, 24% and 65%, respectively. Beta-synuclein (BSN) was not changed in aged brain comparing to adult. Age-related alteration of ASN may affect the nerve terminals structure and function.

  8. Antenatal Antioxidant Prevents Nicotine-Mediated Hypertensive Response in Rat Adult Offspring.

    Science.gov (United States)

    Xiao, DaLiao; Huang, Xiaohui; Li, Yong; Dasgupta, Chiranjib; Wang, Lei; Zhang, Lubo

    2015-09-01

    Previous studies have demonstrated that perinatal nicotine exposure increased blood pressure (BP) in adult offspring. However, the underlying mechanisms were unclear. The present study tested the hypothesis that perinatal nicotine-induced programming of hypertensive response is mediated by enhanced reactive oxygen species (ROS) in the vasculature. Nicotine was administered to pregnant rats via subcutaneous osmotic mini-pumps from Day 4 of gestation to Day 10 after birth, in the absence or presence of the ROS inhibitor N-acetyl-cysteine (NAC) in the drinking water. Experiments were conducted in 8-mo-old male offspring. Perinatal nicotine treatment resulted in a significant increase in arterial ROS production in offspring, which was abrogated by NAC. Angiotensin II (Ang II)-induced BP responses were significantly higher in nicotine-treated group than in saline-treated control group, and NAC treatment blocked the nicotine-induced increase in BP response. Consistent with that, the nicotine treatment significantly increased both Ang II-induced and phorbol [12, 13]-dibutyrate (PDBu, a Prkc activator)-induced arterial contractions in adult offspring, which were blocked by NAC treatment. In addition, perinatal nicotine treatment significantly attenuated acetylcholine-induced arterial relaxation in offspring, which was also inhibited by NAC treatment. Results demonstrate that inhibition of ROS blocks the nicotine-induced increase in arterial reactivity and BP response to vasoconstrictors in adult offspring, suggesting a key role for increased oxidative stress in nicotine-induced developmental programming of hypertensive phenotype in male offspring.

  9. Altered calcium handling and increased contraction force in human embryonic stem cell derived cardiomyocytes following short term dexamethasone exposure.

    Science.gov (United States)

    Kosmidis, Georgios; Bellin, Milena; Ribeiro, Marcelo C; van Meer, Berend; Ward-van Oostwaard, Dorien; Passier, Robert; Tertoolen, Leon G J; Mummery, Christine L; Casini, Simona

    2015-11-27

    One limitation in using human pluripotent stem cell derived cardiomyocytes (hPSC-CMs) for disease modeling and cardiac safety pharmacology is their immature functional phenotype compared with adult cardiomyocytes. Here, we report that treatment of human embryonic stem cell derived cardiomyocytes (hESC-CMs) with dexamethasone, a synthetic glucocorticoid, activated glucocorticoid signaling which in turn improved their calcium handling properties and contractility. L-type calcium current and action potential properties were not affected by dexamethasone but significantly faster calcium decay, increased forces of contraction and sarcomeric lengths, were observed in hESC-CMs after dexamethasone exposure. Activating the glucocorticoid pathway can thus contribute to mediating hPSC-CMs maturation.

  10. Peptidomic Analysis of Cultured Cardiomyocytes Exposed to Acute Ischemic-Hypoxia

    Directory of Open Access Journals (Sweden)

    Lijie Wu

    2017-01-01

    Full Text Available Background: Acute Myocardial Infarction (AMI is a life-threatening cardiovascular disease involving disruption of blood flow to the heart, consequent tissue damage, and sometimes death. Peptidomics, an emerging branch of proteomics, has attracted wide attention. Methods: A comparative peptidomic profiling was used to explore changes induced by acute ischemic-hypoxia in primary cultured neonatal rat myocardial cells. Analysis of six-plex tandem mass tag (TMT labelled peptides was performed using nanoflow liquid chromatography coupled online with an LTQ-Orbitrap Velos mass spectrometer. Results: A total of 220 differentially expressed peptides originating from 119 proteins were identified, of which 37 were upregulated and 183 were downregulated in cardiomyocytes exposed to hypoxia/ischemia conditions. Many of the identified peptides were derived from functional domains of proteins closely associated with cardiomyocyte structure or AMI. Conclusion: Numerous peptides may be involved in process of AMI. These results pave the way for future functional studies of the identified peptides.

  11. EFFECT OF PHORBOL ESTER ON cAMP-DEPENDENT PROTEIN KINASE ACTIVITY IN CARDIOMYOCYTES

    Institute of Scientific and Technical Information of China (English)

    周文华; 肖殿模; 郑超强; 王小鲁; 张俊保

    1995-01-01

    Cardiomyocytes isolated from neonatal rats were treated with phorbol-12-myristate-13-acetate(PMA) ranging from 10-11 to 10-7mol/L for 20 min,causing cytosol protein kinase A (PKA) activity to decrease while particulate PKA activity increase in a concentration-dependent manner.The change of PKA activity induced by PMA was abolished completely by pretreatment of polymyxin B or depletion of protein kinase C (PKC).Type Ⅱ PKA activity in particulate fraction was enhanced remarkably,while that of type I PKA was not altered when the cells were treated with 100 nmol/L PMA.The results suggested that subcellular distribution and activity of PKA in cardiomyocytes may be regulated by PKC.

  12. Analysis of cardiomyocyte movement in the developing murine heart

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Hisayuki [Department of Cardiology, Keio University School of Medicine, Tokyo (Japan); Yuasa, Shinsuke, E-mail: yuasa@a8.keio.jp [Department of Cardiology, Keio University School of Medicine, Tokyo (Japan); Tabata, Hidenori [Department of Anatomy, Keio University School of Medicine, Tokyo (Japan); Tohyama, Shugo; Seki, Tomohisa; Egashira, Toru; Hayashiji, Nozomi; Hattori, Fumiyuki; Kusumoto, Dai; Kunitomi, Akira; Takei, Makoto; Kashimura, Shin; Yozu, Gakuto; Shimojima, Masaya; Motoda, Chikaaki; Muraoka, Naoto [Department of Cardiology, Keio University School of Medicine, Tokyo (Japan); Nakajima, Kazunori [Department of Anatomy, Keio University School of Medicine, Tokyo (Japan); Sakaue-Sawano, Asako; Miyawaki, Atsushi [Life Function and Dynamics, ERATO, JST, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan); Laboratory for Cell Function and Dynamics, Advanced Technology Development Group, Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan); Fukuda, Keiichi [Department of Cardiology, Keio University School of Medicine, Tokyo (Japan)

    2015-09-04

    The precise assemblage of several types of cardiac precursors controls heart organogenesis. The cardiac precursors show dynamic movement during early development and then form the complicated heart structure. However, cardiomyocyte movements inside the newly organized mammalian heart remain unclear. We previously established the method of ex vivo time-lapse imaging of the murine heart to study cardiomyocyte behavior by using the Fucci (fluorescent ubiquitination-based cell cycle indicator) system, which can effectively label individual G1, S/G2/M, and G1/S-transition phase nuclei in living cardiomyocytes as red, green, and yellow, respectively. Global analysis of gene expression in Fucci green positive ventricular cardiomyocytes confirmed that cell cycle regulatory genes expressed in G1/S, S, G2/M, and M phase transitions were upregulated. Interestingly, pathway analysis revealed that many genes related to the cell cycle were significantly upregulated in the Fucci green positive ventricular cardiomyocytes, while only a small number of genes related to cell motility were upregulated. Time-lapse imaging showed that murine proliferating cardiomyocytes did not exhibit dynamic movement inside the heart, but stayed on site after entering the cell cycle. - Highlights: • We directly visualized cardiomyocyte movement inside the developing murine heart. • Cell cycle related genes were upregulated in the proliferating cardiomyocytes. • Time-lapse imaging revealed that proliferating murine cardiomyocytes stayed in place. • Murine ventricular cardiomyocytes proliferate on site during development.

  13. Cardiomyocyte apoptosis in rats with myocardial ischemia/reperfusion injury after Exendin-4 pretreatment%心肌缺血再灌注损伤模型大鼠经艾塞那肽预处理后心肌细胞的凋亡

    Institute of Scientific and Technical Information of China (English)

    李文凯; 尚斌; 连小鹏; 马捷

    2015-01-01

    BACKGROUND:Exendin can regulate blood glucose, blood lipid and blood pressure, exert anti-inflammation and anti-oxidative stress effects, improve myocardial infarction and heart failure, and protect heart vessels. However, the effect on the apoptosis of cardiac muscle cels after ischemia/reperfusion injury remains unclear. OBJECTIVE:To observe the effects of Exendin-4 pretreatment on the cardiomyocyte apoptosis and the expression of Bcl-2 and Bax in rats with myocardial ischemia/reperfusion injury. METHODS:The myocardial ischemia/reperfusion injury model was established in rats and then received Exendin-4 pretreatment. Ischemia/reperfusion group and sham operation group were set. RESULTS AND CONCLUSION:Immunohistochemical staining, TUNEL and reverse transcriptase-polymerase chain reaction results showed that Bcl-2 protein and mRNA expression levels in the Exendin-4 group were significantly increased (P < 0.05), while Bax protein and mRNA expression levels were significantly decreased compared with ischemia/reperfusion group (P < 0.05). In addition, apoptosis index was more significantly decreased in the Exendin-4 group than in the ischemia/reperfusion group (P < 0.05). Exendin-4 can protect rat heart muscle against ischemia/reperfusion injury and effectively inhibit the apoptosis of cardiomyocytes, and the underlying mechanism is mediated by up-regulating Bcl-2 expression and down-regulating Bax expression.%背景:有研究表明艾塞那肽可改善心肌梗死和心力衰竭等过程发挥心血管保护作用,但其对缺血再灌注损伤后心肌细胞凋亡的作用尚未阐明。目的:艾塞那肽预处理心肌缺血再灌注损伤模型大鼠,观察其对心肌组织细胞凋亡及对凋亡因子Bcl-2、Bax表达的影响。方法:建立心肌缺血再灌注损伤模型大鼠,用艾塞那肽进行预处理,并设缺血再灌注组和假手术组作对照。结果与结论:免疫组织化学染色、原位末端标记检测RT-PCR检测显

  14. Histological studies of the effects of monosodium glutamate of the Fallopian tubes of adult female Wistar rats

    Directory of Open Access Journals (Sweden)

    Andrew Osayame Eweka

    2010-01-01

    Full Text Available Background: The effect of monosodium glutamate used as food additive on the fallopian tubes of adult Wistar rat was investigated. Material and Methods: Adult female Wistar rats (n=24 of average weight of 230g were randomly assigned into three groups A, B and C in each group (n=8. The treatment groups (A & B were given 0.04mg/kg and 0.08mg/kg of monosodium glutamate thoroughly mixed with the growers′ mash, respectively on a daily basis. The control group (C received equal amount of feeds (Growers′ mash without monosodium glutamate added for fourteen days. The growers′ mash was obtained from Edo Feeds and Flour Mill Ltd, Ewu, Edo State and the rats were given water liberally. The rats were sacrificed on day fifteen of the experiment. The fallopian tubes were carefully dissected out and quickly fixed in 10% buffered formaldehyde for routine histological procedures. Result: The histological findings in the treated groups showed evidence of cellular hypertrophy, degenerative and atrophic changes, and lysed red blood cells in lumen with the group that received 0.08mg/kg of monosodium glutamate more severe. Conclusion: MSG may have some deleterious effects on the fallopian tubes of adult female Wistar rats at higher doses and by extension may contribute to the causes of female infertility. It is recommended that further studies aimed at corroborating these findings be carried out.

  15. TIME COURSE OF CHOLINESTERASE INHIBITION IN ADULT RATS TREATED ACUTELY WITH CARBARYL CARBOFURAN, FORMETANATE, METHOMYL, METHIOCARB, OXAMYL ON PROPOXUR.

    Science.gov (United States)

    To compare the toxicity of seven N-methyl carbamates, time course profiles for brain and red blood cell (RBC) cholinesterase (ChE) inhibition were established for each. Adult, male, Long Evans rats (n=4-5 dose group) were dosed orally with either carbaryl (30 mg/kg in corn oil); ...

  16. Effects of chronic overload on muscle hypertrophy and mTOR signaling in adult and aged rats

    Science.gov (United States)

    We examined the effect of 28 days of overload on mammalian target of rapamycin (mTOR) and extracellular signal-regulated kinase (ERK) signaling in young adult (Y; 6 mo old) and aged (O; 30 mo old) Fischer 344 x Brown Norway rats subjected to bilateral synergist ablation (SA) of two-thirds of the gas...

  17. Effect of neonatal or adult heat acclimation on testicular and epididymal morphometry and sperm production in rats.

    Science.gov (United States)

    Kurowicka, B; Dietrich, G J; Kotwica, G

    2015-03-01

    The accessory gland weight, testicular and epididymal morphometry and sperm production were analyzed in four groups of rats housed at 20 or 34°C: (1) control rats (CR) kept at 20°C from birth to day 90; (2) adult heat-acclimated rats (AHA) kept at 20°C from birth to day 45 followed by 34°C to day 90; (3) neonatal heat-acclimated rats (NHA) kept at 34°C from birth to day 90 and (4) de-acclimated rats (DA) kept at 34°C from birth to day 45 followed by 20°C to day 90. In NHA and DA rats, accessory gland weight was higher than in controls. Despite the lack of differences in testicular and epididymal morphometry, curvilinear velocity of spermatozoa was lower in the NHA group compared to controls. Areas of seminiferous tubules were lower in the DA than in CR and NHA groups, however, sperm concentration and motility were not affected by the treatment in this group. In AHA rats, epithelium of approximately 20% of seminiferous tubules was degenerated and Sertoli cell number was lower in the remaining tubules. In contrast to sperm motility, epididymal duct area, area of the duct occupied by spermatozoa and cauda epididymis sperm concentration were lower in AHA rats than in the other groups. In conclusion, neonatal heat acclimation did not affect the testicular morphometry and epididymal sperm concentration, suggesting adjustment to high ambient temperature. On the contrary, adult heat acclimation of rats affected the examined parameters, leading to decreased sperm concentration.

  18. Adult and embryonic GAD transcripts are spatiotemporally regulated during postnatal development in the rat brain.

    Directory of Open Access Journals (Sweden)

    Anke Popp

    Full Text Available BACKGROUND: GABA (gamma-aminobutyric acid, the main inhibitory neurotransmitter in the brain, is synthesized by glutamic acid decarboxylase (GAD. GAD exists in two adult isoforms, GAD65 and GAD67. During embryonic brain development at least two additional transcripts exist, I-80 and I-86, which are distinguished by insertions of 80 or 86 bp into GAD67 mRNA, respectively. Though it was described that embryonic GAD67 transcripts are not detectable during adulthood there are evidences suggesting re-expression under certain pathological conditions in the adult brain. In the present study we systematically analyzed for the first time the spatiotemporal distribution of different GADs with emphasis on embryonic GAD67 mRNAs in the postnatal brain using highly sensitive methods. METHODOLOGY/PRINCIPAL FINDINGS: QPCR was used to precisely investigate the postnatal expression level of GAD related mRNAs in cortex, hippocampus, cerebellum, and olfactory bulb of rats from P1 throughout adulthood. Within the first three postnatal weeks the expression of both GAD65 and GAD67 mRNAs reached adult levels in hippocampus, cortex, and cerebellum. The olfactory bulb showed by far the highest expression of GAD65 as well as GAD67 transcripts. Embryonic GAD67 splice variants were still detectable at birth. They continuously declined to barely detectable levels during postnatal development in all investigated regions with exception of a comparatively high expression in the olfactory bulb. Radioactive in situ hybridizations confirmed the occurrence of embryonic GAD67 transcripts in the olfactory bulb and furthermore detected their localization mainly in the subventricular zone and the rostral migratory stream. CONCLUSIONS/SIGNIFICANCE: Embryonic GAD67 transcripts can hardly be detected in the adult brain, except for specific regions associated with neurogenesis and high synaptic plasticity. Therefore a functional role in processes like proliferation, migration or

  19. Elastic interactions synchronize beating in cardiomyocytes.

    Science.gov (United States)

    Cohen, Ohad; Safran, Samuel A

    2016-07-13

    Motivated by recent experimental results, we study theoretically the synchronization of the beating phase and frequency of two nearby cardiomyocyte cells. Each cell is represented as an oscillating force dipole in an infinite, viscoelastic medium and the propagation of the elastic signal within the medium is predicted. We examine the steady-state beating of two nearby cells, and show that elastic interactions result in forces that synchronize the phase and frequency of beating in a manner that depends on their mutual orientation. The theory predicts both in-phase and anti-phase steady-state beating depending on the relative cell orientations, as well as how synchronized beating varies with substrate elasticity and the inter-cell distance. These results suggest how mechanics plays a role in cardiac efficiency, and may be relevant for the design of cardiomyocyte based micro devices and other biomedical applications.

  20. Effects of juvenile isolation and morphine treatment on social interactions and opioid receptors in adult rats: behavioural and autoradiographic studies.

    Science.gov (United States)

    Van den Berg, C L; Van Ree, J M; Spruijt, B M; Kitchen, I

    1999-09-01

    The consequences of juvenile isolation and morphine treatment during the isolation period on (social) behaviour and mu-, delta- and kappa-opioid receptors in adulthood were investigated by using a social interaction test and in vitro autoradiography in rats. Juvenile isolation reduced social exploration in adults. Morphine treatment counteracted this reduction in isolated rats, but decreased social exploration in nonisolated rats. Self-grooming and nonsocial exploration were enhanced after juvenile isolation. Morphine treatment had no effect on self-grooming, but suppressed nonsocial exploration in isolated rats. With respect to the opioid receptors, juvenile isolation resulted in regiospecific increases in mu-binding sites with a 58% increase in the basolateral amygdala and a 33% increase in the bed nucleus of stria terminalis. Morphine treatment in isolated rats reversed this upregulation in both areas. The number of delta-binding sites did not differ between the experimental groups. A general upregulation of kappa-binding sites was observed after juvenile isolation, predominantly in the cortical regions, the hippocampus and the substantia nigra. Morphine treatment did not affect the upregulation of kappa-receptors. The results show that juvenile isolation during the play period causes long-term effects on social and nonsocial behaviours and on the number of mu- and kappa- but not delta-opioid receptors in distinct brain areas. The number of mu-receptors in the basolateral amygdala appears to be negatively correlated with the amount of social exploration in adult rats.

  1. Effect of light-dark changes on the locomotor activity in open field in adult rats and opossums.

    Science.gov (United States)

    Klejbor, I; Ludkiewicz, B; Turlejski, K

    2013-11-01

    There have been no reports on how the light-dark changes determine the locomotor activity of animals in the group of high reactivity (HR) and low reactivity (LR). In the present study we have compared selected parameters of the locomotor activity of the HR and the LR groups of the laboratory opossums and Wistar rats during consecutive, light and dark phases in the open field test. Sixty male Wistar adult rats, at an average weight of 350 g each, and 24 adult Monodelphis opossums of both sexes at an average weight of 120 g each were used. The animals' activity for 2 h daily between the hours of 17:30 and 19:30, in line with the natural light-dark cycle were recorded and then analysed using VideoTrack ver.2.0 (Vievpoint France). According to our results, we noted that a change of the experimental conditions from light to dark involves an increase in the locomotor activity in rats and opossums of the HR group, while there is no effect on the activity of the rats and opossums in the LR group. Locomotor activity in the HR rats, both in the light and dark conditions is characterised by a consistent pattern of change - higher activity in the first stage of the recording and a slowdown (habituation) in the second phase of the observation. The locomotor activity of the opossum, during both light and dark conditions, was observed to be at a consistently high level compared to the rats.

  2. p38MAPK信号转导通路在七氟烷后处理减轻乳鼠心肌细胞缺氧复氧损伤中的作用%The role of p38 mitogen-activated protein kinase pathway in protective effect of sevoflurane postconditioning on cultured neonatal rat cardiomyocytes against anoxia/reoxygenafion injury

    Institute of Scientific and Technical Information of China (English)

    庄欣琪; 吕国义; 杨阔; 徐勇; 邓迺封

    2009-01-01

    cultured neonatal rat cardiomyocytes against anoxia/reoxygenation (A/R) injury. Methods Primary cultured neonatal rat cardiomyocytes were randomly divided into 7 groups: group Ⅰ normal control (C); group Ⅱ A/R; group Ⅲ S-Poatcan + A/R; group ⅣS-Postcon + SB203580 + A/R; group Ⅴ S-Postcon + DMSO + A/R; group Ⅵ SB203580 + A/R and group Ⅶ DMSO + A/R. GroupⅡ-Ⅶ were exposed to 2 h anoxia (95% N2-5% CO2) followed by 1 h reoxygenation. In group Ⅲ, Ⅳ and Ⅴ the cultured myocytes were postconditioned with 20 min 3% sevoflurane in 97% O2 alone (in group Ⅲ) or in conjunction with 5 μmol/L 5B203580 (a specific p38 MAPK inhibitor) (in group Ⅳ) or 0.1% DMSO (in group Ⅴ) followed by 40 min reoxygenation. The cardiomyocytes were reoxygenated in the presence of 5 μmol/L SB203580 in group Ⅵ or 0.1% DMSO in group Ⅶ. The LDH activity, cell survival rate and apoptotic rate were measured at the end of the experiment. The levels of phosphor-p38MAPK (p-p38MAPK) was detected by Western blotting. Results S-Postcon reduced LDH activity and apoptotic rate and increased cell survival rate and the level of p-p38MAPK as compared with group A/R (group Ⅱ). The myocardial protecfive effect of S-Posteon was eliminated by p38MAPK inhibltor-SB203580 and p-p38MAPK level was also decreased at the same time.Conclusion Sevoflurane postconditioning can attenuate anoxia/reoxygenation induced cardiomyocyte injury through activation of p38MAPK signal pathway.

  3. Acute and chronic administration of gold nanoparticles cause DNA damage in the cerebral cortex of adult rats.

    Science.gov (United States)

    Cardoso, Eria; Rezin, Gislaine Tezza; Zanoni, Elton Torres; de Souza Notoya, Frederico; Leffa, Daniela Dimer; Damiani, Adriani Paganini; Daumann, Francine; Rodriguez, Juan Carlos Ortiz; Benavides, Roberto; da Silva, Luciano; Andrade, Vanessa M; da Silva Paula, Marcos Marques

    2014-01-01

    The use of gold nanoparticles is increasing in medicine; however, their toxic effects remain to be elucidated. Studies show that gold nanoparticles can cross the blood-brain barrier, as well as accumulate in the brain. Therefore, this study was undertaken to better understand the effects of gold nanoparticles on rat brains. DNA damage parameters were evaluated in the cerebral cortex of adult rats submitted to acute and chronic administration of gold nanoparticles of two different diameters: 10 and 30nm. During acute administration, adult rats received a single intraperitoneal injection of either gold nanoparticles or saline solution. During chronic administration, adult rats received a daily single injection for 28 days of the same gold nanoparticles or saline solution. Twenty-four hours after either single (acute) or last injection (chronic), the rats were euthanized by decapitation, their brains removed, and the cerebral cortices isolated for evaluation of DNA damage parameters. Our study showed that acute administration of gold nanoparticles in adult rats presented higher levels of damage frequency and damage index in their DNA compared to the control group. It was also observed that gold nanoparticles of 30nm presented higher levels of damage frequency and damage index in the DNA compared to the 10nm ones. When comparing the effects of chronic administration of gold nanoparticles of 10 and 30nm, we observed that occurred significant different index and frequency damage, comparing with control group. However, there is no difference between the 10 and 30nm groups in the levels of DNA damage for both parameters of the Comet assay. Results suggest that gold nanoparticles for both sizes cause DNA damage for chronic as well as acute treatments, although a higher damage was observed for the chronic one.

  4. Cellular distribution and localisation of iron in adult rat brain (substantia nigra)

    Energy Technology Data Exchange (ETDEWEB)

    Meinecke, Ch. [Institute for Experimental Physics II, Faculty for Physics and Geosciences, University of Leipzig, Linnestr. 5, D-04103 Leipzig (Germany)]. E-mail: meinecke@physik.uni-leipzig.de; Morawski, M. [Paul-Flechsig-Institute for Brain research, University of Leipzig, Jahnallee 59, D-04109 Leipzig (Germany); Reinert, T. [Institute for Experimental Physics II, Faculty for Physics and Geosciences, University of Leipzig, Linnestr. 5, D-04103 Leipzig (Germany); Arendt, T. [Paul-Flechsig-Institute for Brain research, University of Leipzig, Jahnallee 59, D-04109 Leipzig (Germany); Butz, T. [Institute for Experimental Physics II, Faculty for Physics and Geosciences, University of Leipzig, Linnestr. 5, D-04103 Leipzig (Germany)

    2006-08-15

    Iron appears to be one of the main factors in the metal induced neurodegeneration. Quantitative information on cellular, sub-cellular and cell specific distributions of iron is therefore important to assess. The investigations reported here were carried out on a brain from an adult rat. Therefore, 6 {mu}m thick embedded, unstained brain sections containing the midbrain (substantia nigra, SN) were analysed. Particle induced X-ray emission (PIXE) using a focussed proton beam (beam - diameter app. 1 {mu}m) was performed to determine the quantitative iron content on a cellular and sub-cellular level. The integral analysis shows that the iron content in the SN pars reticulata is twice as high than in the SN pars compacta. The analysis of the iron content on the cellular level revealed no remarkable differences between glia cells and neurons. This is in contrast to other studies using staining techniques.

  5. ACQUISITION OF FREEZING RESPONSE IN RATS: SEX DIFFERENCES IN ADOLESCENTS AND ADULTS

    Directory of Open Access Journals (Sweden)

    Cristina Vargas-Irwin

    2011-12-01

    Full Text Available Pavlovian fear conditioning is one of the most popular preclinical models in the studyof Post-Traumatic Stress Disorder (PTSD. The aim of the present research wasexplore the sex differences that characterize PTSD by means of this experimentalparadigm, as well as to offer a preliminary description of how these sex differencesbehave throughout development. Forty five naïve rats, of Wistar descent were usedas subjects, with 18 males and 27 females approximately balanced by litter acrossthe two experimental groups: adolescents and adults. The results show significantdifferences in the second measurement of the conditioned stimulus in the interactionbetween sex and age and to compare the tree measurements of the conditionedstimulus. Results are discussed regarding the discrepancies in the literature regardingthe effect of the variables evaluated in the acquisition of Conditioned fear.

  6. Systemic physiology and neuroapoptotic profiles in young and adult rats exposed to surgery

    DEFF Research Database (Denmark)

    Ibrahim, Rami Mossad; Krammer, Caspar Weel; Hansen, Tom Giedsing;

    2015-01-01

    to one of four anaesthetics regimens: (i) sevoflurane/dexmedetomidine, (ii) sevoflurane/fentanyl; (iii) propofol/dexmedetomidine, and (iv) propofol/fentanyl. Animals underwent a dorsal skin flap procedure while physiologic, metabolic and biochemical parameters were closely monitored. Neuroapoptotic...... of sevoflurane and dexmedetomidine resulted in the highest number of caspase-3 positive cells, although the extent of cell death remained relatively low in all experimental groups. CONCLUSION: Combination of anaesthesia and surgery induces significant perturbations of physiological parameters in both young...... and adult spontaneously breathing rats undergoing surgery. These observations further enlighten the need for detailed physiological monitoring under these experimental conditions. Although some statistically significant differences in activated caspase-3 profiles were detected between experimental groups...

  7. Electroconvulsive Stimulation, but not Chronic Restraint Stress, Causes Structural Alterations in Adult Rat Hippocampus

    DEFF Research Database (Denmark)

    Olesen, Mikkel V.; Wörtwein, Gitta; Pakkenberg, Bente

    2015-01-01

    The neurobiological mechanisms underlying depression are not fully understood. Only a few previous studies have used validated stereological methods to test how stress and animal paradigms of depression affect adult hippocampal neurogenesis and whether antidepressant therapy can counteract possible...... changes in an animal model. Thus, in this study we applied methods that are state of the art in regard to stereological cell counting methods. Using a validated rat model of depression in combination with a clinically relevant schedule of electroconvulsive stimulation, we estimated the total number...... induces depression-like behavior, without significantly changing neurogenesis, the total number of neurons or the volume of the hippocampus. Further, electroconvulsive stimulation prevents stress-induced depression-like behavior and increases neurogenesis. The total number of neurons and the granule cell...

  8. Dissociable effects of ethanol consumption during the light and dark phase in adolescent and adult Wistar rats.

    Science.gov (United States)

    Walker, Brendan M; Walker, Jennifer L; Ehlers, Cindy L

    2008-03-01

    In adolescence, high levels of drinking over short episodes (binge drinking) is commonly seen in a proportion of the population. Because adolescence is an important neurodevelopmental period, the effects of binge drinking on brain and behavior has become a significant health concern. However, robust animal models of binge drinking in rats are still being developed and therefore further efforts are needed to optimize paradigms for inducing maximal self-administration of alcohol. In the present experiment, 1-h limited-access self-administration sessions were instituted to model excessive drinking behavior in adolescent and adult Wistar rats. In addition to age, the involvement of sex and phase within the light/dark cycle (i.e., drinking in the light or dark) on sweetened 5% ethanol intake were also evaluated over 14 limited-access sessions using