Browsing by Subject "Zinc"

Now showing 1 - 13 of 13
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    Assembly of Heterometallic Rigid-Rod Complexes and Coordination Oligomers from Gold(I) Metalloligands
    (American Chemical Society, 2015-06-18) Cámara, Verónica; Barquero, Natalia; Bautista, Delia; Gil-Rubio, Juan; Vicente, José; Química Inorgánica
    The reactions of TpylC6H4C≡CAuL (Tpyl = 2,2':6',2''-terpyridin-4'-yl; L = PPh3, CNXy; Xy = 2,6-dimethylphenyl) with MX2·nH2O (M = Fe, X = ClO4; M = Co, X = BF4; M = Zn, X = TfO, ClO4) in a 2:1 molar ratio give complexes [M(TpylC6H4C≡CAuL)2]X2. Similarly, the reactions of PPN[(TpylC6H4C≡C)2Au] (PPN = (Ph3P)2N) with an equimolar amount of MX2·nH2O give coordination oligomers [M{(TpylC6H4C≡C)2Au}]nXn (M = Fe, Zn, X = ClO4; M = Co, X = BF4). The complexes and oligomers have been isolated and characterized. The crystal structures of [Fe(TpylC6H4C≡CAuCNXy)2](ClO4)2 and [Co(TpylC6H4C≡CAuPPh3)2](BF4)2 have been determined by X-ray diffraction. The hydrodynamic sizes of complexes [M(TpylC6H4C≡CAuPPh3)2]X2 and coordination oligomers [M{(TpylC6H4C≡C)2 Au}]nXn have been studied by NMR diffusion spectroscopy and Dynamic Light Scattering (DLS) measurements.
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    Co-localization of the zinc transporter ZnT8 (slc30A8) with ghrelin and motilin in the gastrointestinal tract of pigs
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Schweiger, Markus; Steffl, Martin; Amselgruber, Werner M.
    Zinc is an important co-factor for insulin storage in pancreatic β-cells of different species and the uptake of this ion into insulin containing secretory vesicles is managed by the zinc transporter, ZnT8, a member of the slc30A gene family. Recent studies indicate that this protein is a major autoimmune target in human type 1A diabetes and has also been implicated by genome-wide association studies in type 2 diabetes. Since individuals suffering from type 1 diabetes often develop gastrointestinal motility disorders, we investigated the expression of ZnT8 in the porcine gastrointestinal tract. For this purpose, we studied the cell-type specific expression of ZnT8 in the gut and its co-expression with endocrine hormones that are closely linked to intestinal motility regulation. Nested RT-PCR and immunostaining of sequential serial sections, as well as double-immunostaining using antibodies directed against ZnT8, ghrelin, motilin, neurotensin, serotonin and glucagon-like peptide 1, indicated that ZnT8 is colocalized with ghrelin and motilin. Our findings provide important information about the cell-type specific expression of ZnT8 in the porcine gastrointestinal system. The selective and exclusive expression of ZnT8 in two endocrine cell-types that are engaged in motility functions may be of particular interest for further investigations into type I diabetes-associated gastrointestinal dysfunctions.
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    Deshidratación de los sulfatos de cinc y de cadmio con 2,2-dimetoxipropano y estudio de la acción del amoniaco y etielendiamina sobre las especies obtenidas.
    (Murcia : Universidad de Murcia, Sevicio de Publicaciones, 1970) Monserrat Bernal, Francisco F.; Departamentos y Servicios::Departamentos de la UMU::Bioquímica y Biología Molecular A
    El acetal 2,2-dimetoxípropano, o bien el producto de su recuperación, acetal recuperado, solamente destruye el agua de aquellos hidratos que la contengan —con cualquier tipo de enlace— como moléculas discretas, como en el caso de los sulfates cristalinos de cinc y cadmio. No ejerce acción alguna sobre aquellas especies que la contengan en forma de puentes de hidrógeno como, por ejemplo, el bórax.
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    Determinación espectrofotométrica de cinc en materiales por un proceso de complejación - extracción
    (Murcia, Secretariado de Publicaciones e Intercambio científico, Universidad de Murcia, 1985) Sánchez-Pedreño, C.; Polo, J. L.; Facultad de Ciencias (Química y Matemáticas)
    Dada la importancia actual que presenta el análisis de cinc en cantidades muy pequeñas en diversos materiales, en la bibliografía se encuentra gran número de métodos para su evaluación. Es conocido que el cinc a niveles de trazas es un elemento vital necesario para el crecimiento y reproducción de vegetales y organismos. La bibliografía sobre métodos analíticos para su determinación en materiales biológicos, suelos, productos medicinales, celulósicos, pigmentos, etc.. es extensa. Un grupo importante de procedimientos incluye la formación de especies complejas de Zn(II) con ligandos orgánicos, seguida de la extracción de las mismas en disolventes poco polares y medida final fotométrica o fluorimétrica (1-5). Dentro de este grupo se encuentra el trabajo que se presenta, en el que se estudia la formación en medio alcalino del complejo Zn(II) con 5, 7-dibromo-8-hidroxiquinoleína y su extracción en disolventes orgánicos, con medida final espectrofotométrica. La 8-hidroxiquinoleína y varios de sus derivados han sido frecuentemente utilizados para la determinación de diversos iones, entre ellos el Zn(II) (6). No hemos encontrado ninguna referencia en que se utilice la dibromoxina con la finalidad señalada en las condiciones que aquí se procede. De los estudios realizados se presenta un método espectrofotométrico para la determinación de cinc, sensible, selectivo y de manipulación sencilla. El procedimiento propuesto encuentra amplia aplicabilidad para el análisis de este elemento a niveles de trazas en diversas muestras naturales y artificiales. Se presenta aquí la determinación de Zn(ll) en hojas y compuestos medicinales de uso oftalmológico.
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    Disruption of brain zinc homeostasis promotes the pathophysiological progress of Alzheimer's disease
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Li, Lin-Bo; Wang, Zhan-You
    Zinc is abundant in the brain, where it plays an important role in synaptic plasticity and in learning; however, excessive zinc is toxic to neuronal cells, and dyshomeostasis of zinc in the brain is a contributing factor for Alzheimer’s disease (AD). Deposition of zinc has been detected in senile plaques in the form of zincAβ (β-amyloid) complexes. Recent studies have demonstrated that zinc exposure to the brain enhances βamyloid precursor protein (APP) expression, amyloidogenic APP cleavage and plaque burden. Furthermore, alterations in zinc transporters, which are responsible for zinc homeostasis, occur in AD human brain and transgenic mouse models. These suggest that abnormal brain zinc homeostasis is involved in the pathophysiological progress of AD.
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    Distribution of zinc and zinc transporters in the mouse ovarian follicles and corpus luteum
    (F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2013) Zhong, Man-Li; Guo, Chuang; Chi, Zhi-Hong; Shan, Zhong-Yan; Teng, Wei-Ping; Wang, Zhan-You
    Zinc is essential for female reproduction and it plays a role in sexual development, ovulation, menstruation and estrous cycles. Zinc deficiency may lead to female reproductive system dysfunction. The present study aimed to investigate the expression and distribution patterns of free zinc and the members of zinc transporter (ZnT) family, with zinc autometallographic (AMG), immunohistochemistry and real-time PCR, to explore the relationship of zinc homeostasis in the development and function of the ovary in the mouse. Our data revealed that the free zinc ions and ZnTs are predominantly distributed in the mouse ovarian follicles and corpus luteum. Specifically, AMG staining presented in various stages of the ovarian follicles and corpus luteum. ZnT1-9 mRNA was variously expressed, whereas ZnT10 mRNA was almost undetectable in the ovary. Moreover, the immunoreactivity of all the tested ZnTs, except for ZnT10, was detected with various intensity in the mouse primordial follicles, primary follicles, secondary follicles and antral follicles. In the corpus luteum, the immunoreactivity of ZnT1-5, 7, 8, 10, was abundantly observed in the granular and theca lutein cells and interstitial cells. Collectively, our results suggest that ZnT family proteins are differently distributed and might exert different biological functions in controlling cellular zinc levels, which regulate ovarian development and function in the mouse ovary.
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    Effects of the relationship between 65Zn and blood cells. A dynamic and morphological study
    (F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2013) Vera-Gil, A.; Pérez Castejón, M.J.; Whyte, J.; Cisneros, A.; Recreo, P.; Gascón, M.A.; Whyte, A.; Lahoz, M.; Pérez Castejón, M.C.
    We have studied the dynamic pathway of 65Zn and its autoradiographic location in blood cells, even at the ultra-structural level. We have found evidence that tends to confirm the old biochemical postulates about the capacity of this isotope to displace iron in the haemoglobin molecule. Recently, the bibliography has demonstrated that 57Co is also able to perform this displacement, but unlike 65Zn it does not invalidate the Redox function of the molecule. In the case of 65Zn, the mentioned displacement invalidates this function because the radionuclide can only use valence 2. We have also contributed evidence of erythrocytes destruction by the spleen after the incorporation of 65Zn, as well as the clearly marked degradation of haematic pigments inside the spleen.
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    Invited Review: 65Zn in studies of neurobiology of Zinc
    (Murcia : F. Hernández, 1994) Vera-Gil, A.; Perez-Castejon, M.C.
    The presence of Zinc in the mossy fibre system of the Hippocampi~s is the most thoroughly studied of Zinc relation to the CNS, but many other areas of the CNS are Zinc-containing. Many methods have been used in order to investigate the above mentioned relation, most of then1 being based on histochemistry and physical measurement. 6 5 ~ tnra ce has also been used, but scarcely, probably due to the ciifficulty of radioisotope handling. In the present review we focus on 6 5 ~ nst udies i n the CNS and comment on their advantages and disadvantages.
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    Puerarin and zinc additively prevent mandibular bone loss through inhibiting osteoclastogenesis in ovariectomized rats
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Liu, Hao; Li, Wei; Jia, Shengnan; Li, Binbin
    Puerarin and zinc play a key role in preventing osteoporotic-related bone loss. Previous research on puerarin or zinc mainly focused on the antiosteoporotic effects of long bone. However, it is obscure for puerarin or zinc to prevent mandibular osteoporosis. Here, we explore the effects on additive coadministration of puerarin and zinc on preventing mandibular bone loss in ovariectomized rats, and evaluate the underlying mechanisms ex vivo. Rats were ovariectomized and administrated puerarin, zinc or both. After 12 weeks, bone mineral density (BMD) and histomorphometry of mandibles were measured by micro-CT. The mechanical properties were determined using a threepoint bending test. Then, osteogenic differentiation of primary bone marrow stromal cells (BMSCs) and osteoclastogenesis of bone marrow mononuclear were performed ex vivo. The culture supernatant and serum level of bone biochemical markers including osteoprotegerin (OPG), osteopontin (OPN), receptor activator of nuclear factor (NF)-κB ligand (RANKL), and tartrate-resistant acid phosphatase (TRAP) were detected by ELISA. Culture supernatant and serum levels of calcium were measured using a Plasma Emission Spectrometer. One-way ANOVA was used for statistical analyses. The results showed that administration of puerarin plus zinc prevented the decrease in mandibular BMD and bone morphometrical parameters more effectively than single use of puerarin or zinc (p<0.05), which was similar to the biomechanical tests (p<0.05). Furthermore, puerarin and zinc additively up-regulated OPG, OPN protein levels, Ca ion level and down-regulated RANKL, TRAP protein levels. In conclusion, puerarin and zinc additively prevent mandibular bone loss through inhibiting osteoclastogenesis in ovariectomized rats, which will shed more light on the potential use of puerarin and zinc in the prevention/treatment of oral bone loss clinically.
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    The cellular and subcellular localization of zinc transporter 7 in the mouse spinal cord
    (Murcia : F. Hernández, 2008) Chi, Zhi-Hong; Ren, Hao; Wang, Xin; Rong, Ming; Huang, Liping; Wang, Zhan-You
    The present work addresses the cellular and subcellular localization of the zinc transporter 7 (ZNT7, SLC30a7) protein and the distribution of zinc ions (Zn2+) in the mouse spinal cord. Our results indicated that the ZNT7 immunoreactive neurons were widely distributed in the Rexed’s laminae of the gray matter in all spinal segments examined. The ependyma cells of the central canal and glia cells in the white matter were also shown ZNT7-positive. The ZNT7 immunoreactivity was mainly detected in the perinuclear regions of ZNT7- positive cells in the spinal gray matter. For ependyma cells, the immunoreactivity of ZNT7 was detected in the cytoplasm near the lumina of the central canal. Ultrastructural localization showed that ZNT7 was predominately present in the membrane of the Golgi stacks. The double immunofluorescence studies confirmed this result. Other intracellular organelles including the endoplasmic reticulum, mitochondria and lysosomes were devoid of ZNT7-immunostaining. The chelatable Zn2+ ions in the spinal cord were found predominantly in the terminals of the neuron rather than the cell body in the gray matter. However, overlapping distribution of chelatable Zn2+ ions and ZNT7 was found in the ependyma cells. The present study supports the notion that ZNT7 may function to supply zinc ions to the newly synthesized metalloproteins in the secretory pathway of the spinal neuron and the ependyma cell.
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    Time-course expression of metallothioneins and tissue metals in chronic relapsing form of experimental autoimmune encephalomyelitis
    (Murcia: F. Hernández, 2011) Jakovac, Hrvoje; Grebic, Damir; Tota, Marin; Barac-Latas, Vesna; Mrakovčić-Šutić, Ines; Milin, Čedomila; Radosevic-Stasic, Biserka
    To elucidate the role of metallothioneins (MTs) in the pathomechanisms of autoimmune CNS disorders we estimated the expression of MTs I+II and the tissue concentrations of Zn2+ and Cu2+ in the brain, spinal cord (SC) and in the liver during the periods of attacks and remissions in chronic relapsing experimental autoimmune encephalomyelitis (CR-EAE). Disease was induced in the genetically susceptible Dark Agouti (DA) rats by subcutaneous injection of bovine brain homogenate in CFA. Control rats were treated with CFA. The data, obtained by clinical assessment, immunohistochemistry and inductivity coupled plasma spectrometry, have shown that during the first attack (on the 12th day) MTs I+II were markedly upregulated in subarachnoid regions and perivascular space on astrocytes, microglia and on spinal neurons. Simultaneously, the concentrations of zinc in the SC and zinc and copper in the liver have found to be increased. During the second attack (on the 22nd day) a new overexpression of MTs was found in the cerebellum, in sulcus hippocampi, in spinal neurons and particularly in hepatocytes around the central vein. Concomitantly, in the brain and SC the concentration of copper increased. The data point to a neuroprotective role of MTs and to an important regulatory role of essential metals and hepatic MTs in the pathogenesis of CR-EAE
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    Zinc in hypothalamus and hypophysis of the rat
    (Murcia : F. Hernández, 1994) Pérez-Castejon, C.; Vera-Gil, A.; Barral, M.J.; Perez-Castejon, M.J.; Lahoz, M.
    Zinc has been located using both histochemical and autoradiographic procedures in the neurons of the nuclei of the hypothalamic medial area and in some adenohypophisary cells. Some suggestions about the functional significance of the presence of Zn in these places are made.
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    ZNT7 and Zn2+ are present in different cell populations in the mouse testis
    (Murcia : F. Hernández, 2009) Chi, Zhi-Hong; Feng, Wan-Yu; Gao, Hui-Ling; Zheng, Wei; Huang, Liping; Wang, Zhan-You
    The aim of the present study was to investigate the relation of the spatial distribution between ZNT7 and chelatable zinc ions in the mouse testis. Immunohistochemical results demonstrated a wide distribution of ZNT7 in both seminiferous tubules and interstitial tissues of the testis. The spermatocytes and spermatids in the seminiferous tubules showed strong ZNT7 immunoreactivity whereas zinc autometallographic (AMG) staining was absent. Spermatozoa showed a high level of free zinc, but were void of ZNT7 immunoreactivity. No ZNT7 immunoreactivity and AMG grains were found in spermatogonia. Both ZNT7 and chelatable zinc were detected in Sertoli and Leydig cells. Furthermore, double immunofluorescence study demonstrated that the ZNT7 staining overlapped with that of TGN38 (a trans-Golgi marker), suggesting that ZNT7 was localized in the Golgi apparatus in the ZNT7- positive cells. In conclusion, ZNT7 and chelatable zinc were distributed in different cell populations except for Sertoli and Leydig cells in the mouse testis. ZNT7 may be involved in zinc transportation into the Golgi apparatus for protein packaging in the mouse testis