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1.
Effects of zinc ex vivo and intracellular zinc chelator in vivo on taurine uptake in goldfish retina
Taurine and zinc exert neurotrophic effects. Zinc modulates Na+/Cl−-dependent transporters. This study examined the effect of zinc (ZnSO4) ex vivo and zinc chelator N,N,N′,N′-tetrakis-(2-pyridylmethyl) ethylenediamine (TPEN) in vivo on [3H]taurine transport in goldfish retina. The effect of TPEN in vivo on taurine and zinc levels was determined. Isolated cells
were incubated in Ringer with zinc (0.1–100 μM). Taurine transport was done with taurine (0.001–1 mM) and 50 nM [3H]taurine. Zinc (100 μM) noncompetitively inhibited taurine transport. TPEN was administered intraocularly and retinas extracted
3, 5 and 10 days later. Taurine was determined by HPLC (nmol/mg protein) and zinc by spectrophotometry ICP (mg/mg protein).
Taurine and zinc levels decreased at 3 days and increased at 10 days after TPEN administration. At 10 days after intraocular
TPEN, taurine transport affinity increased (K
s = 0.018 ± 0.006 vs. 0.028 ± 0.008 mM). Apparently, zinc deficiency affects the taurine–zinc complex and taurine availability.
The increased taurine uptake affinity by TPEN was possibly associated with a response to maximize retinal taurine content
at low zinc concentration. 相似文献
2.
Taurine and zinc, highly concentrated in the retina, possess similar properties in this structure, such as neuro-protection,
membrane stabilization, influencing regeneration, and modulating development, maybe by acting in parallel or as interacting
agents. We previously demonstrated that there are some correlations between taurine and zinc levels in hippocampus, dentate gyrus and retina of the developing rat. In the present study we evaluate the possible effects of taurine and zinc on outgrowth
from goldfish retinal explants. The optic nerve was crushed 10 days before plating and culturing retinal explants in Leibovitz
medium with 10% fetal calf serum and gentamicin. Neurites were measured with SigmaScanPro after 5 days in culture. Taurine
(HPLC) and zinc (ICP) concentrations were determined in the retina between 1 and 180 days after crushing the optic nerve.
Zinc sulfate (0.01–100 μM), N,N, N′,N′-tetrakis (pyridylmethyl) ethylenediamine (TPEN, 0.1–5 nM) and diethylenetriamine penta-acetic acid (DTPA, 10–300 μM), intracellular
and extracellular zinc chelators, respectively, were added to the medium. TPEN was also injected intraocular (0.1 nM). Combinations
of them were added with taurine (1–16 mM). Taurine concentrations were elevated in the retina 72 h after the crush, but were
normalized by 180 days, those of zinc increased at 24 h, preceding the increase of taurine. The axonal transport of [3H]taurine from the optic tectum to the retina was not affected in fish with or without crush of the optic nerve at early periods
after the injection, indicating an increase of it post-lesion. Zinc sulfate produced a bell-shaped concentration dependency
on in vitro outgrowth, with stimulation at 0.05 μM, and inhibition at higher levels, also increased the effect of 4 mM taurine at 0.02 μM,
but diminished it at higher concentrations in the medium. TPEN decreased outgrowth at 1 nM, but not at 0.5 nM, although the
simultaneous presence of 4 mM taurine and 0.5 nM TPEN decreased outgrowth respecting the stimulation by taurine alone. The
intraocular administration of TPEN decreased outgrowth in vitro, an effect counteracted by the addition of 4 mM taurine to the culture medium. DTPA decreased outgrowth from 10 μM in the
medium. The present results indicate that an optimal zinc concentration is necessary for outgrowth of goldfish retinal explants
and that, in zinc deficient retina, taurine could stimulate outgrowth. In addition, the observations of variations in tissue
concentrations and of the effects of intraocular administration of TPEN indicate that these effects could occur in vivo.
Special issue dedicated to Dr. Simo S. Oja 相似文献
3.
Grzegorz Satała Beata Duszyńska Tomasz Lenda Gabriel Nowak Andrzej J. Bojarski 《Molecular neurobiology》2018,55(4):2897-2910
The allosteric regulation of G protein-coupled receptors (GPCRs) is a well-known phenomenon, but there are only a few examples of allosteric modulation within the metabotropic serotonergic receptor family. Recently, we described zinc non-competitive interactions toward agonist binding at serotonin 5-HT1A receptors, in which biphasic effects, involving potentiation at sub-micromolar concentrations (10 μM) and inhibition at sub-millimolar concentrations (500 μM) of Zn2+ in radioligand binding assays, were consistent with both the agonist and antagonist-like effects of zinc ions observed in in vivo studies. Here, we showed new data demonstrating zinc allosteric inhibition of both agonist and antagonist binding at human recombinant 5-HT7 receptors stably expressed in HEK293 cells as observed by radioligand binding studies as well as zinc neutral antagonism displayed by the concentration of 10 μM in the functional LANCE assay. The allosteric nature of the effect of Zn on 5-HT7 receptors was confirmed (1) in saturation studies in which zinc inhibited the binding of potent orthosteric 5-HT7 receptor radioligands, the agonist [3H]5-CT, and the two antagonists [3H]SB-269970 and [3H]mesulergine, showing ceiling effect and differences in the magnitude of negative cooperativity (α = 0.15, 0.06, and 0.25, respectively); (2) in competition experiments in which 500 μM of zinc inhibited all radioligand displacements by non-labeled orthosteric ligands (5-CT, SB-269970, and clozapine), and the most significant reduction in affinity was observed for the 5-CT agonist (4.9–16.7-fold) compared with both antagonists (1.4–3.9-fold); and (3) in kinetic experiments in which 500 μM zinc increased the dissociation rate constants for [3H]5-CT and [3H]mesulergine but not for [3H]SB-269970. Additionally, in the functional LANCE test using the constitutively active HEK293 cell line expressing the 5-HT7 receptor, 10 μM zinc had features of neutral antagonism and increased the EC50 value of the 5-CT agonist by a factor of 3.2. Overall, these results showed that zinc can act as a negative allosteric inhibitor of 5-HT7 receptors. Given that the inhibiting effects of low concentrations of zinc in the functional assay represent the most likely direction of zinc activity under physiological conditions, among numerous zinc-regulated proteins, the 5-HT7 receptor can be considered a serotonergic target for zinc modulation in the CNS. 相似文献
4.
Gisel Padula María Virginia Ponzinibbio Rocío Celeste Gambaro Analía Isabel Seoane 《In vitro cellular & developmental biology. Animal》2017,53(7):586-592
Micronutrients are important for the prevention of degenerative diseases due to their role in maintaining genomic stability. Therefore, there is international concern about the need to redefine the optimal mineral and vitamin requirements to prevent DNA damage. We analyzed the cytostatic, cytotoxic, and genotoxic effect of in vitro zinc supplementation to determine the effects of zinc deficiency and excess and whether the upper estimate of the physiological requirement recommended for children is safe. To achieve zinc deficiency, DMEM/Ham’s F12 medium (HF12) was chelated (HF12Q). Lymphocytes were isolated from healthy female donors (age range, 5–10 yr) and cultured for 7 d as follows: negative control (HF12, 60 μg/dl ZnSO4); deficient (HF12Q, 12 μg/dl ZnSO4); lower level (HF12Q + 80 μg/dl ZnSO4); average level (HF12Q + 180 μg/dl ZnSO4); upper limit (HF12Q + 280 μg/dl ZnSO4); and excess (HF12Q + 380 μg/dl ZnSO4). The comet (quantitative analysis) and cytokinesis-block micronucleus cytome assays were used. Differences were evaluated with Kruskal-Wallis and ANOVA (p < 0.05). Olive tail moment, tail length, micronuclei frequency, and apoptotic and necrotic percentages were significantly higher in the deficient, upper limit, and excess cultures compared with the negative control, lower, and average limit ones. In vitro zinc supplementation at the lower and average limit (80 and 180 μg/dl ZnSO4) of the physiological requirement recommended for children proved to be the most beneficial in avoiding genomic instability, whereas the deficient, upper limit, and excess (12, 280, and 380 μg/dl) cultures increased DNA and chromosomal damage and apoptotic and necrotic frequencies. 相似文献
5.
Lei Mao Juncai Chen Quanhui Peng Aiming Zhou Zhisheng Wang 《Biological trace element research》2013,155(1):132-141
Zinc has been shown to be an inhibitor of apoptosis for many years. The present study was designed to investigate effects of three zinc chemical forms on H2O2-induced cell apoptosis in IEC-6 cells via analysis of cell vitality, LDH activity, apoptosis percentage, caspase-3 activity, and Bcl-2, Bax, and caspase-3, -8, and -9 gene expression. Cells were divided into H2O2 and zinc sources+H2O2 groups, and there are three different zinc sources [zinc oxide nanoparticle (nano-ZnO), zinc oxide (ZnO), and zinc sulfate (ZnSO4)] and three concentrations (normal = 25 μM, medium = 50 μM, and high = 100 μM) used in this article. In the present study, we found the striking cytotoxicity of H2O2 higher than 200 μM on cell vitality, LDH activity, and apoptosis percentage in the cells using five different concentrations (50, 100, 200, 400, and 800 μM) of H2O2 for 4 h. Moreover, we observed that cell vitality was increased, LDH activity and apoptotic percentage were decreased, and gene expression level of Bax and caspase-3 and -9 was markedly reduced, while gene expression level of Bcl-2 and ratio of Bcl-2/Bax were increased in normal concentration groups of nano-ZnO and ZnSO4 compared with H2O2 group, but no significant difference was observed in caspase-8 gene expression. Furthermore, medium or, more intensely, high concentrations of nano-ZnO and ZnSO4 enhanced H2O2-induced cell apoptosis. Compared with nano-ZnO and ZnSO4, ZnO showed weakest protective effect on H2O2-induced apoptosis at normal concentration and was less toxic to cells at high level. Taken together, we proposed that preventive and protective effects of zinc on H2O2-induced cell apoptosis varied in IEC-6 cells with its chemical forms and concentrations, and maybe for the first time, we suggested that nano-ZnO have a protective effect on H2O2-induced cell apoptosis in IEC-6 cells. 相似文献
6.
This study, comprising three independent experiments, was conducted to optimize the zinc (Zn) application through seed coating for improving the productivity and grain biofortification of wheat. Experiment 1 was conducted in petri plates, while experiment 2 was conducted in sand-filled pots to optimize the Zn seed coating using two sources (ZnSO4, ZnCl2) of Zn. In the first two experiments, seeds of two wheat cultivars Lasani-2008 and Faisalabad-2008 were coated with 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75 and 2.00 g Zn kg?1 seed using ZnSO4 and ZnCl2 as Zn sources. The results of experiment I revealed that seed coating with 1.25 and 1.50 g Zn kg?1 seed using both sources of Zn improved the seedling emergence. However, seed coated with 1.25 and 1.50 g Zn kg?1 seed using ZnSO4 was better regarding improvement in seedling growth and seedling dry weight. The results of the second experiment indicated that seed coated with 1.25 and 1.50 g Zn kg?1 seed using ZnSO4 improved the seedling emergence and seedling growth of tested wheat cultivars. However, seed coating beyond 1.5 g Zn kg?1 seed using either Zn source suppressed the seedling emergence. Third experiment was carried out in glass house in soil-filled earthen pots. Seeds of both wheat cultivars were coated with pre-optimized treatments (1.25, 1.50 g Zn kg?1 seed) using both Zn sources. Seed coating with all treatments of ZnSO4 and seed coating with 1.25 g Zn kg?1 seed using ZnCl2 improved the seedling emergence and yield-related traits of wheat cultivars. Seed coating with 1.25 g Zn kg?1 seed also improved the chlorophyll a and b contents. Maximum straw Zn contents, before and after anthesis, were recorded from seed coated with 1.5 g Zn kg?1 seed using either Zn source. Increase in grain yield from seed coating followed the sequence 1.25 g Zn kg?1 seed (ZnSO4) >1.25 g Zn kg?1 seed (ZnCl2) >1.5 g Zn kg?1 seed (ZnSO4). However, increase in grain Zn contents from seed coated was 1.5 g Zn kg?1 seed (ZnCl2) >1.25 and 1.5 g Zn kg?1 seed (ZnCl2, ZnSO4) >1.25 g Zn kg?1 seed (ZnSO4). Seed coating with Zn increased the grain Zn contents from 21 to 35 %, while 33–55 % improvement in grain yield was recorded. In conclusion, wheat seeds may be coated with 1.25 g Zn kg?1 seed using either source of Zn for improving the grain yield and grain Zn biofortification. 相似文献
7.
Ling Zhang Yong-Xia Wang Xue Xiao Jiang-Shui Wang Qian Wang Kai-Xuan Li Tian-Yu Guo Xiu-An Zhan 《Biological trace element research》2017,178(2):320-326
An experiment was conducted to investigate the effects of zinc glycinate (Zn-Gly) supplementation as an alternative for zinc sulphate (ZnSO4) on productive and reproductive performance, zinc (Zn) concentration and antioxidant status in broiler breeders. Six hundred 39-week-old Lingnan Yellow broiler breeders were randomly assigned to 6 groups consisting of 4 replicates with 25 birds each. Breeders were fed a basal diet (control group, 24 mg Zn/kg diet), basal diet supplemented with 80 mg Zn/kg diet from ZnSO4 or basal diet supplemented with 20, 40, 60 and 80 mg Zn/kg diet from Zn-Gly. The experiment lasted for 8 weeks after a 4-week pre-test with the basal diet, respectively. Results showed that Zn supplementation, regardless of sources, improved (P?<?0.05) the feed conversion ratio (kilogram of feed/kilogram of egg) and decreased broken egg rate, and elevated (P?<?0.05) the qualified chick rate. Compared with the ZnSO4 group, the 80 mg Zn/kg Zn-Gly group significantly increased (P?<?0.05) average egg weight, fertility, hatchability and qualified chick rate, whereas it decreased (P?<?0.05) broken egg rate. The Zn concentrations in liver and muscle were significantly higher (P?<?0.05) in 80 mg Zn/kg Zn-Gly group than that in ZnSO4 group. Compared with ZnSO4 group, 80 mg Zn/kg Zn-Gly group significantly elevated (P?<?0.05) the mRNA abundances of metallothionein (MT) and copper-zinc superoxide (Cu-Zn SOD), as well as the Cu-Zn SOD activity and MT concentration in liver. Moreover, the 80 mg Zn/kg Zn-Gly group had higher (P?<?0.05) serum T-SOD and Cu-Zn SOD activities than that in the ZnSO4 group. This study indicated that supplementation of Zn in basal diet improved productive and reproductive performance, Zn concentration and antioxidant status in broiler breeders, and the 80 mg Zn/kg from Zn-Gly was the optimum choice for broiler breeders compared with other levels of Zn from Zn-Gly and 80 mg/kg Zn from ZnSO4. 相似文献
8.
Background
Taurine and zinc exert neurotrophic effects in the central nervous system. Current studies demonstrate that Na+/Cl- dependent neurotransmitter transporters, similar to that of taurine, are modulated by micromolar concentrations of zinc. This study examined the effect of zinc sulfate ex vivo on [3H]taurine transport in goldfish retina.Methods
Isolated cells were incubated in Ringer with zinc (0.1–100 µM). Taurine transport was done with 50 nM [3H]taurine or by isotopic dilution with taurine (0.001–1 mM) and 50 nM [3H]taurine.Results
Zinc reduced the capacity of taurine transport without changes in affinity, and caused a noncompetitive inhibition of high affinity taurine transport, with an EC50= 0.072 µM. The mechanism by which zinc affects taurine transport is unknown at the present.Conclusions
There may be a binding site of zinc in the transporter that affects union or translocation of taurine, or possibly the formation of taurine-zinc complexes, rather than free zinc, could affect the operation of the transporter.9.
Harris H. Tallan Ewa Jacobson Charles E. Wright Karmela Schneidman Gerald E. Gaull 《Life sciences》1983,33(19):1853-1860
Cultured human lymphoblastoid cells take up taurine from the medium by two processes: 1) a temperature-dependent, Na+-dependent, saturable “active”-transport system and 2) diffusion. The active transport has properties similar to those reported for taurine transport by other tissues. Apparent Km is about 25 μM and Vmax about 7.2 pmol/min/106 cells; saturation occurs at 100 μM taurine. Uptake is competitively inhibited by the β-amino acids hypotaurine (50% inhibition at 44 μM) and β-alanine (50% at 152 μM), as measured at 50 μM taurine. Taurocyamine inhibits 50% at 260 μM. Chlorpromazine and imipramine are strong uncompetitive inhibitors, giving 50% inhibition at 26 μM and 115 μM, respectively; at these concentrations cellular viability per se is not affected. Ouabain inhibits 40–50% over a concentration range of 4–500 μM. Diffusion of taurine into the cells is proportional to concentration up to 20 mM. However, at the concentration of taurine in human plasma, 40–100 μM, active transport would provide 90% of the taurine taken up. 相似文献
10.
The effects of excess zinc (Zn) on solution-cultured wheat (Triticum aestivum L., cv. Yecora Rojo) and radish (Raphanus sativus L., cv. Cherry Belle) were studied, using both short-term root elongation studies and longer term split-root experiments. Alleviation of Zn rhizotoxicity by Mg and K was observed, with especially dramatic alleviation of root stunting by Mg. In the short-term studies using a simple medium (2 mM CaCl2, pH 6.0), Mg concentrations of 1–5 μM were able to significantly alleviate rhizotoxicity caused by Zn concentrations as high as 60 μM. In the split-root studies, 100 μM Mg was sufficient to abolish Zn toxicity in both wheat and radish. Paradoxically, Mg enhanced uptake and translocation of Zn while simultaneously alleviating toxicity in these longer-term experiments. In short-term experiments, additions of K (0 to 200 μM) to the basal medium alleviated Zn rhizotoxicity to a more limited extent. In split-root experiments, however, the absence or presence of K in test solutions did not affect plant growth or Zn uptake. When increased from a physiological minimum (e.g., 200 μM), Ca also alleviates Zn toxicity, but the effect is very modest in comparison to that of Mg. The results are discussed in relation to the use of short-term assays of metal tolerance in simple salt solutions, and in relation to possible roles of Mg in the physiology of Zn toxicity. 相似文献
11.
In the current study, antidiabetic activity and toxic effects of zinc oxide nanoparticles (ZnO) were investigated in diabetic rats compared to zinc sulfate (ZnSO4) with particular emphasis on oxidative stress parameters. One hundred and twenty male Wistar rats were divided into two healthy and diabetic groups, randomly. Each major group was further subdivided into five subgroups and then orally supplemented with various doses of ZnO (1, 3, and 10 mg/kg) and ZnSO4 (30 mg/kg) for 56 consecutive days. ZnO showed greater antidiabetic activity compared to ZnSO4 evidenced by improved glucose disposal, insulin levels, and zinc status. The altered activities of erythrocyte antioxidant enzymes as well as raised levels of lipid peroxidation and a marked reduction of total antioxidant capacity were observed in rats receiving ZnO. ZnO nanoparticles acted as a potent antidiabetic agent, however, severely elicited oxidative stress particularly at higher doses. 相似文献
12.
Zhongping Deng Lisa A. Dailey Joleen Soukup Jacqueline Stonehuerner Judy D. Richards Kimberly D. Callaghan Funmei Yang Andrew J. Ghio 《Biometals》2009,22(5):803-815
Despite recurrent exposure to zinc through inhalation of ambient air pollution particles, relatively little information is
known about the homeostasis of this metal in respiratory epithelial cells. We describe zinc uptake and release by respiratory
epithelial cells and test the postulate that Zn2+ transport interacts with iron homeostasis in these same cells. Zn2+ uptake after 4 and 8 h of exposure to zinc sulfate was concentration- and time-dependent. A majority of Zn2+ release occurred in the 4 h immediately following cell exposure to ZnSO4. Regarding metal importers, mRNA for Zip1 and Zip2 showed no change after respiratory epithelial cell exposure to zinc while
mRNA for divalent metal transporter (DMT)1 increased. Western blot assay for DMT1 protein supported an elevated expression
of this transport protein following zinc exposure. RT-PCR confirmed mRNA for the metal exporters ZnT1 and ZnT4 with the former
increasing after ZnSO4. Cell concentrations of ferritin increased with zinc exposure while oxidative stress, measured as lipid peroxides, was decreased
supporting an anti-oxidant function for Zn2+. Increased DMT1 expression, following pre-incubations of respiratory epithelial cells with TNF-α, IFN-γ, and endotoxin, was
associated with significantly decreased intracellular zinc transport. Finally, incubations of respiratory epithelial cells
with both zinc sulfate and ferric ammonium citrate resulted in elevated intracellular concentrations of both metals. We conclude
that exposure to zinc increases iron uptake by respiratory epithelial cells. Elevations in cell iron can possibly affect an
increased expression of DMT1 and ferritin which function to diminish oxidative stress. Comparable to other metal exposures,
changes in iron homeostasis may contribute to the biological effects of zinc in specific cells and tissues. 相似文献
13.
Valeria R. Martínez María V. Aguirre Juan S. Todaro Oscar E. Piro Gustavo A. Echeverría Luciana G. Naso Evelina G. Ferrer Patricia A. M. Williams 《Biological trace element research》2018,186(2):413-429
A new losartan [2-butyl-5-chloro-3-[[4-[2-(2H-tetrazol-5-yl)phenyl]phenyl]methyl]imidazol-4-yl]methanol zinc(II) complex [Zn(Los)Cl], was synthesized and characterized. The crystal structure was determined by x-ray diffraction methods. When aqueous solutions of the ligand and the metal were mixed, the known and more soluble powder [Zn(Los)2].3H2O (ZnLos) complex has been obtained. The interactions with phosphatases showed a concerted mechanism displayed by the Zn ions and ZnLos up to 500 μM concentration: a decrease of the acid phosphatase (AcP) associated with an increase in the alkaline phosphatase (ALP) activities. The complex and ZnSO4 showed a cytotoxic behavior on human lung A549 cancer cell line at concentrations higher than 75 μM with reactive oxygen species (ROS) generation and GSH (and GSH/GSSG ratio) depletion. Apoptotic cells were observed using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) method, a mechanism accompanied by upregulation of BAX protein, downregulation of Bcl-XL and release of caspase-3. The BAX/Bcl-XL ratio was found to be significantly higher in cells exposure to ZnLos than cells treated with ZnSO4, in agreement with the higher apoptotic percentage of cells found for the complex. Cell death was found to be produced by apoptosis and no necrosis has been observed. On the contrary, losartan exerted low effects on phosphatases, produced some reduction of cancer cell viability (concentrations >?250 μM, number of apoptotic cells similar to the basal) with low ROS depletion, without alteration of the GSH/GSSG and low BAX/Bcl-XL ratios. In the MRC-5, normal lung fibroblasts cell line only ZnSO4 at concentrations higher than 200 μM displays cytotoxic effects. 相似文献
14.
Ling Zhang Jiang-Shui Wang Qian Wang Kai-Xuan Li Tian-Yu Guo Xue Xiao Yong-Xia Wang Xiu-An Zhan 《Biological trace element research》2018,181(2):323-330
This study was conducted to investigate the effects of maternal zinc glycine (Zn-Gly) supplementation as an alternative for zinc sulfate (ZnSO4) on mortality, zinc (Zn) concentration, and antioxidant status in a developing embryo and 1-day-old chick. Six hundred 39-week-old broiler breeders were randomly assigned to 6 treatments, each treatment including 5 replicates with 20 birds each. Six treatments received a basal diet (control, 24 mg Zn/kg diet) or a basal diet supplemented with ZnSO4 (80 mg Zn/kg) or Zn-Gly (20, 40, 60, or 80 mg Zn/kg), respectively. The experiment lasted for 8 weeks after a 4-week pre-experiment with a basal diet. At the last week, 100 eggs per replicate were randomly collected for incubation. Compared with the control treatment, Zn supplementation decreased (P < 0.05) embryo mortalities of the late stage and the whole period, increased (P < 0.05) liver Zn concentration in the embryo of d9, d19, and 1-day-old chick, and improved (P < 0.05) antioxidant status in the embryo of d19 and 1-day-old chick. Compared with the ZnSO4 treatment, 80 mg Zn/kg Zn-Gly treatment significantly decreased (P < 0.05) the late stage embryo mortality and increased (P < 0.05) liver Zn concentration in the embryo of d9, d19, and 1-day-old chick. The 80 mg Zn/kg Zn-Gly treatment significantly increased (P < 0.05) copper-zinc superoxide dismutase activity in d19 embryo and 1-day-old chick, total superoxide dismutase activity in 1-day-old chick, and copper-zinc superoxide dismutase messenger RNA (mRNA) abundance of d9 embryo and 1-day-old chick than that in ZnSO4 treatment. The liver metallothionein concentration of the developing embryo and 1-day-old chick and its mRNA abundance of d19 embryo were also significantly increased (P < 0.05) in the 80 mg Zn/kg Zn-Gly treatment in comparison with ZnSO4 treatment. In conclusion, maternal Zn supplementation decreased embryo mortalities of the late stage and the whole period by increasing liver Zn concentration and antioxidant status in d19 embryo and 1-day-old chick, and 80 mg Zn/kg from Zn-Gly treatment was the optimum choice. 相似文献
15.
Wen Hua Yang Li Ping Zheng Hui Yan Yuan Jian Wen Wang 《Journal of Plant Growth Regulation》2014,33(2):384-396
Glaucocalyxin (Gla) A–C are major ent-kaurane diterpenoids isolated from Isodon japonicus var. glaucocalyx (Maxim.) H. W. Li. This study investigated the possible interference of these diterpenoids with root growth and its mechanism of action in lettuce (Lactuca sativa L.) seedlings. Results indicated the dual stimulatory and inhibitory effects of Gla A and B on root growth and their phytotoxic effects on root hair development. The promotion of root growth by lower levels of Gla A and B (20–40 μM) resulted from enhanced cell length and increased mitotic activity. However, higher concentrations (80–200 μM) of Gla A and B had inhibitory effects. In addition, Gla A and B inhibited root hair development of lettuce seedlings in a dose-dependent manner at concentrations between 20 and 200 μM. Exposure of lettuce roots to Gla A and B at 200 μM increased levels of malondialdehyde and the generation of O 2 ·? , indicating lipid peroxidation and induction of oxidative stress. Activities of the antioxidant enzymes superoxide dismutase, catalase, and peroxidase were significantly elevated. Reactive oxygen species (ROS) scavengers dihydroxybenzene disulfonic acid (Tiron) and dimethylthiourea at 100 μM could efficiently alleviate the phytotoxicity induced by Gla A and B at 200 μM. These results demonstrated that the deleterious effect of Gla A and B at higher concentrations (80–200 μM) on roots may occur through the imposition of oxidative stress on cell growth and cell division. Due to the lack of an α,β-unsaturated ketone in α-methylenecyclopentanone moiety, Gla C could not induce ROS generation and exhibited no effect on the roots, even at the highest concentration (200 μM). Therefore, the α-methylenecyclopentanone moiety in the ent-kaurene diterpenoids was presented as an essential possible active center for the phytotoxicity. 相似文献
16.
Plantago ovata Forsk is an annual herb with immense medicinal importance, the seed and husk of which is used in the treatment of chronic constipation, irritable bowel syndrome, diarrhea since ancient times. Zinc, an essential metal, is required by plants as they form important components of zinc finger proteins and also aid in synthesis of photosynthetic pigments such as chlorophyll. However, in excess amount Zn causes chlorosis of leaf and shoot tissues and generate reactive oxygen species. The present study is aimed at investigating the changes in expression levels of MT2 gene in Plantago ovata under zinc stress. Data show up to 1.66 fold increase in expression of PoMT2 in 1000 µM ZnSO4·7H2O treated sample. Our study also describes alteration of MT2 gene expressions in Plantago ovata as observed through Real time PCR (qPCR) done by \(2^{{ - \Delta \Delta}} C_T\) method. In this study we have observed an upregulation (or induction) in the PoMT2 gene expression level in 500 and 800 µM ZnSO4·7H2O treated samples but found saturation on further increasing the dose to 1000 µM of ZnSO4·7H2O. Determination of the phenotypic and biochemical changes in Plantago ovata due to exposure to zinc stress of concentrations 500, 800 and 1000 µM revealed oxidative stress. The enhanced expression of MT2 gene in Plantago ovata has a correlation with the increased total antioxidant activity and increased DPPH radical scavenging activity. 相似文献
17.
Adaptation of the Common Ice Plant to High Copper and Zinc Concentrations and Their Potential Using for Phytoremediation 总被引:1,自引:0,他引:1
V. P. Kholodova K. S. Volkov Vl. V. Kuznetsov 《Russian Journal of Plant Physiology》2005,52(6):748-757
A facultative halophite Mesembryanthemum crystallinum L. (the common ice plant) was shown to grow successively at the high concentrations of Cu and Zn. Although 25 μM CuSO4 or 800 μM ZnSO4 retarded markedly plant growth, they did not interfere with the completion of plant development and the formation of viable
seeds. In such plants, leaves accumulated more than 200 μg of Cu and 1700 μg of Zn per 1 g of dry weight. A damaging effect
of heavy metals (HMs) was manifested in a reduced content of water in leaves and proline accumulation in them. As copper is
a metal with transient valence, copper salts are more toxic than zinc salts, which was manifested in a stronger inhibition
of the chlorophyll synthesis. Both HMs induced oxidative stress, as evident from increased activities of guaiacol peroxidase
and lipoxygenase. Moderate Cu and Zn concentrations did not damage cell membranes in leaves, as evident from the absence of
their action on electrolyte leakage either under optimum conditions or after heat treatment. A capability of a substantial
HM accumulation by the common ice plant and their considerable transport to shoots (up to 50 μg of Cu and 560 μg of Zn per
plant) make it possible to consider the common ice plant as a promising phytoremediator.
__________
Translated from Fiziologiya Rastenii, Vol. 52, No. 6, 2005, pp. 848–858.
Original Russian Text Copyright ? 2005 by Kholodova, Volkov, Kuznetsov. 相似文献
18.
Dilina do Nascimento Marreiro Artemizia Francisca de Sousa Nadir do Nascimento Nogueira Francisco Erasmo Oliveira 《Biological trace element research》2009,129(1-3):20-27
Studies have evidenced that zinc metabolism is altered in the presence of Down syndrome, and zinc seems to have a relationship with the metabolic alterations usually present in this syndrome. In this work, the effect of zinc supplementation on thyroid hormone metabolism was evaluated in adolescents with Down syndrome. A prospective study was carried out on 16 adolescents with Down syndrome (age: 10–19 years) who were randomized for treatment with 30 mg zinc daily for 4 weeks. Diet evaluation was accomplished y using a 3-day dietary record, and the analysis was performed by the NutWin program, version 1.5. Anthropometric measurements were performed for evaluation of body composition. The Zn-related nutritional status of the groups was evaluated by means of zinc concentration determinations in plasma and erythrocytes using the method of atomic absorption spectroscopy, and the thyroid hormone was obtained by radioimmunoassay. The diet of patients with Down syndrome, before and after the intervention presented reduced energy level and adequate zinc concentrations. Mean plasma zinc values were 59.2?±?13.2 and 71.0?±?21.9 μg/dL before and after the intervention, respectively. Erythrocyte concentrations of the mineral before supplementation, instead, were 51.5 μg/dL?±?11.1 μg Zn/gHb, and at the end of the experiment, they were 42.9?±?8/5 μg Zn/gHb, with a significant statistical difference (p?<?0.05). Serum concentrations of T4 hormone before and after zinc supplementation were 1.26?±?0.20 and 1.54?±?0.63 pg/mL, respectively. Mean T3 values before intervention were 2.47?±?037 pg/mL and, after supplementation, 2.25?±?0.67 pg/mL, without significant statistical difference (p?>?0.05). Intervention with zinc showed to be effective in the stabilization of the concentrations of this mineral in plasma and erythrocytes, but had no influence on the metabolism of thyroid hormones. 相似文献
19.
Benliang Deng Xuehui Jin Yang Yang Zhiwei Lin Yaling Zhang 《Plant Growth Regulation》2014,72(3):269-277
Riboflavin (vitamin B2) is required for normal plant growth and development. Previous studies have shown that riboflavin application can enhance pathogen resistance in plants. Here, we investigated the role of riboflavin in increasing drought tolerance (10 % PEG6000 treatment) in plants. We treated 4 week-old tobacco plants with five different levels of riboflavin (0, 4, 20, 100 and 500 μM) for 5 days and examined their antioxidant responses and levels of drought tolerance. Compared with the controls, low and moderate levels of riboflavin treatment enhanced drought tolerance in the tobacco plants, whereas higher concentrations of riboflavin (500 μM) impaired drought tolerance. Further analysis revealed that plants treated with 500 μM riboflavin accumulated higher levels of ROS (O2 ? and H2O2) and lipid peroxide than the control plants or plants treated with low levels of riboflavin. Consistent with this observation, the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) were higher in plants treated with low or moderate (4, 20 and 100 μM) levels of riboflavin compared with the control. We also found that chlorophyll degraded rapidly in control and 500 μM riboflavin-treated plants under drought stress conditions. In addition, the survival times of the riboflavin-treated plants were significantly modified by treatment with reduced glutathione, a well-known ROS scavenger, under drought stress conditions. Thus, riboflavin-mediated ROS production may determine the effects of riboflavin on drought tolerance in tobacco plants. 相似文献
20.
Zinc fertilizer placement affects zinc content in maize plant 总被引:1,自引:0,他引:1
Yue-Qiang Zhang Li-Li Pang Peng Yan Dun-Yi Liu Wei Zhang Russell Yost Fu-Suo Zhang Chun-Qin Zou 《Plant and Soil》2013,372(1-2):81-92