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1.
Plant mitochondrial electrical potential monitored by fluorescence quenching of rhodamine 123 总被引:4,自引:0,他引:4
The suitability of the fluorescent dye rhodamine 123 for qualitative and quantitative determinations of the electrical potential
difference (ΔΨ) in isolated pea (Pisum sativum L.) stem mitochondria was evaluated. A fluorescence quenching of rhodamine
123, as a consequence of dye uptake, occurred following mitochondria energization by both external and internal substrates.
This quenching was associated to the generation of ΔΨ, because it was completely released by uncouplers and respiratory inhibitors.
The conversion of the proton gradient (ΔpH) into ΔΨ, induced by nigericin or a permeant weak acid (phosphate), increased the
quenching. The uptake of the probe was accompanied by 40 % of unspecific binding in coupled, but not in uncoupled, mitochondria.
Rhodamine 123 quenching varied linearly with a K+-diffusion potential. ADP induced a transient and cyclic change of fluorescence
which was associated to ATP synthesis. Consequently, rhodamine 123 did not influence oxygen consumption by mitochondria in
both state 4 and 3, thus indicating that, at the concentrations assayed, the probe was not toxic. It is concluded that rhodamine
123, followed by fluorescence quenching, is a suitable probe to study the energetics of isolated plant mitochondria.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
3.
Single nucleotide polymorphisms in vascular endothelial growth factor gene VEGF, 1498C/T and 936 C/T are associated with colorectal cancer. We sought to determine whether such genetic variability in VEGF contributes to susceptibility of colorectal adenoma (CRA), a presumably precancerous state of colorectal cancer. In this
research, two aforementioned polymorphisms were investigated for CRA susceptibility in a Chinese case–control study. The epidemiological
risk factors were collected through questionnaire. The plasma VEGF levels were measured via enzyme-linked immunosorbent assay
(ELISA). The Taqman-Probe assay was used to determine genotypes in 224 CRA patients and 200 CRA-free controls. The clinicopathological
data of each sample were collected for further correlation analysis. According to data analysis males, cigarette smokers,
patients who carry metabolic syndrome or familial antecedent of adenomas were significantly associated with CRA risk. Plasma
VEGF levels of CRA patients were higher than those of controls (P = 0.003). This difference is independent of genotypes. The carriers with 936CT and CT+TT had higher risk of CRA in comparison
with controls (CT vs. CC, OR 2.00, 95% CI 1.23–3.25, P = 0.006; CT+TT vs. CC, OR 2.04, 95% CI 1.28–3.26, P = 0.003). 936-T allele was associated with increased risk of CRA (OR 1.91, 95% CI 1.25–2.91, P = 0.003). Both CRA and control show no difference in the genotype of 1498C/T and the allele frequency of C−/T−. CRA patients
with haplotype 1498T+936T presented significantly higher risk than those with wild-type 1498T+936C. Moreover, patients carrying
936CT+TT and 936-T allele demonstrated a tendency for villous adenoma. CRA patients have elevated plasma VEGF levels. The
VEGF 936C/T polymorphism and 1498T+936T haplotype were found to be associated with increased CRA susceptibility. 相似文献
4.
Ana?L.?Di Virgilio Josefina?Rivadeneira Cecilia?I.?Muglia Miguel?A.?Reigosa Nataliya?Butenko Isabel?Cavaco Susana?B.?Etcheverry
The complex of vanadyl(IV) cation with oxodiacetate, VO(oda) caused an inhibitory effect on the proliferation of the human
colon adenocarcinoma cell line Caco-2 in the range of 25–100 μM (P < 0.001). This inhibition was partially reversed by scavengers of free radicals. The difference in cell proliferation in
the presence and the absence of scavengers was statistically significant in the range of 50–100 μM (P < 0.05). VO(oda) altered lysosomal and mitochondria metabolisms (neutral red and MTT bioassays) in a dose–response manner
from 10 μM (P < 0.001). Morphological studies showed important transformations that correlated with the disassembly of actin filaments
and a decrease in the number of cells in a dose response manner. Moreover, VO(oda) caused statistically significant genotoxic
effects on Caco-2 cells in the low range of concentration (5–25 μM) (Comet assay). Increment in the oxidative stress and a
decrease in the GSH level are the main cytotoxic mechanisms of VO(oda). These effects were partially reversed by scavengers
of free radicals in the range of 50–100 μM (P < 0.05). Besides, VO(oda) interacted with plasmidic DNA causing single and double strand cleavage, probably through the action
of free radical species. Altogether, these results suggest that VO(oda) is a good candidate to be evaluated for alternative
therapeutics in cancer treatment. 相似文献
5.
G. Ren H. Chen L. Z. Zhang X. Y. Lan T. B. Wei M. J. Li Y. J. Jing C. Z. Lei J. Q. Wang 《Molecular biology reports》2010,37(1):417-422
Heterozygous mutations in LHX4 are associated with combined pituitary hormone deficiency. In this study, the polymorphism of LHX4-HaeIII locus was revealed in 822 individuals from four Chinese cattle breeds. The PCR–RFLP analysis showed that there were three
genotypes: GG, GA, AA. The frequencies of genotype GG ranged from 0.6620 to 0.9789 in analyzed populations. The genotypic
frequencies of LHX4 locus in the four populations all agreed with Hardy–Weinberg equilibrium (P > 0.05). Distributions of genotypic frequencies of different breeds (QC, NY, JX, CH) at this locus were found to be significantly
different based on a χ
2 test (P < 0.001). The genetic diversity analysis revealed the JX cattle possessed intermediate genetic diversity, and the other three
Chinese cattle breeds belonged to poor genetic diversity. Correlation analysis with growth traits in the NY breed indicated
that: the animals with genotype GA had greater body weight than those with genotype GG (P < 0.05); the animals with GA genotype owned significantly longer body length than the ones with GG genotype (P < 0.05) at 18 and 24 months. 相似文献
6.
Abdul Lateef Molan Mary Ann Lila John Mawson Shampa De 《World journal of microbiology & biotechnology》2009,25(7):1243-1249
The prebiotic effects of water extracts of two blueberry (BBE) cultivars (‘Centurion’ and ‘Maru’) were studied using pure
and mixed cultures of human faecal bacteria. The results demonstrated for the first time that addition of BBE from both cultivars
to broth media containing pure cultures of Lactobacillus
rhamnosus and Bifidobacterium
breve resulted in a significant increase (P < 0.05–0.0001) in the population size of these strains. Batch fermentation system was used to monitor the effect of BBE addition
on the mixed faecal bacterial populations (obtained from healthy human donors). Addition of BBE from both cultivars to batch
cultures inoculated with mixed human faecal cultures resulted in a significant increase in the number of lactobacilli (P < 0.01–0.0001) and bifidobacteria (P < 0.05–0.0001). Furthermore, a significant influence on the population size of lactobacilli and bifidobacteria was observed
after administration of extracts from both cultivars to rats daily for 6 days in comparison with the control group. In rats
gavaged orally with 4 ml kg−1 day−1 of BBE for 6 days, the population size of lactobacilli (P < 0.05) and bifidobacteria (P < 0.05–0.01) was increased significantly. We hypothesize that BBE could modify the bacterial profile by increasing the numbers
of beneficial bacteria and thereby improving gut health. 相似文献
7.
S. H. Mousavi Z. Tayarani-Najaran M. Asghari H. R. Sadeghnia 《Cellular and molecular neurobiology》2010,30(4):591-598
The serum/glucose deprivation (SGD)-induced cell death in cultured PC12 cells represents a useful in vitro model for the study
of brain ischemia and neurodegenerative disorders. Nigella sativa L. (family Ranunculaceae) and its active component thymoquinone (TQ) has been known as a source of antioxidants. In the present
study, the protective effects of N. sativa and TQ on cell viability and reactive oxygen species (ROS) production in cultured PC12 cells were investigated under SGD
conditions. PC12 cells were cultured in DMEM medium containing 10% (v/v) fetal bovine serum, 100 units/ml penicillin, and
100 μg/ml streptomycin. Cells were seeded overnight and then deprived of serum/glucose for 6 and 18 h. Cells were pretreated
with different concentrations of N. sativa extract (15.62–250 μg/ml) and TQ (1.17–150 μM) for 2 h. Cell viability was quantitated by MTT assay. Intracellular ROS production
was measured by flow cytometry using 2′,7′-dichlorofluorescin diacetate (DCF-DA) as a probe. SGD induced significant cells
toxicity after 6, 18, or 24 h (P < 0.001). Pretreatment with N. sativa (15.62–250 μg/ml) and TQ (1.17–37.5 μM) reduced SGD-induced cytotoxicity in PC12 cells after 6 and 18 h. A significant increase
in intracellular ROS production was seen following SGD (P < 0.001). N. sativa (250 μg/ml, P < 0.01) and TQ (2.34, 4.68, 9.37 μM, P < 0.01) pretreatment reversed the increased ROS production following ischemic insult. The experimental results suggest that
N. sativa extract and TQ protects the PC12 cells against SGD-induced cytotoxicity via antioxidant mechanisms. Our findings might raise
the possibility of potential therapeutic application of N. sativa extract and TQ for managing cerebral ischemic and neurodegenerative disorders. 相似文献
8.
The membrane potential (ΔΨm) dependence of the generation of reactive oxygen species (ROS) in isolated guinea-pig brain mitochondria
respiring on NADH-linked substrates (glutamate plus malate) was addressed. Depolarization by FCCP was without effect on H2O2 formation in the absence of bovine serum albumin (BSA). Addition of BSA (0.025%) to the assay medium hyperpolarized mitochondria
by 6.1 ± 0.9 mV (from 169 ± 3 to 175.1 ± 2.1 mV) and increased the rate of H2O2 formation from 207 ± 4.5 to 312 ± 12 pmol/min/mg protein. Depolarization by FCCP (5–250 nM) in the presence of BSA decreased
H2O2 formation but only to the level observed in the absence of BSA. Rotenone stimulated the formation of H2O2 both in the absence and presence of BSA. It is suggested that H2O2 formation in mitochondria supported by NADH-linked substrates is sensitive to changes in ΔΨm only when mitochondria are highly
polarized and even then, 60% of ROS generation is independent of ΔΨm. This is in contrast to earlier reports on the highly
ΔΨm sensitive ROS formation related to reverse electron flow observed in well-coupled succinate-supported mitochondria.
Special issue dedicated to John P. Blass. 相似文献
9.
Hai Wang Hong Ao QiuZhen Pan RongQi Li MengBin Zhao ZhengXing Lian Ning Li ChangXin Wu 《中国科学:生命科学英文版》2007,50(2):178-185
To investigate the effects of different states of donor cells on the development of reconstructed sheep embryos, we designed five treatments of donor cells, including cell passage, cell size, serum starvation, colchicine treatment and gene transfection. Results are as follows: (Ⅰ) Compared with 16-18 passage cells, the morula/blastocyst rate of 5-7 passage cells as donor nuclei was significantly higher (17.3% vs. 4.9%, P<0.05), suggesting the advantage of short-time cultured cells in supporting the development of reconstructed embryos. (Ⅱ) The morula/blastocyst rate of reconstructed embryos derived from medium cells (15-25μm) as donor nuclei was higher than that from large cells (25-33μm) and small cells (8-15μm)( 20.0% vs. 8.0%, 9.7%), indicating that reconstructed embryos from medium cells had a greater potentiality to develop into morula/blastocysts than those from small or large ones. (Ⅲ) The morula/blastocyst rate of reconstructed embryos from donor cells of SS (serum starvation) was lower than that from donor cells of NSS (non-serum starvation), but no significant difference was detected between SS and NSS(11.8% vs. 18.6%, P>0.05). (Ⅳ) Fetal fibroblasts treated with 0.05μmol/L colchicine exhibited a higher morula/blastocyst rate of reconstructed embryos than those treated with 0.10 μmol/L colchicine and untreated ones (27.5% vs. 12.1%, 17.1%), however, no significant difference among the three treatments was detected (P>0.05). (Ⅴ) The morula/blastocyst rate of reconstructed embryos from fetal fibroblasts transfected with GFP gene only was 3.1%, significantly lower than that from non-transgenic cells (3.1% vs. 20.4%, P<0.05). In conclusion, our results demonstrated that fetal fibroblasts of fewer passages, medium size could ensure a higher morula/blastocyst rate of reconstructed embryos. Serum starvation of donor cells might be unnecessary to the development of reconstructed embryos. Donor cells treated with 0.05μmol/L colchicine could facilitate the development of reconstructed embryos. Additionally, as cells transfected with GFP gene were used as donor nuclei, adverse effect on the development of reconstructed embryos was observed. Therefore, the developmental efficiency of reconstructed embryos could be improved if proper treatments to donor cells were used. 相似文献
10.
Yoval-Sánchez B Jasso-Chávez R Lira-Silva E Moreno-Sánchez R Rodríguez-Zavala JS 《Journal of bioenergetics and biomembranes》2011,43(5):519-530
Ethanol is one of the most efficient carbon sources for Euglena gracilis. Thus, an in-depth investigation of the distribution of ethanol metabolizing enzymes in this organism was conducted. Cellular
fractionation indicated localization of the ethanol metabolizing enzymes in both cytosol and mitochondria. Isolated mitochondria
were able to generate a transmembrane electrical gradient (Δψ) after the addition of ethanol. However, upon the addition of
acetaldehyde no Δψ was formed. Furthermore, acetaldehyde collapsed Δψ generated by ethanol or malate but not by D-lactate.
Pyrazole, a specific inhibitor of alcohol dehydrogenase (ADH), abolished the effect of acetaldehyde on Δψ, suggesting that
the mitochondrial ADH, by actively consuming NADH to reduce acetaldehyde to ethanol, was able to collapse Δψ. When mitochondria
were fractionated, 27% and 60% of ADH and aldehyde dehydrogenase (ALDH) activities were found in the inner membrane fraction.
ADH activity showed two kinetic components, suggesting the presence of two isozymes in the membrane fraction, while ALDH kinetics
was monotonic. The ADH Km values were 0.64–6.5 mM for ethanol, and 0.16–0.88 mM for NAD+, while the ALDH Km values were 1.7–5.3 μM for acetaldehyde and 33–47 μM for NAD+. These novel enzymes were also able to use aliphatic substrates of different chain length and could be involved in the metabolism
of fatty alcohol and aldehydes released from wax esters stored by this microorganism. 相似文献
11.
D. O Otieno C. Kurz-Besson J. Liu M. W. T. Schmidt R. Vale-Lobo do T. S. David R. Siegwolf J. S. Pereira J. D. Tenhunen 《Plant and Soil》2006,283(1-2):119-135
Studies were conducted to examine changes in soil (Ψs) and plant water status during summer in a 16-year old Quercus suber plantation in southern Portugal. Continuous measurements were conducted between May 2003 and August 2004, while discontinuous
measurements were conducted on a monthly basis between May and September 2003 and repeated between March and September 2004.
Intensive measurements were conducted on five trees with mean height and DBH of 5.3 m and 11.6 cm, respectively, growing at
close proximity to each other. Weather conditions and soil water potential (Ψs) at the rhizosphere of each of the trees measured
at 0.3 and 1 m soil depth were continuously monitored. Predawn (Ψpd) and midday (Ψmd) leaf water potentials were determined
every month. Soil and plant samples were also collected in June and September from different locations within the study site
for δ18O isotope composition analysis. Pressure–volume (p–v) curves were constructed from plant shoots at different times during the vegetative period to determine osmotic potential
at full saturation (Π100), water potential at turgor loss point (Ψtlp), relative water content at turgor loss point (R*tlp) and bulk modulus of elasticity (ε). Significant P < 0.05 decline in Ψs occurred between May and September, the lowest value recorded being –2.0 MPa. Decline in soil moisture
affected tree water status, but decline in leaf water potential varied significantly (P < 0.05) among the trees. At the end of summer drought, lowest Ψpd measured was –1.7 MPa while the highest measured during
this time was –0.8 MPa. Differences among trees were attributed to differences in rooting depth, as shown by regression analysis
of 18O isotopes. Radial stem growth ceased when Ψs within the upper 0.3 m depth approached –1.5 MPa. The upper soil layers contributed
approximately 33% of the total tree water requirement, between spring and mid summer when drought was experienced by trees.
Deep soil layers however, supplied most of the water required during drought and no growth was recorded during this time.
Stressed trees increased solute concentration of their tissues by a Magnitude of 0.7 MPa while bulk tissue elastic modulus
increased by about 17 MPa. The study emphasizes the significance of roots as determinants of tree productivity and survival
in the Mediterranean ecosystems. 相似文献
12.
Abbas Ali Gheisari Abbas Sanei Abdolhossein Samie Mohamad Mehdi Gheisari Majid Toghyani 《Biological trace element research》2011,142(3):557-571
This experiment was conducted to evaluate the effect of zinc, manganese, and copper sources (inorganic vs. organic) in the
diet on laying performance and eggshell quality characteristics. One hundred and eighty Hy-Line W-36 layers at 38 weeks of
age were allocated to 36-layer cages of five hens each. Each six cages were randomly assigned to one of the six experimental
diets fed from 38 to 53 week of age. In three experimental treatments, the basal diet was supplemented with 65–75–7 or 65–75–7
or 40–40–7 mg/kg of Zn, Mn, and Cu, respectively, from their oxide or sulfate sources. Three other groups were fed diets supplemented
with 20–20–3.5 or 40–40–7.5 or 60–60–10.5 mg/kg of organic forms of Zn, Mn, and Cu, respectively. Dietary treatments significantly
did affect feed intake (P < 0.001), feed conversion ratio (P < 0.001) and percentage of broken eggs (P < 0.05). Substitution of Zn and Mn oxides (65 and 75 mg kg−1, respectively) with equal amounts of their sulfate forms significantly improved feed intake, feed conversion ratio, percentage
of broken eggs, and Haugh Unit (P < 0.05). In addition, laying hens maintained their performance when substitution of Zn and Mn oxides and Cu sulfate (65,
75, and 7 mg kg−1, respectively) reduced up to 20, 20, and 3.5 mg kg−1 by amino acid complexes of the microelements. The results showed that a corn–soybean diet supplemented with the organic forms
of Zn, Mn, and Cu at a dosage 50% to 75% lower than NRC recommendation is sufficient to maintain laying performance and can
improve eggshell and albumen qualities of the egg in laying hens. 相似文献
13.
Hyperglycemia induces apoptosis and p53 mobilization to mitochondria in RINm5F cells 总被引:1,自引:0,他引:1
Ortega-Camarillo C Guzmán-Grenfell AM García-Macedo R Rosales-Torres AM Avalos-Rodríguez A Durán-Reyes G Medina-Navarro R Cruz M Díaz-Flores M Kumate J 《Molecular and cellular biochemistry》2006,281(1-2):163-171
The mechanisms related to hyperglycemia-induced pancreatic β-cell apoptosis are poorly defined. Rat insulin-producing cells
(RINm5F) cultured in high glucose concentrations (30 mM) showed increased apoptosis and protein p53 translocation to mitochondria.
In addition, hyperglycemia induced both the disruption of mitochondrial membrane potential (Δ < eqid1 > m), and an increase in reactive oxygen species (ROS), as shown by fluorescence changes of JC-1 and dichlorodihydrofluorescein-diacetate
(DCDHF-DA), respectively. The increased intracellular ROS by high glucose exposure was blunted by mitochondrial-function and
NADPH-oxidase inhibitors. We postulate that the concomitant mobilization of p53 protein to the mitochondria and the subsequent
changes on the Δ < eqid2 > m, lead to an important pancreatic β-cell apoptosis mechanism induced by oxidative stress caused by hyperglycemia.
This work is part of the thesis required for the doctorate degree in Biological Sciences at the Universidad Autónoma Metropolitana,
Mexico City, Mexico. 相似文献
14.
To evaluate the association of the IBD5 locus to the predisposition of inflammatory bowel diseases (IBDs), a series of meta-analyses
between five IBD5 variants (OCTN1 C1672T, OCTN2 G-207C, OCTN1/2 TC haplotype, IGR2096a_1, IGR2198a_1 and IGR2230a_1) and Crohn’s disease (CD) and ulcerative colitis (UC) were performed, which included a total of 26 studies. Overall, five
IBD5 variants in a per-allele model of inheritance were significantly associated with elevated CD risk (for OCTN1: OR = 1.23, 95% CI = 1.16–1.30, P < 0.001; for OCTN2: OR = 1.20, 95% CI = 1.11–1.30, P < 0.001; for IGR2096a_1: OR = 1.36, 95% CI = 1.24–1.46, P < 0.001; for IGR2198a_1: OR = 1.34, 95% CI = 1.24–1.46, P < 0.001; for IGR2230a_1: OR = 1.35, 95% CI = 1.23–1.48, P < 0.001) and OCTN1/2 TC haplotype (OR = 1.32, 95% CI = 1.22–1.43, P < 0.001). In the subgroup analysis, the statistically significant associations were also observed in adult- and pediatric-onset
CD and in Caucasians for five IBD5 variants and the OCTN1/2 TC haplotype. A statistically significant increase in the risk of UC was detected in a recessive model of inheritances for
OCTN1 (OR = 1.23, 95% CI = 1.08–1.40, P < 0.001), OCTN2 (OR = 1.18, 95% CI = 1.05–1.33, P = 0.006), IGR2096a_1 (OR = 1.37, 95% CI = 1.15–1.62, P < 0.001) and IGR2198a_1 (OR = 1.35, 95% CI = 1.10–1.66, P = 0.004); the increased risks of UC were maintained in the adult and Caucasian subgroups, but not the pediatric subgroup.
In summary, our results suggested that the IBD5 locus contributes to the susceptibility of CD in a per-allele manner in adults,
children and Caucasians, and the locus contributes to the susceptibility of UC in a recessive manner in adult and Caucasian
populations. 相似文献
15.
Ahmed W Malik M Saeed I Khan AA Sadeque A Kaleem U Ahmed N Ajmal M Azam M Qamar R 《Molecular biology reports》2011,38(4):2541-2548
A case–control association study on 229 Myocardial Infarction (MI) patients and 217 healthy controls was carried out to determine
the role of tissue-plasminogen activator (t-PA) (Alu-repeat insertion (I)/deletion (D)) and plasminogen activator inhibitor
(PAI-1) (4G/5G insertion/deletion) polymorphisms with MI in the Pakistani population. In MI patients the genotype distribution
of the PAI-1 gene was not found to be different when compared with the unaffected controls (P > 0.05, χ2 = 1.03). The risk allele 4G was also not associated with MI (P > 0.05, χ2 = 0.46, odds ratio (OR) = 1.1 (95% confidence interval (CI) = 0.84–1.43), P > 0.05). Similarly, the genotype frequencies of t-PA I/I, I/D and D/D were not different from the unaffected controls (P > 0.05, χ2 = 1.60), and the risk allele “I” was not found to be associated with MI (P > 0.05, χ2 = 1.35, OR = 0.86 (95% CI = 0.66–1.11), P > 0.05). However, when the data were distributed along the lines of gender a significant association of the 4G/4G PAI-1 genotype
was observed with only the female MI patients (P < 0.05, z-test = 2.21). When the combined genotypes of both the polymorphisms were analyzed, a significant association of
MI was observed with the homozygous DD/4G4G genotype (P < 0.01, z-test = 2.61), which was specifically because of the female samples (P = 0.01, z-test = 2.53). In addition smoking (P < 0.001, χ2 = 13.52, OR = 3.45 (95% CI = 1.77–6.94)), diabetes (P < 0.001, χ2 = 22.45, OR = 8.89 (95% CI = 2.96–29.95)), hypertension (OR = 7.76 (95% CI = 2.88–22.68), P < 0.001) family history (P < 0.001, χ2 = 13.72, OR = 3.7 (95% CI = 1.71–8.18)) and lower HDL levels (P < 0.05) were found to be significantly associated with the disease. In conclusion the PAI-1 gene polymorphism was found to
have a gender specific role in the female MI patients. 相似文献
16.
Gerasimos S. Filippatos W. Frank Hughes Renli Qiao J. Iasha Sznajder Bruce D. Uhal 《In vitro cellular & developmental biology. Animal》1997,33(3):195-200
Summary Active transport of sodium by pulmonary alveolar epithelial cells (AEC) is believed to be an important component of edema
clearance in the normal and injured lung. Data supporting this premise have come from measurements of sodium movement across
AEC monolayers or from perfused lung model systems. However, direct measurement of fluid flux across AEC monolayers has not
been reported. In the present work, AEC were studied with an experimental system for the measurement of fluid flux (Jv) across
functionally intact cell monolayers. Primary adult rat type II alveolar epithelial cells were cultured on 0.8 μm nuleopore
filters previously coated with gelatin and fibronectin. Intact monolayers were verified by high electrical resistance (> 1000
Θ) at 4–5 d of primary culture. At the same time interval, transmission electron microscopy revealed cells with type I cell-like
morphology throughout the monolayer. These were characterized by both adherens and tight junctional attachments. Fluid flux
across the monolayers was measured volumetrically over a period of 2 h in the presence of HEPES-buffered DMEM containing 3%
fatty acid-free bovine serum albumin. Flux (Jv) was inhibited 39% by 1 × 10−4
M ouabain (P < 0.01) and 27% by 5 × 10−4
M amiloride (P < 0.05). These data support the concept that AEC Na+/K+-ATPase and Na+ transport systems are important determinants of AEC transepithelial fluid movement in vitro. 相似文献
17.
Chemokines regulates the trafficking of leukocytes to the site of inflammation hence may be implicated in cardiac events.
Currently no consistent effects have been revealed their role in acute myocardial infarction (MI). The aim of current study
was to investigate the impact of human chemokine receptor genetic variants, CCR5-Δ32 insertion/deletion, CCR5-59029-A/G, CX3CR1-V249I
and CX3CR1-T280 M on acute MI. 230 acute MI and 300 controls were examined. Patients carrying CCR5-Δ32 genotype were at three
times higher risk of developing MI odds ratio (OR, 3.24, CI 1.127–9.356, P = 0.04). Significant association was found with risk of acute MI in recipients who possessed homozygous 59029-A allele (OR
1.47, CI 1.03–2.09, P = 0.03). While CX3CR1-I249 and M280 were found to be protective in MI patients with OR 0.46, CI 0.32–0.66, P < 0.0001 and OR 0.36, CI 0.24–0.55, P < 0.0001, respectively. It might be possible that risk of acute MI is associated with genetic variation in chemokine receptors,
i.e., CCR5 and CX3CR1. 相似文献
18.
The polyphasic patterns of fluorescence induction rise in pea leaves in vivo and after the treatment with ionophores have
been studied using a Plant Efficiency Analyzer. To analyze in detail photosystem II (PS II) electron transfer processes, an
extended PS II model was applied, which included the sums of exponential functions to specify explicitly the light-driven
formation of the transmembrane electric potential (ΔΨ(t)) as well as pH in the lumen (pHL(t)) and stroma (pHS(t)). PS II model parameters and numerical coefficients in ΔΨ(t), pHL(t), and pHS(t) were evaluated to fit fluorescence induction data for different experimental conditions: leaf in vivo or after ionophore
treatment at low or high light intensity. The model imitated changes in the pattern of fluorescence induction rise due to
the elimination of transmembrane potential in the presence of ionophores, when ΔΨ = 0 and pHL(t), pHS(t) changed to small extent relative to control values in vivo, with maximum ΔΨ(t) ∼ 90 mV and ΔΨ(t) ∼ 40 mV for the stationary state at ΔpH ≅ 1.8. As the light intensity was increased from 300 to 1200 μmol m−2 s−1, the heat dissipation rate constants increased threefold for nonradiative recombination of P680+Phe− and by ∼30% for P680+QA−. The parameters ΔΨ, pHS and pHL were analyzed as factors of PS II redox state populations and fluorescence yield. The kinetic mechanism of fluorescence quenching
is discussed, which is related with light-induced lumen acidification, when +QA− and P680+ recombination probability increases to regulate the QA reduction. 相似文献
19.
E-Jian Lee Yu-Chang Hung Hung-Yi Chen Tian-Shung Wu Tsung-Ying Chen 《Neurochemical research》2009,34(6):1157-1166
We examined whether a nitric oxide scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-l-oxyl-3-oxide (carboxy-PTIO), could offer neuroprotective actions and improve cerebral energy metabolism in a model of stroke.
Sixty C57BL/10J mice were given either carboxy-PTIO (0.3–1.2 mg/kg) or vehicle intraperitoneally, 0.5 h after permanent middle
cerebral artery occlusion, to evaluate the dose–response effects. An additional 70 animals received carboxy-PTIO (0.6 mg/kg)
or vehicle, 2–6 h post-ischemia, for establishing the therapeutic window. Subgroups of animals, treated with carboxy-PTIO
(0.6 mg/kg) or vehicle, were used for measuring cerebral bioenergetic metabolites (ATP, ADP, AMP, adenosine). Mice treated
with carboxy-PTIO (0.6 mg/kg) had dose-specifically reduced brain infarction, significantly by 27–30% (P < 0.05), even when therapy was delayed up to 4 h after the ischemic insult (P < 0.05). Four hour post-ischemia, ATP depleted in the ischemic hemisphere (P < 0.05). Administration with carboxy-PTIO not only improved the recovery of ATP in the ischemic hemisphere (P < 0.05), but also enhanced adenosine content across the ischemic and non-ischemic hemispheres (P < 0.05). The neuroprotection of carboxy-PTIO may be partly attributed to the beneficial effects of improving cerebral energy
metabolism. 相似文献
20.
Fu RH Hran HJ Chu CL Huang CM Liu SP Wang YC Lin YH Shyu WC Lin SZ 《Biotechnology letters》2011,33(5):903-910
Modulation of dendritic cell (DC) fate and function may be one approach for the treatment of inflammatory and autoimmune diseases.
n-Butylidenephthalide (BP), derived from Angelica sinensis, at 40 μg/ml significantly decreased the secretion of interleukin-6 and tumor necrosis factor-α by lipopolysaccharide (LPS)-stimulated
activation of cultured murine DC2.4 cells (P < 0.01). LPS-induced major histocompatibility complex class II (P < 0.05), CD86 (P < 0.01) and CD40 (P < 0.01) expression on DC2.4 cells was also inhibited by BP. The endocytic capacity of LPS-stimulated DC2.4 cells was increased
by BP (P < 0.01). The antigen-presenting capacity of LPS-stimulated DC2.4 cells was decreased by BP (P < 0.05). Moreover, we confirmed BP attenuates the responses of LPS-stimulated activation of DCs via suppression of NF-κB-dependent
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