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排序方式: 共有866条查询结果,搜索用时 265 毫秒
1.
Yasumasa Kunifuji Terumasa Nakamura Masayuki Takasugi 《Biological trace element research》1987,14(3):237-248
Cd induced changes of Zn and Cd distribution in the liver and kidneys were studied in relation to Cd metallothionein (MT)
synthesis. Wistar male rats were given CdCl2 by sc injection of .8, 1.5, and 3.0 mg Cd/kg three times a week for three weeks. Cd levels of liver and kidneys increased
with the increment of Cd dosage and 80–90% of Cd was found in the cytosol. The MT fractions contained 80–89% cytosolic Cd
in the liver and 55–75% Cd in the kidneys. Zn concentrations in the liver increased following Cd administration, But Zn in
the kidneys showed only slight increase. There was a distinct decrease of Cu concentration in the liver of the 3.0 mg group.
In contrast, Cu concentrations in the kidneys increased about three times in the .8 and 1.5 mg Cd groups, but Cu in the 3.0
mg group showed only 1.5 times increase. The changes of these metal concentrations were observed mainly in the cytosol. Non-MT-Cd
in the kidneys was maximum in the 1.5 mg group, but the 3.0 mg group showed significant decrease. In parallel with this decrease
of Cd, Cu and Zn in the kidneys showed similar decrease. When the kidneys are injured, Zn and Cu appear to leak from this
organ. 相似文献
2.
The effects of nutritional copper deficiency on carrageenin edema in the rat were investigated with emphasis on studying the
correlation between the degree of copper deficiency and the degree of edema. Carrageenin paw edema in both copper-sufficient
and copper-deficient groups of rats was compared after either 20, 40, or 60 d on respective diets. The degree of copper deficiency
was quantitated by analyzing total copper concentrations in a number of tissues. Other copper dependent parameters were also
determined. Results indicated that: (1) although copper sufficient rats showed relatively little change in the degree of edema,
copper-deficient rats showed a steady and significant increase in edema from d 20 to 40 to 60; (2) paw edema in copper-deficient
animals was highly and negatively correlated to the concentrations of copper in the liver; the correlation with liver Cu,Zn-superoxide
dismutase activity, however, was inconsistent; (3) paw edema was not correlated either to copper concentration in tissues
other than liver or to plasma ceruloplasmin activity; and (4) aggravation of carrageenin edema in copper-deficient animals
seemed to be mediated via an as yet unknown secondary effect of copper deficiency. 相似文献
3.
Serum copper and zinc levels were determined in 20 healthy women and in 100 women with gynecological tumors. Malignant and
benign tumor cases were separated according to their postoperative, histopathological examinations. The stages of malignant
and benign tumors were also established histologically. Seventy benign and 30 malignant genital tumors (carcinoma of cervix
in situ, cervix, ovary endometrium, and vulva) of the patients were differentiated histopathologically.
The serum Cu/Zn ratios of patients were increased significantly from the control group (0.32±0.35) to the benign group (1.22±0.63)
and from the benign group to the malignant group (2.24±1.03). Nine of 30 malignant cases were determined as false negative
(30%) and 15 of 70 benign cases were determined as false positive (14.2%) according to the serum Cu/Zn ratios of patients.
Serum copper levels of 30 malignant and 10 benign tumor cases showed linear correlation with serum ceruloplasmin values. 相似文献
4.
Usually the toxicity of superoxide is attributed lo its ability to reduce metal ions and subsequently reoxidation of the metal by hydrogen peroxide yields deleterious oxidizing species. As many other nontoxic biological reductants reduce metal compounds, we suggest that part of the mechanism of superoxide toxicity results from its ability to oxidize metal ions bound to biological targets, which subsequently degrade the target via an intramolecular electron Transfer reaction. 相似文献
5.
Yan Ming Ling Yihling Huang Shansheng Gong Shuqing Xu Zhenxing 《Biological trace element research》1991,29(3):281-288
Contents of Cu and Zn of into-pulmonary blood (IPB), out-pulmonary blood (OPB), Lung tissue, and supernatant and macrophages of Lung Lavage were determined in superior mesenteric artery occlusion (SMAO) shock of rabbits. Zn of pulmonary tissue was 11.42 +/- 0.60 and 14.52 +/- 1.78 (micrograms/g wet wt) in SMAO shock and control groups, respectively. Content of Zn was found to be lower, Cu was not changed, and Cu/Zn ratio increased in lung tissue in SMAO shock. Contents of Cu and Zn in other samples were not changed. The results suggest that lower Zn in lung tissue related to acute lung injury. 相似文献
6.
7.
Gerhard Sandmann 《Archives of microbiology》1986,145(1):76-79
Fifteen species from different genera of blue-green algae have been examined for their formation of plastocyanin (PC) and cytochrome c-553 (cyt c-553) in high or low Cu media. In addition to species which contain only cyt c-553 and those which completely exchange their cyt c-553 by PC, a new regulatory type was detected in which this exchange was incomplete. By comparing different species, it could be shown that either this incomplete exchange of cyt c-553 by PC as well as lack of PC in some other blue-green algae is not caused by restricted Cu uptake but is due to different biosynthetic and regulatory properties. Occurrence of PC and cyt c-553 cannot be used as a taxonomic criterium to classify blue-green algae. However, formation of either one or both of these redox components fits well into a line of evolution of the photosynthetic apparatus from the blue-green algae via green algae to higher plants.Abbreviations PC
plastocyanin; cyt c-553, cytochrome c-553 相似文献
8.
Summary The release of intact CU(I)8-thionein from copper-resistant copper-loaded yeast cells, strain X 2180-1Aa, has been shown. This copper(I)-thiolate-rich protein was characterized and compared with the chemical and physicochemical properties of intracellular yeast Cu-thionein. The same molecular mass and stoichiometry of 8 mol copper atoms/mol protein was found. No detectable difference between the Cu-thioneins was seen in luminescence emission, electronic absorption in the ultraviolet region, chiroptical data or amino acid composition. The importance of stable Cu(I)-thiolates in Cu-thionein as a safe vehicle for transporting copper in a non-reactive manner is confirmed. 相似文献
9.
Erasmus Otabbong 《Plant and Soil》1990,123(1):89-93
The effect of Si(OH)4 on Cr toxicity and elemental concentrations in ryegrass were investigated in a growth chamber using an acid and a neutral
mineral soil. Each soil was treated with 50 mg Cr, as CrO3, kg−1 soil dry weight, singly, or in combination with 25 mg Si as Si(OH)4. Plants growing in unamended soils were used as controls.
Chromium toxicity, expressed as decrease in shoot or root dry weight, was increased by the Si. This increase was accompanied
by a higher Cr uptake particularly on the acid soil. The shoot and root dry weights were significantly correlated (P=1%) with the concentration of Cr, where r=−0.80 and −0.65, respectively. Uptake of Al, Cu, Fe, P and Zn did not show any
consistent relationship to the magnitude of Cr toxicity. 相似文献
10.
James M. Caffrey Harry A. Smith John C. Schmitz Andrea Merchant Earl Frieden 《Biological trace element research》1990,25(1):11-19
The hemolysis of red blood cells (RBC) induced by Cu(II) is modified by ceruloplasmin (Cp) and albumin. The time course of hemolysis for rabbit RBC by Cu(II) consisted of two parts, an induction period followed by a catastrophic lysis period. The induction period decreased and the lysis rate increased with increasing Cu(II) concentration. Cp or albumin, modified Cu(II) induced hemolysis, by increasing the duration of the induction period and decreasing the overall rate of hemolysis of RBC. The catastrophic lysis period coincided with a sharp increase in the formation of metHb within the cell and in a rapid uptake of Cu(II). The presence of Cp led to an increase in the induction period prior to the rapid increase in metHb formation and in Cu(II) uptake. Porcine Cp was prepared with either two or three nonprosthetic copper binding sites (sites where Cu(II) is easily removed by passing over Chelex-100). Cp with three nonprosthetic binding sites gave more protection than Cp with two. Likewise, albumin can be prepared with three and five nonprosthetic copper binding sites. The albumin with five sites gave more protection than the albumin with three sites. 相似文献