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1.
Effects of altered dietary zinc on levels of zinc, copper, magnesium, and calcium in organ and peripheral tissues were studied. When rats fed a zinc-deficient diet (1.3 μg Zn/g) for 28 d were compared with rats fed a control diet (37.5 μg Zn/g), levels of zinc were slightly lower in plasma, hair, and skin and 50% lower in femur and pancreas, whereas the levels of copper were higher in all tissue except plasma. Magnesium levels were higher than controls in the heart and lower in the spleen, whereas the calcium levels were lower in plasma, lung, spleen, kidney, and skin and strikingly higher in brain, hair, and femur. When rats fed a zinc-supplemented diet (1.0 mg Zn/g) were compared to the same conrols, levels of zinc in these were higher in all organs and peripheral tissues studied, except heart, lung, and liver; copper levels were higher in liver, kidney, and spleen; magnesium levels were significantly higher in the spleen, but were little affected in other tissues, although calcium levels were higher in pancreas, spleen, kidney, and skin and lower in plasma and hair. These data indicate that overall copper organ and peripheral tissue levels are affected inversely, and zinc and calcium levels directly, by zinc nutriture.  相似文献   

2.
The concentrations of copper, iron, and zinc in the major organs of Wistar albino (Rattus norvegicus) and wild black rats (Rattus rattus) were measured by means of atomic absorption spectroscopy. The copper levels in the kidneys and liver of the Wistar albino rats (WARs) were significantly higher (p<0.05) than in the wild black rats (WBRs). There were no significant differences in the concentrations of zinc in the liver, lungs, kidneys, and brain between the two study groups, but zinc was significantly higher in the spleen (p<0.05) and lower in the heart (p<0.05) of WAR, compared to WBRs. Iron was significantly higher (p<0.05) in the heart and spleen of WBRs, compared to WARs.There were no extreme differences in the organ concentrations of trace elements between the two species, but, cumulatively, the WARs tend to have higher metallic concentrations in their system than the WBRs. The potential of these differences on the experimental results should not be overlooked and will serve as basis to further consider the complex interrelationships of these animals in their microenvironments and macroenvironments.  相似文献   

3.
The accumulation of cadmium, its affinity for metallothioneins (MTs), and its relation to copper, zinc, and selenium were investigated in the experimental mudpuppy Necturus maculosus and the common toad Bufo bufo captured in nature. Specimens of N. maculosus were exposed to waterborne Cd (85???g/L) for up to 40?days. Exposure resulted in tissue-dependent accumulation of Cd in the order kidney, gills > intestine, liver, brain > pancreas, skin, spleen, and gonads. During the 40-day exposure, concentrations increased close to 1???g/g in kidneys and gills (0.64?C0.95 and 0.52?C0.76; n?=?4), whereas the levels stayed below 0.5 in liver (0.14?C0.29; n?=?4) and other organs. Cd exposure was accompanied by an increase of Zn and Cu in kidneys and Zn in skin, while a decrease of Cu was observed in muscles and skin. Cytosol metallothioneins (MTs) were detected as Cu,Zn?Cthioneins in liver and Zn,Cu?Cthioneins in gills and kidney, with the presence of Se in all cases. After exposure, Cd binding to MTs was clearly observed in cytosol of gills as Zn,Cu,Cd?Cthionein and in pellet extract of kidneys as Zn,Cu,Cd?Cthioneins. The results indicate low Cd storage in liver with almost undetectable Cd in liver MT fractions. In field trapped Bufo bufo (spring and autumn animals), Cd levels were followed in four organs and found to be in the order kidney > liver (0.56?C5.0???g/g >0.03?C0.72???g/g; n?=?11, spring and autumn animals), with no detectable Cd in muscle and skin. At the tissue level, high positive correlations between Cd, Cu, and Se were found in liver (all r?>?0.80; ???=?0.05, n?=?5), and between Cd and Se in kidney (r?=?0.76; n?=?5) of autumn animals, possibly connected with the storage of excess elements in biologically inert forms. In the liver of spring animals, having higher tissue level of Cd than autumn ones, part of the Cd was identified as Cu,Zn,Cd?Cthioneins with traces of Se. As both species are special in having liver Cu levels higher than Zn, the observed highly preferential Cd load in kidney seems reasonable. The relatively low Cd found in liver can be attributed to its excretion through bile and its inability to displace Cu from MTs. The associations of selenium observed with Cd and/or Cu (on the tissue and cell level) point to selenium involvement in the detoxification of excessive cadmium and copper through immobilization.  相似文献   

4.
Although the analysis of metallothionein (MT) by radioimmunoassay (RIA) is not a common technique, its use is preferred over other methods since it offers the advantages of sensitivity and specificity. In this paper we present data on the basal levels of MT in rat tissues and physiological fluids of female Sprague-Dawley rats. The mean basal MT concentrations of the following organs and fluids were determined by RIA to be: liver (9.8 μg/g), kidney (68 μ/g), brain (0.8 μg/g), spleen (1.0 μg/g), heart (5.4 μg/g), plasma (11 ng/ml), and urine (200–300 μg/g creatinine). Following subcutaneous exposure to inorganic mercury (0.2 μmol/kg/d, 5 d a week for up to 4 wk), the metal accumulated primarily in the kidney. There was also a simultaneous accumulation of zinc in the liver and of zinc and copper in the kidney. Induction of MT did take place in liver, kidney, brain, and spleen. No increases in the MT contents of blood and urine were noted. The excess zinc and copper in the kidney of exposed animals were found to be associated predominantly with MT. No overt signs of mercury toxicity were noted in these animals and the incidence of proteinurea was nil. The data are discussed with reference to methods of MT determination in animal tissues and in relation to mercury metabolism and toxicity.  相似文献   

5.
The objective of this study in 2009 was to examine whether levels of cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb) and chromium (Cr) were higher in the leaves than in the stems of a submerged aquatic plant Ceratophyllum demersum in Anzali wetland. Cadmium, Pb and Cr concentrations were highest in the leaves. The mean concentrations of Cd and Cr in the leaves at all the sampling sites ranged between 0.94–1.26 μg g?1 and 1.03–2.71 μg g?1, respectively. Lead also had its highest concentrations in the leaves. The mean concentration of Pb in the leaves at all sampling sites ranged between 7.49–11.88 μg g?1. Copper and Zn concentrations were highest in the stems. The mean concentrations of Cu and Zn in the stems at all sampling sites ranged between 10.79–17.91 μg g?1 and 19.89–40.01 μg g?1, respectively. Cadmium and Pb concentrations were higher in the leaves than in the stems, while Zn concentration was higher in the stems than in the leaves. Accumulation of Cu and Cr in the organs of C. demersum was in descending order of leaf ~ stem, since there was no significant difference between their mean concentrations in the leaves and stems.  相似文献   

6.
The interaction between dietary copper and zinc as determined by tissue concentrations of trace elements was investigated in male Sprague-Dawley rats. Animals were fed diets in a factorial design with two levels of copper (0.5, 5 μg/g) and five levels of zinc (1, 4.5, 10, 100, 1000 μg/g) for 42 d. In rats fed the low copper diet, as dietary zinc concentration increased, the level of copper decreased in brain, testis, spleen, heart, liver, and intestine. There was no significant effect of dietary copper on tissue zinc levels. In the zinc-deficient groups, the level of iron was higher in most tissues than in tissues from controls (5 μg Cu, 100 μg Zn/g diet). In the copper-deficient groups, iron concentration was higher than control values only in the liver. These data show that dietary zinc affected tissue copper levels primarily when dietary copper was deficient, that dietary copper had no effect on tissue zinc, and that both zinc deficiency and copper deficiency affected tissue iron levels.  相似文献   

7.
The concentrations of copper, iron, and zinc in the major organs of Wistar albino (Rattus norvegicus) and wild black rats (Rattus rattus) were measured by means of atomic absorption spectroscopy. The copper levels in the kidneys and liver of the Wistar albino rats (WARs) were significantly higher (p<0.05) than in the wild black rats (WBRs). There were no significant differences in the concentrations of zinc in the liver, lungs, kidneys, and brain between the two study groups, but zinc was significantly higher in the spleen (p<0.05) and lower in the heart (p<0.05) of WAR, compared to WBRs. Iron was significantly higher (p<0.05) in the heart and spleen of WBRs, compared to WARs. There were no extreme differences in the organ concentrations of trace elements between the two species, but, cumulatively, the WARs tend to have higher metallic concentrations in their system than the WBRs. The potential of these differences on the experimental results should not be overlooked and will serve as basis to further consider the complex interrelationships of these animals in their microenvironments and macroenvironments.  相似文献   

8.
Bank voles free living in a contaminated environment have been shown to be more sensitive to cadmium (Cd) toxicity than the rodents exposed to Cd under laboratory conditions. The objective of this study was to find out whether benzo(a)pyrene (BaP), a common environmental co-contaminant, increases Cd toxicity through inhibition of metallothionein (MT) synthesis-a low molecular weight protein that is considered to be primary intracellular component of the protective mechanism. For 6 weeks, the female bank voles were provided with diet containing Cd [less than 0.1 μg/g (control) and 60 μg/g dry wt.] and BaP (0, 5, and 10 μg/g dry wt.) alone or in combination. At the end of exposure period, apoptosis and analyses of MT, Cd, and zinc (Zn) in the liver and kidneys were carried out. Dietary BaP 5 μg/g did not affect but BaP 10 μg/g potentiated rather than inhibited induction of hepatic and renal MT by Cd, and diminished Cd-induced apoptosis in both organs. The hepatic and renal Zn followed a pattern similar to that of MT, attaining the highest level in the Cd + BaP 10-μg/g group. These data indicate that dietary BaP attenuates rather than exacerbates Cd toxicity in bank voles, probably by potentiating MT synthesis and increasing Zn concentration in the liver and kidneys.  相似文献   

9.
Mice were given either cadmium (Cd), copper (Cu) or zinc (Zn) ad lib, and levels of the metals in the heart, kidneys and liver were measured together with organ contents of sodium (Na) and calcium (Ca). The contents of Cd increased more than 100-fold in all organs, whereas Zn increased by a factor of 2-4. Copper accumulated only in the liver. Cadmium exposure caused the Na and Ca contents in the kidneys to increase by a factor of 2-3, but caused a statistically significant reduction in the Na content of the liver. Cadmium also caused a reduction in the Ca content of the heart. Copper caused a statistically significant doubling of the Na content in the heart, but a significant reduction in the Ca content in this organ. Zinc caused a reduction in the Ca content of the heart. However, the mechanisms behind these effects are not clear. The accumulation of Cd in the kidneys and heart was associated with a gradual change in the Na and Ca levels in these organs, but trace metal accumulation was not associated with any conspicuous changes in the Na or Ca contents in any other organ. Copper was not accumulated in heart, but Cu intake still had marked effects on the Na and Ca contents in this organ. Since the tissue contents of Na and Ca are likely to be physiologically important, these ions may have potential as biomarkers for toxic stress. Since the effects of Cd and Cu differed markedly, the tissue contents of Na and Ca may also be used in a trace metal-specific system of fingerprint biomarkers.  相似文献   

10.
The concentrations of copper, molybdenum and zinc were measured in the liver of normal grazing sheep and lambs from Eastern Norway, and in sheep dead of chronic copper poisoning. The following mean values were found: Normal sheep: 173 ± 130 μg Gu/g wet weight, 1.0 ±0.3 μg Mo/g, and 49 ± 10 μg Zn/g; lambs: 129 ± 59 μg Gu/g, 0.9 ± 0.3 μg Mo/g, and 46 ±9 μg Zn/g; sheep dead of copper poisoning: 429 ± 249 μg Gu/g, 0.4 ± 0.1 μg Mo/g, and 43 ± 2d μg Zn/g. Sheep with low liver copper (Gu < 10 μg/g) were also analyzed for molybdenum and zinc, with the following results: 1.0 ± 0.2 μg Mo/g, and 45 ± 8 μg Zn/g wet weight. The differences in liver copper between all the groups, and the differences in molybdenum concentrations between the normal sheep and the lambs and between the normal sheep and the poisoned sheep were significant (P < 0.001). No significant correlations between liver copper/liver molybdenum or liver copper/liver zinc were detected.  相似文献   

11.
Zn, Mg, Cu, Ca and Fe were determined spectrophotometrically in liver, kidneys, muscle, spleen and blood of Bufo regularis after a single i.m. injection of 6.2 mg Cd/kg (which represents the 96 hr LD50) alone or in combination with 40 mg EDTA/kg (the minimal EDTA concentration causing 100% survival over that period). Cadmium administration caused recognizable effects on the essential metals levels in different tissues and organs. In the majority of the tissues and organs studied, zinc and copper concentrations returned to their normal ranges in animals that received both cadmium and EDTA. In contrast, magnesium, calcium and iron contents not only returned back to their control values but also exceeded them.  相似文献   

12.
The concentrations of copper, zinc and molybdenum were measured in liver samples from 21 normal slaughter pigs (average age about 6 months) and in 36 sows (average age about 2 years). The following mean values were found: Slaughter pigs: 15 ± 8 µg Cu/g, 45 ± 7 μg Zm/g and 1.0 ± 0.2 μg Mo/g wet weight; sows: 46 ± 70 μg Cu/g, 70 ± 26 μg Zn/g and 1.3 ± 0.3 μg Mo/g wet weight. The concentrations of all 3 elements were significantly higher in the sows than in the young pigs. There was no correlation between the concentrations of copper, zinc or molybdenum. The recorded copper levels in the slaughter pigs were in accordance with the levels of non-supplemented pigs given in the literature. The soluble hepatic copper- and zinc-binding proteins were separated into 3 different fractions by gel filtration. With increasing copper and zinc levels in the liver, a higher relative amount of these elements were found in the low molecular weight fraction.  相似文献   

13.
1. Male Wistar rats were exposed to fluoride (F) at concentrations of 100- and 200 ppm in their drinking water for 6- and 16 weeks.2. The high F intake caused several-fold increase in the F concentrations in the testes and bone as compared with control rats, both after the 6- and 16wk exposure; the bone F, but not testicular F, appeared to increase with dose and time.3. F exposure (100- and 200 ppm) decreased significantly the concentrations of zinc (Zn) in the testes, plasma, liver and kidneys particularly in the 16 wk groups; in the bone Zn tended to increase, however.4. The iron concentrations of the testes and plasma were not affected by F, whereas those of the liver, kidneys and bone appeared to increase under the influence of F.5. The concentrations of copper and manganese in the testes, liver and kidneys were not changed by F exposure.6. Fifty percent of the 100- and 200 ppm F rats after 16 weeks exhibited histopathologic changes in the germinal epithelium of the testes, which resembled those in Zn-deficient rats.7. The data suggest that a deprivation of testicular Zn due to a high F intake may be directly responsible for the injury of testicular tubules.  相似文献   

14.
Thyroid hormones are involved in copper and zinc distribution in rat tissues. We examined the influence of thyroparathyroidectomy (TPTY) and of a replacement therapy by T4 on Cu and Zn organ distribution. MT levels were also measured both in basal conditions and after induction by cadmium. The results confirm that a lack of T4 modified Cu and Zn in serum and tissues. In serum, TPTY increased Cu (+15%) and ceruloplasmin (+18%), and decreased Zn (−18%). In tissues, Cu was altered in liver (+13%), kidney (−24%), heart (−16%) duodenum (−18%), and Zn in liver (+25%) and kidney (−10%). The soluble fractions (100,000 g supernatant) were mainly affected in liver and kidney, and the subcellular fractions in heart and duodenum. MT levels were modified in basal conditions only in liver (+57%) and kidney (−36%). T4 administration partially prevented the effect of TPTY on both elements and MT concentrations. Therefore, no evidence is provided for a direct role of T4 in the metabolism of MT in a way comparable to the effects of glucocorticoids. However, MT could mediate the consequences of TPTY on metal distribution in certain organs, such as liver and kidney.  相似文献   

15.
The present study was designed to investigate the effect of mercuric chloride administration on copper, zinc, and iron concentrations in the liver, kidney, lung, heart, spleen, and muscle of rats. The results showed that after dose and time exposure to mercuric chloride, the concentration of mercury in the six tissues was significantly elevated. Data showed that there were no interaction between mercury and tissue iron. There was a considerable elevation of the content of copper in the kidney and liver. The most significant changes in the copper concentration took place in the kidneys. About a twofold increase in the copper content of the kidney was noted after exposure to mercuric chloride (3 mg and 5 mg/kg). Only slight elevations in the copper content occurred in the liver, especially in high dose and longer exposure time. In the remaining organs, the copper content was not changed significantly (p>0.05). The most significant changes in the zinc concentration took place in liver, kidney, lung, and heart (5 mg/kg). Marked changes in kidney zinc concentrations were observed at any of the specified doses. Zinc concentrations were significantly increased in kidney of rats sacrificed 9–48 h after sc injection of HgCl2 (5 mg/kg); in liver obtained from rats at 18, 24, or 48 h after injection; and in lung after 24 or 48 h of treatment. The heart and spleen zinc concentrations were elevated at 24 and 48 h after injection of HgCl2 (5 mg/kg), respectively. The results of this study implicate that effects on copper and zinc concentrations of the target tissues of mercury may play an important role in the pathogenesis of acute mercuric chloride intoxication.  相似文献   

16.
The regional brain distribution of metallothionein (MT), zinc, and copper in the brain was determined in nine anatomical regions (olfactory bulb, cortex, corpus striatum, hippocampus, thalamus plus hypothalamus, pons plus medulla oblongata, cerebellum, midbrain, and white matter) and was compared between two different strains of rat (Sprague-Dawley [SD] and Lewis). No significant difference was observed in the whole-brain MT level between the two strains (17.8 ± 3.4 μg/g in SD rats and 20.3 ± 2.3 μg/g in Lewis rats). In SD rats, however, MT was more highly expressed in the white matter than in the other regions studied. In contrast, MT concentration was highest in the cortex and lowest in the olfactory bulb in Lewis rats. The MT levels in the cortex, corpus striatum, hippocampus, and thalamus plus hypothalamus were significantly lower in SD rats than in Lewis rats. In both strains, the olfactory bulb contained markedly higher levels of both zinc and copper than the other regions (27.9 ±6.8 μg/g zinc in SD rats and 27.6 ± 6.9 μg/g zinc in Lewis rats, and 5.2 ± 1.5 μg/g copper in SD rats and 11.1 ± 4.8 μg/g copper in Lewis rats). The next high-est zinc levels were seen in the hippocampus, whereas the next highest copper levels were in the corpus striatum in both SD and Lewis rats. The high levels of zinc and copper in the olfactory bulb were not accompanied by concomitant high MT concentrations. These results indicate that the strain of rat as well as the anatomical brain region should be taken into account in MT and metal distribution studies. However, the highest concentrations of zinc and copper in olfactory bulb were common to both SD and Lewis rats. The discrepancy between MT and the metal levels in olfactory bulb suggests a role for other proteins in addition to MT in the homeostatic control of zinc and copper.  相似文献   

17.
Summary Correlated responses to selection for increased 3–6 week postweaning gain in male mice were estimated for seven internal organs (testes, spleen, liver, kidneys, heart, small intestine (S intest) and stomach) weighed at specific degrees of maturity in body weight (37.5, 50.0, 62.5, 75.0, 87.5 and 100%). Correlated responses in organ weights were generally large, but the magnitude and direction of response depended upon whether 1) comparisons were made at the same age, degree of maturity or body weight and 2) absolute or proportional organ weights were used. The selected line (M16) weighed more and had larger organ weights than controls (ICR) when compared at either the same degree of maturity or the same age, indicating positive genetic correlations between body weight and the respective organ weights. Positive correlated responses were found in spleen weight/body weight at all degrees of maturity and in liver and S intest weights as a proportion of body weight at some degrees of maturity. Testes, kidneys, heart and stomach weights as a proportion of body weight had negative correlated responses, though this was consistent only for kidneys across all degrees of maturity. Correlated responses in organ weights adjusted for body weight by covariance analysis were positive for spleen, S intest and stomach and negative for testes and kidneys. Based on the constrained quadratic model, degree of maturity in organ weight relative to degree of maturity in body weight responded positively for testes, kidneys and S intest and negatively for spleen and liver. Selection for increased growth caused negative correlated responses in allometric growth of testes, kidneys, S intest and stomach.Paper No. 10,545 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, 27695-7601. The use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Research Service of the products named, nor criticism of similar ones not mentioned  相似文献   

18.
The present study was designed to investigate the effects of Zn administration on metallothionein concentrations in the liver, kidney, and intestine of copper-loaded rats. Male CD rats were fed a diet containing 12 mg Cu and 67 mg Zn/kg body wt. They were divided into either acute or chronic experimental protocols. Rats undergoing acute experiments received daily ip injections of either Cu (3 mg/kg body wt) or Zn (10 mg/kg body wt) for 3 d. Chronic experiments were carried out on rats receiving Cu ip injections on d 1, 2, 3, 10, 17, and 24, Cu injections plus a Zn-supplemented diet containing 5 g Zn/kg solid diet, or a Zn-supplemented diet alone. Rats injected Zn or Cu had increased MT concentrations in liver and kidney. Zn produced the most important effects and the liver was the most responsive organ. Rats fed a Zn-supplemented diet had significantly higher MT concentrations in liver and intestine with respect to controls. Increased MT synthesis in the liver may contribute to copper detoxification; the hypothesis of copper entrapment in enterocytes cannot be confirmed.  相似文献   

19.
Zinc (Zn) is an essential nutrient that is required in humans and animals for many physiological functions, including immune and antioxidant function, growth, and reproduction. The present study was performed to investigate the effects of three Zn levels, including Zn adequate (35.94 mg/kg, as a control), Zn deficiency (3.15 mg/kg), and Zn overload (347.50 mg/kg) in growing male rats for 6 wk. This allowed for evaluation of the effects that these Zn levels might have on body weight, organ weight, enzymes activities, and tissues concentrations of Zn and Cu. The results showed that Zn deficiency has negative effects on growth, organ weight, and biological parameters such as alkaline phosphatase (ALP) and Cu−Zn superoxide dismutase (Cu−Zn SOD) activities, whereas Zn overload played an effective role in promoting growth, improving the developments of organs and enhancing immune system. Hepatic metallothionein (MT) concentration showed an identical increase tendency in rats fed both Zn-deficient and Zn-overload diets. The actual mechanism of reduction of Cu concentration of jejunum in rats fed a Zn-overload diet might involve the modulation or inhibition of a Cu transporter protein by Zn and not by the induction of MT.  相似文献   

20.
Increasing litter sizes in modern swine production have raised an urgent need for artificial rearing strategies and formula feeding. The current experiment was conducted to study the influence of formula trace element concentration according to recommendations for weaned piglets on the mRNA concentration of zinc (Zn)-related genes in the jejunum, liver and pancreas of neonatal piglets. Eight artificially reared piglets were fed a cow-milk-based formula (Group FO) containing 100 mg Zn/kg dry matter. Eight of their sow-reared littermates (Group SM) were used as control. After 14 d, all 16 piglets were killed and the jejunum, liver and pancreas were evaluated for Zn, copper, manganese (Mn) and iron (Fe) concentration and mRNA concentration of metal and Zn-specific transporters, metallothioneins (MT) and interleukin 6 (IL-6). In Group FO the Zn concentration in liver tissue was increased (< 0.05). Furthermore, Fe and Mn concentrations in liver and jejunal tissue were higher (< 0.05) in Group FO, whereas neither Zn transporters nor MT in jejunal and pancreatic tissue showed differences between both groups. In the liver of Group FO, MT mRNA concentration was higher (< 0.05), whereas Zn transporter protein 1 and divalent metal-ion transporter 1 (DMT1) mRNA concentration was lower (< 0.05). Besides Zn-induced expression of transporters and MT, the significantly increased IL-6 expression in Group FO suggests the involvement of cytokine-mediated Mn and Fe sequestration in the liver and jejunum. The results revealed that dietary trace element concentration used in the study likely exceeded the requirements of neonatal pigs as reflected by homeostatic counter-regulation in different organs.  相似文献   

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