Cadmium, zinc, copper and metallothionein levels in the kidney and liver of humans from central Poland

Comparison of Copper Concentration Between Rejected Renal Grafts and Cancerous Kidneys

In the body, disorders in the composition and concentration of trace elements, including copper, can lead to the development of various alterations that may result in incorrect functioning of the kidneys. Data on the concentrations of copper in human kidneys are discussed; however, little is known about the concentration of trace elements within rejected renal grafts and kidneys with tumor lesions. The aim of our study was to compare the copper concentration between cancerous kidneys and rejected renal grafts with the division on renal cortex and renal medulla. Material consisted of kidneys from patients hospitalized at the Department of Urology and General Surgery and Transplantation of the Independent Public Clinical Hospital No. 2 at the Pomeranian Medical University in Szczecin, north-western Poland. The study material consisted of kidneys with tumor lesions (n = 33), and renal grafts (n = 10), obtained from patients belongs to the north-western areas of Poland. The examination was performed using ICP-AES method. Regarding the pathological kidneys, excluding grafts, the concentration of Cu in the renal cortex was 52% higher than in medullary region and the difference between the compared concentrations was statistically confirmed (p < 0.05). Taking into account renal grafts, the concentration of Cu in the medulla was slightly lower than in the cortex (less than 3%). In summary, copper in rejected and cancerous kidneys tends to accumulate in higher amount in the renal cortex than medulla, what can be explained by the fact that renal corpuscles, where the first phase of filtration is performed, are located only in the cortical region of the kidney. Furthermore, renal grafts accumulate significantly less copper than kidneys with neoplastic changes, what could have been caused by immunosuppressive medicines used by the graft recipients. The lower copper concentration in renal grafts could be a consequence of the altered immune system, including inflammatory process or/and non-immune mechanisms. Additionally, cancerous and non-cancerous kidneys exhibit different perfusion rate in renal glomeruli, what can finally lead to disparity in chemical elements concentration, including copper.

Review of polyphenol-rich products as potential protective and therapeutic factors against cadmium hepatotoxicity

Recently, the growing attention of the scientific community has been focused on the threat to health created by environmental pollutants, including toxic metals such as cadmium (Cd), and on the need of finding effective ways to prevent and treat the unfavorable health effects of exposure to them. Particularly promising for Cd, and thus arousing the greatest interest, is the possibility of using various ingredients present in plants, including mainly polyphenolic compounds. As the liver is one of the target organs for this toxic metal and disturbances in the proper functioning of this organ have serious consequences for health, the aim of the present review was to discuss the possibility of using polyphenol-rich food products (e.g., chokeberry, black and green tea, blueberry, olive oil, rosemary and ginger) as the strategy in protection from this xenobiotic hepatotoxicity and treatment of this heavy metal-induced liver damage. Owing to the ability of polyphenols to bind ions of Cd and the strong antioxidative potential of these compounds, as well as their abundance in dietary products, it seems to be of high importance to consider the possibility of using polyphenols as potential preventive and therapeutic agents against Cd hepatotoxicity, determined by its strong pro-oxidative properties. Although most of the data on the effectiveness of polyphenols comes from studies in animals, the fact that some of them are derived from experimental models that reflect human exposure to this metal allows us to assume that some polyphenol-rich food products may be promising protective agents against Cd hepatotoxicity in humans.

Cadmium, lead and mercury concentrations in pathologically altered human kidneys

Heavy metals, including cadmium (Cd), lead (Pb) and mercury (Hg) act as nephrotoxic agents, particularly in the renal cortex. The aim of the study was to determine the concentrations of Cd, Pb and Hg in kidneys removed from patients due to lesions of various etiologies and from patients after the rejection of transplanted kidneys. Additionally, we determined the influence of selected biological and environmental factors on the concentrations of toxic metals. The study material consisted of kidneys with tumor lesions (n = 27), without tumors (n = 7) and its extracted grafts (n = 10) obtained from patients belongs to the north-western areas of Poland. The determined metal concentrations in the renal cortex and medulla may be arranged in the following descending order: Cd > Pb > Hg. The highest concentrations of Cd and Hg were found in the cortex, while the maximum content Pb was observed in the medulla. Significant correlations were found in the concentrations of the same metals between cortex and medulla and between Pb and Hg in the renal medulla. Pb content was higher in the renal medulla of men than in the cortex of the elderly (above 60 years of age). The highest concentrations of Pb and Hg were found in the cortex and medulla, of the kidneys had not neoplastic changes, and lower content of these metals were found in the extracted kidney grafts. In summary, renal grafts accumulate less heavy metals than cancerous kidneys, what could have been caused by immunosuppressors taken by the graft recipients. Moreover, sex, age and smoking are key factors responsible for xenobiotics concentrations.

Impairing both HMA4 homeologs is required for cadmium reduction in tobacco

In tobacco, the heavy metal P1B-ATPases HMA4.1 and HMA4.2 function in root-to-shoot zinc and cadmium transport. We present greenhouse and field data that dissect the possibilities to impact the two homeologous genes in order to define the best strategy for leaf cadmium reduction. In a first step, both genes were silenced using an RNAi approach leading to >90% reduction of leaf cadmium content. To modulate HMA4 function more precisely, mutant HMA4.1 and HMA4.2 alleles of a Targeting Induced Local Lesions IN Genomes (TILLING) population were combined. As observed with RNAi plants, knockout of both homeologs decreased cadmium root-to-shoot transfer by >90%. Analysis of plants with segregating null and wild-type alleles of both homeologs showed that one functional HMA4 allele is sufficient to maintain wild-type cadmium levels. Plant development was affected in HMA4 RNAi and double knockout plants that included retarded growth, necrotic lesions, altered leaf morphology and increased water content. The combination of complete functional loss (nonsense mutation) in one homeologous HMA4 gene and the functional reduction in the other HMA4 gene (missense mutation) is proposed as strategy to limit cadmium leaf accumulation without developmental effects.

A new index for evaluation of cadmium pollution in birds and mammals

The degree of cadmium (Cd) contamination in wildlife is often used as an indicator in the environmental monitoring of Cd poisoning. However, previous studies have not clarified the correlation between levels in wildlife and levels in the environment by comparing levels among different species of animals; therefore, assessing the level of pollution in this manner is not considered a reliably accurate indicator of levels in the environment. The aim of this study was to establish a new indicator for the non-polluted warm-blooded animals, one that is not species-dependent, which will facilitate using different species for Cd monitoring. First, the previous publications regarding Cd contents in wildlife, 27 reports in which Cd contents were represented as arithmetic means and described for both kidney and liver were selected. A regression line (CSRL) between Cd contents of kidney and that of liver was obtained in a high correlation coefficient (R (2) = 0.943, P < 0.01). The mean values from land and waterfowl, terrestrial mammals, seabirds, marine mammals, and non-polluted humans were located on the line and aligned in order. CSRL might allow an accurate determination of whether an animal is polluted by Cd. CSRL was confirmed using well-established and widely recognized pollution models such as Itai-itai patients and Cd-exposed experimental animals. The Cd contents from these models were located in different positions relative to CSRL depending on the level of contamination. Thus, this new indicator determining the Cd-pollution status of animals would be useful for environmental monitoring.

Metal composition of human hepatic and renal metallothionein

This article is based on data on the levels of metals (Cd, Zn, Cu) and metallothionein (MT) determined radiochemically with 203Hg in renal cortex and liver of 137 autopsy cases. From this number, for 23 cases, the gel filtration of the cytoplasmic fraction of the organs was performed. The molar content of metals in the MT fraction (Sephadex G-50) amounted to 46.9, 50.2, and 2.0% for Cd, Zn, and Cu in renal cortex, respectively, and to 8.3, 83.6, and 9.1% for Cd, Zn, and Cu in the liver, respectively. In parallel with the increase of Cd and MT in renal cortex, increasing saturation was found of the MT fraction by Cd, occurring at the expense of Zn and Cu. Equimolar amounts of Cd and Zn in the MT fraction are found at Cd level of 0.5 micromol Cd/g wet wt of renal cortex. In the liver, analogous dependency (elevation of %Zn, depression of %Cd and %Cu) were observed in relation to Zn and MT levels in this organ. The basic level of Zn (not bound with MT) was estimated at 0.5 micromol/g for both renal cortex and liver. A deficit of non-MT Zn in kidneys is proposed as an alternative mechanism of toxic Cd action.

The monitoring of cadmium, zinc and copper in the kidneys and liver of humans deceased in the region of Cracow (Poland)

Cadmium, zinc and copper levels were determined in the renal cortex and liver of 60 inhabitants of Cracow, Poland. Cadmium levels in the renal cortex were contained in broad limits of 5-176 μg/g, mean 50.6 μg/g (wet weight). Maximum levels were found in the age group of about 50-60 years. The levels were slightly higher in men (53 μg/g) than in women (45 μg/g), with no effect of location within the region. The levels in smokers (62 μg/g) were much higher than in non-smokers (32 μg/g). The above relations were less pronounced for cadmium levels in the liver. Whole body retention of cadmium followed the pattern of cadmium in renal cortex. The level of zinc in renal cortex reflected those of cadmium. A significant proportion of the population (54% in smokers, 9% in non-smokers) showed cadmium levels in renal cortex exceeding the reference level of 50 μg/g recently accepted for general population. In the view of the authors the exposure to cadmium of the population of Cracow is excessive and calls for attention.

Cadmium, zinc, copper, and metallothionein levels in the kidney and liver of inhabitants of upper Silesia (Poland)

The levels of Cd, Zn, Cu and metallothionein (MT) were determined in renal cortex and liver of 75 subjects decreased in the period 1986-1989 in the area of Upper Silesia (Katowice). The mean age of the population studied was 53.6 +/- 14.6 years. The determined levels (mean +/- SD) were: 43.1 +/- 23.5 micrograms Cd/g; 52.5 +/- 17.4 micrograms Zn/g; 2.2 +/- 0.7 microgram Cu/g; 0.80 +/- 0.36 mumol Hg/g in renal cortex and 3.5 +/- 2.5 micrograms Cd/g; 82.8 +/- 34.3 micrograms Zn/g; 4.5 +/- 2.6 micrograms Cu/g; 0.69 +/- 0.44 mumol Hg/g in the liver. The level of Cd in renal cortex was 40% higher in smokers compared to nonsmokers and was independent of the gender. Whole-body retention of Cd was 34.1 +/- 18.5 mg; smoking elevated the value from 27.1 to 38.2 mg. Compared with a similar study made in central Poland (Lódź), a significant difference was found only regarding the level of Zn and MT in the liver, pointing to the possibility that exposure to this element in the region of Upper Silesia may be higher.