Antioxidant enzyme activities and trace element concentrations in ischemia-reperfusion

In this study, we investigated the impact of ischemia-reperfusion on antioxidant enzyme activities and trace element concentrations. For this purpose, ischemia was initiated by clamping superior mesenteric artery of Wistar (albino) rats for 30 min, followed by reperfusion for 20 min. Immediately after reperfusion, blood samples were taken and examined for red cell copper-zinc superoxide dismutase (Cu-Zn-SOD), catalase (CAT), and glutathione peroxidase (GPx) activities spectrophotometrically and plasma zinc, copper, and magnesium concentrations by atomic absorption spectrophotometer. In the ischemiareperfusion group, red cell Cu-Zn-SOD activity and plasma zinc and copper concentrations were increased significantly (p<0.001) when compared to the control group; however, the increases in GPx activity and plasma magnesium concentration were not significant (p>0.05). We also found a significant (p<0.01) decrease in catalase activity. Free radicals released as a consequence of ischemia-reperfusion caused significant alterations in antioxidant enzymes and in the concentrations of trace elements. Presented at III International Congress of Pathophysiology 1998, Lahti, Finland.     

Effect of exposure to high isoflavone-containing diets on prenatal and postnatal offspring mice

Isoflavone (IF), a type of phytoestrogen, has multiple beneficial effects, but too much phytoestrogen can have adverse effects on offspring. To examine whether chronic exposure to high IF has adverse effects on reproductive development, mice offspring were exposed to IF through dietary administration to dams during pregnancy and lactation and to the offspring directly after weaning until sacrifice. In male offspring, there was no difference between the IF group and controls; however, in female offspring in the IF group, remarkably earlier puberty and induction of multioocyte follicles on postnatal day (PND) 21 were observed. Gene expression levels of estrogen receptor beta decreased in the ovary and vagina on PND 21. These results suggest that chronic exposure to higher than normal levels of IF induces alterations in the reproductive development of female mice through an estrogenic effect.     

Laboratory gloves as a source of trace element contamination

Contamination in a trace element laboratory can come from a variety of sources, including laboratory gloves. Therefore, vinyl and latex gloves were obtained from as many manufacturers as would supply gloves. These gloves were either prepared for acid-washing and subsequent soaking in an acid solution, or immersed in an acid solution for a duration of either 1 min or 1 h. Incubation washes were analyzed for a variety of trace elements by flame atomic abosrption spectroscopy (AAS) or inductively coupled mass spectrometry (ICP-MS). Results indicated that only three brands of vinyl gloves were acceptable for use in a trace element laboratory, whereas others had contamination of different elements. Latex gloves contained such high levels of biologically important elements that they were not considered suitable for routine trace element work. Vinyl gloves of choice should be routinely acid-washed before use in a trace element laboratory.     

Particle sources and trace element reactivity in the Humber plume

Samples of suspended particulate matter (SPM) collected from the Humber Estuary had higher concentrations of particulate metals than SPM from Holderness coastal waters (U.K.). Characterised SPM from both sources was used in laboratory experiments involving the uptake of radiotracer¹⁰⁹Cd,¹³⁷Cs,⁵⁴Mn and⁶⁵Zn. Kinetic experiments, over five days, showed that the rate and extent of uptake was highly dependent on particle type, with¹⁰⁹Cd,⁵⁴Mn and⁶⁵Zn being more reactive with Humber Estuary particles than those from Holderness and¹³⁷Cs having the opposite trend. Adsorption experiments were also carried out on suspensions in which SPM from the Humber Estuary and Holderness coastal water were mixed in various proportions. These experiments revealed that K_d for⁶⁵Zn increased linearly with the proportion of Humber SPM, K_d for¹³⁷Cs decreased linearly with increase in Humber SPM and K_d for⁵⁴Mn and¹⁰⁹Cd displayed non-linear behaviour. The results of the study were used to develop an algorithm for predicting the partition coefficients in the Humber Plume based on the extent of particle mixing from the two source regions. The use of^206/207Pb ratios in determining the extent of particle mixing is discussed, along with the application of the algorithm to the modelling of particulate trace metal behaviour in the Humber-Wash coastal zone.     

Effect of protein deficiency on macroelement and trace element levels of weanling rats' small intestine and liver tissues

Protein energy malnutrition has become a major health issue in developing countries. In the present study, the effect of protein deficiency on the small intestine and liver tissue content of macroelements and trace elements was investigated in weanling rats. Forty-five male weanling Wistar albino rats were divided into three groups. The control group (C) was fed a standard diet containing 25% casein, whereas the two experimental groups E1 and E2 consumed 12% and 3% casein, respectively, over a period of 45 d. The tissue samples were analyzed for zinc, copper, iron, manganese, calcium, and magnesium by atomic absorption spectroscopy. The protein-deficient groups showed increased levels of iron in both tissues and decreased manganese in small intestine tissue from the E1 group. No other differences were found for the other elements. These results suggest that protein deficiency might cause iron accumulation in the liver and intestine and decreases of manganese in the small intestine.     

Effects of trace element levels on platelet aggregation

Platelet aggregation was measured by an optical method in 32 patients with iron-deficiency anemia at the time of diagnosis and after a period of supplementation with iron. Epinephrine- and adenosine diphosphate-induced platelet aggregation were lower in anemic patients than in the controls (p<0.05). After iron-supplementation therapy, these values showed no significant differences. If induced by collagen or ristocetin, platelet aggregation was the same for patients and controls, but increased after treatment of patients (p<0.05). The plasma zinc values did not show significant differences among the subjects included in this study. These results show that iron is involved in the enzymatic systems that regulate platelet aggregation. The exact nature of this interaction is still to be determined.     

Speciation of trace element compounds in samples of biota from marine ecosystems

Abstract

The toxicity, mobility, bioavailability and bioaccumulation of metals are dependent on the particular physico-chemical form in which the element occurs in the environment. Special attention has been paid to metals which are essential for the proper functioning of organisms if present in appropriate amounts but are toxic if in excess (i.e. Se, Cr), and also to non-essential elements (i.e. Hg, Pb, Cd, Sn and As). To assess the potential hazard to the health of marine organisms, qualitative and quantitative analyses of metal species accumulating along the food chain needs to be carried out. This paper reviews the available information on the speciation of trace elements in the food chain in marine ecosystems and the analytical tools used for acquiring reliable information in this field. Advantages and limitations of commonly used techniques indicate that all metal species in different samples need diverse extraction, separation and detection conditions. Although not recommending which procedure is the most suitable to determine a given compound, speciation analysis has the potential to be a powerful tool for the identification of trace element species in biological samples.     

Lipid peroxidation products,and vitamin and trace element status in patients with cancer before and after chemotherapy,including adriamycin

Adriamycin is a potent chemotherapeutic agent used in the treatment of human neoplastic diseases. A major side effect limiting the use of this drug is its toxic effect on the heart. Several hypotheses have been proposed to explain the cardiotoxicity of Adriamycin. However, the most plausible hypothesis seems to be the reduction of Adriamycin and free radical production, which induces lipid peroxidation and oxidative damages in the heart. We have thus undertaken this preliminary study to investigate Adriamycin-induced lipid peroxidation by the measurement of plasma thiobarbituric acid reactant materials and antioxidant systems, namely glutathione content, glutathione peroxidase activity, and vitamin and trace element status, in patients with cancer before and after chemotherapy, including Adriamycin. The concentration of thiobarbituric acid reactant materials in plasma of patients with cancer was higher than in controls and was further increased after chemotherapy. Blood glutathione and plasma glutathione peroxidase activity, as well as plasma zinc and selenium in patients with cancer, were decreased, but not further modified by chemotherapy. However, only zinc and selenium levels reached a significant level. In contrast, plasma vitamin E and β-carotene levels were not significantly increased in patients with cancer. Finally, plasma vitamin A and copper levels were not modified either in patients with cancer or by chemotherapy.     

Plasma paroaoxonase activities, lipoprotein oxidation, and trace element interaction in asthmatic patients

Paraoxonase (PON1) protects low and high-density lipoproteins (LDL and HDL) against oxidation induced by reactive oxygen species formation facilitated by iron (Fe) and copper (Cu) ions. Plasma PON1, arylesterase, oxidized LDL (Ox-LDL), Cu, Fe, thiobarbituric acid-reactive substances (TBARS), lipid, lipoprotein, and apolipoprotein profile in bronchial asthma were determined and the relations among these parameters in different steps of asthma were interpreted. A total of 58 individuals, 30 asthmatics and 28 controls, were included into the scope of this study. Plasma PON1, arylesterase, and TBARS levels were measured spectrophotometrically. Determination of plasma oxidized LDL, Cu, and Fe levels were performed by enzyme-linked immunosorbent assay, atomic absorption spectrophotometry, and the automated TPTZ method, respectively. Apo-A-1 and Apo-B levels were determined immunoturbidometrically. Plasma total cholesterol, triglyceride, and HDL cholesterol levels were enzymatically determined. Plasma LDL levels were estimated using the Fridewald formula. The average plasma PON1 and arylesterase activities in the group of patients were lower than those of the individuals in the control group, but there was no statistically significant difference found between them (p>0.05). No significant difference was found in plasma Apo-A-1, Apo-B, total cholesterol, triglyceride, HDL, and LDL concentrations between the control and patient groups (p>0.05). Plasma oxidized LDL (p<0.05), Cu (p<0.01), Fe (p<0.01), and TBARS (p<0.001) levels in patients with asthma were found to be significantly higher than for the control group. Increases in Cu, Fe, lipid peroxidation, and oxidized LDL levels supported by relative decreases in PON1 activities observed in asthmatic patients might be introduced as the striking findings as well as the possible potential indicators of this airway disease, the prevalence of which has increased dramatically over recent decades.     

Antioxidant defense and trace element imbalance in patients with postradiation syndrome

More than 6000 residents of Latvia were involved in recovery work in Chernobyl. They were healthy men exposed to substantial ionizing radiation (0.01–0.5 Gy). Now, these recovery workers suffer from “postradiation syndrome”: dizziness and poor memory, headache, local pains, and so forth. The biochemical mechanism of “postradiation syndrome” has not been completely established. In this Phase I study, we have investigated how exposure to radiation impacts antioxidative defense and trace element concentrations in the blood of recovery workers. Thirty-five patients with postradiation syndrome (men, age range 33–50 yr) and 15 healthy men similar in age as control subjects were studied for the effects on plasma chemiluminescence, the activity of antioxidant enzymes, and the concentration of ceruloplasmin and concentrations of selenium (Se), zinc (Zn), and copper (Cu) in blood. The results revealed that plasma chemiluminescence was significantly increased (3.5-fold to 5.5-fold), the activity of catalase in erythrocytes was significantly elevated, and the activity of glutathione peroxidase in plasma was significantly reduced in examined patients. Concentrations of Zn and Cu were significantly higher and the concentration of Se was lower in these patients. We conclude that the patients exposed to ionizing radiation have diminished blood antioxidant defense associated with pronounced Se deficiency and imbalance of Zn and Cu. Presented in part on the SFRR (Europe) Summer Meeting in Dresden, July 2–5, 1999.     

Risk assessment of population exposure to toxic trace elements via consumption of vegetables and fruits grown in some mining areas of Armenia

Consumption of unsafe food is one of the most important public health concerns. Trace elements’ contamination caused by direct or indirect activities of mining industries is of importance in this respect. The present study was conducted to assess the chronic dietary exposure and related health risks of trace elements through the intake of selected vegetables and fruits grown under the impact of mining industry in Syunik region (Armenia). Consumption data were obtained via food frequency questionnaire and the concentrations of Cu, Mo, Ni, Cr, Pb, Zn, Hg, and Cd in different fruits and vegetables were determined. Moreover, by combining concentration data with consumption data, estimated daily intake, and target hazard quotient were assessed for each element. The results obtained showed that mean concentrations for Pb and Hg in some vegetables exceeded maximum acceptable levels set by international organizations. Hazard indexes > 1 have been obtained in some cases indicating that for some vegetables (particularly for potato, carrot, maize, onion leaf, grape, bean, beet, sweet pepper, eggplant, and tomato) habitual consumption has a potential to pose adverse health effect to the local population.     

Uptake and distribution of trace metal elements in wheat seedlings

The uptake and distribution of eight metallic elements were examined in wheat seedlings for a period of 12 d with a radioactive multitracer technique. The radioactive nuclides of the seedlings were simultaneously determined by γ-ray spectrometry. All of the elements studied were taken up by the wheat seedlings and mainly accumulated in the roots. Only some elements were transported to shoots and leaves of the seedlings or bound to leaf proteins, and two elements were transported into the chloroplast. Uptake of most elements reached a maximum on the fifth or the eighth day and then gradually decreased afterward. In the cases of ^95mTc and ⁷²Se, the uptake increased continuously within 12 d without the peak uptake. The change of elemental concentrations was dependent on uptake and excretion rates. The dynamics of metal elements taken up by the wheat seedlings and their distribution in roots, shoots, and leaves were different for each element, suggesting that it may depend on the characteristics of the elements.     

Effects of isoflurane exposure during pregnancy on postnatal memory and learning in offspring rats

Emerging evidence has demonstrated that exposure to anesthetics early in life caused neurohistopathologic changes and persistent behavioral impairments. In this study, a maternal fetal rat model was developed to study the effects of isoflurane exposure during pregnancy on postnatal memory and learning in the offspring. Pregnant rats at gestational day 14 were either exposed to 1.3% isoflurane in a humidified 100% oxygen carrier gas or simply humidified 100% oxygen without any inhalational anesthetic for 2 h every day before delivery. Four weeks later, spatial learning and memory of the offspring were examined using the Morris Water Maze. The expression levels of GAP-43 and NPY in the hippocampal CA1 region of the pups were determined by immunohistochemistry and RT-PCR. Simultaneously, the ultrastructure changes in synapse of the hippocampus were also observed by transmission electron microscopy (TEM). Isoflurane exposure during pregnancy impaired postnatal spatial memory and learning in the offspring as shown by the longer escape latency and the fewer original platform crossings in the Morris Water Maze test. The number and optical densities of GAP-43 and NPY positive cells, as well as the levels of GAP-43 and NPY mRNA, decreased significantly in the hippocampus of isoflurane-exposed pups. Furthermore, TEM studies showed remarkable changes in synaptic ultrastructure of hippocampus. These results indicate that isoflurane exposure during pregnancy could cause postnatal spatial memory and learning impairments in offspring rats, which may be partially explained by the down-regulation of GAP-43 and NPY in the hippocampal area.     

Determination of main and trace element contents in human brain by NAA and ICP-AES methods

A study was undertaken to determine the average values for elements in normal human brain (11 individuals, age group 65–75). Twelve brain parts were selected from both hemispheres. Determinations were carried out by NAA and ICP-AES. The main elements (Na, K, Mg, Ca, Fe, P, S) and trace elements (Al, B, Co, Cr, Cu, Mn, Ni, Pb, Zn) were investigated. Quality control was ensured by using NBS Bovine Liver SRM. The results obtained with independent methods were compared, and the data show a good correlation. On the basis of these investigations, the regional distribution of elements can be given.     

Determination of trace boron in microsamples of biological tissues

A benign-by-design method for the determination of boron (B) in microsamples of biological tissues was developed. This is a simple, automated, microdigestion method. Use of reagents and generation of waste are minimized, and the use of toxic/hazardous reagents is eliminated as compared to currently available B methodology. Microsamples are accommodated by the method; 100–400 mg sam ples were used in this study. B is determined by inductively coupled plasma atomic emission spectrometry (ICPAES) at 249.678 nm. The instrument detection limit for B is 0.01 Μg/mL. Interference studies have been investigated for 21 common elements. Over 250 analyses of standard reference materials were analyzed during the study dura tion. Recoveries for a series of biological tissues, both plant and ani mal, ranged from 82–104%.     

Log-normal distribution of the trace element data results from a mixture of stocahstic input and deterministic internal dynamics

In previous article, we showed a log-normal distribution of boron and lithium in human urine. This type of distribution is common in both biological and nonbiological applications. It can be observed when the effects of many independent variables are combined, each of which having any underlying distribution. Although elemental excretion depends on many variables, the one-compartment open model following a first-order process can be used to explain the elimination of elements. The rate of excretion is proportional to the amount present of any given element; that is, the same percentage of an existing element is eliminated per unit time, and the element concentration is represented by a deterministic negative power function of time in the elimination time-course. Sampling is of a stochastic nature, so the dataset of time variables in the elimination phase when the sample was obtained is expected to show Normal distribution. The time variable appears as an exponent of the power function, so a concentration histogram is that of an exponential transformation of Normally distributed time. This is the reason why the element concentration shows a log-normal distribution. The distribution is determined not by the element concentration itself, but by the time variable that defines the pharmacokinetic equation.     

Effect of exposure of pregnant rats to cadmium on prenatal and postnatal development of the young

Cadmium chloride in doses of 2, 12 and 40 mg Cd/kg was administered per os to pregnant rats from the 7th to 16th day of pregnancy. In another experiment female rats were exposed to cadmium oxide at a concentration of 0.02 mg Cd/m3 or 0.16 mg Cd/m3 for 5 hours a day and 5 days weekly for a period of 5 months or 1 mg Cd/m3 for 4 months. The exposure was then continued during mating and from the 1st to 20th day of pregnancy. A decrease in fertility was only observed in females exposed by inhalation to cadmium oxide at a concentration of 1 mg Cd/m3, at which concentration cadmium exhibits a considerable toxic effect on the whole organism. The young of females orally treated with CdCl2 in a dose of 40 mg Cd/kg displayed congenital defects in the form of sirenomelia or amelia, as well as raised cadmium levels in tissues. A retardation of intrauterine development manifested by lower body weight and slowed down osteogenesis was observed in the other groups. A cadmium concentration increase was not found in the tissues of the young in these groups. Inhalation exposure to 0.16 mg Cd/m3 of females prior to and during pregnancy induced in their young a decrease in viability, lower body weight gain, prolongation of latency in the negative-geotaxis test, lower locomotor activity and deteriorated development of the conditioned-reflex response. The offspring of females exposed to 0.02 mg Cd/m3 displayed lowered locomotor activity and worsened consolidation of the conditioned-reflex response.     

Biological evaluation of trace element data in human ovaries by statistical analysis

Analysis of variance, analysis of covariance, correlation coefficient, multiple correlation, and partial correlation coefficient statistical tests were applied to Cs, Cr, Co, Fe, Rb, Sc, Se, and Zn content in human ovaries in order to evaluate statistically the possible relationships between these trace elements at: the ovary as an organ, each ovarian phase separately, each morphological part independent of the ovarian phase, and between cortex and medulla within the ovarian phases. The element Cs seems to have a homogenous distribution between cortex and medulla within reproductive and menopausal phase. Zinc shows a trend to have an antagonistic relation with Cs, Cr, Co, and Fe during fetal and reproductive phases and not during menopausal phase. The relationship between Zn and Cs when Fe is kept constant could be used as a tool for the decontamination of the ovary from an abnormal Cs content or for the inhibition of the accumulation of the same element to the ovarian tissue.     

Application of PIXE analysis to the study of the regional distribution of trace elements in normal human brain

A particle-induced X-ray emission (PIXE) analysis method is presented, which allows measurement of eight elements (i.e., K, Ca, Mn, Fe, Cu, Zn, Se, and Rb) in human brain samples of only a few mg dry weight. The precision and accuracy of the method were investigated by analyzing animal brain matter with both PIXE and instrumental neutron activation analysis (INAA). The method was applied to measure the 8 elements in 46 different regions of 3 human brains. The sections analyzed originated from either the left or the right cerebral hemisphere, brain stem, and cerebellum. For one of the brains, sections were also analyzed from 26 corresponding regions of both hemispheres. For all elements, similar concentrations were found in the corresponding areas of the left and right sides of the brain. The concentrations (in μg/g dry weight) of the elements K, Fe, Cu, Zn, Se, and Rb were consistently higher in cortical structures than in white matter. Deep nuclei and brain stem, which have a mixed composition, showed intermediate values for K, Zn, Se, and Rb. A hierarchical cluster analysis indicated that the various brain regions clustered into two large groups, one comprising gray and mixed matter regions and the other, white and mixed matter brain areas.