Tissue distribution and urinary excretion of essential elements in rats orally exposed to aluminum chloride

The purpose of this study was to determine disorders in the metabolism of the essential elements (Ca, Fe, Cu, and Zn) in some tissues of rats, as well as to detect the dynamics of urinary excretion of these metals after oral administration of 20 mgAl/kg every day for 8 wk. The elements were determined in brain, kidneys, blood, and urine of the animals in 1st, 2nd, 3rd, 4th, and 8th wk after the exposure to AlCl₃. After the 1st wk of aluminium administration, we observed increase of Ca and a decrease of Fe in blood. In brain Ca, Fe, and Cu concentrations were significantly higher in Al-treated rats than in controls after 8-wk exposure. The concentration changes of the essential metals in the tissue were accompanied by increase of the Ca, Fe, and Zn urinary excretion. We assume that the increase in urinary excretion of Ca and the decrease of Fe in the blood may be sensitive indicators of oral aluminium administration.     

Diurnal changes in the fine structure of photoreceptors in an abalone,Nordotis discus

Summary The ultrastructure of the synapses in the brain of the monogenean Gastrocotyle trachuri (Platyhelminthes) is described. The synapses consist of one presynaptic terminal separated by a uniformly wide synaptic cleft, from one or more postsynaptic elements. The presynaptic terminals are characterized by the presence of paramembranous dense projections and associated synaptic vesicles. The postsynaptic elements while possessing membrane densities, are usually devoid of vesicles.The structure of the synapses in the brain of Gastrocotyle is compared to synapses from other platyhelminths.     

The neuroprotective role of l-cysteine towards the effects of short-term exposure to lanthanum on the adult rat brain antioxidant status and the activities of acetylcholinesterase, (Na+,K+)- and Mg2+-ATPase

Lanthanum (La) is a rare earth element that is widely used for industrial, medical and agricultural purposes. Its neurotoxic effects are linked to its physical and chemical properties and its interaction with certain trace elements and membrane-bound enzymes. The aim of this study was to investigate the effects of short-term La-administration (as LaCl₃, 53 mg/kg) on the adult rat whole brain total antioxidant status (TAS) and the activities of acetylcholinesterase (AChE), Na⁺,K⁺-ATPase and Mg²⁺-ATPase, as well as the potential effect of the co-administration of the antioxidant l-cysteine (Cys, 7 mg/kg) on the above parameters. Twenty-eight male Wistar rats were divided into four groups: A (saline-treated control), B (La), C (Cys),and D (La and Cys). All rats were treated once daily with intraperitoneal injections of the tested compounds, for 1-week. Rats were sacrificed by decapitation and the above mentioned parameters were measured spectrophotometrically. Rats treated with La exhibited a significant reduction in brain TAS (−36%, P < 0.001, BvsA), that was partially limited by the co-administration of Cys (−13%, P < 0.01, DvsA), while Cys (group C) had no effect on TAS. The rat brain AChE activity was found significantly increased by both La (+23%, P < 0.001, BvsA) and Cys (+59%, P < 0.001, CvsA), while it was adjusted to control levels by the co-administration of La and Cys. The activity of rat brain Na⁺,K⁺-ATPase was significantly decreased by La-administration (−28%, P < 0.001, BvsA), while Cys supplementation could not reverse this decrease. The activity of Mg²⁺-ATPase exhibited a slight but statistically significant reduction due to La (−8%, P < 0.01, BvsA), that was further reduced by Cys co-administration (−25%, P < 0.001, DvsA). The above findings suggest that La short-term in vivo administration causes a statistically significant decrease in the rat brain TAS and an increase in AChE activity. Both effects can be, partially or totally, reversed into control levels by Cys co-administration, which could thus be considered for future applications as a neuroprotective agent against chronic exposure to La. The activities of Na⁺,K⁺- and Mg²⁺-ATPase that were inhibited by La, could not be reversed by Cys co-administration. A role for the already reported concentration-dependent interaction of La with Ca-binding sites (such as Ca²⁺-ATPase) might be considered for certain of the above phenomena.     

Brain Trace Element Concentration of Rats Treated with the Plant Alkaloid, Vincamine

Trace elements are essential for normal brain functions. Tiny amounts of these elements help in the formation of neurotransmitters and involved in the antioxidant defense and intracellular redox regulation and modulation of neural cells. Vincamine is a plant alkaloid used clinically as a peripheral vasodilator that increases cerebral blood flow and oxygen and glucose utilization by neural tissue to combat the effect of aging. Neurodegenerative diseases associated with aging characterized by a disturbance in trace element levels in the brain. The objective of this study was to determine the level of zinc (Zn), copper (Cu), iron (Fe), Selenium (Se), and chromium (Cr) in the brain of rats treated with vincamine. Vincamine was injected i.m. to rats at a dose of 15 mg/Kg bodyweight daily for 14 days. Twenty-four hours after the last injection, rats were killed, and brains were ashed and digested by concentrated acids and analyzed for trace elements concentrations by flame emission atomic absorption spectrophotometer. The results showed that Zn was the highest trace element in the brain of control rats (3.134?±?0.072 ppm) and Cr was the lowest (0.386?±?0.027 ppm). Vincamine administration significantly (p?<?0.01) reduced the brain Fe concentration (1.393?±?0.165 ppm) compared to control (2.807?±?0.165 ppm). It was concluded that Zn was the highest trace element in the brain of rats. Vincamine administration resulted in approximately 50% reduction in brain Fe concentration which suggests its beneficial effect to prevent the oxidative stress of Fe in neurodegenerative diseases such as Parkinson’s, Alzheimer’s, and Huntington’s diseases.     

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.     

Effect of subchronic exposure to arsenic on levels of essential trace elements in mice brain and its gender difference

The interactions of toxic metals with essential metals may result in disturbances in the homeostasis of essential elements. However, there are few reports about toxic effect of arsenic (As) on the levels of essential trace elements in the central nervous system. To investigate whether subchronic exposure to As disturbs levels of main essential trace elements in the brain of mice and whether the gender difference in the response to As are altered, the concentrations of As, Iron (Fe), copper (Cu), selenium (Se), zinc (Zn) and Chromium (Cr) in the cerebrum and cerebellum of mice exposed to As subchronically were examined by inductively coupled plasma-mass spectrometry (ICP-MS). The gender difference in the changed levels of these essential trace elements was also statistically analyzed. The concentration of As was significantly higher in the cerebrum or cerebellum of mice exposed to As than that in control group (P < 0.05). It indicates that As can accumulate in brain of mice after subchronic exposure. The concentrations of Fe, Se and Cr in the cerebrum or cerebellum were significantly lower in mice exposed to As than those in control group (P < 0.05). On the contrary, the concentration of Cu in the cerebrum or cerebellum was significantly higher in mice exposed to As (P < 0.05). Our results indicate that subchronic exposure to As may decrease the levels of Fe, Se and Cr or increase the level of Cu in the brain of mice. Moreover, the significant gender difference was found relative to the effect of As on concentration of Se in cerebrum and concentrations of Cu and Se in cerebellum of mice. Therefore, more experiments are required to further understand mechanisms whereby As interacts with essential elements in brain and induces the gender difference.     

Brain copper, iron, magnesium, zinc, calcium, sulfur and phosphorus storage in Wilson's disease.

PROJECT: Wilson's disease (WD) is an inherited disorder of copper metabolism characterised by juvenile liver cirrhosis and by neurological symptoms. Copper levels in brain in WD have been reported to be 10 to 15 fold normal values, depending on the different brain regions. Being very few data on copper distribution in central nervous system in WD available, it seemed of interest to study the concentration of copper and of other trace elements (Zn, P, Mg, Ca, Fe and S) in the brain of a patient died for WD. PROCEDURE: a 56 year old woman affected by WD was admitted to our hospital with signs of hepatic failure and died few days later. At autopsy, a brain slice extending from the left to the right hemisphere was divided in 28 samples. On each sample Copper, Iron, Magnesium, Phosphorus, Sulphur, Zinc and Calcium were determined by Induced Coupled Plasma Atomic Emission Spectroscopy. RESULTS: the mean concentration of copper, ranging from 88 to 158 microg/g of dry tissue in all the brain specimens was higher than literature reference values, while that of the other tested elements was considerably lower. CONCLUSIONS: 1) In the brain of WD patient examined the status of trace elements was extensively altered. Further studies are necessary to correlate the concentration of trace elements with pathological lesions and with clinical pictures. 2) The elements considered in our study showed an uneven distribution in different brain areas.     

Concentration of rare earth elements,As, and Th in human brain and brain tumors,determined by neutron activation analysis

Toxic elements As and Th, six rare-earth elemental profiles of brain tumor tissues from 16 patients of astrocytomas (grade I–III), and normal human brain tissues of 18 male, age-matched autopsies serving as controls have been studied by radiochemical neutron activation analysis. P-204 [di(2-ethylhexyl) phosphate] extraction chromatography column was used for group separation of rare-earth element (REE) by one step. Compared with the normal brain tissues, the analytical results showed that the concentrations of Th, La, Ce, Gd, and Lu were significantly higher in tumor tissues (P<0.01 or 0.001). The possible effects of REE on tumor cell were discussed.     

Ytterbium and trace element distribution in brain and organic tissues of offspring rats after prenatal and postnatal exposure to ytterbium

Lanthanides, because of their diversified physical and chemical effects, have been widely used in a number of fields. As a result, more and more lanthanides are entering the environment and eventually accumulating in the human body. Previous studies indicate that the impact of lanthanides on brain function cannot be neglected. Although neurological studies of trace elements are of paramount importance, up to now, little data are provided regarding the status of micronutritional elements in rats after prenatal and long-term exposure to lanthanide. The aim of this study is to determine the ytterbium (Yb) and trace elements distribution in brain and organic tissues of offspring rats after prenatal and long-term exposure to Yb. Wistar rats were exposed to Yb through oral administration at 0,0.1, 2, and 40 mg Yb/kg concentrations from gestation day 0 through 5 mo of age. Concentrations of Yb and other elements (Mg, Ca, Fe, Cu, Mn, and Zn) in the serum, liver, femur, and brain regions (cerebral cortex, hippocampus, cerebellum, and the rest) of offspring rats at the age of 0 d, 25 d, and 5 mo were analyzed by inductively coupled plasma-mass spectrometry. The accumulation of Yb in the brain, liver, and femur is observed; moreover, the levels of Fe, Cu, Mn, Zn, Ca, and Mg in the brain and organic tissues of offspring rats are also altered after Yb exposure. This disturbance of the homeostasis of trace elements might induce adverse effects on normal physiological functions of the brain and other organs.     

Changes in free radicals,trace elements,and neurophysiological function in rats with liver damage induced byD-galactosamine

The changes in trace elements, free radicals, and neurophysiological function were investigated in rats with liver damage induced byd-galactosamine (GalN). The elevated results showed that all the parameters related to free radical metabolism changed after administration of GalN. Relative free radical concentration, malonaldehyde (MDA), and oxidized glutathione (GSSG) elevated, but reduced glutathione (GSH) decreased. Concurrently, zinc, copper, manganese, and selenium contents in liver were significantly reduced, whereas iron was elevated. In rats with hepatic encephalopathy (HE) owing to fulminant hepatic failure (FHF) induced by a high dosage of GalN, the latencies of VEPs were delayed. Moreover, there is a correlation between Zn content of brain and the latencies of VEPs. The results of this study suggested that lipid peroxidation by free radicals might be responsible for GalN-induced liver damage in which trace elements were involved, and that change in brain Zn might play a role in the neural inhibition of HE owing to FHF.     

Thyroid function and deiodinase activities in rats with marginal iodine deficiency

The hypothesis tested was whether marginal iodine deficiency for a period of 6 wk affects iodothyronine deiodinase activities in liver and brain of rats. Male rats were fed purified diets either deficient or sufficient in iodine; the diets were fed on a restricted basis (60% ofad libitum intake). Body weight gain of the two groups was comparable. Iodine deficiency was evidenced by increased thyroid weight (26%), reduced urinary iodine excretion (80%), and reduced plasma T₄ concentrations (22%). Activities of liver type I and brain type III deiodinase were unchanged, but the activity of type II deiodinase in brain was increased (28%) in the iodine-deficient rats. Food restrictionper se significantly lowered T₃ (30%) and T₄ (22%) concentrations in plasma and decreased type III deiodinase activity in brain (30%). These results indicate that in marginal iodine deficiency the activities of hepatic type I deiodinase and brain type III deiodinase are unchanged, whereas that of brain type II deiodinase is increased.     

A comprehensive study on the contents and leaching of trace elements from fly-ash originating from polish hard coal by NAA and AAS methods

In order to assess the environmental risks associated with the emission of fly-ash into the atmosphere and its storage on waste heaps, the trace element contents of fly-ashes from burning Polish hard coal were determined by a newly developed INAA method. Leaching of trace elements from the fly-ash by water and H₂SO₄ solution (pH≈2.5) simulating acid rain, respectively, was studied using AAS and spectrophotometric methods. Analogous experiments were done with neutron-irradiated fly-ash, following the composition of the eluate gamma-spectrometrically. The new fine fly-ash (CTA-FFA-1) candidate reference material was prepared, and the certification was undertaken on the basis of an international intercomparison run. Preliminary evaluation of results shows that at least 38 elements will be certified and, in addition, the “information values” for at least 12 elements will be given.     

Concentrations of copper, iron, and zinc in the major organs of the wistar albino and wild black rats

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.     

Estimation of cholinesterase and choline acetyltransferase in bovine anterior pituitary, posterior pituitary, and pineal body

Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were estimated colorimetrically with thiocholine (SCh) esters as substrates in homogenates of bovine anterior pituitary (AP), posterior pituitary (PP), and pineal body (PB), and the levels were referred to those of whole rat brain. The levels of BuChE were very similar in all four tissues, approximately 10.25 μm -BuSCh hydrolysed/g tissue/hr; indicating that this enzymic activity represents a common structural component, perhaps vascular elements. Acetyl-thiocholine (ASCh) hydrolysis by AChE for brain, PP, PB, and AP was 338, 37,24, and 6 μm /g/hr, respectively. Choline acetyltransferase (ChAc) was estimated by the formation of [¹⁴C]acetylcholine from [¹⁴C]acetyl CoA. ChAc activity of posterior pituitary was generally found to be 15–20 per cent that of brain; the activity was always lowest in the anterior pituitary and pineal body, sometimes undetectable, but generally 5–10 per cent that of brain. The basis for the interpretation that cholinergic components in the posterior pituitary are due to acetylcholme-containing nerve endings and in anterior pituitary and pineal body to axons of sympathetic neurons was discussed.     

Effect of bacoside A on brain antioxidant status in cigarette smoke exposed rats

Free radicals mediated oxidative stress has been implicated in the pathogenesis of smoking-related diseases and antioxidant nutrients are reported to prevent the oxidative damage induced by smoking. Therefore, the present study was conducted to evaluate the antioxidant role of bacoside A (triterpenoid saponin isolated from Bacopa monniera) against chronic cigarette smoking induced oxidative damage in rat brain. Adult male albino rats were exposed to cigarette smoke for a period of 12 weeks and simultaneously administered with bacoside A (10 mg/kg b.w./day, p.o.). Antioxidant status of the brain was assessed from the levels of reduced glutathione, vitamin C, vitamin E, and vitamin A and the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. The levels of copper, iron, zinc and selenium in brain and serum ceruloplasmin activity were also measured. Oxidative stress was evident from the diminished levels of both enzymatic and non-enzymatic antioxidants. Alterations in the levels of trace elements with accumulation of copper and iron, and depletion of zinc and selenium were also observed. Bacoside A administration improved the antioxidant status and maintained the levels of trace elements. These results suggest that chronic cigarette smoke exposure enhances oxidative stress, thereby disturbing the tissue defense system and bacoside A protects the brain from the oxidative damage through its antioxidant potential.     

Effects of tin and lead on organ levels of essential minerals in rabbits

The effect of tin and lead on levels of essential metals (Zn, Cu, Ca, Fe) in rabbit tissues was compared in relation to the route of administration. Animals received intraperitoneally, or per os, SnCl2 (2 mg Sn/kg) or Pb(CH3COO)2 (3.5 mg Pb/kg) every day for 5 d or for 1 mo. Copper, zinc, iron, and calcium were determined by AAS in the liver, kidneys, spleen, brain, bone marrow, and blood; lead and tin concentration were measured in the blood of animals. Tin and lead administered per os caused either no changes or the decreased concentration of endogenous metals in several tissues. The other route of administration (ip) of both metals generally contributed to the increased storage of essential elements. Blood tin levels of tin treated animals were only about less than or equal to 1/10 of blood lead concentrations of rabbits exposed to lead.     

Selenium and mercury are redistributed to the brain during viral infection in mice

As part of the general host response to coxsackievirus B3 (CB3) infection, the concentration of essential and nonessential trace elements changes in different target organs of the infection. Essential (e.g., Se) and nonessential (e.g., Hg) trace elements are known to interact and affect inflammatory tissue lesions induced by CB3 infection. However, it is unknown whether these changes involve the brain. In the present study, the brain Hg and Se contents were measured through inductively coupled plasma-mass spectrometry and their distribution investigated by means of nuclear microscopy in the early phase (d 3) of CB3 infection in normally fed female Balb/c mice. Because of the infection, the concentration of Hg (4.07±0.46 ng/g wet wt) and Se (340±16 ng/g wet wt) in the brain increased twofold for Hg (8.77±1.65 ng/g wet wt, p<0.05) and by 36% for Se (461±150 ng/g wet wt, ns). Nuclear microscopy of brain sections from mice having elevated Se and Hg concentrations failed to find localized levels of the elements high enough to make detection possible, indicating approximately homogeneous tissue distribution. Although the pathophysiological interpretation of these findings requires further research, the increase of Hg in the brain during infection might have an influence on the pathogenesis of the disease.     

Multi-element analysis of trace element levels in human autopsy tissues by using inductively coupled atomic emission spectrometry technique (ICP-AES).

Autopsy tissue samples from the brain front lobe, cerebellum, heart, kidney (cortex and medulla), liver, pancreas, spleen and ovary were analysed for AL, B, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, Sr and Zn in 30 (17 women and 13 men) subjects ranging in age from 17 to 96 years at Haukeland University Hospital in Norway. The tissues were selected from macroscopically normal organs and samples were handled according to guidelines recommended to avoid contamination in the pre-analytical phase. Concentration of the trace elements were determined by the inductively coupled plasma atomic emission spectrometry technique (ICP-AES). In most tissues the concentrations of the essential trace elements followed the order Fe> Zn> Cu> Mn> Se> Cr> Co except in the ovary where Se was higher than Mn. The liver was the major site of deposition for Co, Cu and Mn as well as the spleen for Co, brain front lobe for Cu and pancreas for Mn. Ba, Sr and Ni built up in the ovary foLLowed by the kidney. Older subjects accumulated Ba and Sr in most tissues, whereas Al accumulated in the kidney cortex and Cd in the brain cerebellum. Generally males had higher concentrations of trace elements in the different tissue sampLes than females with the exception of Mn in the brain front lobe and heart and Sr in the liver. ICP-AES is a useful method to assess the concentration and the profiLe of trace elements in human autopsy tissues.