Release of pre-absorbed cadmium from cultured cells by the addition of copper ion

Summary The biological interaction between cadmium and copper has been studied. Cadmium uptake of KB cells was specifically inhibited by the addition of copper ions to the culture medium. Cadmium which had already been taken up by the cells was released following the addition of copper ions.The authors are grateful to Dr. M. Ishizawa for his helpful discussion.     

Metal accumulation inAgaricus bisporus: Influence of Cd and Cu on growth and tyrosinase activity

Summary To investigate heavy metal uptake in the common mushroomAgaricus bisporus, commercial cultures of the fungus were exposed to different amounts of copper ad cadmium. In contrast to copper, cadmium already exerted pronounced toxic effects at low concentrations (>10 M) in the compost and concomitantly enhanced the uptake of copper. Tyrosinase activity measured in the fruit bodies increased sharply, when small amounts of Cd (10 M) were added to copper-rich compost. Gel filtration experiments with crude extracts from fruit bodies demonstrated the absence of a low molecular weight metal binding protein.Acknowledgments. This work was supported by the Schweizerischer Nationalfonds grant 3.420–0.78 (to K.L.) and by Hauser Champignonkulturen AG. We are indepted to Dr D. Rast for helpful discussions.     

Muscle lipofuscin content and satellite cell volume is increased after high altitude exposure in humans

Summary Muscle ultrastructural changes during a typical expedition to the Himalayas were analyzed by taking muscle biopsies from seven climbers before and after their sojourn at high altitude (over 5000 m for 8 weeks). M. vastus lateralis samples were analyzed morphometrically from electron micrographs. A quantitative evaluation was made of lipofuscin, satellite cells and myonuclei. Significant increases of the volume densities of lipofuscin (+235%) and satellite cells (+215%) were observed.     

Muscle lipofuscin content and satellite cell volume is increased after high altitude exposure in humans

Muscle ultrastructural changes during a typical expedition to the Himalayas were analyzed by taking muscle biopsies from seven climbers before and after their sojourn at high altitude (over 5000 m for 8 weeks). M. vastus lateralis samples were analyzed morphometrically from electron micrographs. A quantitative evaluation was made of lipofuscin, satellite cells and myonuclei. Significant increases of the volume densities of lipofuscin (+ 235%) and satellite cells (+ 215%) were observed.     

Stereological analysis of lipofuscin in the central nervous system ofTorpedo marmorata: correlation with superoxide dismutase distribution

Summary It was observed that superoxide dismutase activity was inversely proportional to the amount of lipofuscin present in the various anatomotopographical areas of theTorpedo marmorata central nervous system. These results support the theory that age pigments are a product of free lipoperoxidation induced by free radicals.Part of the present work was presented at XIIth Int. Pigment Cell Conference, Giessen (FRG), 17–19 September 1983.     

Effect of latent iron deficiency on the levels of iron,calcium, zinc,copper, manganese,cadmium and lead in liver,kidney and spleen of growing rats

Summary Feeding a marginally low iron content diet (18–20 mg iron/kg diet) to weaned (21-day-old) rats for 8 weeks produced a significant decrease in liver non-heme iron (66%, p<0.001) but no change in blood hemoglobin. Total iron contents of liver (56%, p<0.01), spleen (20%, p<0.05), and kidney (19%, p<0.05) were also found to decrease along with increased zinc, copper, calcium, manganese lead and cadmium in various organs. The magnitude of alteration of a metal was different in different organs. However, liver was found to be the most affected organ. Two weeks of rehabilitation with iron-sufficient diet (390 mg iron/kg diet) normalized these altered levels.     

Cadmium-induced changes in avian renal morphology

Summary The effects of i.m. administered cadmium on growth rate and nephromorphology were studied in young pullets. The growth rate of pullets treated with 0.6 mg Cd²⁺/kg at 48-h intervals was severely retarded, reaching only 50% of normal growth by 21 days. Such a decrease in growth rate was prevented when cadmium was given with either ferric or magnesium EDTA chelate. Electron micrographs of kidney tissue from cadmium intoxicated birds revealed massive intracellular disorganisation of proximal tubular cells, showing increased vacuolation and dilated endoplasmic reticulum. Mitochondria were few and swollen with reduced cristae. Some disorganisation was noted in the group treated with MgEDTA in conjunction with cadmium, with normal morphology observed in the group treated FeEDTA plus cadmium.In general, glomerular morphology of intoxicated pullets appeared normal, except that a 25% increase in thickness of the glomerular basement membrane was evident. No such membrane thickening was observed in any of the chelate treated groups.These findings indicate that both chelates can provide certain levels of protection, in terms of growth rate and morphology, from cadmium intoxication. The possible mechanisms by which chelates offer protection have been discussed, but many questions remain unanswered.     

Stereological analysis of lipofuscin in the central nervous system of Torpedo marmorata: correlation with superoxide dismutase distribution

It was observed that superoxide dismutase was inversely proportional to the amount of lipofuscin present in the various anatomotopographical areas of the Torpedo marmorata central nervous system. These results support the theory that age pigments are a product of free lipoperoxidation induced by free radicals.     

The effect of ascorbic acid on cadmium accumulation in guinea pig tissues

Accumulation of cadmium in organs of guinea pigs after subchronic oral cadmium treatment (1 mg Cd/animal/24 h) was in the following order: kidneys > liver > heart > testes > brain. The preventive effects of high doses of ascorbic acid (AA) against cadmium deposition were more pronounced in the testes, heart and brain, and in the kidney only after short-term cadmium treatment. Ascorbic acid had no protective effect on cadmium accumulation in the liver.     

The effect of ascorbic acid on cadmium accumulation in guinea pig tissues.

Accumulation of cadmium in organs of guinea pigs after subchronic oral cadmium treatment (1 mg Cd/animal/24 h) was in the following order: kidneys > liver > heart > testes > brain. The preventive effects of high doses of ascorbic acid (AA) against cadmium deposition were more pronounced in the testes, heart and brain, and in the kidney only after short-term cadmium treatment. Ascorbic acid had no protective effect on cadmium accumulation in the liver.     

Menkes disease

Menkes disease is caused by mutations in the copper-transporting P_1B-type ATPase ATP7A. ATP7A has a dual function: it serves to incorporate copper into copper-dependent enzymes, and it maintains intracellular copper levels by removing excess copper from the cytosol. To accomplish both functions, the protein traffics between different cellular locations depending on copper levels.The mechanism for sensing the concentration of copper, for trafficking, as well as the details of the mechanism of copper translocation across the membrane are unknown. Received 24 September 2007; received after revision 12 October 2007; accepted 17 October 2007     

Lysosomal changes related to ageing and physical exercise in mouse cardiac and skeletal muscles

Summary Physical exercise increased the activities of arylsulphatase, cathepsin D and -glucuronidase in mouse skeletal muscle but not in cardiac muscle. Exercise-induced lysosomal response was more prominent in young adult than in senescent mice. The lipofuscin content of cardiac and skeletal muscles increased markedly during ageing and was also found to increase slightly after exertion in young mice, but not in senescent ones.This study was supported by the grants from the Ministry of Education and the Academy of Finland.     

Effect of acetylhomocysteine thiolactone on nucleolar cytology and lipofuscinogenesis in electric lobe neurons

Summary Treatment with acetylhomocysteine thiolactone significantly reduces the cellular level of lipofuscin in neurons of the electric lobe ofTorpedo marmorata. At the same time, this drug produces a 45% decrease in nucleolar volume in these neurons, reflecting decreased cellular synthetic activity.     

Über den Einfluss von Natriumsulfit,Natriumtellurit und Natriumselenit auf die Retention von Zink,Kadmium und Quecksilber im Organismus

Summary The influence of sodium sulfite, sodium tellurite and sodium selenite on the retention of zinc, cadmium and mercury in mice was studied. The retention of mercury was increased by sodium selenite and by sodium tellurite. The retention of cadmium was increased only by sodium selenite. Sodium sulfite did not influence the retention of metals studied. The retention of zinc was not influenced by any compounds used.     

The absence of melanopsin alters retinal clock function and dopamine regulation by light

The retinal circadian clock is crucial for optimal regulation of retinal physiology and function, yet its cellular location in mammals is still controversial. We used laser microdissection to investigate the circadian profiles and phase relations of clock gene expression and Period gene induction by light in the isolated outer (rods/cones) and inner (inner nuclear and ganglion cell layers) regions in wild-type and melanopsin-knockout (Opn ₄ ^?/? ) mouse retinas. In the wild-type mouse, all clock genes are rhythmically expressed in the photoreceptor layer but not in the inner retina. For clock genes that are rhythmic in both retinal compartments, the circadian profiles are out of phase. These results are consistent with the view that photoreceptors are a potential site of circadian rhythm generation. In mice lacking melanopsin, we found an unexpected loss of clock gene rhythms and of the photic induction of Per1-Per2 mRNAs only in the outer retina. Since melanopsin ganglion cells are known to provide a feed-back signalling pathway for photic information to dopaminergic cells, we further examined dopamine (DA) synthesis in Opn ₄ ^?/? mice. The lack of melanopsin prevented the light-dependent increase of tyrosine hydroxylase (TH) mRNA and of DA and, in constant darkness, led to comparatively high levels of both components. These results suggest that melanopsin is required for molecular clock function and DA regulation in the retina, and that Period gene induction by light is mediated by a melanopsin-dependent, DA-driven signal acting on retinal photoreceptors.     

Metallothionein induced in the frogXenopus laevis

Summary A low molecular weight cadmium- and copper-binding protein, induced in the liver of the frog,Xenopus laevis, by the administration of cadmium, was shown to consist of a single isoprotein and was characterized as an amphibian metallothionein based on its high cysteine and metal content, its low molecular weight, and the lack of aromatic amino acids.The authors thank Dr K. Kubota for his encouragement.     

Lipofuscin accumulation in squirrel monkey spinal cord consequent to protein malnutrition during gestation

Summary The formation of lipofuscin pigment in the anterior horn cells of the cervical spinal cord has shown in the fetuses and neonates under the extrinsic influence of maternal protein deprivation during the gestation period in the squirrel monkeys.Acknowledgments. This work was supported by US PHS grants RR-00165 HD-06087 from National Institute of Health. The technical assistance of Miss Judie Seubert is greatly appreciated.     

Cadmium-induced changes in avian renal morphology

The effects of i.m. administered cadmium on growth rate and nephromorphology were studied in young pullets. The growth rate of pullets treated with 0.6 mg Cd2+/kg at 48-h intervals was severely retarded, reaching only 50% of normal growth by 21 days. Such a decrease in growth rate was prevented when cadmium was given with either ferric or magnesium EDTA chelate. Electron micrographs of kidney tissue from cadmium intoxicated birds revealed massive intracellular disorganisation of proximal tubular cells, showing increased vacuolation and dilated endoplasmic reticulum. Mitochondria were few and swollen with reduced cristae. Some disorganisation was noted in the group treated with MgEDTA in conjunction with cadmium, with normal morphology observed in the group treated with FeEDTA plus cadmium. In general, glomerular morphology of intoxicated pullets appeared normal, except that a 25% increase in thickness of the glomerular basement membrane was evident. No such membrane thickening was observed in any of the chelate treated groups. These findings indicate that both chelates can provide certain levels of protection, in terms of growth rate and morphology, from cadmium intoxication. The possible mechanisms by which chelates offer protection have been discussed, but many questions remain unanswered.     

Effect of latent iron deficiency on the levels of iron, calcium, zinc, copper, manganese, cadmium and lead in liver, kidney and spleen of growing rats

Feeding a marginally low iron content diet (18-20 mg iron/kg diet) to weaned (21-day-old) rats for 8 weeks produced a significant decrease in liver non-heme iron (66%, p less than 0.001) but no change in blood hemoglobin. Total iron contents of liver (56%, p less than 0.01), spleen (20%, p less than 0.05), and kidney (19%, p less than 0.05) were also found to decrease along with increased zinc, copper, calcium, manganese lead and cadmium in various organs. The magnitude of alteration of a metal was different in different organs. However, liver was found to be the most affected organ. Two weeks of rehabilitation with iron-sufficient diet (390 mg iron/kg diet) normalized these altered levels.