Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined the effect of a selenium-deficient diet on two experimental models of glomerular disease, the puromycin aminonucleoside (PAN)-induced nephrotic syndrome, a model of minimal change disease, and passive Heymann nephritis, a complement-dependent and neutrophil-independent model that resembles membranous nephropathy. The specific activity of selenium-dependent glutathione peroxidase was markedly reduced in the liver, the kidney cortex, and in glomeruli in weanling male Sprague-Dawley rats placed on a selenium-deficient diet for 6 wk compared with rats fed a selenium-replete diet, with no significant differences in the specific activities of superoxide dismutase or catalase. PAN-injected selenium-deficient rats had a marked and significantly greater proteinuria throughout the course of the experiment compared with PAN-injected selenium-replete rats with no significant histological differences. In the passive Heymann nephritis model induced by injecting anti-Fx1A immunoglobulin G, rats fed a selenium-deficient diet had significantly higher urinary protein (day 5: 91 +/- 16 mg/24 h, n = 10) compared with rats fed a selenium-replete diet (52 +/- 5 mg/24 h, n = 11) with no differences in the amount of antibody deposited in the kidney. The most likely explanation for the effect of a selenium-deficient diet is that selenium deficiency resulted in a marked reduction of glutathione peroxidase, thus indicating an important role of glutathione peroxidase in these models of glomerular injury.
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PMID:Effect of selenium-deficient diet in experimental glomerular disease. 163 44

The concentration of cadmium in the New Zealand dredge oyster Tiostrea lutaria (commonly known as a Bluff oyster) is sufficiently high so that the ingestion of just one oyster can more than double a normal daily dietary intake of cadmium for a New Zealand adult. A survey of 75 adults (18-76 years old) associated with the oyster fishing industry in Bluff, Southland, New Zealand, was carried out before and at the end of the oyster season. Preseason intakes (from dietary history questionnaires and from 3-day fecal collections) of cadmium, selenium, zinc, copper, and manganese were normal for a New Zealand adult not consuming Bluff oysters. The subjects were classified according to their reported average oyster consumption during the 6 months of the oyster fishing season; the subjects who consumed more oysters were more likely to smoke cigarettes. The end-season fecal output of cadmium confirmed the reported average oyster intakes: Category I (0-5 oysters/week): 15 +/- 8 (mean +/- SD) micrograms Cd/day; Category II (6-23 oysters/week): 84 +/- 134 micrograms Cd/day; Category III (24-71 oysters/week): 129 +/- 144 micrograms Cd/day; Category IV (72+ oysters/week): 233 +/- 185 micrograms Cd/day. The fecal output of selenium as well was increased by the consumption of many oysters but the fecal outputs of zinc, copper, and manganese were not. Using fecal cadmium excretion to predict dietary cadmium intake, 8-15% of the subjects in this study were identified as having an intake of cadmium which has been associated with an increased prevalence of tubular proteinuria. The highest individual daily fecal excretion of cadmium at the end of the season was 580 micrograms Cd/day, i.e., a daily excretion equivalent to more than 10 times above the weekly intake provisionally considered tolerable (400-500 micrograms Cd/week; WHO, 1972). Continued investigations on this population group will determine whether there are any health consequences of these extremely high cadmium intakes.
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PMID:Unusually high intake and fecal output of cadmium, and fecal output of other trace elements in New Zealand adults consuming dredge oysters. 337 Dec 88

The administration of selenium concomitantly with lead in rats restrained the lead induced enzymuria, proteinuria, enhanced urinary excretion of delta-aminolevulinic acid, inhibition of the activities of certain renal enzymes, blood delta-aminolevulinic acid dehydratase and blood, liver and kidney uptake of lead. The protective effect of selenium against lead toxicity may be attributed to a competition between selenium and lead for binding with the functional bioligands or to the in vivo formation of lead selenide.
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PMID:Role of selenium in protection against lead intoxication. 661 4

The nephrotoxicity associated with mercury may be manifested as either acute tubular necrosis or an immune complex glomerulonephritis, depending upon the conditions under which the patient is exposed to the metal. Two patients with industrial exposure to mercury developed the nephrotic syndrome due to membranous glomerulonephritis. A multidisciplinary approach was used to define more precisely the pathogenetic mechanisms involved in the production of the glomerular lesion. Although glomeruli were normal by light microscopy, immunohistochemical studies demonstrated confluent finely granular epimembranous deposits of IgG and C3. This distribution was confirmed at the ultrastructural level with immunoelectron microscopy. High resolution elemental analysis of electron dense inclusions in tubular epithelial phagolysosomes demonstrated energy dispersion spectra characteristic of coexisting mercury and selenium. Eluates from the biopsy material were not immunoreactive against normal rat or human kidney. There was no immunoreactivity of epimembranous deposits with antibodies having renal tubular epithelial antigen or urinary uromucoid specificity. These observations suggest that a distinctive immunopathologic lesion is associated with mercury-associated membraneous glomerulonephritis, that the role of the metal itself may only be coincidental, and that the involved antigen remains unknown. Prednisone therapy had no documented persistent beneficial influence upon the level of proteinuria in one patient who has been lost to follow-up. In one patient not treated with steroid therapy, withdrawal of exposure to the metal resulted in disappearance of mercury from body fluids and clinical remission.
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PMID:Membranous glomerulonephritis associated with industrial mercury exposure. Study of pathogenetic mechanisms. 704 18

Several studies indicate the pathophysiological importance of reactive oxygen species in rats with nephrotic syndrome induced by puromycin aminonucleoside, an experimental model of the human minimal change disease. The role of reactive oxygen species in these rats was further evaluated, examining the effect of dietary deficiency and supplementation of antioxidants (vitamin E and selenium) on biochemical and renal ultrastructural alterations induced by puromycin aminonucleoside. Male Wistar rats, weaned at 3 weeks, were placed on diets normal, deficient or supplemented in vitamin E and selenium for 4 weeks. At the end of this period, rats were divided in two groups: control (sacrificed without any further treatment) and nephrotic (injected with puromycin aminonucleoside and sacrificed 7 and 22 days later). In control rats, the dietary deficiency or supplementation of antioxidants resulted in no significative differences in renal function, proteinuria or kidney ultrastructure. However, kidney lipoperoxidation, kidney glutathione peroxidase activity and circulating levels of vitamin E changed according to the amount of antioxidants in the diet. Seven days after the injection of puromycin aminonucleoside, rats fed normal, deficient or supplemented diets, developed nephrotic syndrome. However, proteinuria, hypoproteinemia, renal dysfunction and ultrastructural alterations were higher in rats fed a deficient diet. In contrast, proteinuria and kidney ultrastructural alterations were lower in rats fed a supplemented diet. Kidney lipoperoxidation and glutathione peroxidase activity increased on day 7 in rats fed a normal or a deficient diet, but not in rats fed a supplemented diet. This study shows that nephrotic syndrome induced by puromycin aminonucleoside in rats is modified by dietary antioxidants (vitamin E and selenium). Dietary supplementation ameliorates it and dietary deficiency exacerbates it.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of dietary antioxidants on puromycin aminonucleoside nephrotic syndrome. 764 24

As nephron population is lost from injury or disease the remaining nephrons undergo functional and anatomic hypertrophy. The compensatory or secondary events responsible for these changes may exert a detrimental effect on the remaining nephrons that ultimately leads to their destruction. Most studies have examined how these alterations cause glomerular injury. Although glomerular injury and functional alterations are the initial result of these events, tubulointerstitial disease may be the major determinate of subsequent nephron loss and progressive renal failure. Proteinuria has been used largely as an indicator of the severity of the glomerular involvement. However, an alternative hypothesis is that the proteinuria, resulting from the glomerular injury, actually perpetuates renal injury as a result of its damaging effect on renal tubules and the surrounding interstitium. Because of being the major protein fraction it has been assumed that albumin is largely, if not solely, responsible for the induction of tubulointerstitial injury. However, with glomerular disease all protein classes can be excreted. One protein of interest is transferrin. In association with the glomerular transferrin leak, iron also would be presented to the tubule fluid. Iron is a transition element capable of catalyzing the Haber Weiss reaction with formation of hydroxyl radicals. Normally, iron is maintained in a nonreactive state in virtually all biologic tissues and fluid. However, at the reduced pH of tubule fluid iron can dissociate from transferrin and assume a reactive state capable of catalyzing hydroxyl radical formation. The kidney in patients with the nephrotic syndrome appears to be unduly susceptible to free radical injury, as documented by its increase iron content in association with depletion of copper and selenium.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Role of iron and oxygen radicals in the progression of chronic renal failure. 831 Oct 72

Growth and injury represent recurrent and related themes in the study of progressive renal disease. We have previously demonstrated that a prooxidant diet, one deficient in antioxidants, selenium and vitamin E, induces renal enlargement, proteinuria, mild tubulointerstitial disease and diminished glomerular filtration rate (GFR). Our present study represents continued examination of these processes. We demonstrate that these diets increase thymidine incorporation into DNA and net DNA content in renal tissue, and induce expression of the mRNA for the proto-oncogene, c-myc, and the histone, H2b. We localize increased DNA synthesis as occurring mainly in the distal renal tubular epithelium. These deficient kidneys also exhibit interstitial expansion that parallels the pattern of DNA synthesis in that both processes are more prominent in the medulla than in the cortex. mRNAs for collagens I, III and IV in conjunction with transforming growth factor-beta1 (TGF-beta1) are up-regulated in the kidney in rats maintained on the deficient diet. In complementary in vitro studies, the exposure of rat kidney fibroblasts, NRK 49F cells, to noncytolytic doses of hydrogen peroxide, induces collagen III, collagen IV and TGF-beta1 mRNA. Induction of these genes is also observed in mesangial cells so exposed to noncytolytic doses of hydrogen peroxide. A final aspect of our study was the examination of renal generation of hydrogen peroxide and the profile of the hydrogen peroxide-degrading enzymes. Deficient kidneys exhibit increased mitochondrial generation of hydrogen peroxide independent of oxygen consumption but in conjunction with suppression of glutathione peroxidase mRNA and activity. Lipid peroxidation was increased twofold in the cortex and medulla of the deficient kidneys. Surprisingly, catalase activity, measured in the cortex and medulla, and whole kidney catalase mRNA were also reduced in rats maintained on the antioxidant deficient diet, effects that may further compromise the clearance of hydrogen peroxide. These changes in catalase represent an adverse response to this dietary deficiency, and may be relevant to decreased catalase activity described in chronic renal insufficiency. Thus, a chronic prooxidant state, with features that mimic those of clinical uremia, increases DNA synthesis of renal tubular epithelium, induces mRNA expression for collagens I, III and IV in conjunction with the mRNA for the fibrogenic cytokine, TGF-beta1. Oxidants also induce collagen III, collagen IV and TGF-beta1 mRNA in vitro.
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PMID:Redox regulation of renal DNA synthesis, transforming growth factor-beta1 and collagen gene expression. 946 Oct 96

Epidemiological studies and in vitro analysis demonstrate correlations between selenium status and human pre-eclampsia (PET). Selenium is an essential component in the anti-oxidant proteins glutathione peroxidase and thioredoxin reductase, which are produced in lower amounts in pre-eclamptic placenta. This study examined the effect of modulating dietary selenium content in pregnant rats. Rats were fed diets containing no selenium, 239 microg/kg selenium or 1000 microg/kg selenium, four weeks prior to and following conception. Significant pregnancy-specific increases in systolic blood pressure (116.4 +/- 5.2 mmHg vs 108 +/- 6.8 mmHg vs 111.4 +/- 4.7 mmHg) and proteinuria (9.68 +/- 2.12 microg/ml vs 5.93 +/- 1.59 microg/ml vs 4.43 +/- 0.96 microg/ml) were demonstrated in animals fed a selenium free-diet when compared with normal or high selenium diets. Placental weight and pup number were not affected by selenium deprivation, however a significant decrease in the pup weight was evident. Selenium deprivation caused dose-dependent decreases in liver glutathione peroxidase (28.55 +/- 3.82 mmoles/min/mg vs 34.68 +/- 8.64 mmoles/min/mg) and thioredoxin reductase (2.37 +/- 1.25 U/mg vs 6.68 +/- 1.82 U/mg) activity, whereas superoxide dismutase activity remained constant. Placental activity of these enzymes also decreased leading to oxidative stress as measured by increased lipid peroxides (17.92 +/- 1.78 micromoles/mg vs 8.30 +/- 5.52 micromoles/mg) and protein carbonyls in tissue extracts from selenium-free animals. These results suggest that selenium deficiency in pregnant rats leads to symptoms similar to those seen in human PET and may provide an experimental model for studying this complex disease.
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PMID:Selenium deficiency as a model of experimental pre-eclampsia in rats. 1550 10

Selenium (Se) deficiency reduces glutathione peroxidase (GPx) activity, resulting in increased oxidative stress. We examined how Se deficiency induces renal injury via oxidative stress over time during the Se-deficient period. Seventy-two male Wistar rats were divided into two groups and fed either a control or Se-deficient diet. Rats were sacrificed on weeks 1, 2, 4, 6, 9, and 12. Blood and urine samples were collected, and the kidneys were removed. Urinalysis was performed, and creatinine clearance (Ccr) was calculated. Expressions of cellular GPx (cGPx) and phospholipid hydroperoxidase GPx (PHGPx) mRNA and GPx activity were measured. Histology was evaluated by light microscopy with immunohistochemistry for 4-hydroxy-2-nonenal (HNE) and vimentin. The Se-deficient diet caused significant decreases in GPx activity and cGPx mRNA expression but no change in PHGPx mRNA, together with significant proteinuria and glucosuria and slight decline in Ccr. The Se-deficient diet induced calcification in the kidney and increased the distribution of HNE and vimentin immunostaining in proximal tubuli, particularly around the outer medulla stripe. However, the histological damage did not progress after 6 weeks of deficiency. Se deficiency induces proteinuria and glucosuria with renal calcification, which may be primarily induced by injury of proximal tubuli via oxidative stress.
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PMID:Effect of selenium-deficient diet on tubular epithelium in normal rats. 1710 41

Mercury, cadmium, and other heavy metals have a high affinity for sulfhydryl (-SH) groups, inactivating numerous enzymatic reactions, amino acids, and sulfur-containing antioxidants (NAC, ALA, GSH), with subsequent decreased oxidant defense and increased oxidative stress. Both bind to metallothionein and substitute for zinc, copper, and other trace metals reducing the effectiveness of metalloenzymes. Mercury induces mitochondrial dysfunction with reduction in ATP, depletion of glutathione, and increased lipid peroxidation; increased oxidative stress is common. Selenium antagonizes mercury toxicity. The overall vascular effects of mercury include oxidative stress, inflammation, thrombosis, vascular smooth muscle dysfunction, endothelial dysfunction, dyslipidemia, immune dysfunction, and mitochondrial dysfunction. The clinical consequences of mercury toxicity include hypertension, CHD, MI, increased carotid IMT and obstruction, CVA, generalized atherosclerosis, and renal dysfunction with proteinuria. Pathological, biochemical, and functional medicine correlations are significant and logical. Mercury diminishes the protective effect of fish and omega-3 fatty acids. Mercury, cadmium, and other heavy metals inactivate COMT, which increases serum and urinary epinephrine, norepinephrine, and dopamine. This effect will increase blood pressure and may be a clinical clue to heavy metal toxicity. Cadmium concentrates in the kidney, particularly inducing proteinuria and renal dysfunction; it is associated with hypertension, but less so with CHD. Renal cadmium reduces CYP4A11 and PPARs, which may be related to hypertension, sodium retention, glucose intolerance, dyslipidemia, and zinc deficiency. Dietary calcium may mitigate some of the toxicity of cadmium. Heavy metal toxicity, especially mercury and cadmium, should be evaluated in any patient with hypertension, CHD, or other vascular disease. Specific testing for acute and chronic toxicity and total body burden using hair, toenail, urine, serum, etc. with baseline and provoked evaluation should be done.
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PMID:The role of mercury and cadmium heavy metals in vascular disease, hypertension, coronary heart disease, and myocardial infarction. 1740 90


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