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1.
Plast Reconstr Surg ; 152(5): 1036-1046, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36912938

RESUMO

BACKGROUND: Lipedema, diagnosed most often in women, is a progressive disease characterized by the disproportionate and symmetrical distribution of adipose tissue, primarily in the extremities. Although numerous results from in vitro and in vivo studies have been published, many questions regarding the pathology and genetic background of lipedema remain unanswered. METHODS: In this study, adipose tissue-derived stromal/stem cells were isolated from lipoaspirates derived from nonobese and obese donors with or without lipedema. Growth and morphology, metabolic activity, differentiation potential, and gene expression were evaluated using quantification of lipid accumulation, metabolic activity assay, live-cell imaging, reverse transcription polymerase chain reaction, quantitative polymerase chain reaction, and immunocytochemical staining. RESULTS: The adipogenic potential of lipedema and nonlipedema adipose tissue-derived stromal/stem cells did not rise in parallel with the donors' body mass index and did not differ significantly between groups. However, in vitro differentiated adipocytes from nonobese lipedema donors showed significant upregulation of adipogenic gene expression compared with nonobese controls. All other genes tested were expressed equally in lipedema and nonlipedema adipocytes. The adiponectin/leptin ratio was significantly reduced in adipocytes from obese lipedema donors compared with their nonobese lipedema counterparts. Increased stress fiber-integrated smooth muscle actin was visible in lipedema adipocytes compared with nonlipedema controls and appeared enhanced in adipocytes from obese lipedema donors. CONCLUSIONS: Not only lipedema per se but also body mass index of donors affect adipogenic gene expression substantially in vitro. The significantly reduced adiponectin/leptin ratio and the increased occurrence of myofibroblast-like cells in obese lipedema adipocyte cultures underscores the importance of attention to the co-occurrence of lipedema and obesity. These are important findings toward accurate diagnosis of lipedema. CLINICAL RELEVANCE STATEMENT: Our study highlights not only the difficulty in lipedema diagnostics but also the tremendous need for further studies on lipedema tissue. Although lipedema might seem to be an underestimated field in plastic and reconstructive surgery, the power it holds to provide better treatment to future patients can not be promoted enough.


Assuntos
Leptina , Lipedema , Humanos , Feminino , Leptina/metabolismo , Lipedema/diagnóstico , Lipedema/patologia , Adiponectina/metabolismo , Adipócitos/fisiologia , Obesidade/complicações , Células Cultivadas
2.
Br J Cancer ; 122(10): 1441-1444, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32203223

RESUMO

Elevated levels of serum ferritin (SF) are observed in several types of cancer; however, little is known on the association between ferritin and glioma, the most frequent type of human primary brain tumour. Here we report that GBM patients show significantly increased pre-surgical SF levels (i.e. ferritinaemia) within the SF reference range and a marked ferritin immunoreactivity of resected tumour tissue. Our findings account for an indirect association between ferritin synthesis in glioma-tissue and altered SF levels, which limits the clinical value of SF as a tumour marker in glioma. Importantly, we show for the first time that GBM-derived glioma cells release ferritin in vitro, which exerts an apoptosis-stimulating activity. Albeit the pathophysiologic context of apoptosis induction by a tumour-derived ferritin remains to be defined, our findings account for a distinct growth-regulatory role of these ferritin species in tumour biology.


Assuntos
Biomarcadores Tumorais/sangue , Ferritinas/sangue , Glioblastoma/sangue , Glioma/sangue , Apoptose/genética , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Feminino , Ferritinas/genética , Regulação Neoplásica da Expressão Gênica/genética , Glioblastoma/genética , Glioblastoma/patologia , Glioma/genética , Glioma/patologia , Humanos , Masculino , Inclusão em Parafina , Transdução de Sinais/genética
3.
Antioxidants (Basel) ; 6(2)2017 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-28531132

RESUMO

ß-Carotene has been shown to increase the risk of developing lung cancer in smokers and asbestos workers in two large scale trails, the Beta-Carotene and Retinol Efficacy Trial (CARET) and the Alpha-Tocopherol Beta-carotene Cancer Prevention Trial (ATBC). Based on this observation, it was proposed that genotoxic oxidative breakdown products may cause this effect. In support of this assumption, increased levels of sister chromatid exchanges, micronuclei, and chromosomal aberrations were found in primary hepatocyte cultures treated with a mixture of cleavage products (CPs) and the major product apo-8'carotenal. However, because these findings cannot directly be transferred to the lung due to the exceptional biotransformation capacity of the liver, potential genotoxic and cytotoxic effects of ß-carotene under oxidative stress and its CPs were investigated in primary pneumocyte type II cells. The results indicate that increased concentrations of ß-carotene in the presence of the redox cycling quinone dimethoxynaphthoquinone (DMNQ) exhibit a cytotoxic potential, as evidenced by an increase of apoptotic cells and loss of cell density at concentrations > 10 µM. On the other hand, the analysis of micronucleated cells gave no clear picture due to the cytotoxicity related reduction of mitotic cells. Last, although CPs induced significant levels of DNA strand breaks even at concentrations ≥ 1 µM and 5 µM, respectively, ß-carotene in the presence of DMNQ did not cause DNA damage. Instead, ß-carotene appeared to act as an antioxidant. These findings are in contrast with what was demonstrated for primary hepatocytes and may reflect different sensitivities to and different metabolism of ß-carotene in the two cell types.

4.
Free Radic Biol Med ; 111: 244-252, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28167130

RESUMO

Lipid peroxidation, the oxidative degradation of membrane lipids by reactive oxygen species generates a large variety of breakdown products such as alkanes, aldehydes, ketones, alcohols, furans and others. Due to their reactivity aldehydes (alkanals, 2-alkenals, 2,4-alkadienals, 4-hydroxyalkenals) received a lot of attention, in particular because they can diffuse from the site of formation and interact with proteins and nucleic acids thus acting as second toxic messengers. The major aldehydic peroxidation product of membrane lipids is 4-hydroxynonenal (HNE). Since HNE and other 4-hydroxyalkenals are strong alkylating agents they have therefore been considered to be the biologically most important peroxidation products. Although initially research focused on the toxicological potential of these compounds it is now well known that they play also a crucial role in cell signaling under physiological and pathophysiological conditions. Thus, it is obvious that the biological effects will be determined by the intracellular concentrations which can trigger adaptation, DNA damage and cell death. This review will not cover all these aspects but will concentrate on the genotoxic properties of selected lipid oxidation products important in the context of pathophysiological developments together with a chapter on epigenetic modifications.


Assuntos
Acroleína/toxicidade , Aldeídos/toxicidade , Histona Desacetilases/metabolismo , Mutagênicos/toxicidade , Oxisteróis/toxicidade , Acroleína/metabolismo , Aldeídos/metabolismo , Animais , Células CHO , Células Cultivadas , Cricetulus , Epigênese Genética , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Histona Desacetilases/genética , Humanos , Peroxidação de Lipídeos , Linfócitos/citologia , Linfócitos/efeitos dos fármacos , Mutagênicos/metabolismo , Oxisteróis/metabolismo , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento
5.
J Neurosci Res ; 95(1-2): 251-259, 2017 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-27870411

RESUMO

During the course of serious discussion, an unexpected interruption may induce forgetting of the original topic of a conversation. Sex, age, and sex hormone levels may affect frequency and extension of forgetting. In a list-method directed forgetting paradigm, subjects have to learn two word lists. After learning list 1, subjects receive either a forget or a remember list 1 cue. When the participants had learned list 2 and completed a distraction task, they were asked to write down as many recalled items as possible, starting either with list 1 or list 2 items. In the present study, 96 naturally cycling women, 60 oral contraceptive users, 56 postmenopausal women, and 41 young men were assigned to one of these different experimental conditions. Forget-cued young subjects recall fewer list 1 items (list 1 forgetting) but more list 2 items (list 2 enhancement) compared with remember-cued subjects. However, forget-cued postmenopausal women showed reduced list 1 forgetting but enhanced list 2 retention. Remember-cued naturally cycling women recalled more list 1 items than oral contraceptive users, young men, and postmenopausal women. In forget-cued follicular women, salivary progesterone correlated positively with recalled list 2 items. Salivary 17ß-estradiol did not correlate with recalled list 1 or list 2 items in either remember- or forget-cued young women. However, salivary 17ß-estradiol correlated with item recall in remember-cued postmenopausal women. Our findings suggest that sex hormones do not globally modulate verbal memory or forgetting, but selectively affect cue-specific processing. © 2016 Wiley Periodicals, Inc.


Assuntos
Envelhecimento/fisiologia , Estradiol/metabolismo , Transtornos da Memória/metabolismo , Rememoração Mental/fisiologia , Progesterona/metabolismo , Caracteres Sexuais , Vocabulário , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Sinais (Psicologia) , Feminino , Humanos , Masculino , Transtornos da Memória/fisiopatologia , Pessoa de Meia-Idade , Saliva/metabolismo , Aprendizagem Verbal/fisiologia , Adulto Jovem
6.
Biomolecules ; 5(4): 2247-337, 2015 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-26437435

RESUMO

This review on recent research advances of the lipid peroxidation product 4-hydroxy-nonenal (HNE) has four major topics: I. the formation of HNE in various organs and tissues, II. the diverse biochemical reactions with Michael adduct formation as the most prominent one, III. the endogenous targets of HNE, primarily peptides and proteins (here the mechanisms of covalent adduct formation are described and the (patho-) physiological consequences discussed), and IV. the metabolism of HNE leading to a great number of degradation products, some of which are excreted in urine and may serve as non-invasive biomarkers of oxidative stress.


Assuntos
Peroxidação de Lipídeos/fisiologia , Acetilcisteína/metabolismo , Animais , Ácidos Graxos Insaturados/metabolismo , Humanos , Estresse Oxidativo/fisiologia
7.
Biomolecules ; 5(2): 808-47, 2015 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-25970586

RESUMO

Iron and oxygen share a delicate partnership since both are indispensable for survival, but if the partnership becomes inadequate, this may rapidly terminate life. Virtually all cell components are directly or indirectly affected by cellular iron metabolism, which represents a complex, redox-based machinery that is controlled by, and essential to, metabolic requirements. Under conditions of increased oxidative stress­i.e., enhanced formation of reactive oxygen species (ROS)­however, this machinery may turn into a potential threat, the continued requirement for iron promoting adverse reactions such as the iron/H2O2-based formation of hydroxyl radicals, which exacerbate the initial pro-oxidant condition. This review will discuss the multifaceted homeodynamics of cellular iron management under normal conditions as well as in the context of oxidative stress.


Assuntos
Homeostase , Ferro/metabolismo , Estresse Oxidativo , Animais , Heme/metabolismo , Humanos , Distúrbios do Metabolismo do Ferro/genética , Distúrbios do Metabolismo do Ferro/metabolismo , Proteínas de Ligação ao Ferro/genética , Proteínas de Ligação ao Ferro/metabolismo , Proteínas Reguladoras de Ferro/genética , Proteínas Reguladoras de Ferro/metabolismo , Oxigênio/metabolismo
8.
Free Radic Biol Med ; 80: 48-58, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25532933

RESUMO

Several pathologies are associated with elevated levels of serum ferritin, for which growth inhibitory properties have been reported; however, the underlying mechanisms are still poorly defined. Previously we have described cytotoxic properties of isoferritins released from primary hepatocytes in vitro, which induce apoptosis in an iron and oxidative stress-dependent mode. Here we show that this ferritin species stimulates endosome clustering and giant endosome formation in primary hepatocytes accompanied by enhanced lysosomal membrane permeability (LMP). In parallel, protein modification by lipid peroxidation-derived 4-hydroxynonenal (HNE) is strongly promoted by ferritin, the HNE-modified proteins (HNE-P) showing remarkable aggregation. Emphasizing the prooxidant context, GSH is rapidly depleted and the GSH/GSSG ratio is substantially declining in ferritin-treated cells. Furthermore, ferritin triggers a transient upregulation of macroautophagy which is abolished by iron chelation and apparently supports HNE-P clearance. Macroautophagy inhibition by 3-methyladenine strongly amplifies ferritin cytotoxicity in a time- and concentration-dependent mode, suggesting an important role of macroautophagy on cellular responses to ferritin endocytosis. Moreover, pointing at an involvement of lysosomal proteolysis, ferritin cytotoxicity and lysosome fragility are aggravated by the protease inhibitor leupeptin. In contrast, EGF which suppresses ferritin-induced cell death attenuates ferritin-mediated LMP. In conclusion, we propose that HNE-P accumulation, lysosome dysfunction, and macroautophagy stimulated by ferritin endocytosis provoke lysosomal "metastability" in primary hepatocytes which permits cell survival as long as in- and extrinsic determinants (e.g., antioxidant availability, damage repair, EGF signaling) keep the degree of lysosomal destabilization below cell death-inducing thresholds.


Assuntos
Autofagia/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Ferritinas/farmacologia , Hepatócitos/efeitos dos fármacos , Membranas Intracelulares/efeitos dos fármacos , Lisossomos/efeitos dos fármacos , Adenina/análogos & derivados , Adenina/farmacologia , Aldeídos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Meios de Cultivo Condicionados/química , Endocitose , Fator de Crescimento Epidérmico/farmacologia , Feminino , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Hepatócitos/metabolismo , Hepatócitos/ultraestrutura , Membranas Intracelulares/metabolismo , Membranas Intracelulares/ultraestrutura , Quelantes de Ferro/farmacologia , Leupeptinas/farmacologia , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Lisossomos/metabolismo , Lisossomos/ultraestrutura , Imagem Molecular , Permeabilidade/efeitos dos fármacos , Cultura Primária de Células , Inibidores de Proteases/farmacologia , Agregados Proteicos , Ratos , Ratos Endogâmicos F344
9.
Acta Biochim Pol ; 57(3): 313-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20827448

RESUMO

Infrared (IR)-A irradiation can be useful in back and musculoskeletal pain therapy. In this study joint and vertebral column pain and mobility were measured during two weeks of IR-A irradiation treatment of patients suffering from degenerative osteoarthritis of hip and knee, low back pain, or rheumatoid arthritis. Additionally, before and after IR-A treatment MDA serum levels were measured to check if MDA variations accompany changes in pain intensity and mobility. Two-hundred and seven patients were divided into verum groups getting IR-irradiation, placebo groups getting visible, but not IR irradiation, and groups getting no irradiation. In osteoarthritis significant pain reduction according to Visual Analogue Scale and mobility improvements occurred in the verum group. Even though beneficial mean value changes occurred in the placebo group, the improvements in the placebo and No Irradiation groups were without statistical significance. In low back pain, pain and mobility improvements (by 35-40%) in the verum group were found, too. A delayed (2nd week) mobility improvement in rheumatoid arthritis was seen. However, pain relief was seen immediately. In patients suffering from low back pain or rheumatoid arthritis, the pain and mobility improvements were accompanied by significant changes of MDA serum levels. However, MDA appears not a sensitive biofactor for changes of the pain intensity in degenerative osteoarthritis. Nevertheless, unaffected or lowered MDA levels during intensive IR-A therapy argue against previous reports on free radical formation upon infrared. In conclusion, rapid beneficial effects of IR-A towards musculoskeletal pain and joint mobility loss were demonstrated.


Assuntos
Artrite Reumatoide/radioterapia , Raios Infravermelhos/uso terapêutico , Dor Lombar/radioterapia , Malondialdeído/sangue , Osteoartrite/radioterapia , Dor/radioterapia , Idoso , Artrite Reumatoide/sangue , Artrite Reumatoide/fisiopatologia , Feminino , Humanos , Dor Lombar/sangue , Dor Lombar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Osteoartrite/sangue , Osteoartrite/fisiopatologia , Dor/sangue
10.
Free Radic Biol Med ; 48(10): 1347-57, 2010 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-20172024

RESUMO

Previously, we have demonstrated an apoptosis-inducing activity of an acidic, H-chain-rich isoferritin secreted from primary rat hepatocytes in vitro. Because this proapoptotic property may be responsible for the growth-inhibitory and immunosuppressive effects described for certain ferritin species, we aimed to address the mechanism by which ferritin can trigger cell death. Suggesting a pivotal role for iron, iron chelation by desferrioxamine significantly abrogates ferritin-mediated apoptosis and necrosis in primary rat hepatocytes and substantially lowers the extent of protein modification by 4-hydroxynonenal (HNE)-a major lipid peroxidation (LPO) product. Furthermore, supplementing the cultures with the radical-scavenging compound trolox also provided significant protection from ferritin-mediated apoptosis. Moreover, a significant increase in micronucleated cells upon exposure to ferritin indicates that ferritin also introduces damage to DNA. Based on these observations we therefore propose that endocytosis of extracellular ferritin increases the level of free ferrous iron in the lysosomal compartment, promoting Fenton chemistry-based oxidative stress involving LPO and increased lysosomal membrane permeability. Subsequently, the release of reactive lysosomal content leads to cellular damage, in particular modification of protein and DNA induced by HNE and other reactive aldehydic LPO products. Together, these effects will trigger apoptosis and necrosis based on the upregulation of p53, increased mitochondrial membrane permeability, and proapoptotic Fas signaling as described recently. In conclusion, based on their iron-storing ability, secreted acidic isoferritins may act as soluble mediators of oxidative stress under certain physiological and pathophysiological conditions.


Assuntos
Ferritinas/metabolismo , Hepatócitos/metabolismo , Ferro/metabolismo , Aldeídos/imunologia , Aldeídos/metabolismo , Animais , Anticorpos Monoclonais , Apoptose/efeitos dos fármacos , Técnicas de Cultura de Células , Células Cultivadas , Cromanos/farmacologia , Desferroxamina/farmacologia , Feminino , Sequestradores de Radicais Livres/farmacologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Quelantes de Ferro/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo , Ratos , Ratos Endogâmicos F344
11.
J Cell Physiol ; 212(1): 157-64, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17348034

RESUMO

Previously we have demonstrated an apoptosis inducing activity for a rat hepatocyte conditioned medium (CM) presumably mediated by acidic isoferritins. Here, we present support for this assumption since isoferritins purified from different rat hepatocyte CM significantly enhanced the frequency of apoptotic cells in primary rat hepatocytes, an effect completely inhibited by a neutralizing anti-H-ferritin antibody. The apoptosis induction appears to be related to a 43 kDa ferritin subunit contained in the isoferritins released from primary hepatocytes, presumably representing a ferritin heavy/light chain heterodimer. In addition, these isoferritins immunologically crossreact with antibodies raised against placental isoferritin p43-PLF (which also contains a 43 kDa ferritin subunit) and melanoma-derived H-chain ferritin, representing ferritin isoforms which reveal immunomodulatory properties. Furthermore, p53 and FasL are upregulated upon isoferritin treatment in a time dependent mode, and apoptosis induction can be suppressed by neutralizing anti-FasL antibodies. Proapoptotic Bid is upregulated too and translocated into mitochondria in primary hepatocytes exposed to the isoferritins purified from the CM. Finally, epidermal growth factor (EGF) and dexamethasone (DEX), which counteract proapoptotic mitochondrial signalling, almost completely abolished the proapoptotic effect of the hepatocyte derived isoferritins. In conclusion, our findings demonstrate that acidic isoferritins with homology to immunomodulatory ferritin isoforms (p43-PLF, melanoma-derived-H-chain ferritin) are released from hepatocytes in vitro, and are able to stimulate upregulation of p53 and mediate apoptosis involving Fas (CD95) signalling as well as addressing the intrinsic mitochondrial proapoptotic pathway.


Assuntos
Apoptose/efeitos dos fármacos , Ferritinas/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Animais , Apoptose/fisiologia , Células Cultivadas , Meios de Cultivo Condicionados/farmacologia , Relação Dose-Resposta a Droga , Proteína Ligante Fas/metabolismo , Feminino , Ferritinas/farmacologia , Mitocôndrias/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344 , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo
12.
FEMS Yeast Res ; 5(3): 271-80, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15556089

RESUMO

Functional ribosomes synthesize proteins in all living cells and are composed of two labile associated subunits, which are made of rRNA and ribosomal proteins. The rRNA of the small 40S subunit (SSU) of the functional eukaryotic 80S ribosome decodes the mRNA molecule and the large 60S subunit (LSU) rRNA catalyzes protein synthesis. Recent fine structure determinations of the ribosome renewed interest in the role of ribosomal proteins in modulation of the core ribosomal functions. RpL10/Grc5p is a component of the LSU and is a multifunctional translational regulator, operating in 60S subunit biogenesis, 60S subunit export and 60S subunit joining with the 40S subunit. Here, we report that rpL10/Grc5p functionally interacts with the nuclear export factor Nmd3p in modulation of the cellular polysome complement and with the small subunit protein rpS6 in subunit joining and differential protein expression.


Assuntos
Proteína S6 Ribossômica/fisiologia , Proteínas Ribossômicas/fisiologia , Ribossomos/fisiologia , Leveduras/fisiologia , Sequência de Bases , DNA Fúngico/química , DNA Fúngico/genética , Eletroforese em Gel Bidimensional , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Proteína Ribossômica L10 , Proteína S6 Ribossômica/genética , Proteínas Ribossômicas/genética , Ribossomos/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Leveduras/genética
13.
Cancer Lett ; 198(2): 153-60, 2003 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-12957353

RESUMO

beta-Glucans belong to the class of substances known as biological response modifiers with a broad range of activity. We have investigated two types of glucans: (1-->3)-beta-D glucan from the baker's yeast Saccharomyces cerevisiae and beta-glucan-chitin complex from the mycelium of filamentous fungus Aspergillus niger. Since these fibrillar beta-glucans are insoluble in water, their water-soluble derivatives--carboxymethyl glucan (CM-G), sulfoethyl glucan (SE-G), and carboxymethyl chitin-glucan (CM-CG) were prepared and tested. The aim of the present work was to investigate the protective effect of the prepared glucan derivatives against oxidative DNA damage induced by H2O2 and visible light-excited Methylene Blue in V79 hamster lung cells. The level of DNA damage (DNA strand breaks) was measured using the single cell gel electrophoresis, so called comet assay. Our findings demonstrate that all three tested glucans reduce oxidative DNA damage. The ability to reduce genotoxic activity increased in the order: CM-G

Assuntos
Anticarcinógenos/uso terapêutico , Dano ao DNA/efeitos dos fármacos , Glucanos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , beta-Glucanas , Animais , Aspergillus niger/química , Linhagem Celular , Cricetinae , Glucanos/isolamento & purificação , Saccharomyces cerevisiae
14.
Nutr Cancer ; 42(1): 117-24, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12235643

RESUMO

Hepatocytes freshly isolated from male Wistar rats fed a common diet or a vitamin A- or vitamin E-supplemented diet (each for 21, 28, or 41 days) were assayed for sensitivity to DNA breakage and cytogenetic changes induced by carcinogens. Different indirectly acting carcinogens were assayed. N-nitrosomorpholine (NMOR) was the only agent that induced DNA breaks, chromosomal aberrations, and micronuclei in all experiments. Benzo[a]pyrene (B[a]p) and dimethyldibenzo [c,g]carbazole (diMeDBC) induced only DNA breaks in all experiments. Occasionally, B[a]P induced chromosomal aberrations and micronuclei, and diMeDBC induced micronuclei, but not chromosomal aberrations. These results demonstrated that the tested carcinogens assayed at concentrations highly effective in a hypoxanthine phosphoribosyltransferase/V79 system significantly increased DNA damage, while cytogenetic changes were less frequent. In hepatocytes from rats fed vitamin A, a reduction in the severity of all three end points was observed after NMOR treatment. After B[a]P treatment, we found a reduction in DNA breaks and chromosomal aberrations; after treatment with diMeDBC, we observed a reduction in DNA breaks. Treatment with vitamin E was less effective: it reduced DNA strand breaks induced by B[a]P and partially reduced those induced by diMeDBC and NMOR and the level of micronuclei induced by NMOR and B[a]P. Both vitamins reduced the level of DNA strand breaks induced by the oxidative effect of a visible light-excited photosensitizer.


Assuntos
Carcinógenos/toxicidade , Aberrações Cromossômicas , Dano ao DNA/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Vitamina A/administração & dosagem , Vitamina E/administração & dosagem , Animais , Benzo(a)pireno/toxicidade , Carbazóis/toxicidade , Células Cultivadas , Hepatócitos/ultraestrutura , Masculino , Nitrosaminas/toxicidade , Ratos , Ratos Wistar
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