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1.
Medicine (Baltimore) ; 100(51): e28430, 2021 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-34941194

RESUMO

RATIONALE: Pulmonary toxoplasmosis (PT) is an infectious disease that can be fatal if reactivation occurs in the recipients of hematopoietic stem cell transplantation (HSCT) who were previously infected with Toxoplasma gondii. However, whether the toxoplasmosis reactivation is an actual risk factor for patients receiving immunosuppressive therapies without HSCT remains unclear. Therefore, reactivated PT is not typically considered as a differential diagnosis for pneumonia other than in patients with HSCT or human immunodeficiency virus (HIV). PATIENT CONCERNS: A 77-year-old man presented with fever and nonproductive cough for several days. He was hospitalized due to atypical pneumonia that worsened immediately despite antibiotic therapy. Before 4 months, he was diagnosed with immune thrombocytopenia (ITP) and received corticosteroid therapy. Trimethoprim-sulfamethoxazole (ST) was administered to prevent pneumocystis pneumonia resulting from corticosteroid therapy. DIAGNOSIS: The serological and culture test results were negative for all pathogens except T. gondii immunoglobulin G antibody. Polymerase chain reaction, which can detect T. gondii from frozen bronchoalveolar lavage fluid, showed positive results. Therefore, he was diagnosed with PT. INTERVENTION: ST, clindamycin, and azithromycin were administered. Pyrimethamine and sulfadiazine could not be administered because his general condition significantly worsened at the time of polymerase chain reaction (PCR) examination. OUTCOMES: The patient died of acute respiratory distress syndrome despite anti-T. gondii treatment. An autopsy revealed a severe organizing pneumonia and a small area of bronchopneumonia. LESSONS: PT should be considered as a differential diagnosis in patients with pneumonia, particularly in seropositive patients who receive immunosuppressive therapies even for other than HSCT or HIV.


Assuntos
Corticosteroides/efeitos adversos , Pneumonia por Pneumocystis/prevenção & controle , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Exacerbação dos Sintomas , Toxoplasmose/complicações , Combinação Trimetoprima e Sulfametoxazol/administração & dosagem , Corticosteroides/uso terapêutico , Idoso , Humanos , Masculino , Pneumonia por Pneumocystis/complicações , Trombocitopenia , Toxoplasma/isolamento & purificação , Toxoplasmose/diagnóstico , Toxoplasmose/prevenção & controle
2.
Behav Processes ; 140: 16-18, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28385628

RESUMO

A novel type of filial cannibalism has been reported in pipefishes, in which the eggs are absorbed through the male's brood-pouch epithelium. The present study explored the applicability of stable isotope analysis for the detection of paternal brood cannibalism in the seaweed pipefish Syngnathus schlegeli. As expected, the δ15N values for liver, which conveys short-term dietary information about the recent reproductive season, were higher in males than in females. In contrast, the δ15N values for muscle, which reflects longer-term feeding habits that span both the reproductive and non-reproductive seasons, did not significantly differ between the sexes. This finding indicates that males occupy a higher trophic position than females only during the reproductive season, and it is probable that this difference is a result of paternal uptake of nutrients from embryos in the brood pouch.


Assuntos
Canibalismo , Marcação por Isótopo/métodos , Smegmamorpha/fisiologia , Animais , Feminino , Fígado/química , Masculino
3.
Zoological Lett ; 1: 15, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26605060

RESUMO

BACKGROUND: Lake Tanganyika in the African Great Rift Valley is known as a site of adaptive radiation in cichlid fishes. Diverse herbivorous fishes coexist on a rocky littoral of the lake. Herbivorous cichlids have acquired multiple feeding ecomorphs, including grazer, browser, scraper, and scooper, and are segregated by dietary niche. Within each ecomorph, however, multiple species apparently coexist sympatrically on a rocky slope. Previous observations of their behavior show that these cichlid species inhabit discrete depths separated by only a few meters. In this paper, using carbon (C) and nitrogen (N) stable isotope ratios as markers, we followed the nutritional uptake of cichlid fishes from periphyton in their feeding territories at various depths. RESULTS: δ(15)N of fish muscles varied among cichlid ecomorphs; this was significantly lower in grazers than in browsers and scoopers, although δ(15)N levels in periphyton within territories did not differ among territorial species. This suggests that grazers depend more directly on primary production of periphyton, while others ingest animal matter from higher trophic levels. With respect to δ(13)C, only plankton eaters exhibited lower values, suggesting that these fishes depend on production of phytoplankton, while the others depend on production of periphyton. Irrespective of cichlid ecomorph, δ(13)C of periphyton correlated significantly with habitat depth, and decreased as habitat depth became deeper. δ(13)C in territorial fish muscles was significantly related to that of periphyton within their territories, regardless of cichlid ecomorph, which suggests that these herbivorous cichlids depend on primary production of periphyton within their territories. CONCLUSIONS: Carbon and nitrogen stable isotope ratios varied among ecomorphs and among cichlid species in the same ecomorphs sympatrically inhabiting a littoral area of Lake Tanganyika, suggesting that these cichlids are segregated by nutrient source due to varying dependency on periphyton in different ecomorphs (especially between grazers and browsers), and due to segregation of species of the same ecomorph by feeding depth, grazers and browsers in particular.

4.
PLoS One ; 9(4): e96219, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24769853

RESUMO

Phospholipid-derived fatty acids (PLFA) and respiratory quinones (RQ) are microbial compounds that have been utilized as biomarkers to quantify bacterial biomass and to characterize microbial community structure in sediments, waters, and soils. While PLFAs have been widely used as quantitative bacterial biomarkers in marine sediments, applications of quinone analysis in marine sediments are very limited. In this study, we investigated the relation between both groups of bacterial biomarkers in a broad range of marine sediments from the intertidal zone to the deep sea. We found a good log-log correlation between concentrations of bacterial PLFA and RQ over several orders of magnitude. This relationship is probably due to metabolic variation in quinone concentrations in bacterial cells in different environments, whereas PLFA concentrations are relatively stable under different conditions. We also found a good agreement in the community structure classifications based on the bacterial PLFAs and RQs. These results strengthen the application of both compounds as quantitative bacterial biomarkers. Moreover, the bacterial PLFA- and RQ profiles revealed a comparable dissimilarity pattern of the sampled sediments, but with a higher level of dissimilarity for the RQs. This means that the quinone method has a higher resolution for resolving differences in bacterial community composition. Combining PLFA and quinone analysis as a complementary method is a good strategy to yield higher resolving power in bacterial community structure.


Assuntos
Ácidos Graxos/metabolismo , Sedimentos Geológicos/microbiologia , Fosfolipídeos/metabolismo , Proteobactérias/metabolismo , Quinonas/metabolismo , Biomarcadores/análise , Biomarcadores/metabolismo , Biomassa , Análise por Conglomerados , Microbiologia Ambiental , Ácidos Graxos/isolamento & purificação , Sedimentos Geológicos/química , Microbiota , Fosfolipídeos/isolamento & purificação , Quinonas/isolamento & purificação
5.
Mar Environ Res ; 85: 45-53, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23321299

RESUMO

Tuna-farming is expanding worldwide, necessitating the monitoring/managing of its effects on the natural environment. In Japan, tuna-farming is conducted on coral reefs that have been damaged by mass-bleaching events and crown-of-thorns starfish (COTS) outbreaks. This study focused on the coral community on an artificial substrate of tuna-farm to reveal the possible effects of tuna-farming on the natural environment. Corals flourished on ropes suspended in the farm in the Amami Islands, southern Japan. These were moored 3 m below the sea-surface in 50-m-deep water. The coral community on the rope was analyzed and compared with those on natural substrata on two adjacent COTS-damaged reefs and with that in a protected reef. Corals were monitored throughout a year. Sixty coral species grew on the ropes, that corresponds to 27.3% of the 220 species known from Amami. The coral community was unique, dominated by massive faviid corals. On the ropes, the water temperature rarely exceeded 30.0 °C and no corals on the rope were severely bleached or covered by sedimentation during the observations. The tuna-farm infrastructure provided corals with a suitable habitat, and species-rich coral communities were established. These coral communities are an important node connecting tuna-farms and the natural environment.


Assuntos
Antozoários , Biodiversidade , Pesqueiros , Animais , Antozoários/classificação , Recifes de Corais , Japão , Dinâmica Populacional , Atum
6.
Mar Environ Res ; 71(4): 247-56, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21334741

RESUMO

This study determined the factors contributing to the spatial distribution of 14 metal concentrations in the surface sediments of Beppu Bay on the basis of comparisons of the organic geochemical properties and environmental parameters through principal component analysis (PCA) and redundancy analysis (RDA). The results of PCA and RDA showed that the concentrations of V, Cr, Co, and As were closely related to the distances between the sampling sites and the Oita River. This indicated that these metals originated from the river's drainage area. The Mn, Cu, Mo, and Cd concentrations were related to the water depth. These results indicated that the Mo, Cd, and Cu deposition processes were controlled by oxygen depletion, and that these elements accumulated in the deeper parts of the bay under anoxic conditions.


Assuntos
Sedimentos Geológicos/química , Metais/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Japão , Análise de Componente Principal , Água do Mar/química , Poluição Química da Água/estatística & dados numéricos
7.
Mar Pollut Bull ; 60(10): 1803-9, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20594561

RESUMO

The Seto Inland Sea (SIS) receives waste runoff from ∼24% of Japan's total population, yet it is also important in regional fisheries, recreation and commerce. During August 2006 we measured carbon and nitrogen stable isotopes of particulate organic matter (POM) and zooplankton across urban population gradients of the SIS. Results showed a consistent trend of increasing δ(15)N in POM and zooplankton from the western to eastern subsystems of the SIS, corresponding to increasing population load. Principal components analysis of environmental variables indicated high positive loadings of δ(15)N and δ(13)C with high chlorophyll-a and surface water temperatures, and negative loadings of low salinities related to inputs from large rivers and high urban development in the eastern SIS. Anthropogenic nitrogen was therefore readily integrated into the SIS food web from primary production to copepods, which are a critical food source for many commercially important fishes.


Assuntos
Carbono/química , Monitoramento Ambiental/métodos , Nitrogênio/química , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/química , Isótopos de Carbono/química , Atividades Humanas , Japão , Isótopos de Nitrogênio/química , Poluição Química da Água
8.
Mar Pollut Bull ; 58(11): 1615-23, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19698960

RESUMO

Organisms collected from a coastal ecosystem in Japan were analyzed for concentrations of 205 polychlorinated biphenyls (PCBs) congeners; analyses were guided by delta(13)C and delta(15)N measurements. The regression slopes of log PCB concentration on delta(15)N value are regarded as indices of biomagnification in food webs. The slope (wet weight basis) of SigmaPCBs was +0.104; the slope (lipid weight basis) was close to zero. Lipid content increased from 0.06% in a primary producer to 8.32% in the highest trophic level consumer. Hence, biomagnification of SigmaPCBs (wet weight basis) can be attributed to increase of lipid content through the food web. For most of the congeners, the slopes (wet weight basis) exceeded those (lipid weight basis) by ca. 0.10. Slopes increased with increasing PCB chlorination levels between chlorine numbers 1-6; slopes decreased at higher chlorination levels. This decrease is likely caused by a decrease in membrane permeability with increasing molecular weight.


Assuntos
Bifenilos Policlorados/análise , Poluentes Químicos da Água/análise , Animais , Isótopos de Carbono , Monitoramento Ambiental , Peixes/metabolismo , Cadeia Alimentar , Invertebrados/metabolismo , Japão , Lipídeos/análise , Isótopos de Nitrogênio , Oceano Pacífico , Bifenilos Policlorados/metabolismo , Alga Marinha/metabolismo , Poluentes Químicos da Água/metabolismo
9.
Mar Pollut Bull ; 58(8): 1217-1224, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19376538

RESUMO

Bivalves, crabs, fishes, seawater, and sediment collected from the inner part of Tokyo Bay, Japan, were measured for 20 polybrominated diphenyl ether (PBDE) and 5 polychlorinated biphenyl (PCB) congeners. To determine the trophic levels of the organisms, carbon and nitrogen stable isotope ratios (delta(13)C and delta(15)N) were also measured. Bioconcentration factors of PBDE and PCB congeners increased as the octanol-water partition coefficient (K(ow)) rose to log K(ow)=7, above which they decreased again. Biomagnification of PCBs and several PBDE congeners (BDE47, 99, 100, 153 and 154) up the trophic ladder was confirmed by a positive correlation between their concentrations and delta(15)N. Other PBDE congeners showed a negative or no correlation, suggesting their biotransformation through metabolism. The more hydrophobic congeners of both PBDEs (Br=2-6) and PCBs (Cl=6-9) were biomagnified more. It thus appears that PBDEs are less biomagnified than PCBs.


Assuntos
Cadeia Alimentar , Éteres Difenil Halogenados/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Éteres Difenil Halogenados/análise , Japão , Biologia Marinha , Oceano Pacífico , Poluentes Químicos da Água/análise
10.
Mar Pollut Bull ; 58(5): 663-71, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19261300

RESUMO

Biomagnification profiles of polycyclic aromatic hydrocarbons (PAHs), alkylphenols, and polychlorinated biphenyls (PCBs) from the innermost part of Tokyo Bay, Japan were analyzed using stable carbon (delta(13)C) and nitrogen (delta(15)N) isotope ratios as guides to trophic web structure. delta(15)N analysis indicated that all species of mollusks tested were primary consumers, while decapods and fish were secondary consumers. Higher concentrations of PCBs occurred in decapods and fish than in mollusks. In contrast, concentrations of PAHs and alkylphenols were lower in decapods and fish than in mollusks. Unlike PCBs, whose concentrations largely increased with increasing delta(15)N (i.e. increasing trophic level), all PAHs and alkylphenols analyzed followed a reverse trend. Molecular weights of PAHs are lower than those of PCBs, therefore low membrane permeability caused by large molecular size is an unlikely factor in the "biodilution" of PAHs. Organisms at higher trophic levels may rapidly metabolize PAHs or they may assimilate less of them.


Assuntos
Isótopos de Carbono/análise , Monitoramento Ambiental , Cadeia Alimentar , Isótopos de Nitrogênio/análise , Poluentes Químicos da Água/análise , Animais , Decápodes/química , Decápodes/metabolismo , Japão , Modelos Lineares , Moluscos/química , Moluscos/metabolismo , Músculos/química , Oceanos e Mares , Perciformes/metabolismo , Fenóis/análise , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Água do Mar/análise
11.
Int J Neuropsychopharmacol ; 12(2): 191-9, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19079814

RESUMO

The effectiveness and safety of yokukansan (TJ-54), a traditional Japanese medicine (kampo) for the treatment of the behavioural and psychological symptoms of dementia (BPSD), were evaluated in 106 patients diagnosed as having Alzheimer's disease (AD) (including mixed-type dementia) or dementia with Lewy bodies. Patients were randomly assigned to group A (TJ-54 treatment in period I and no treatment in period II; each period lasting 4 wk) or group B (no treatment in period I and TJ-54 treatment in period II). BPSD and cognitive functions were evaluated using the Neuropsychiatric Inventory (NPI) and the Mini-Mental State Examination (MMSE), respectively. Activities of daily living (ADL) were evaluated using Instrumental Activities of Daily Living (IADL) in outpatients and the Barthel Index in in-patients. For the safety evaluation, adverse events were investigated. Significant improvements in mean total NPI score associated with TJ-54 treatment were observed in both periods (Wilcoxon test, p=0.040 in period I and p=0.048 in period II). The mean NPI scores significantly improved during TJ-54 treatment in groups A and B (p=0.002 and p=0.007, respectively) but not during periods of no treatment. Among the NPI subscales, significant improvements were observed in delusions, hallucinations, agitation/aggression, depression, anxiety, and irritability/lability. The effects of TJ-54 persisted for 1 month without any psychological withdrawal symptoms in group A. TJ-54 did not show any effect on either cognitive function or ADL. No serious adverse reactions were observed. The present study suggests that TJ-54 is an effective and well-tolerated treatment for patients with BPSD.


Assuntos
Sintomas Comportamentais , Demência/complicações , Demência/psicologia , Medicamentos de Ervas Chinesas/uso terapêutico , Medicina Tradicional Chinesa , Idoso , Idoso de 80 Anos ou mais , Sintomas Comportamentais/tratamento farmacológico , Sintomas Comportamentais/etiologia , Sintomas Comportamentais/psicologia , Viés , Estudos Cross-Over , Avaliação de Medicamentos , Feminino , Humanos , Japão/epidemiologia , Masculino , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Testes Neuropsicológicos , Estatísticas não Paramétricas
12.
Biol Lett ; 4(4): 362-5, 2008 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-18492646

RESUMO

Syngnathid fish (pipefish and seahorses) are unique among teleost fish in that their ovary consists of a rolled sheet with germinal ridge(s) on the dorsal side running along the entire length of the sheet. A distinct difference is seen in the ovarian structure between polygamous Syngnathus pipefish and monogamous seahorses (Hippocampus spp.), the former having one germinal ridge and the latter with two ridges. This study examined the ovarian structure and the mode of egg production in a monogamous pipefish Corythoichthys haematopterus. The ovary of C. haematopterus had two germinal ridges like that observed in monogamous seahorses. There were two distinct groups of follicles in the ovary, one being a cohort of extremely small follicles and the other a cohort of follicles developing and increasing in size with the passage of time. We suggest that the ovarian structure and the mode of egg production in this pipefish are adaptations to monogamy.


Assuntos
Ovário/anatomia & histologia , Comportamento Sexual Animal , Smegmamorpha/anatomia & histologia , Adaptação Fisiológica , Animais , Feminino , Oócitos/crescimento & desenvolvimento , Ovário/crescimento & desenvolvimento , Ovário/fisiologia , Smegmamorpha/crescimento & desenvolvimento , Smegmamorpha/fisiologia
13.
Chemosphere ; 72(1): 104-14, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18313720

RESUMO

The present study elucidated the biomagnification profiles of persistent organic pollutants (POPs) through a tropical aquatic food web of Vietnam based on trophic characterization using stable nitrogen analysis. Various biological samples collected from the main stream of the Mekong Delta were provided for the analysis for both POPs, and stable nitrogen and carbon isotope ratios. Of the POPs analyzed, dichlorodiphenyltrichloroethane and its metabolites (DDTs) were the predominant contaminants with concentrations ranging from 0.058 to 12 ng/g wet weight, followed by polychlorinated biphenyls (PCBs) at 0.017-8.9 ng/g, chlordane compounds (CHLs) at 0.0043-0.76 ng/g, tris-4-chlorophenyl methane (TCPMe) at N.D.-0.26 ng/g, hexachlorocyclohexane isomers (HCHs) at N.D.-0.20 ng/g and hexachlorobenzene (HCB) at 0.0021-0.096 ng/g. Significant positive increases of concentrations in DDTs, CHLs, and TCPMe against the stable nitrogen ratio (delta(15)N) were detected, while, concentrations of HCHs and HCB showed no significant increase. The slopes of the regression equations between the log-transformed concentrations of these POPs and delta(15)N were used as indices of biomagnification. The slopes of the POPs for which positive biomagnification was detected ranged from 0.149 to 0.177 on a wet weight basis. The slopes of DDTs and CHLs were less than those reported for a marine food web of the Arctic Ocean, indicating that less biomagnification had occurred in the tropical food web. Of the isomers of CHLs, unlike the studies of the Arctic Ocean, oxychlordane did not undergo significant biomagnification through the food web of the Mekong Delta. This difference is considered to be due to a lack of marine mammals, which might metabolize cis- and trans-chlordane to oxychlordane, in the Mekong Delta ecosystem. The biomagnification profile of TCPMe is reported for the first time in the present study.


Assuntos
Isótopos de Carbono/química , Cadeia Alimentar , Isótopos de Nitrogênio/química , Poluentes da Água/análise , Vietnã
14.
Arch Environ Contam Toxicol ; 54(3): 504-15, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18026776

RESUMO

In the present study, we report the concentrations of 21 trace elements (V, Cr, Mn, Co, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sn, Sb, Cs, Ba, Hg, Tl, Pb, and Bi), as well as the results of the analysis of stable carbon and nitrogen isotopes, of the various biota that make up the food web in the main stream of the Mekong Delta near Can Tho, South Vietnam. A significant trophic level-dependent increase was found in concentrations of Se, Rb, and Hg with increasing delta(15)N, indicating that an overall biomagnification of these elements occurred. However, the increase of Hg concentration per trophic level was lower than in previous studies. In contrast, the concentration of Mn showed an opposite trend in the food web of the Mekong Delta. In addition to these overall trends, the present study revealed that the biomagnification profiles of trace metals differ between crustaceans and fishes; concentrations of Mn, Cu, Zn, As, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Tl, and Pb were significantly higher in crustaceans, whereas fishes showed higher concentrations of Cr, Rb, and Hg (trophic level determined by delta(15)N). The differences in the biomagnification profile between the major taxa might be attributed to differences in metal accumulation and in detoxification abilities such as possessing a metal-binding protein, e.g., metallothionein (MT).


Assuntos
Arsênio/metabolismo , Isótopos de Carbono/metabolismo , Cadeia Alimentar , Metais/metabolismo , Isótopos de Nitrogênio/metabolismo , Selênio/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Crustáceos/metabolismo , Monitoramento Ambiental , Peixes/metabolismo , Fitoplâncton/metabolismo , Vietnã
15.
Environ Int ; 33(6): 750-8, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17376529

RESUMO

Organochlorines such as PCBs, DDTs, HCHs, CHLs and HCB were determined in pooled whole body homogenized of fish samples collected from five locations during 1998 and 2003 in order to understand their contamination status, temporal and spatial variation in Indonesian waters. PCBs and DDTs were the predominant contaminants with concentrations from 9.7 to 2700 ng/g lipid wt. and 12 to 1100 ng/g lipid wt., respectively, while HCHs (nd-24 ng/g lipid wt.), CHL compounds (nd-81 ng/g lipid wt.) and HCB (0.22-28 ng/g lipid wt.) were one to two orders of magnitude lower. Among the locations, PCBs and CHLs were higher in the samples from highly industrialized and thickly populated-locations, whereas OC pesticides such as DDTs and HCHs were particularly more prominent in suburban and rural areas. Levels of OCs observed in the waters surrounding Java Island were higher than those in Sumatra Island, implying significant use of OCs in highly populated Java Island. Concentrations of PCBs and DDTs in fish from Jakarta Bay were significantly lower in the samples collected in 2003 as compared to fish in 1998, indicating decreasing trend of these compounds in the Indonesian environment. Recent estimated average daily intakes of PCBs (0.81 microg/person/day), DDTs (1.1 microg/person/day), HCHs (0.018 microg/person/day), CHLs (0.010 microg/person/day) were much lower than the threshold values recommended by various agencies, suggesting minimal risk of this compound via fish ingestion to Indonesians.


Assuntos
Peixes/metabolismo , Hidrocarbonetos Clorados/metabolismo , Animais , Indonésia
16.
J Pharmacol Exp Ther ; 318(3): 1323-9, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16775197

RESUMO

We examined the effects of adrenomedullin on cardiac oxidative stress and collagen accumulation in aldosterone-dependent malignant hypertensive rats. Spontaneously hypertensive rats (SHRs) were treated with one of the following combinations for 4 weeks: tap water and vehicle [0.5% ethanol, subcutaneously (s.c.), n = 5], 1% NaCl in drinking water and vehicle (n = 8), 1% NaCl and aldosterone (0.75 microg/h s.c., n = 8), and 1% NaCl, aldosterone, and adrenomedullin (1.3 microg/kg/h s.c., n = 8). Systolic blood pressure (SBP) and left ventricular (LV) weight were higher in aldosterone-treated SHRs than vehicle- or vehicle/1% NaCl-treated SHRs. Thiobarbituric acid reactive substances (TBARS) levels and NADPH oxidase activity in LV tissues of aldosterone-treated SHRs were also higher than those of vehicle- or vehicle/1% NaCl-treated SHRs, and these changes were associated with increases in LV mRNA levels of p22phox, gp91phox, fibronectin, collagen types I and III, as well as collagen content. Treatment with adrenomedullin did not alter SBP or LV weight but attenuated aldosterone-induced increases in TBARS levels, NADPH oxidase activity, and mRNA levels of p22phox, gp91phox, fibronectin, collagen types I and III, as well as collagen content in LV tissues. These data suggest that NADPH oxidase-mediated reactive oxygen species production is involved in the pathogenesis of cardiac collagen accumulation in aldosterone-dependent malignant hypertensive rats and that the cardioprotective effects of adrenomedullin are mediated through the suppression of this pathway.


Assuntos
Aldosterona/farmacologia , Colágeno/metabolismo , Coração/efeitos dos fármacos , Hipertensão/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Peptídeos/farmacologia , Adrenomedulina , Animais , Pressão Sanguínea/efeitos dos fármacos , Cardiotônicos/farmacologia , Fibronectinas/genética , Masculino , Miocárdio/metabolismo , NADPH Oxidases/metabolismo , Potássio/urina , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Sódio/urina
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