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1.
Environ Sci Pollut Res Int ; 31(14): 20941-20952, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38381291

RESUMO

Zinc and copper have been used as growth promotors in alternative to antibiotics in pig's diet. The aim was the ascertainment of the Zn and Cu concentrations in piglets' liver and kidney and their impact in the reduced susceptibility to Zn, Cu, and antibiotics in enterococci, used as microbiota biomarker. Zn and Cu were determined in the livers and kidneys of 43 piglets slaughtered in Portugal, by flame atomic absorption spectrometry. Enterococci were isolated from feces for determining the identification of species (E. faecalis, E. faecium, and Enterococcus spp.); susceptibility to vancomycin, ciprofloxacin, linezolid, tigecycline, ampicillin, imipenem, and metals; and Cu tolerance genes. In piglets with Zn and Cu high or toxic levels, enterococci had reduced susceptibility to ions, reinforced by the presence of Cu tolerance genes and by resistance to antibiotics. The study relevance is to show the relationship between these metals' levels and decreased susceptibility to Cu, Zn, and antibiotics by enterococci. From the results, it could be supposed that the piglets were being fed with high doses of Zn and Cu which could select more resistant bacteria to both antibiotics and metals that could spread to environment and humans.


Assuntos
Cobre , Enterococcus , Humanos , Animais , Suínos , Antibacterianos/farmacologia , Fígado , Rim , Fezes/microbiologia , Zinco , Testes de Sensibilidade Microbiana , Enterococcus faecalis/genética , Farmacorresistência Bacteriana
2.
Biol Trace Elem Res ; 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38147233

RESUMO

Metal ions such as zinc and copper have been used as alternatives to antibiotics, to improve animal health and growth rates in pig farming. This study aims to determine antibiotic residues and Zn concentration in piglets' livers (n = 56) and kidneys (n = 60); and to examine the correlation between the use of Zn and antibiotics, and resistance to Zn and antibiotics of Escherichia coli isolated from piglets' faeces (n = 60). Samples were collected from randomly selected healthy piglets (n = 60); antibiotic residues were quantified by ultra-high-performance-liquid-chromatography time-of-flight mass spectrometry (UHPLC-ToF-MS); Zn was quantified using flame atomic absorption spectrometry (FAAS); microbiological methods were used for E. coli isolation, antibiotic susceptibility, and Zn minimal inhibitory concentration; and Real-Time PCR was used for gene detection. The presence of antibiotic residues and Zn concentrations in the liver was found to be negatively correlated, whilst no significant difference was observed in the kidney. In E. coli isolated from piglet faeces considered to be susceptible or multi-drug-resistant, no significant difference was found between Zn concentrations in the liver and in the kidney, which appears to indicate that Zn accumulated in the liver and in the kidney does not promote resistance to antibiotics in E. coli. The isolates showed tolerance to Zn which would suggest that antibiotic resistance and phenotypic tolerance to Zn in these isolates are not related. The genes zitB and zntA associated to Zn tolerance, were predominantly found in the more resistant Zn isolates. The findings provide insights on how Zn use in pig production maintains antibiotic resistance and metal tolerance in bacteria, with implications for One Health.

3.
Front Cell Infect Microbiol ; 13: 1169552, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37829607

RESUMO

Introduction: Zoonotic transmission is a challenge for the control and elimination of malaria. It has been recorded in the Atlantic Forest, outside the Amazon which is the endemic region in Brazil. However, only very few studies have assessed the antibody response, especially of IgM antibodies, in Neotropical primates (NP). Therefore, in order to contribute to a better understanding of the immune response in different hosts and facilitate the identification of potential reservoirs, in this study, naturally acquired IgM antibody responses against Plasmodium antigens were evaluated, for the first time, in NP from the Atlantic Forest. Methods: The study was carried out using 154 NP samples from three different areas of the Atlantic Forest. IgM antibodies against peptides of the circumsporozoite protein (CSP) from different Plasmodium species and different erythrocytic stage antigens were detected by ELISA. Results: Fifty-nine percent of NP had IgM antibodies against at least one CSP peptide and 87% against at least one Plasmodium vivax erythrocytic stage antigen. Levels of antibodies against PvAMA-1 were the highest compared to the other antigens. All families of NP showed IgM antibodies against CSP peptides, and, most strikingly, against erythrocytic stage antigens. Generalized linear models demonstrated that IgM positivity against PvCSP and PvAMA-1 was associated with PCR-detectable blood-stage malaria infection and the host being free-living. Interestingly, animals with IgM against both PvCSP and PvAMA-1 were 4.7 times more likely to be PCR positive than animals that did not have IgM for these two antigens simultaneously. Discussion: IgM antibodies against different Plasmodium spp. antigens are present in NP from the Atlantic Forest. High seroprevalence and antibody levels against blood-stage antigens were observed, which had a significant association with molecular evidence of infection. IgM antibodies against CSP and AMA-1 may be used as a potential marker for the identification of NP infected with Plasmodium, which are reservoirs of malaria in the Brazilian Atlantic Forest.


Assuntos
Malária , Plasmodium , Animais , Brasil/epidemiologia , Formação de Anticorpos , Proteínas de Protozoários , Imunoglobulina M , Estudos Soroepidemiológicos , Antígenos de Protozoários , Malária/veterinária , Primatas , Florestas , Anticorpos Antiprotozoários , Peptídeos , Plasmodium vivax
4.
Clin Exp Dermatol ; 47(8): 1578-1581, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35340055

RESUMO

M2 macrophages are copious in generalized pustular psoriasis (GPP). M2 macrophages seem to acquire new skills and share common characteristics in GPP. HAM56 may play a role in attracting immature neutrophils to the inflammatory environment in GPP.


Assuntos
Interleucinas , Macrófagos , Doenças da Imunodeficiência Primária , Psoríase , Dermatopatias Vesiculobolhosas , Doença Aguda , Humanos , Interleucinas/deficiência , Macrófagos/imunologia , Neutrófilos , Psoríase/tratamento farmacológico
5.
Front Cell Infect Microbiol ; 11: 678996, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34055672

RESUMO

Human malaria due to zoonotic transmission has been recorded in the Atlantic Forest, an extra-Amazonian area in Brazil, which are a challenge for malaria control. Naturally acquired humoral immune response against pre-erythrocytic and erythrocytic antigens of Neotropical primates (NP) was evaluated here to improve the knowledge about the exposure of those animals to the malaria transmission and support the identification of the potential reservoirs of the disease in the Atlantic Forest. Blood samples of 154 monkeys from three areas of the Atlantic Forest were used to identify IgG antibodies against peptides of the repeat region of the major pre-erythrocytic antigen, the circumsporozoite protein (CSP), of Plasmodium vivax (PvCSP), Plasmodium brasilianum/Plasmodium malariae (Pb/PmCSP), and Plasmodium falciparum (PfCSP) by ELISA. Antibodies against erythrocytic recombinant antigens of P. vivax, Apical membrane antigen 1 (PvAMA-1), Erythrocyte binding protein 2 (PvEBP-2) and domain II of Duffy binding protein (PvDBPII) were also evaluated. Parameters, such as age, sex, PCR positivity, and captivity, potentially associated with humoral immune response were analyzed. Eighty-five percent of NP had antibodies against at least one CSP peptide, and 76% against at least one P. vivax erythrocytic antigen. A high percentage of adults compared to non-adults were seropositive and showed increased antibody levels. Neotropical primates with PCR positive for P. simium had a significantly higher frequency of positivity rate for immune response against PvEBP-2, PvDBPII and also higher antibody levels against PvDBPII, compared to PCR negative NPs for this species. Monkeys with PCR positive for P. brasilianum/P. malariae showed higher frequency of seropositivity and antibody levels against Pb/PmCSP. Levels of antibodies against Pb/PmCSP, PvEBP-2 and PvDBPII were higher in free-living than in captive monkeys from the same area. All Platyrrhine families showed antibodies against CSP peptides, however not all showed IgG against erythrocytic antigens. These findings showed a high prevalence of naturally acquired antibodies against CSP repeats in all studied areas, suggesting an intense exposure to infected-mosquitoes bites of NP from all families. However, mainly monkeys of Atelidae family showed antibodies against P. vivax erythrocytic antigens, suggesting blood infection, which might serve as potential reservoirs of malaria in the Atlantic Forest.


Assuntos
Malária , Parasitos , Plasmodium , Animais , Anticorpos Antiprotozoários , Antígenos de Protozoários , Brasil , Eritrócitos , Florestas , Imunidade Humoral , Malária/veterinária , Plasmodium vivax , Primatas , Proteínas de Protozoários
6.
Pathogens ; 10(2)2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33503848

RESUMO

Acute chagasic encephalitis is a clinically severe central nervous system (CNS) manifestation. However, the knowledge of the nervous form of Chagas disease is incomplete. The role of the muscarinic acetylcholine receptor (mAChR) on mice behavior and brain lesions induced by Trypanosoma cruzi (Colombian strain) was herein investigated in mice treated with the mAChR agonist and antagonist (carbachol and atropine), respectively. Immunosuppressed or non-immunosuppressed mice were intracerebroventricularly (icv) or intraperitoneally (ip) infected. All groups were evaluated 15 d.p.i. (days post infection). Intraperitoneally infected animals had subpatent parasitemia. Patent parasitemia occurred only in icv infected mice. The blockade of mAChR increased the parasitemia, parasitism and lesions compared to its activation. Infected not treated (INT ip) mice did not present meningitis and encephalitis, regardless of immunosuppression. INT icv brains presented higher cellularity, discrete signs of cellular degeneration, frequent presence of parasites and focal meningitis. The immunosuppressed atropine + icv mice presented increased intracellular parasitism associated with degenerative parenchymal changes, while carbachol + icv mice presented discrete meningitis, preservation of the cortex and absence of relevant parasitism. Cholinergic receptor blockage increased impairment of coordination vs. receptor activation. Muscarinic cholinergic pathway seems to be involved in immune mediated cell invasion events while its blockade favored infection evolution, brain lesions, and behavioral alterations.

7.
J Infus Nurs ; 43(4): 208-212, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32618954

RESUMO

The aim of this study was to assess the knowledge of nursing teams that care for hospitalized adolescents undergoing glucocorticoid infusion and to develop an educational protocol for nursing care during pulse therapy. This descriptive, exploratory study with a qualitative approach was developed in a unit specializing in adolescent health at a university hospital in the state of Rio de Janeiro, Brazil. The instrument used for data collection was a semistructured interview conducted in a private room on the unit. The main results indicated that nursing knowledge was focused on the need to evaluate hemodynamic parameters, the care required during infusion therapy, and the complications resulting from the treatment. Educational material was developed to support a holistic view of the adolescent undergoing pulse therapy. Based on information received from the nursing team, it was determined that, although the team performed all the technical aspects of the infusion procedure well, their care did not address specific needs of the adolescent patient, guidance on infection prevention, or hemodynamic evaluation. After evaluating the nursing team's experience, knowledge, and perceptions, the researchers were able to develop appropriate protocols to guide care for hospitalized adolescents undergoing glucocorticoid infusion therapy.


Assuntos
Saúde do Adolescente , Corticosteroides/administração & dosagem , Conhecimentos, Atitudes e Prática em Saúde , Recursos Humanos de Enfermagem Hospitalar/educação , Pulsoterapia/normas , Administração Intravenosa , Adolescente , Corticosteroides/efeitos adversos , Adulto , Brasil , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Entrevistas como Assunto , Pessoa de Meia-Idade , Pulsoterapia/efeitos adversos , Pesquisa Qualitativa , Adulto Jovem
8.
Surg. cosmet. dermatol. (Impr.) ; 12(1): 83-86, jan.-mar. 2020.
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1363746

RESUMO

O tratamento isolado do queloide apresenta resultado variável e, muitas vezes, insatisfatório. A combinação de terapêuticas tem se mostrado uma alternativa eficaz, principalmente para os casos recalcitrantes. A excisão cirúrgica e a irradiação no pós-operatório imediato com feixe de elétrons é uma alternativa efetiva na cicatrização e redução da taxa de recidiva dessas lesões. Os autores descrevem um paciente que apresentava queloide volumoso recalcitrante que obteve bom resultado terapêutico.


Isolated keloid treatment has variable and often unsatisfactory results. The combination of therapies has proven to be an effective alternative mainly for recalcitrant cases. Surgical excision and immediate postoperative electron beam irradiation is an effective alternative in healing and reducing the recurrence rate of these lesions. The authors describe a patient with recalcitrant bulky keloid who had a good therapeutic outcome.

9.
Probiotics Antimicrob Proteins ; 9(4): 371-379, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28374172

RESUMO

Several studies have demonstrated a diversity of bacterial species in human milk, even in aseptically collected samples. The present study evaluated potential probiotic bacteria isolated from human milk and associated maternal variables. Milk samples were collected from 47 healthy women and cultured on selective and universal agar media under aerobic and anaerobic conditions. Bacterial isolates were counted and identified by Biotyper Matrix-Assisted Laser Desorption Ionization-Time of Flight mass spectrometry and then tested for probiotic properties. Total bacteria in human milk ranged from 1.5 to 4.0 log10 CFU/mL. The higher bacterial counts were found in colostrum (mean = 3.9 log10 CFU/mL, 95% CI 3.14-4.22, p = 0.00001). The most abundant species was Staphylococcus epidermidis (n = 76). The potential probiotic candidates were Lactobacillus gasseri (n = 4), Bifidobacterium breve (n = 1), and Streptococcus salivarius (n = 4). Despite the small sample size, L. gasseri was isolated only in breast milk from mothers classified into a normal weight range and after a vaginally delivered partum. No potential probiotics showed antagonism against pathogens, but all of them agglutinated different pathogens. Nine bacterial isolates belonging to the species L. gasseri, B. breve, and S. salivarius were selected as potential probiotics. The present study confirms the presence in breast milk of a bacterial microbiota that could be the source of potential probiotic candidates to be used in the formula of simulated maternal milk.


Assuntos
Colostro/microbiologia , Leite Humano/microbiologia , Probióticos , Adulto , Carga Bacteriana , Bifidobacterium breve/isolamento & purificação , Feminino , Humanos , Lactobacillus gasseri/isolamento & purificação , Staphylococcus epidermidis/isolamento & purificação , Streptococcus salivarius/isolamento & purificação , Adulto Jovem
10.
Mem Inst Oswaldo Cruz ; 111(9): 570-6, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27580347

RESUMO

Plasmodium falciparum and Plasmodium vivax have evolved with host switches between non-human primates (NHPs) and humans. Studies on the infection dynamics of Plasmodium species in NHPs will improve our understanding of the evolution of these parasites; however, such studies are hampered by the difficulty of handling animals in the field. The aim of this study was to detect genomic DNA of Plasmodium species from the faeces of New World monkeys. Faecal samples from 23 Alouatta clamitans from the Centre for Biological Research of Indaial (Santa Catarina, Brazil) were collected. Extracted DNA from faecal samples was used for molecular diagnosis of malaria by nested polymerase chain reaction. One natural infection with Plasmodium simium was identified by amplification of DNA extracted from the faeces of A. clamitans. Extracted DNA from a captive NHP was also used for parasite genotyping. The detection limit of the technique was evaluated in vitro using an artificial mixture of cultured P. falciparum in NHP faeces and determined to be 6.5 parasites/µL. Faecal samples of New World primates can be used to detect malaria infections in field surveys and also to monitor the genetic variability of parasites and dynamics of infection.


Assuntos
Alouatta/parasitologia , DNA de Protozoário/genética , Malária/veterinária , Doenças dos Macacos/parasitologia , Plasmodium/isolamento & purificação , Animais , Brasil , Fezes , Genótipo , Malária/parasitologia , Plasmodium/classificação
11.
Mem. Inst. Oswaldo Cruz ; 111(9): 570-576, Sept. 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-794731

RESUMO

Abstract Plasmodium falciparum and Plasmodium vivax have evolved with host switches between non-human primates (NHPs) and humans. Studies on the infection dynamics of Plasmodium species in NHPs will improve our understanding of the evolution of these parasites; however, such studies are hampered by the difficulty of handling animals in the field. The aim of this study was to detect genomic DNA of Plasmodium species from the faeces of New World monkeys. Faecal samples from 23 Alouatta clamitans from the Centre for Biological Research of Indaial (Santa Catarina, Brazil) were collected. Extracted DNA from faecal samples was used for molecular diagnosis of malaria by nested polymerase chain reaction. One natural infection with Plasmodium simium was identified by amplification of DNA extracted from the faeces of A. clamitans. Extracted DNA from a captive NHP was also used for parasite genotyping. The detection limit of the technique was evaluated in vitro using an artificial mixture of cultured P. falciparum in NHP faeces and determined to be 6.5 parasites/µL. Faecal samples of New World primates can be used to detect malaria infections in field surveys and also to monitor the genetic variability of parasites and dynamics of infection.


Assuntos
Animais , Alouatta/parasitologia , DNA de Protozoário/genética , Malária/veterinária , Doenças dos Macacos/parasitologia , Plasmodium/isolamento & purificação , Brasil , Fezes , Genótipo , Malária/parasitologia , Plasmodium/classificação
12.
PLoS One ; 10(6): e0131339, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26107662

RESUMO

Plasmodium simium is a parasite from New World monkeys that is most closely related to the human malaria parasite Plasmodium vivax; it also naturally infects humans. The blood-stage infection of P. vivax depends on Duffy binding protein II (PvDBPII) and its cognate receptor on erythrocytes, the Duffy antigen receptor for chemokines (hDARC), but there is no information on the P. simium erythrocytic invasion pathway. The genes encoding P. simium DBP (PsDBPII) and simian DARC (sDARC) were sequenced from Southern brown howler monkeys (Alouatta guariba clamitans) naturally infected with P. simium because P. simium may also depend on the DBPII/DARC interaction. The sequences of DBP binding domains from P. vivax and P. simium were highly similar. However, the genetic variability of PsDBPII was lower than that of PvDBPII. Phylogenetic analyses demonstrated that these genes were strictly related and clustered in the same clade of the evolutionary tree. DARC from A. clamitans was also sequenced and contained three new non-synonymous substitutions. None of these substitutions were located in the N-terminal domain of DARC, which interacts directly with DBPII. The interaction between sDARC and PvDBPII was evaluated using a cytoadherence assay of COS7 cells expressing PvDBPII on their surfaces. Inhibitory binding assays in vitro demonstrated that antibodies from monkey sera blocked the interaction between COS-7 cells expressing PvDBPII and hDARC-positive erythrocytes. Taken together, phylogenetic analyses reinforced the hypothesis that the host switch from humans to monkeys may have occurred very recently in evolution, which sheds light on the evolutionary history of new world plasmodia. Further invasion studies would confirm whether P. simium depends on DBP/DARC to trigger internalization into red blood cells.


Assuntos
Sistema do Grupo Sanguíneo Duffy/genética , Eritrócitos/parasitologia , Plasmodium vivax/genética , Plasmodium/genética , Alouatta , Animais , Anticorpos Antiprotozoários/imunologia , Células COS , Chlorocebus aethiops , Sistema do Grupo Sanguíneo Duffy/imunologia , Eritrócitos/imunologia , Evolução Molecular , Variação Genética , Haplótipos , Humanos , Filogenia , Plasmodium/imunologia , Plasmodium vivax/imunologia , Polimorfismo de Nucleotídeo Único , Conformação Proteica , Proteínas de Protozoários/genética , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/imunologia , Análise de Sequência de DNA
13.
Mem Inst Oswaldo Cruz ; 109(5): 641-53, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25099335

RESUMO

Blood infection by the simian parasite, Plasmodium simium, was identified in captive (n = 45, 4.4%) and in wild Alouatta clamitans monkeys (n = 20, 35%) from the Atlantic Forest of southern Brazil. A single malaria infection was symptomatic and the monkey presented clinical and haematological alterations. A high frequency of Plasmodium vivax-specific antibodies was detected among these monkeys, with 87% of the monkeys testing positive against P. vivax antigens. These findings highlight the possibility of malaria as a zoonosis in the remaining Atlantic Forest and its impact on the epidemiology of the disease.


Assuntos
Alouatta/parasitologia , Malária/veterinária , Doenças dos Macacos/epidemiologia , Plasmodium/classificação , Animais , Anticorpos Antiprotozoários/sangue , Brasil/epidemiologia , Florestas , Malária/epidemiologia , Malária/parasitologia , Doenças dos Macacos/parasitologia , Reação em Cadeia da Polimerase
14.
Mem. Inst. Oswaldo Cruz ; 109(5): 641-653, 19/08/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-720431

RESUMO

Blood infection by the simian parasite, Plasmodium simium, was identified in captive (n = 45, 4.4%) and in wild Alouatta clamitans monkeys (n = 20, 35%) from the Atlantic Forest of southern Brazil. A single malaria infection was symptomatic and the monkey presented clinical and haematological alterations. A high frequency of Plasmodium vivax-specific antibodies was detected among these monkeys, with 87% of the monkeys testing positive against P. vivax antigens. These findings highlight the possibility of malaria as a zoonosis in the remaining Atlantic Forest and its impact on the epidemiology of the disease.


Assuntos
Animais , Alouatta/parasitologia , Malária/veterinária , Doenças dos Macacos/epidemiologia , Plasmodium/classificação , Anticorpos Antiprotozoários/sangue , Brasil/epidemiologia , Florestas , Malária/epidemiologia , Malária/parasitologia , Doenças dos Macacos/parasitologia , Reação em Cadeia da Polimerase
15.
São Paulo; IDPC; 2014. 70 p. ilus.
Monografia em Português | Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1082244

RESUMO

O implante da valva pulmonar (ITVP) Melody proporcionou um importante avanço terapêutico para pacientes no pós-operatório tardio de algumas cerdiopatias congênitas com disfunção de condutos ou próteses biológicas na via de saída do ventriculo direito (VSVD). Trata-se de opção menos invasiva e com menor taxa de complicação que a substituição valvar com tórax aberto, resultando em redução da necessidade de cirurgias repetidas e consequente melhor qualidade de vida...


Assuntos
Cardiopatias Congênitas , Implante de Prótese de Valva Cardíaca , Valva Pulmonar
16.
Environ Toxicol Pharmacol ; 20(1): 22-5, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21783563

RESUMO

Small concentrations of mercury reduce the force development of the rat right myocardium and inhibit the sodium pump. This inhibition might increase the amount of activator Ca(2+) in the sarcoplasmic reticulum available upon activation. We further investigated whether this action could potentiate positive inotropic effects produced by Ca(2+) increment (0.62-1.25mM) and isoproterenol (20nM). Right ventricular strips contracting isometrically were treated with 0.1 and 1µM HgCl(2). Results showed that after HgCl(2) treatment the magnitude of both inotropic interventions was increased. Considering that Hg(2+) amongst its effects induces hypertension and might be associated with cardiovascular diseases these potentiating effects might have hazardous consequences.

17.
Comp Biochem Physiol C Toxicol Pharmacol ; 134(3): 375-83, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12643984

RESUMO

Personal exposure to mercury vapor and the release of mercury from or during removal of amalgam dental fillings increases its blood and plasma concentration. However, it is not known if these very small amounts affect cardiac function. The effects of continuous exposure to 5 and 20 nM of HgCl(2) on the cardiac contractility were investigated in isometric and tetanic contractions of right ventricular strips and in Langendorff perfused rat hearts. The continuous exposure for 2 h produced a small but significant reduction of the isometric twitch force and time to peak tension shortened. Relative post-rest potentiation was not affected by this concentration of HgCl(2) suggesting a lack of action of the metal on the sarcoplasmic reticulum activity. Tetanic tension, in contrast to twitch force, was intensively reduced suggesting an important depressant action on the activity of contractile proteins. In perfused hearts beating spontaneously, isovolumic systolic pressure reduced progressively and the diastolic pressure increased. Although occurring heart rate reduction, it was similar for both controls and mercury treated hearts. Also, time dependent changes in coronary perfusion pressure were similar to controls. Results suggested that cardiac effects may be observed after continuous exposure to very small concentrations of mercury, probably as a result of the cell capacity to concentrate mercury. These results also indicate that continuous professional exposure to mercury followed by its absorption might have toxicological consequences affecting cardiac function, and being considered hazardous.


Assuntos
Mercúrio/toxicidade , Contração Miocárdica/efeitos dos fármacos , Função Ventricular Direita/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Técnicas In Vitro , Contração Isométrica/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar
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