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Resumen Se calcula que el cuerpo humano está conformado por billones de células, las cuales sufren cientos de miles de lesiones al día en su DNA. Aunque el DNA no es la única biomolécula que sufre daños, su importancia radica en que es la única que no puede ser sustituida por la célula, así que, cuando esta sufre daños, la célula debe repararlos, tolerarlos o, en el caso extremo, activar las vías que la llevarán a la muerte, ya que lo importante es mantener la integridad celular y la homeostasis del organismo. Hay miles de agentes que pueden dañar al DNA, algunos los produce la misma célula y se les denomina 'agentes endógenos', mientras que otros son agentes externos y se les conoce como 'agentes exógenos'. La célula no puede evitar el daño causado por los agentes endógenos, ya que son productos de la actividad metabólica, por ejemplo; así que, cuando suceden se activan de forma inmediata los mecanismos celulares para mitigarlos. Lo mismo pasa con los daños causados por agentes exógenos, ya que la célula hará todo lo posible por disminuir los efectos adversos que pueden causar. El problema se pone de manifiesto cuando la célula no puede reparar los daños o los repara mal o son tantos que los mecanismos de reparación se ven rebasados, es entonces cuando el daño permanece en el DNA y se genera un estado de inestabilidad cromosómica que puede conducir a la célula a la disfunción y a la malignización. Este estado de inestabilidad cromosómica se puede ver reflejado en el aumento de rompimientos de DNA o de micronúcleos en las células expuestas, lo que se puede cuantificar por medio de métodos especiales como el 'Ensayo Cometa' y el 'Ensayo de Micronúcleos', ya que identificar el daño en el DNA es una forma de evaluar el potencial tóxico que tienen los agentes a los que están expuestas las poblaciones, permite conocer los mecanismos de acción que tienen y, además, ayuda a comprender los factores que influyen en el detrimento de la salud poblacional.

Abstract It is estimated that the human body is made of trillions of cells, which suffer hundreds of thousands of DNA lesions every day. Although DNA is not the only biomolecule that suffers damage, its importance lies in the fact that it is the only biomolecule that cannot be replaced by the cell, so when it suffers damage, the cell must repair it, tolerate or, in a extreme case, activate pathways that will lead to death, since the objective is to maintain cell integrity and the homeostasis of the organism.There are thousands of agents that can damage DNA, some are produced by the cell and are called 'endogenous, while others are external agents and are known as 'exogenous. The cell cannot avoid the damage caused by endogenous agents, since they are products of its metabolic activity, for example, so when they occur, cellular mechanisms are immediately activated to mitigate them. The same happens with the damage caused by exogenous agents, since the cell will do everything possible to diminish the adverse effects they can cause. The problem becomes apparent when the cell is unable to repair the damage or poorly repairs it, or repairs so much that the mechanisms are overwhelmed, when the damage remains in the DNA and a state of chromosomal instability is generated that can lead the cell to dysfunction and malignization. This state of chromosomal instability can be reflected in increased DNA breaks or micronuclei in exposed cells, which can be quantified by special methods such as the 'Comet Assay' and the 'Micronucleus Assay'. Since identifying DNA damage is a way of evaluating the toxic potential of the agents to which populations are exposed, it allows us to know their mechanisms of action and helps to understand the factors that influence the detriment in population's health.

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Abstract The objective of this study was to assess air quality in relation to vehicular traffic flow in cities located at different elevations in the Bodoquena microregion, state of Mato Grosso do Sul, Brazil. To do so, a micronucleus test was carried out using the TRAD-MCN bioassay on young Tradescantia buds collected from February to November 2018 in seven cities of the microregion with different traffic flow intensities. Meteorological parameters were evaluated, and vehicular traffic was counted to determine traffic flow in each city. With data from the Shuttle Radar Topography Mission (SRTM) and processing in Esri ArcGIS® software version 10.5.1, the regions was mapped based on an Elevation Model. Morphoanatomical analyses were performed according to standard methodology. Measurements were taken of thickness, length and width of tissues and structures, including the upper and lower cuticle, upper and lower epidermis, hypodermis and mesophyll. The greatest traffic flow was found in the cities of Bodoquena, Guia Lopes da Laguna, Jardim, and Porto Murtinho, with the period from 5:00 to 6:00 p.m. showing the highest traffic flow. The greatest frequency of mutagenic alterations was found in the city of Guia Lopes da Laguna, although the results did not differ significantly from Bonito, Caracol, and Jardim. Throughout the biomonitoring, the summer and autumn seasons showed the greatest micronuclei frequencies in all evaluated cities. Variations in the tissue/structure thickness was observed across cities and seasons, but with a decrease in thickness during autumn. In general, the tissues/structures were smaller for the cities of Nioaque and Porto Murtinho, while the anatomical and morphological characteristics of leaf length and thickness showed no differences among cities. We found limited correlation between micronuclei frequency and traffic flow, supporting the hypothesis that although mutagenic alterations are observed in T. pallida, in this microregion the changes are numerically lower when compared to other regions of the state. In light of the genotoxic and morphoanatomical factors assessed herein, the Bodoquena microregion appears to be well preserved in terms of air quality, presenting low micronuclei frequency and a limited reduction in tissues and leaf structures, regardless of the season.

Resumo O objetivo deste trabalho foi avaliar a qualidade do ar com base no fluxo veicular das cidades localizadas em diferentes altitudes na microrregião da Bodoquena, no estado de Mato Grosso do Sul, Brasil. Para tal, foi realizado o teste de micronúcleo, por meio do bioensaio TRAD-MCN em botões jovens de Tradescantia coletadas no período entre fevereiro a novembro de 2018 em sete cidades da microrregião da Bodoquena, com diferentes intensidades de fluxo veicular. Foram avaliados os parâmetros meteorológicos, os veículos foram contados para determinar o tráfego de veículos em cada cidade e altitude. A partir da topografia Shuttle Radar (SRTM) e processamento no software Esri ArcGIS® versão 10.5.1 foi possível mapear a área com base no Modelo de Elevação. As análises morfoanatômicos foram realizadas conforme metodologia padrão. As mensurações de espessura, comprimento, largura dos tecidos e estruturas como a cutícula superior, cutícula inferior, face superior e face inferior da epiderme, hipoderme e mesófilo foram avaliadas. O maior fluxo veicular foi encontrado nas cidades de Bodoquena, Guia Lopes da Laguna, Jardim e Porto Murtinho. O horário das 17:00 às 18:00h foi o que apresentou maiores fluxo de veículos. A maior frequência de alterações mutagênicas foi encontrada na cidade de Guia Lopes, não diferindo de Bonito, Caracol e Jardim. Ao longo do biomonitoramento observou-se que as estações de verão e outono foram as que apresentaram maiores frequências de micronúcleo independente da cidade avaliada. Observou-se que a correlação entre a frequência de micronúcleos e o fluxo veicular foi baixa, apoiando a tese de que essa microrregião, embora apresente alterações mutagênicas em T. pallida, as alterações numericamente são pequenas quando comparadas a outras regiões do estado de Mato Grosso do Sul. Observou-se uma variação na espessura dos tecidos/estruturas que é variável entre as diferentes cidades e estações do ano. De forma geral os tecidos/estrutura apresentaram redução na espessura para as cidades de Nioaque e Porto Murtinho quanto aos aspectos anatômicos e morfológicos, sendo que, para o comprimento e espessura foliar não foi observado diferenças entre as cidades. Em relação as estações do ano, observou-se que no outono a espessura dos tecidos/estruturas são menores. Diante dos fatores genotóxicos e morfoanatômicos aqui avaliados, a microrregião da Bodoquena parece estar bem preservada em termos de qualidade do ar, apresentando baixa frequência de micronúcleos e redução limitada de tecidos e estruturas foliares, independentemente da estação do ano.

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Introducción: las radiaciones ionizantes (RI) pueden inducir la formación de micronúcleos (MN). La frecuencia de MN se utiliza como biomarcador de daño genético inducido por (RI). Objetivo: evaluar el daño al ADN resultante de la exposición ocupacional a RI en personal de clínicas veterinarias o afines. Metodología: se utilizó el ensayo de micronúcleos con bloqueo de la citocinesis (MNBC) para comparar la frecuencia observada del biomarcador en 40 individuos expuestos ocupacionalmente a RI con respecto a un grupo control de 32 participantes, ambos grupos pertenecen a personal veterinario. Además, se registraron variables demográficas, de estilo de vida y ocupacionales que pudieran influir en la formación de MN. Resultados: el análisis univariado no registró diferencias significativas en la frecuencia de MN entre los grupos de estudio (p=0,118). Mediante análisis multivariado se obtuvo que aproximadamente un 27% (R2 ajustado= 0,269) de la variabilidad de la frecuencia de MN puede explicarse por la influencia conjunta de la edad, el sexo y el número de radiografías realizadas por el individuo. La edad es la variable de mayor importancia relativa (β = 0,504), seguida del sexo del participante (β = -0,316) y el número de radiografías realizadas por día (β = 0,214). Conclusiones: La frecuencia de MN tiende a aumentar en mujeres, a medida que aumenta la edad del participante y a mayor número de radiografías realizadas.

Introduction: Ionizing radiation (RI) can induce the formation of micronuclei (MN). The formation of MN is used as a biomarker of radiation-induced genetic damage. Objective: assess DNA damage resulting from occupational exposure to RI in veterinary personnel. Methodology: the cytokinesis-block micronucleus assay (MNBC) was used to compare the observed frequency of MN in 40 individuals occupationally exposed to ionizing radiation with respect to a control group of 32 participants, both groups belonging to veterinary personnel. In addition, demographic, lifestyle and occupational variables that could influence the formation of MN were recorded. Results: univariate analysis did not show significant differences in the frequency of MN between the study groups (p=0.118). Using multivariate analysis, it was found that approximately 27% (adjusted R2= 0.269) of the variability in the frequency of MN can be explained by the joint influence of age, sex and the number of radiographic images performed by the participant. Age is the variable with the greatest relative importance (β = 0.504), followed by the sex of the participant (β = -0.316) and the number of X-rays performed per day (β = 0.214). Conclusions: the frequency of MN tends to increase in women, as the participant's age increases and as the number of radiographic images performed increases.

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Resumen Introducción: las radiaciones ionizantes (RI) son capaces de perjudicar el ADN; para evaluar este fenómeno es posible utilizar la formación de micronúcleos como biomarcador de efecto temprano del daño radioinducido. El ensayo de micronúcleos con bloqueo de la citocinesis (MNBC) es una técnica citogenética que permite demostrar el impacto de agentes genotóxicos. Propósito: en el presente trabajo se describieron mecanismos moleculares involucrados en la radioinducción de micronúcleos, la técnica del MNBC, los criterios de análisis, sus aplicaciones dentro de la investigación biológica y su extensión a la clínica, con énfasis en su empleo como biomarcador del daño genético en grupos sobreexpuestos a RI. Argumentos para la discusión: el MNBC se considera un método confiable, simple y rápido y existe evidencia de su aplicabilidad para el estudio de los efectos biológicos en casos de riesgo ocupacional y en accidentes radiológicos aislados o a gran escala. Conclusiones: el MNBC es una herramienta valiosa que posibilita estimar las consecuencias por dosis bajas de RI en poblaciones involucradas y, a la vez, orientar la toma de decisiones en cuanto a su prevención o atenuación . De igual forma, puede ser utilizado en análisis del campo de la radiobiología, a fin de detallar las incidencias de las radiaciones ionizantes sobre el ADN.

Abstract Introduction. Ionizing radiation (IR) is capable of causing DNA damage. For the evaluation of this phenomenon it is possible to use chromosomal aberrations as biomarkers. The Cytokinesis-Block Micronucleus assay (CBMN) is a cytogenetic technique that allows to demonstrate the effect of genotoxic agents.Proposition:in the present review, we will describe the molecular mechanisms involved in micronucleus radioinduction, the micronucleus technique and criteria for analysis, its applications within biological research and its extension in clinical research, with emphasis on its application as a biomarker of radioinduced genetic damage. Arguments for discussion: the CBMN is considered a reliable, simple and fast technique and there is evidence of its applicability in the evaluation of biological effects in occupationally exposed personnel and in isolated or large-scale radiological accidents. Conclusions: the CBMN a valuable tool in estimating radiological risk in populations exposed to low doses of IR, allowing to guide decision-making regarding prevention or mitigation of exposure to IR in populations involved. Similarly, the cbmn can be used in research in the field of radiobiology, as a means to describe the effects of ionizing radiation on DNA.

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Introducción: La ranitidina es un fármaco que esta asociado a mutagénesis por generar alteraciones genéticas y/o carcinogenesis celular pero se desconoce su rol a nivel genotóxico en eritrocitos policromáticos. Por tanto, se investigó el efecto de ranitidina sobre el ADN en eritrocitos policromáticos micronucleados (EPC) en ratas albinas (Rattus novergicus, cepa Holtzman) mediante el test de micronúcleos. Materiales y métodos: Se estudiaron cuatro grupos de ratas: control negativo con suero salino fisiológico (0,5 ml por 15 días); control positivo con ciclofosfamida (dosis 50 mg/kg por 2 días) y dos grupos experimentales tratados con ranitidina (dosis 2 y 4 mg/kg por 15 días). Las ratas se sometieron a eutanasia y se obtuvo preparados citológicos con tinción de giemsa 5 % por 30 min. Resultados: Se encontró un aumento del tamaño e incremento significativo del número de micronúcleos en los EPC de 285 ± 10 de los grupos experimentales con una dosis de 4 mg/kg; así mismo, en comparación al control negativo con 70 ± 6. El índice de genotoxicidad fue tres veces mayor en los grupos experimentales (12,10 ± 0.49; 2 mg/kg RNT y 14,26 ± 0,51; 2 mg/kg RNT) en relación al control negativo (3,52 ± 0,32). Conclusiones: La ranitidina genera un estímulo creciente del índice genotóxico con elevada frecuencia de micronúcleos en EPC de R. norvegicus cepa Holtzman.

Background:Ranitidine is a drug that is associated with mutagenesis by generating genetic alterations and / or cell carcinogenesis, but its genotoxicity in polychromatic erythrocytes is unknown. Therefore, the effect of ranitidine on DNA of micronucleated polychromatic erythrocytes (EPC) in albino rats (Rattus norvegicus,Holtzmanstrain)wasresearchedbythemicronucleustest. Materials and methods: Four groups of rats were studied: negative control with physiological saline solution (0.5 ml for 15 days); positive control with cyclophosphamide (dose 50 mg / kg for 2 days) and two experimental groups treated with ranitidine (doses 2 and 4 mg / kg for 15 days). The rats were euthanized and cytological preparations were obtained by 30 min staining in 5% giemsa. An increase in the size and significant increase in the number Results:of micronuclei in the EPC was found in the experimental groups of 285.27 ± 10.25, compared to the negative control of 70.38 ± 6.47. The genotoxicity index was three times higher in the experimental groups (12.10 ± 0.49; 2 mg / kg NRTand 14.26 ± 0.51; 2 mg / kg NRT) in relation to the negative control (3.52 ± 0 , 32). Ranitidine generates an increasing stimulus of the genotoxic Conclusions:index with a high frequency of micronuclei in EPC of R. norvegicusstrain Holtzman

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RESUMEN Objetivos. Determinar el efecto genotóxico de la tartrazina en linfocitos de sangre periférica de Mus musculus BALB/c. Materiales y métodos. Se realizó un estudio experimental, a través de cinco grupos, con cinco ratones en cada uno. Se les registró el peso durante 17 semanas y, en la semana 15 se les administró suero fisiológico (control negativo), dicromato de potasio 25 mg/kg de peso corporal (pc) (control positivo) y tartrazina a dosis de 0,75 mg/kg pc, 7,5 mg/kg pc y 75 mg/kg pc, durante siete días, a excepción del control positivo que fue en dosis única. Luego, cada 24 h se obtuvo una muestra de sangre periférica de la cola y se realizó el frotis, secado y coloración. Posteriormente, se realizó el conteo de 1000 linfocitos por muestra de cada ratón, en todos los tratamientos. Resultados. Los tres tratamientos con tartrazina no causaron diferencias significativas en el peso de ratones a la semana 15, pero sí produjeron diferencias significativas en la frecuencia de linfocitos micronucleados, siendo el tratamiento con tartrazina de 75 mg/kg pc el de mayor efecto genotóxico, induciendo un promedio de 1,63 ± 0,08 linfocitos micronucleados, comparado con el control positivo que generó un promedio de 1,42 ± 0,08 linfocitos micronucleados. Conclusiones. La tartrazina produjo un efecto genotóxico, incrementando el número de linfocitos micronucleados, a dosis de 0,75; 7,5 y 75 mg/kg pc y no afecta el peso corporal durante siete días de administración en M. musculus BALB/c.

ABSTRACT Objectives. To determine the genotoxic effect of tartrazine on peripheral blood lymphocytes of BALB/c Mus musculus. Materials and methods. An experimental study was carried out using five groups, with five mice in each group. Their weight was registered for 17 weeks, and at week 15 they were administered physiological saline solution (negative control), potassium dichromate at 25 mg/kg body weight (bw) (positive control) and tartrazine at doses of 0.75 mg/kg bw, 7.5 mg/kg bw and 75 mg/kg bw, for seven days, with the exception of the positive control which was a single dose. Then, every 24 hours, a peripheral blood sample was obtained from the tail, which was then smeared, dried and stained. Subsequently, 1000 lymphocytes were counted for each sample from each mouse, for all treatment groups. Results. The three tartrazine treatments did not cause significant differences in the weight of mice at week 15, but did produce significant differences in the frequency of micronucleated lymphocytes, with the 75 mg/kg bw tartrazine treatment having the greatest genotoxic effect, inducing an average of 1.63 ± 0.08 micronucleated lymphocytes, compared to the positive control which obtained an average of 1.42 ± 0.08 micronucleated lymphocytes. Conclusions. Tartrazine produced a genotoxic effect, increasing the number of micronucleated lymphocytes, at doses of 0.75; 7.5 and 75 mg/kg bw and did not affect body weight during seven days of administration to BALB/c M. musculus.

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Las maloclusiones representan un problema de salud bucodental, que se resuelven mediante la colocación de aparatología ortodóncica fija (AOF). Esta aparatología provoca corrosión y liberación de iones metálicos por las aleaciones que la constituyen y por el tiempo prolongado del tratamiento. El objetivo de este trabajo fue analizar las alteraciones citotóxicas y genotóxicas de las células de la mucosa oral provocadas por el uso de AOF, reportadas en la literatura y evaluadas con ensayo de micronúcleos (MN); el cual es uno de los ensayos más utilizados para identificar el daño al ácido desoxirribonucleico (ADN). Se realizó una revisión de la literatura de los últimos 10 años, donde se incluye- ron nueve estudios, el 55% de estos mostró evidencia de daño citotóxico y genotóxico posterior a la terapia ortodóncica. El promedio de incremento de MN debido al uso de AOF en estos estudios, fue tres veces mayor con respecto a las células bucales sin trata- miento, este dato es similar a reportes de células orales precancerosas investigadas por otros autores. Además los artículos evaluados, reportaron alteración celular a partir de la primera semana de la colocación de los dispositivos y señalaron que hay una disminu- ción del daño con el tiempo de exposición. En conclusión, el ensayo de MN utilizado en la cavidad bucal demostró ser útil para detectar alteraciones en el ADN debido al uso de AOF. Los datos analizados permiten a los ortodoncistas implementar mejoras en la terapéutica ortodóncica.

Malocclusions represent an oral health problem, which is resolved by the placement of fixed orthodontic appliances (FOA). This orthodontic appliance causes corrosion and release of metal ions due to the alloys they constitute and due to the prolonged time of treatment. The objective of this work was to analyze the cytotoxic and genotoxic altera- tions from oral mucosa cells, caused by the use of FOA, reported in the literature and evaluated with micronucleus (MN) test, which is one of the most widely used tests to identify damage to deoxyribonucleic acid (DNA). A review of the literature of the last 10 years was carried out, where nine studies were included, 55% of these studies showed evidence of cytotoxic and genotoxic damage after orthodontic therapy. The increased average in MN due to the use of FOA in these studies, represent values of approximately three-fold more respect to oral cells without treatment, this data is similar to reports of precancerous oral cells that have been reported by other authors. Besides, the articles analyzed reported cell alterations after the first week of the devices placement and indica- ted a decrease in damage with exposure time. In conclusion, the MN test used in the oral cavity was useful in detecting DNA alterations due to the use of FOA. The data analyzed allow orthodontists to implement improvements in orthodontic therapy.

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Abstract This research aimed to conduct a systematic review and metanalysis to compare the frequency of cell damage in crack users and nonusers, through Micronucleous (MN) test in buccal mucosa cells. A comprehensive search was carried out on MEDLINE via PubMeb, Web of Science, LILACS and the grey literature without restrictions. It was included case-control studies that report the frequency of micronuclei in the oral mucosa of adult crack users and nonusers. A review protocol was registered with PROSPERO (CRD42018115672), and conducted in accordance with the PRISMA guidelines for the report of this systematic review. Furthermore, study quality was evaluated using an adapted Newcastle-Ottawa Scale for cross-sectional studies.The original search yielded 27 references, after eligibility criteriaonly five articles were included. The number of micronuclei was higher in crack users compared to nonusers. Also, secondary outcomes: binucleated cells, nuclear buds, pyknosis, karyorrhexis and karyolysis had higher prevalence in crack users.Crack use is associated with genotoxic and mutagenic effects because there is a higher frequency of micronuclei in exfoliated cells of crack users. In addition, MN test proved to be a goodbiomarker to assess the mutagenic impact of crack use in oral epithelium.

Resumen Esta investigación tuvo como objetivo realizar una revisión sistemática y un meta-análisis para comparar la frecuencia de daño celular en usuarios de crack y sin crack, a través de la prueba de micronúcleos (MN) en células de la mucosa bucal. Se realizó una búsqueda exhaustiva en MEDLINE a través de PubMeb, Web of Science, LILACS y la literatura gris sin restricciones. Se incluyeron estudios de casos y controles que informaron la frecuencia de micronúcleos en la mucosa oral de usuarios adultos de crack y sin crack. Se registró un protocolo de revisión con PROSPERO (CRD42018115672), y se realizó de acuerdo con las pautas de PRISMA para el informe de esta revisión sistemática. Además, la calidad del estudio se evaluó mediante una escala Newcastle-Ottawa adaptada para estudios transversales. La búsqueda original arrojó 27 referencias, después de los criterios de elegibilidad se incluyeron un total de cinco artículos. El número de micronúcleos fue mayor en los usuarios de crack en compa ración con los usuarios sin crack. Además, los resultados secundarios de células binucleadas, yemas nucleares, picnosis, cario- rrexis y cariólisis tuvieron una mayor prevalencia en los usuarios de crack. El uso de crack se asocia con efectos genotóxicos y mutagénicos porque hay una mayor frecuencia de micronúcleos en las células exfoliadas de los usuarios de crack. Además, la prueba de MN demostró ser un buen biomarcador para evaluar el impacto mutagénico del uso de crack en el epitelio oral.

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El test de micronúcleos (MN) es un biomarcador de genotoxicidad no destructivo que permite detectar daño cromosómico y otras alteraciones nucleares (AN). Phrynops hilarii es un quelonio de agua dulce que habita regiones del centro-norte de Argentina. El objetivo principal fue determinar la presencia de MN y otras AN en eritrocitos de poblaciones naturales de P. hilarii comparando sus frecuencias entre tres sitios, dos antropizados y uno de control (ciudades de Diamante y Paraná) de Entre Ríos, Argentina, durante el periodo 2015-2016. Dieciocho individuos (seis por sitio de muestreo) fueron evaluados en los sitios: 1- PD: Parque Nacional Pre-Delta (control), 2- AG: Salto Ander Egg (agroecosistema) y 3- SU: Caleta Club Náutico (sistema urbano). Se extrajo sangre de la vena femoral. Las muestras se tiñeron con el método May Grünwald-Giemsa y se observaron bajo un microscopio con el objetivo de inmersión. Las frecuencias de micronúcleos (FMN) y alteraciones nucleares (FAN) se determinaron cada 1000 eritrocitos observados. Se encontró diferencia significativa (p<0,05) entre el sitio PD y los otros sitios (AG y SU), tanto para FMN (p=0,0021) como para FAN (p=0,0011). Los valores de las frecuencias más altos correspondieron al sitio AG (FMN: 3,33±0,62; FAN: 4,67±0,56). Finalmente, el biomonitoreo con P. hilarii fue útil, por lo que podría considerarse como especie bioindicadora para evaluar la calidad de los ambientes de Argentina.

The micronucleus test (MN) is a biomarker of non-destructive genotoxicity that allows chromosomal damage and other nuclear alterations (NA) to be detected. Phrynops hilarii is a freshwater chelonium that inhabits regions of central-northern Argentina. The main objective was to determine the presence of MN and other NA in erythrocytes of natural populations of P. hilarii comparing their frequencies between three sites, two anthropized and one of control (cities of Diamante and Paraná) of Entre Ríos, Argentina, during the period 2015-2016. Eighteen individuals (six per sampling site) were evaluated at the sites: 1- PD: Pre-Delta National Park (control), 2- AG: Salto Ander Egg (agroecosystem) and 3- SU: Caleta Club Náutico (urban system). Blood was obtained from the femoral vein. The samples were stained with the May Grünwald-Giemsa method and observed under a microscope with an immersion objective. Micronucleus (MNF) and nuclear alterations (NAF) frequencies were determined every 1000 erythrocytes observed. A significant difference (p<0.05) was found between the PD site and the other sites (AG and SU), both for MNF (p=0.0021) and for NAF (p=0.0011). The highest frequency values corresponded to the AG site (MNF: 3.33 ± 0.62; NAF: 4.67 ± 0.56). Finally, biomonitoring with P. hilarii was useful, so it could be considered as a bioindicator species to assess the quality of Argentina's environments.

RESUMO

Os herbicidas estão entre os insumos químicos mais utilizados na agricultura e apresentam ação toxicológica para as plantas. Dentre os herbicidas existentes, o glifosato e a sua formulação comercial Roundup® são os mais utilizados devido à eficácia no controle de ervas daninhas. Entretanto, estudos sugerem que estes herbicidas podem provocar distúrbios a organismos aquáticos, principalmente o Roundup®, que além do glifosato ativo, apresenta na composição componentes surfactantes que aumentariam o seu potencial toxicológico para os seres vivos. Desta forma, o presente estudo teve como objetivo comparar o potencial mutagênico e desenvolvimento gonadal do princípio ativo glifosato e sua formulação Roundup® em peixes Danio rerio. Para isso, exemplares adultos de D. rerio permaneceram em aquários expostos à concentração de 65 µg/L de cada herbicida. Foram realizadas contagens de micronúcleos, calculado o índice gonadossomático (IGS) e verificado os estágios de maturação gonadal. Os resultados demonstraram que os peixes expostos aos herbicidas apresentaram aumentos significativos na frequência de micronúcleos, bem como no IGS, e maior ocorrência de ovários com estágios em maturação e maduros. Não foram verificadas diferenças significativas na comparação dos herbicidas, exceto um aumento na frequência de ovários maduros nas fêmeas expostas ao glifosato. Observou-se que, mesmo em pequenas concentrações, os herbicidas poderiam ter ocasionado efeitos nocivos para os peixes D. rerio, podendo induzir efeitos clastogênicos nos eritrócitos, assim como distúrbios reprodutivos, aumentando a preocupação sobre os impactos que estes herbicidas podem acarretar sobre o ciclo de vida destes organismos.(AU)

The herbicides are among the most used chemical inputs in the agriculture and present a great toxicological action for the plants. Among the existing herbicides, glyphosate and its commercial formulation Roundup® are the most used due to their effectiveness in control of weeds. However, studies suggest that these herbicides can cause disturbances to aquatic organisms, mainly the Roundup®, that besides active glyphosate, it presents in the composition components surfactants that would increase its toxicological potential for the alive beings. Therefore, the aim of this study is to compare the mutagenic potential and gonadal development of the active principle glyphosate and its formulation Roundup® in fish Danio rerio. Thus, adult copies of D. rerio stayed in aquariums exposed to a concentration of 65 µg / L of each herbicide. Micronucleus counts were performed and the Gonadossomatic index (GSI) was calculated and the stages of gonadal maturation were verified. The results demonstrated that the fish exposed to the herbicides, presented significant increases in the micronucleus frequency, as well as in GSI and larger occurrence of ovaries with stages in maturation and mature. There were no significant differences in herbicide comparison, except an increase in the frequency of mature ovaries in the exposed females to glyphosate. It was observed that even in small concentrations, the herbicides could presented harmful effects for the fish D. rerio, could have caused clastogenic effects in the erythrocytes, as well as, reproductive disturbances, increasing the concern about the impacts that these herbicides can have on the life cycle of these organisms.(AU)

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