Alterações nucleares eritrocitárias como resposta genotóxica em peixes do Sistema Estuarino do Rio Paciência (SERP), Maranhão
Data
2024-09-02
Autores
Rao, Marcela Luglio 
Orientadores
Azevedo, Juliana de Souza
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Os micronúcleos e outras alterações nucleares eritrocitárias (ANEs) são biomarcadores genotóxicos, que fornecem informações quanto aos efeitos de poluentes em organismos aquáticos. Os micronúcleos, em específico, tem sua formação diretamente associada a falhas na divisão cromossômica do eritrócito, provocada pela ação de agentes tóxicos presentes no meio. O Sistema Estuarino do Rio Paciência (SERP) se destaca de outros estuários do litoral maranhense, em virtude da sua alta produtividade biológica, sendo um ambiente aberto, dominado por processos físicos, químicos e biológicos associados ao hidrodinamismo associado às macromarés. Em razão da escassez de dados sobre os efeitos genotóxicos em espécies de peixes do SERP, este estudo busca verificar a presença de efeitos toxicogenéticos em cinco espécies de bagres do SERP (Arius proops, Arius rugispinis, Aspistor quadriscutis, Bagre bagre e Cathorops spixii), considerando as diferenças espaciais e entre as espécies. A partir da análise de esfregaços sanguíneos de 74 peixes coletados em maio de 2022 em dois setores do SERP (Dunas: mais salino; Ilha Sarney: maior contribuição do rio Paciência), foi possível identificar e quantificar, nas cinco espécies, ANEs como micronúcleos, notched, lobeb, blebbed, vacuolizated, double bubbled e dacriócitos. A. proops foi a espécie em que se observou a maior frequência de micronúcleos (0-8,7‰). Para as demais ANEs, as maiores frequências foram observadas em B. bagre (notched: 1,5-5,8‰; lobed: 0,7-17,3‰; e blebbed: 0-4,6‰). No contexto espacial, C. spixii e A. quadriscutis apresentaram as maiores frequências de micronúcleos, ambos com valor variando de 0 a 1,5‰. Considerando o ponto Dunas, a espécie que apresentou a maior frequência de ANEs foi A. rugispinis (notched: 0,9-7,6‰; lobed: 0-10,4‰; dacriócitos: 8,1-38,3‰), seguida por B. bagre (notched: 1,5-5,8‰; lobed: 0,7-17,3‰; blebbed: 0-4,6‰; dacriócitos: 0-31‰). Em relação aos peixes coletados no ponto Ilha Sarney, A. proops apresentou maior frequência de ANEs (notched: 1,4-5,9‰; lobed: 5,4-8,1‰; blebbed: 0-2,4‰; double bubbled: 0-0,5; dacriócitos: 2,4-21,5‰). A presença de MN em todas as cinco espécies de bagres evidencia a presença de agentes tóxicos clastogênicos e/ou aneugênicos nas águas do SERP. A alta frequência observada de dacriócitos, que surgem em casos de hipotermia, anemia e hipóxia nos animais, sugere condições metabólicas alteradas dos animais, o que reforça que as águas do SERP apresentam poluentes toxicogenéticos, principalmente na região das Dunas, local em que há maior presença humana.
Micronuclei and other nuclear abnormalities in erythrocytes (NAEs) are genotoxic biomarkers that provide information on the effects of pollutants on aquatic organisms. Micronuclei are directly associated with failures in the chromosomal division of the erythrocyte, caused by the action of toxic agents present in the environment. The Paciência River Estuarine System (PRES) stands out from other estuaries on the coast of Maranhão due to its high biological productivity, as it is an open environment dominated by physical, chemical and biological processes associated with the hydrodynamics of the macrotidal tides. Due to the scarcity of data on genotoxic effects in fish species in the SERP, the goal of this study to verify the presence of toxicogenetic effects in five species of catfish in the SERP (Arius proops, Arius rugispinis, Aspistor quadriscutis, Bagre bagre and Cathorops spixii), considering spatial differences and differences between species. From the analysis of blood smears from 74 fish collected in May 2022 in two areas of the PRES (Dunas: more saline; Ilha Sarney: greater contribution from the Paciência River), it was possible to identify and quantify, in the five species, NAEs such as micronuclei, notched, lobbed, blebbed, vacuolized, double bubbled and dacryocytes. A. proops was the species with the highest frequency of micronuclei (0-8.7‰). For the other NAEs, the highest frequencies were observed in B. bagre (notched: 1.5-5.8‰; lobed: 0.7-17.3‰; and blebbed: 0-4.6‰). In the spatial context, C. spixii and A. quadriscutis showed the highest frequencies of micronuclei, both with values ranging from 0 to 1.5‰. Considering the Dunas site, the species with the highest frequency of NAEs was A. rugispinis (notched: 0.9-7.6‰; lobed: 0-10.4‰; dacryocytes: 8.1-38.3‰), followed by B. bagre (notched: 1.5-5.8‰; lobed: 0.7-17.3‰; blebbed: 0-4.6‰; dacryocytes: 0-31‰). In relation to the fish sampled at Ilha Sarney, A. proops showed a higher frequency of NAEs (notched: 1.4-5.9‰; lobed: 5.4-8.1‰; blebbed: 0-2.4‰; double bubbled: 0-0.5; dacryocytes: 2.4-21.5‰). The presence of micronuclei in all five catfish species shows the presence of clastogenic and/or aneugenic toxic agents in the waters of the PRES. The high frequency of dacryocytes, which appear in cases of hypothermia, anemia and hypoxia in the animals, suggests altered metabolic conditions in the animals, which suggests that the waters of the PRES have toxicogenic pollutants, especially in the Dunes region, where there is a greater human presence.
Micronuclei and other nuclear abnormalities in erythrocytes (NAEs) are genotoxic biomarkers that provide information on the effects of pollutants on aquatic organisms. Micronuclei are directly associated with failures in the chromosomal division of the erythrocyte, caused by the action of toxic agents present in the environment. The Paciência River Estuarine System (PRES) stands out from other estuaries on the coast of Maranhão due to its high biological productivity, as it is an open environment dominated by physical, chemical and biological processes associated with the hydrodynamics of the macrotidal tides. Due to the scarcity of data on genotoxic effects in fish species in the SERP, the goal of this study to verify the presence of toxicogenetic effects in five species of catfish in the SERP (Arius proops, Arius rugispinis, Aspistor quadriscutis, Bagre bagre and Cathorops spixii), considering spatial differences and differences between species. From the analysis of blood smears from 74 fish collected in May 2022 in two areas of the PRES (Dunas: more saline; Ilha Sarney: greater contribution from the Paciência River), it was possible to identify and quantify, in the five species, NAEs such as micronuclei, notched, lobbed, blebbed, vacuolized, double bubbled and dacryocytes. A. proops was the species with the highest frequency of micronuclei (0-8.7‰). For the other NAEs, the highest frequencies were observed in B. bagre (notched: 1.5-5.8‰; lobed: 0.7-17.3‰; and blebbed: 0-4.6‰). In the spatial context, C. spixii and A. quadriscutis showed the highest frequencies of micronuclei, both with values ranging from 0 to 1.5‰. Considering the Dunas site, the species with the highest frequency of NAEs was A. rugispinis (notched: 0.9-7.6‰; lobed: 0-10.4‰; dacryocytes: 8.1-38.3‰), followed by B. bagre (notched: 1.5-5.8‰; lobed: 0.7-17.3‰; blebbed: 0-4.6‰; dacryocytes: 0-31‰). In relation to the fish sampled at Ilha Sarney, A. proops showed a higher frequency of NAEs (notched: 1.4-5.9‰; lobed: 5.4-8.1‰; blebbed: 0-2.4‰; double bubbled: 0-0.5; dacryocytes: 2.4-21.5‰). The presence of micronuclei in all five catfish species shows the presence of clastogenic and/or aneugenic toxic agents in the waters of the PRES. The high frequency of dacryocytes, which appear in cases of hypothermia, anemia and hypoxia in the animals, suggests altered metabolic conditions in the animals, which suggests that the waters of the PRES have toxicogenic pollutants, especially in the Dunes region, where there is a greater human presence.