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Previous issue date: 2015-03-19 / Agrochemicals are water contaminants, resulting from anthropogenic activities, having as main
objective the elimination of some form of life and, therefore, being harmful even to non-target species.
It is utmost importance the standardization and the use of bioindicators, especially of native
organisms, besides the development of toxicity tests or bioassays to assess the impacts of the agroindustrial
activities. Thus, it was sought to identify possible biochemical changes, to evaluate the
oxidative balance and the survival of individuals of catfish Rhamdia quelen, in two aged groups, facing
acute toxicity tests with different concentrations of Roundup? (glyphosate: 18, 36, 72 and 144?g/L),
Primoleo? (atrazine: 2.5, 5, 10 and 15?g/L) and Facet? (quinclorac: 1.75, 3.5, 7 and 14?g/L). The
procedures were performed with fingerlings (individuals with total length between 6 and 8 cm) and
sexually newly matured individuals, called young-adult (with total length of more than 18 cm). All the
animals were purchased from a farm and were kept for 7 days in a period called Acclimatization. After,
agrochemicals were applied individually, at concentrations similar to those reported for the natural
environment and allowed by law in our country. After 7 days of exposuring to the agrochemical, the
animals were euthanized by cervical spinal cord section and the gill, liver, kidney and muscle tissues
were separated and frozen at -20?C. In fingerlings, pools were performed, grouping the tissue from
three individuals, due to their low weight; the tissues from young-adult were analyzed individually. It
was estimated the effect of this agrochemicals on intermidiate metabolism, by determining the
glycogen levels, total proteins, total lipids and triacylglycerols, on the two length ranges. It was also
evaluated the effect of this agrochemicals on the oxidative status determining the activity of
superoxide dismutase (SOD) and catalase (CAT), and levels of lipid peroxidation (TBARS) in all the
tissues from the animals on the two length ranges. The experimental procedures and the biochemical
readings were performed in triplicate. It was also observed the effect of this agrochemicals on the
survival of the individuals in experimental culture conditions, in both aged groups, searching for
confirmation of sublethallity of determined concentrations for testing. The results are organized into
three articles. The first is entitled Metabolic parameters and oxidative balance Rhamdia quelen
changed after exposure to herbicides of rice crops (Roundup?, Primoleo? and Facet?), for submission
to the journal Archives of Environmental Contamination and Toxicology, which presents the results
obtained for the metabolism and the oxidative balance of fingerlings, which seem to have been able to
modulate their enzymes as not to suffer oxidative damage front to Roundup? herbicide (by increasing
CAT) and Primoleo? (without changes in SOD and CAT). The Facet? led to the increase of lipid
peroxidation, especially in the gill, kidney and muscle tissues, despite the higher SOD, prejudicing the
species significantly. The biochemical composition tissue of juveniles of R. quelen changed
significantly, which may cause damages, mainly in the gill tissue, leading to a loss of homeostasis and
it may result the death of the animals and/or the decrease of the reproductive success, when
chronically exposed to these substances and concentrations. The second article entitled Metabolic
changes in silver catfish exposed to herbicide of rice crop Roundup?, Primoleo? and Facet?, is
concerned to the young-adult metabolism, for submission to the journal Environmental Pollution.
There were changes in the metabolic profile of all sampled tissues, showing a differentiated tissue
responsiveness, being the gills and the kidneys the most affected organs by the exposure to
agrochemicals. The herbicide Facet? changed the gill tissue significantly, and it was suggested that
the relevant Brazilian agencies regulate its use in protective standards for the environment. Finally, the
third manuscript Article Oxidative status and lipid peroxidation determined by the exposure to
agrochemicals Roundup?, Primoleo? and Facet? in Rhamdia quelen approaches the oxidative stress
suffered by young-adults to be submitted to the journal Ecotoxicology and Environmental Safety. In
this work the liver and kidney tissues were the most affected, and it can be infered that the Facet?
(quinclorac) was the most toxic herbicide to the sexually newly matured individuals, followed by
Primoleo? (atrazine) and after by Roundup? (glyphosate). One can suggest, from this set of results, a
review of the current legislation in our country, to include products with the quinclorac active principle
into the toxic list to be controlled in the natural environment. / Os agroqu?micos s?o contaminantes aqu?ticos decorrentes das atividades antropog?nicas, tendo
como principal objetivo a elimina??o de alguma forma de vida, sendo, portanto, lesivos inclusive ?
esp?cies n?o-alvo. ? de extrema import?ncia a padroniza??o e a utiliza??o de esp?cies
bioindicadoras, em especial de organismos aut?ctones, al?m do desenvolvimento de testes de
toxicidade ou bioensaios para avalia??o dos impactos decorrentes das atividades agroindustriais.
Assim, buscou-se verificar poss?veis altera??es bioqu?micas, avaliar o balan?o oxidativo e a
sobreviv?ncia de indiv?duos do jundi? Rhamdia quelen, em duas faixas et?rias, frente a testes de
toxicidade aguda com diferentes concentra??es de Roundup? (glifosato: 18, 36, 72 e 144?g/L),
Primoleo? (atrazina: 2,5, 5, 10 e 15?g/L) e Facet? (quinclorac: 1,75, 3,5, 7 e 14?g/L). Foram
realizados os procedimentos com alevinos (indiv?duos com comprimento total entre 6 e 8 cm) e
indiv?duos rec?m-maturados sexualmente, chamados alevin?es (com comprimento total superior a 18
cm). Todos os animais foram comprados de uma piscicultura e permaneceram por 7 dias em um
per?odo denominado Aclimata??o. Ap?s, os agroqu?micos foram aplicados individualmente, em
concentra??es semelhantes ?s relatadas para o ambiente natural e permitido pela legisla??o vigente
em nosso pa?s. Ap?s 7 dias de exposi??o ao agroqu?mico, os animais foram eutanasiados por sec??o
de medula cervical, e foram separados os tecidos branquial, hep?tico, renal e muscular, sendo
congelados a -20?C. Nos alevinos, foram realizados agrupamentos dos tecidos de tr?s indiv?duos,
devido seu baixo peso; os tecidos dos alevin?es foram analisados individualmente. Estimou-se o
efeito destes agroqu?micos sobre o metabolismo intermedi?rio, atrav?s da determina??o dos n?veis de
glicog?nio, prote?nas totais, lip?deos totais e triacilglicer?is, nas duas faixas de comprimento. Avaliouse
tamb?m o efeito destes agroqu?micos sobre o status oxidativo determinando a atividade das
enzimas super?xido dismutase (SOD) e catalase (CAT), al?m dos n?veis de lipoperoxida??o (TBARS)
nos quatro tecidos dos animais, das duas faixas de comprimento. Os procedimentos experimentais e
as leituras biqu?micas foram realizados em triplicata. Ainda observou-se o efeito destes sobre a
sobreviv?ncia dos indiv?duos em condi??es de cultivo experimental, nas duas faixas et?rias,
buscando a confirma??o da subletalidade das concentra??es determinadas para os testes. Os
resultados est?o organizados em tr?s artigos, sendo o primeiro intitulado Par?metros metab?licos e
balan?o oxidativo de Rhamdia quelen alterado frente ? exposi??o a herbicidas de lavoura de arroz
(Roundup?, Primoleo? e Facet?), para a submiss?o ? Revista Archives of Environmental
Contamination and Toxicology, onde s?o apresentados os resultados obtidos para o metabolismo e o
balan?o oxidativo dos alevinos, que parecem ter conseguido modular suas enzimas a ponto de n?o
sofrerem dano oxidativo frente aos herbicidas Roundup? (pelo aumento da CAT) e Primoleo? (sem
altera??es nas enzimas SOD e CAT). O Facet? provocou o aumento da lipoperoxida??o,
principalmente nos tecidos branquial, renal e muscular, apesar da eleva??o da SOD, agredindo
significativamente a esp?cie. A composi??o bioqu?mica tecidual dos juvenis de R. quelen sofreu
altera??es significativas, podendo acarretar a danos principalmente no tecido branquial, conduzindo ?
perda da homeostase e podendo acarretar na morte dos animais e/ou a diminui??o do sucesso
reprodutivo, quando expostos cronicamente a estas subst?ncias e nestas concentra??es. O 2? artigo,
intitulado Altera??es metab?licas em jundi?s expostos aos herbicidas de lavoura de arroz Roundup?,
Primoleo? e Facet?, versa sobre o metabolismo de alevin?es, para submiss?o ? Revista
Environmental Pollution. Houve altera??es no perfil metab?lico de todos os tecidos amostrados,
evidenciando uma responsividade tecidual diferenciada, sendo as br?nquias e os rins os ?rg?os mais
afetados com a exposi??o aos agroqu?micos. O herbicida Facet? alterou significativamente o tecido
branquial, sendo sugerido que os ?rg?os brasileiros competentes regulamentem o seu uso em
normas protetivas ao meio ambiente. Por fim, o manuscrito do artigo Status oxidativo e
lipoperoxida??o determinados pela exposi??o aos agroqu?micos Roundup?, Primoleo? e Facet? em
Rhamdia quelen, aborda o estresse oxidativo sofrido pelos alevin?es, a ser submetido ? Revista
Ecotoxicology and Environmental Safety. Neste trabalho os tecidos hep?tico e renal foram os mais
afetados, e podemos inferir que o Facet? (quinclorac) foi o agroqu?mico mais t?xico aos indiv?duos
rec?m-maturados sexualmente, seguido do Primoleo? (atrazina) e ap?s o Roundup? (glifosato). Podese,
a partir deste conjunto de resultados, sugerir uma revis?o na legisla??o vigente em nosso pa?s, a
fim de incluir produtos com o princ?pio ativo quinclorac na lista de t?xicos a serem controlados no
ambiente natural.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/6048 |
| Date | 19 March 2015 |
| Creators | Persch, Tanilene Sotero Pinto |
| Contributors | Oliveira, Guendalina Turcato |
| Publisher | Pontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Zoologia, PUCRS, Brasil, Faculdade de Bioci?ncias |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 2008925231902741151, 600, 600, 600, 36528317262667714, -6482652380601267558 |
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