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Craig R. White - One of the best experts on this subject based on the ideXlab platform.
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the effect of ambient oxygen on the thermal performance of a cockroach Nauphoeta cinerea
The Journal of Experimental Biology, 2020Co-Authors: Emily J Lombardi, Candice L Bywater, Craig R. WhiteAbstract:ABSTRACT The oxygen and capacity-limited thermal tolerance (OCLTT) hypothesis proposes that the thermal tolerance of an animal is shaped by its capacity to deliver oxygen in relation to oxygen demand. Studies testing this hypothesis have largely focused on measuring short-term performance responses in animals under acute exposure to critical thermal maximums. The OCLTT hypothesis, however, emphasises the importance of sustained animal performance over acute tolerance. The present study tested the effect of chronic hypoxia and hyperoxia during development on moderate to long-term performance indicators at temperatures spanning the optimal temperature for growth in the speckled cockroach, Nauphoeta cinerea. In contrast to the predictions of the OCLTT hypothesis, development under hypoxia did not significantly reduce growth rate or running performance, and development under hyperoxia did not significantly increase growth rate or running performance. The effects of developmental temperature and oxygen on tracheal morphology and metabolic rate were also not consistent with OCLTT predictions, suggesting that oxygen delivery capacity is not the primary driver shaping thermal tolerance in this species. Collectively, these findings suggest that the OCLTT hypothesis does not explain moderate to long-term thermal performance in N.cinerea, which raises further questions about the generality of the hypothesis.
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Oxygen-induced plasticity in tracheal morphology and discontinuous gas exchange cycles in cockroaches Nauphoeta cinerea
Journal of Comparative Physiology B, 2014Co-Authors: Hamish Bartrim, Philip G D Matthews, Sussan Lemon, Craig R. WhiteAbstract:The function and mechanism underlying discontinuous gas exchange in terrestrial arthropods continues to be debated. Three adaptive hypotheses have been proposed to explain the evolutionary origin or maintenance of discontinuous gas exchange cycles (DGCs), which may have evolved to reduce respiratory water loss, facilitate gas exchange in high CO_2 and low O_2 micro-environments, or to ameliorate potential damage as a result of oversupply of O_2. None of these hypotheses have unequivocal support, and several non-adaptive hypotheses have also been proposed. In the present study, we reared cockroaches Nauphoeta cinerea in selected levels of O_2 throughout development, and examined how this affected growth rate, tracheal morphology and patterns of gas exchange. O_2 level in the rearing environment caused significant changes in tracheal morphology and the exhibition of DGCs, but the direction of these effects was inconsistent with all three adaptive hypotheses: water loss was not associated with DGC length, cockroaches grew fastest in hyperoxia, and DGCs exhibited by cockroaches reared in normoxia were shorter than those exhibited by cockroaches reared in hypoxia or hyperoxia.
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discontinuous gas exchange exhibition is a heritable trait in speckled cockroaches Nauphoeta cinerea
Journal of Evolutionary Biology, 2013Co-Authors: Natalie G Schimpf, Philip G D Matthews, Craig R. WhiteAbstract:The function and mechanism underlying discontinuous gas exchange in terrestrial arthropods continues to be debated. Three adaptive hypotheses have been proposed to explain the evolutionary origin or maintenance of discontinuous gas exchange cycles (DGCs), which may have evolved to reduce respiratory water loss, facilitate gas exchange in high CO2 and low O2 micro-environments, or to ameliorate potential damage as a result of oversupply of O2. None of these hypotheses have unequivocal support, and several non-adaptive hypotheses have also been proposed. In the present study, we reared cockroaches Nauphoeta cinerea in selected levels of O2 throughout development, and examined how this affected growth rate, tracheal morphology and patterns of gas exchange. O2 level in the rearing environment caused significant changes in tracheal morphology and the exhibition of DGCs, but the direction of these effects was inconsistent with all three adaptive hypotheses: water loss was not associated with DGC length, cockroaches grew fastest in hyperoxia, and DGCs exhibited by cockroaches reared in normoxia were shorter than those exhibited by cockroaches reared in hypoxia or hyperoxia.
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Discontinuous gas exchange exhibition is a heritable trait in speckled cockroaches Nauphoeta cinerea.
Journal of evolutionary biology, 2013Co-Authors: Natalie G Schimpf, Philip G D Matthews, Craig R. WhiteAbstract:The regulation of insect respiratory gas exchange has long been an area of interest. In particular, the reason why insects from at least five orders exhibit patterns of gas exchange that include regular periods of spiracular closure has been the source of much controversy. Three adaptive hypotheses propose that these discontinuous gas-exchange cycles (DGCs) evolved to either limit water loss across respiratory surfaces, facilitate gas exchange in underground environments or to limit oxidative damage. It is possible that DGCs evolved independently multiple times and for different reasons, but for DGCs to be a plausible target for natural selection, they must be heritable and confer a fitness benefit. In a previous study of cockroaches Nauphoeta cinerea, we demonstrated that DGCs are repeatable and extend survival under food and water restriction. Here, we show for the first time that DGCs are heritable, suggesting that they are a plausible target for natural selection.
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standard metabolic rate is associated with gestation duration but not clutch size in speckled cockroaches Nauphoeta cinerea
Biology Open, 2012Co-Authors: Natalie G Schimpf, Philip G D Matthews, Craig R. WhiteAbstract:Metabolic rate varies significantly between individuals, and these differences persist even when the wide range of biotic and abiotic factors that influence metabolism are accounted for. It is important to understand the life history implications of variation in metabolic rate, but they remain poorly characterised despite a growing body of work examining relationships between metabolism and a range of traits. In the present study we used laboratory-bred families (one sire to three dams) of Nauphoeta cinerea (Olivier) (speckled cockroaches) to examine the relationship between standard metabolic rate (SMR) and reproductive performance (number of offspring and gestation duration). We show that SMR is negatively associated with female gestation duration. Age at mating is negatively associated with gestation duration for females, and mass is negatively associated with the average gestation duration of the females a male was mated with. In addition to the results in the current literature, the results from the present study suggest that the association between metabolism and life history is more complex than simple relationships between metabolism and various fitness traits. Future work should consider longitudinal, ontogenetic as well as selective and quantitative genetic breeding approaches to fully examine the associations between metabolism and fitness.
Remy Brossut - One of the best experts on this subject based on the ideXlab platform.
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changes of species specific cuticular hydrocarbon profiles in the cockroaches Nauphoeta cinerea and leucophaea maderae reared in heterospecific groups
Entomologia Experimentalis Et Applicata, 1997Co-Authors: Cl Everaerts, Jeanpierre Farine, Remy BrossutAbstract:The cuticular hydrocarbon profiles of the cockroaches Nauphoeta cinerea and Leucophaea maderae are species-specific when maintained in homospecific rearings. When individuals were reared in mixed species colonies, they initially remained in homospecific groups under different shelters. However, after 14 days they formed one heterospecific group with cuticular profiles showing characteristics of both species. When individuals were returned in monospecific rearings, their cuticular hydrocarbon profiles returned to species-specific ones within 3 weeks.
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male dominant subordinate relationships cuticular profiles and sex pheromone in Nauphoeta cinerea dictyoptera blaberidae
Insectes Sociaux, 1997Co-Authors: Cl Everaerts, F Fenauxbenderitter, Jeanpierre Farine, Remy BrossutAbstract:In the cockroach Nauphoeta cinerea, male-male aggressive interactions result in dominant-subordinate relationships. Once dominance relationships are established, a male can recognize the status of another individual, likely through chemical cues. The aim of this study was to determine the effect of these male-male interactions on cuticular chemical profiles and on the relative composition of the male sex pheromone. The results of chemical analyses of males reared in pairs for 30 days clearly showed significant differences in both cuticular profiles and sex pheromone of dominant and subordinate individuals. The possible role of these compounds as recognition cues was discussed.
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Male dominant/subordinate relationships, cuticular profiles and sex pheromone in Nauphoeta cinerea (Dictyoptera, Blaberidae)
Insectes Sociaux, 1997Co-Authors: Cl Everaerts, F. Fenaux-benderitter, Jeanpierre Farine, Remy BrossutAbstract:In the cockroach Nauphoeta cinerea, male-male aggressive interactions result in dominant-subordinate relationships. Once dominance relationships are established, a male can recognize the status of another individual, likely through chemical cues. The aim of this study was to determine the effect of these male-male interactions on cuticular chemical profiles and on the relative composition of the male sex pheromone. The results of chemical analyses of males reared in pairs for 30 days clearly showed significant differences in both cuticular profiles and sex pheromone of dominant and subordinate individuals. The possible role of these compounds as recognition cues was discussed.
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2-methylthiazolidine and 4-ethylguaiacol, male sex pheromone components of the cockroach Nauphoeta cinerea (Dictyoptera, Bladeridae) : A reinvestigation
Journal of Chemical Ecology, 1992Co-Authors: Daniel Sirugue, Jeanpierre Farine, Odile Bonnard, Jean-luc Le Quéré, Remy BrossutAbstract:In Nauphoeta cinerea, male calling behavior is associated with sex pheromone release by the sternal glands. The male pheromone that attracts females from a distance is a mixture of 2-methylthiazolidine and 4-ethylguaiacol. It is active at very low concentrations, 0.05 and 0.01 ng, respectively. Two other compounds, 3-hydroxy-2-butanone and 2-methyl-2thiazoline, act at close range, keeping the female in the vicinity of the male. The function of the volatile pheromone and those of previously described contact pheromones are discussed in regard to their possible involvement in the establishment of male dominant-subordinate relationships.
Allan Pinto Leal - One of the best experts on this subject based on the ideXlab platform.
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The Insecticidal Activity of Rhinella schneideri (Werner, 1894) Paratoid Secretion in Nauphoeta cinerea Cocroaches.
Toxins, 2020Co-Authors: Allan Pinto Leal, Maria Eduarda Rosa, Raquel Soares Oliveira, Bruna Trindade Borges, Yuri Correia Barreto, Etiely Karnopp, Flávia Luana Goulart, Velci Queiróz De Souza, Manuela M. Laikowski, Sidnei MouraAbstract:Rhinella schneideri is a common toad found in South America, whose paratoid toxic secretion has never been explored as an insecticide. In order to evaluate its insecticidal potential, Nauphoeta cinerea cockroaches were used as an experimental model in biochemical, physiological and behavioral procedures. Lethality assays with Rhinella schneideri paratoid secretion (RSPS) determined the LD50 value after 24 h (58.07µg/g) and 48 h exposure (44.07 µg/g) (R2 = 0.882 and 0.954, respectively). Acetylcholinesterase activity (AChE) after RSPS at its highest dose promoted an enzyme inhibition of 40%, a similar effect observed with neostigmine administration (p < 0.001, n= 5). Insect locomotion recordings revealed that RSPS decreased the distance traveled by up to 37% with a concomitant 85% increase in immobile episodes (p < 0.001, n = 36). RSPS added to in vivo cockroach semi-isolated heart preparation promoted an irreversible and dose dependent decrease in heart rate, showing a complete failure after 30 min recording (p < 0.001, n ≥ 6). In addition, RSPS into nerve-muscle preparations induced a dose-dependent neuromuscular blockade, reaching a total blockage at 70 min at the highest dose applied (p < 0.001, n ≥ 6). The effect of RSPS on spontaneous sensorial action potentials was characterized by an increase in the number of spikes 61% (p < 0.01). Meanwhile, there was 42% decrease in the mean area of those potentials (p < 0.05, n ≥ 6). The results obtained here highlight the potential insecticidal relevance of RSPS and its potential biotechnological application.
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entomotoxic activity of prasiola crispa antarctic algae in Nauphoeta cinerea cockroaches identification of main steroidal compounds
Marine Drugs, 2019Co-Authors: Graziela Holken Lorensi, Maria Eduarda Rosa, Ana Paula Zanatta, Raquel Soares Oliveira, Carlos Gabriel Moreira De Almeida, Allan Pinto Leal, Patricia De Brum Vieira, Yuri Correia Barreto, Carlos Jose Brito Ramos, Filipe De Carvalho VictoriaAbstract:Prasiola crispa is a macroscopic green algae found in abundance in Antarctica ice free areas. Prasiola crispan-hexaneextract (HPC) induced insecticidal activity in Nauphoeta cinerea cockroaches after 24 h of exposure. The chemical analysis of HPC revealed the presence of the followingphytosterols: β-sitosterol, campesterol and stigmasterol. The incubation of cockroach semi-isolated heart preparations with HPC caused a significant negative chronotropic activity in the heartbeats. HPC affected the insect neuromuscular function by inducing a complete inhibition of the cockroach leg-muscle twitch tension. When the isolated phytosterols were injected at in vivo cockroach neuromuscular preparations, there was a progressive inhibition of muscle twitches on the following order of potency: β-sitosterol > campesterol > stigmasterol. HPC also provoked significant behavioral alterations, characterized by the increase or decrease of cockroach grooming activity, depending on the dose assayed. Altogether, the results presented here corroborate the insecticide potential of Prasiola crispa Antarctic algae. They also revealed the presence of phytosterols and the involvement of these steroidal compounds in the entomotoxic activity of the algae, potentially by modulating octopaminergic-cholinergic pathways. Further phytochemical-combined bioguided analysis of the HPC will unveil novel bioactive compounds that might be an accessory to the insecticide activity of the algae.
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neurotoxic effects of sublethal concentrations of cyanobacterial extract containing anatoxin a s on Nauphoeta cinerea cockroaches
Ecotoxicology and Environmental Safety, 2019Co-Authors: Douglas Silva Dos Santos, Maria Eduarda Rosa, Ana Paula Zanatta, Raquel Soares Oliveira, Carlos Gabriel Moreira De Almeida, Allan Pinto Leal, Miriam SanzAbstract:Abstract The detection of cyanotoxins, such as the anatoxin-a(s), is essential to ensure the biological safety of water environments. Here, we propose the use of Nauphoeta cinerea cockroaches as an alternative biological model for the biomonitoring of the activity of anatoxin-a(s) in aquatic systems. In order to validate our proposed model, we compared the effects of a cyanobacterial extract containing anatoxin-a(s) (CECA) with those of the organophosphate trichlorfon (Tn) on biochemical and physiological parameters of the nervous system of Nauphoeta cinerea cockroaches. In brain homogenates from cockroaches, CECA (5 and 50 μg/g) inhibited acetylcholinesterase (AChE) activity by 53 ± 2% and 51 ± 7%, respectively, while Tn (5 and 50 μg/g) inhibited AChE activity by 35 ± 4% and 80 ± 9%, respectively (p 0.05). Finally, CECA (50 µg/g), Tn (0.3 µg/g) and neostigmine (50 µg/g) caused significant neuromuscular failure, as indicated by the monitoring of the in vivo neuromuscular function of the cockroaches, during 100 min (n = 6, p
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entomotoxic activity of rhinella icterica spix 1824 toad skin secretion in Nauphoeta cinerea cockroaches an octopamine like modulation
Pesticide Biochemistry and Physiology, 2018Co-Authors: Allan Pinto Leal, Raquel Soares Oliveira, Patricia De Brum Vieira, Ana Paula Perin, Bruna Trindade Borges, Tiago Gomes Dos Santos, Lucia Vinade, Chiara Valsecchi, Chariston Andre Dal BeloAbstract:Abstract Rhinella icterica is a poisonous toad whose toxic secretion has never been studied against entomotoxic potential. Sublethal doses of Rhinella icterica toxic secretion (RITS) were assayed in Nauphoeta cinerea cockroaches, in order to understand the physiological and behavioral parameters, over the insect central and peripheral nervous system. RITS (10 μg/g) injections, induced behavioral impairment as evidenced by a significant decrease (38 ± 14%) in the distance traveled (p
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entomotoxicidade do veneno de sapo rhinella icterica em baratas Nauphoeta cinerea
Anais do Salão Internacional de Ensino Pesquisa e Extensão, 2017Co-Authors: Yuri Correia Barreto, Raquel Soares Oliveira, Lucia Vinade, Chariston Andre Dal Belo, Allan Pinto LealAbstract:INTRODUCAO: Os sapos sao animais venenosos de interesse biotecnologico devido aos compostos bioativos presentes no seu veneno. Rhinella icterica e uma especie de anuro venenoso comum no Brasil, no qual a atividade biologica de seu veneno nunca foi descrita anteriormente. Este trabalho investigou os mecanismos da atividade entomotoxica do veneno do sapo R. icterica (VSRI). METODOLOGIA: O veneno foi extraido de sapos coletados no municipio de Derrubadas (RS), com autorizacao do Sistema de Autorizacao e Informacao em Biodiversidade (SISBIO) licenca de coletor n°: 24041-2. Baratas adultas Nauphoeta cinerea foram utilizadas como modelo experimental. A atividade neuromuscular do VSRI foi avaliada usando a preparacao musculo coxal adutor metatoracico (MCAM) segundo descrito por Martinelli et al. (2014). A Cardiotoxicidade foi avaliada utilizando a preparacao coracao semi-isolada (CSI) de barata in vivo de acordo com Rodrigues et al., (2012), frequencia cardiaca foi contabilizada visualmente durante 30 min. O comportamento de higienizacao (grooming) foi medido conforme descrito em (Carrazoni et al., 2016). Para avaliar a atividade locomotora in vivo, quatro insetos foram filmados durante 10 min e os filmes analisados utilizando softwares conforme Adedara et al. (2015). odos os dados foram expressos como media ± erro (E.P.M), sendo os mesmos analisados pelo teste two-way ANOVA, seguido dos testes Tukey ou Dunnett, sendo considerado significativos quando P
Leam Sreng - One of the best experts on this subject based on the ideXlab platform.
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sensory asymmetries in the olfactory system underlie sexual pheromone communication in the cockroach Nauphoeta cinerea
Neuroscience Letters, 2003Co-Authors: Leam SrengAbstract:In most insect species, males process female sex pheromone information in specific macroglomeruli in the olfactory lobes of their brains. The purpose of this report is to present a novel system of pheromone perception. In Nauphoeta cinerea cockroaches, males produce sex pheromones that induce mating behavior in females but neither sex has macroglomeruli. In this study, we show that female N. cinerea show asymmetry in the number of glomeruli whereas males do not. Females have more glomeruli on the right side and amputation of the right antenna reduced female ability to find a male and mate whereas amputation of the left antenna did not. We show that a key factor in female mating behavior is perception of the male sex pheromone seducin by the right antenna and the asymmetrically organized deutocerebral glomeruli associated with it. In the symmetrical olfactory system of males the detection of seducin may be involved in establishing dominance hierarchies.
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cuticular hydrocarbon profiles of dominant versus subordinate male Nauphoeta cinerea cockroaches
Journal of Chemical Ecology, 2002Co-Authors: Estelle Roux, Eric Provost, Maurice Roux, Leam Sreng, Jeanluc ClementAbstract:Interactions between male Nauphoeta cinerea cockroaches are characterized by an elaborate ritual that leads to a stable dominant–subordinate hierarchy between two individuals. Chemical signals involving volatile sex pheromones and cuticular hydrocarbons play an important role in establishing and maintaining dominance status. The present study was performed to identify cuticular hydrocarbons in two- and three-times dominant or subordinate individuals obtained by forcing dyadic encounters. Two methods, i.e., solid-phase microextraction (SPME) and organic solvent extraction, were used to isolate cuticular hydrocarbons. A total of 23 peaks of cuticular hydrocarbons were identified. Analysis showed quantitative differences in hydrocarbon profiles of three-times dominant and subordinate individuals according to extraction method and dominance status. Dominant individuals were characterized by higher proportions of the monomethylalkanes 11- and 13-MeC36, 13- and 15-MeC38, and 11-, 13-, and 15-MeC35, while subordinate individuals had higher proportions of the following monomethylalkanes: 7-, 9-, and 11-MeC31, 5-MeC31, 3- and 8-MeC32, and 9-, 10- , 11-, and 12-MeC32. Discussion focuses on the reliability of hydrocarbons as indicators of dominance status and on their correlation with physiological processes.
Chariston Andre Dal Belo - One of the best experts on this subject based on the ideXlab platform.
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entomotoxic activity of rhinella icterica spix 1824 toad skin secretion in Nauphoeta cinerea cockroaches an octopamine like modulation
Pesticide Biochemistry and Physiology, 2018Co-Authors: Allan Pinto Leal, Raquel Soares Oliveira, Patricia De Brum Vieira, Ana Paula Perin, Bruna Trindade Borges, Tiago Gomes Dos Santos, Lucia Vinade, Chiara Valsecchi, Chariston Andre Dal BeloAbstract:Abstract Rhinella icterica is a poisonous toad whose toxic secretion has never been studied against entomotoxic potential. Sublethal doses of Rhinella icterica toxic secretion (RITS) were assayed in Nauphoeta cinerea cockroaches, in order to understand the physiological and behavioral parameters, over the insect central and peripheral nervous system. RITS (10 μg/g) injections, induced behavioral impairment as evidenced by a significant decrease (38 ± 14%) in the distance traveled (p
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neurotoxicidade induzida por extrato e fracoes de manilkara rufula em baratas da especie Nauphoeta cinerea
Anais do Salão Internacional de Ensino Pesquisa e Extensão, 2018Co-Authors: Bruna Trindade Borges, Maria Eduarda Rosa, Raquel Soares Oliveira, Lucia Vinade, Yuri Correia Barreto, Chariston Andre Dal Belo, Patricia De Brum VieiraAbstract:Plantas adaptadas a regioes de clima extremo como o bioma da Caatinga possuem uma variedade de metabolitos secundarios. A Manilkara rufula e uma planta nativa dessa regiao, havendo poucos relatos sobre sua acao biologica. Buscando estudar a especie M. rufula, analises entomotoxicas foram realizadas com o objetivo de avaliar a atividade do extrato bruto e fracoes enriquecidas desta planta sobre o sistema nervoso de insetos. Para isso, baratas da especie Nauphoeta cinerea foram utilizadas como modelo experimental. O extrato bruto de M. rufula (EBMR) e suas fracoes metanolicas (FMMR) e aquosas (FAMR) foram preparadas em Milli-Q e DMSO 0,5% nas seguintes concentracoes: 25, 50 e 100 (EBMR) e 10, 20 e 40 µg/g de animal (fracoes). Tambem foram ensaiados os neuromoduladores octopamina (15 µg/g de animal) e fentolamina (0,01 µg/g de animal), um antagonista de receptores octopaminergicos. Como testes comportamentais foram realizados: ensaio de grooming e ensaio dos padroes de locomocao. Para teste eletrofisiologico foi utilizado o ensaio com registros dos potenciais de acao espontâneos sensoriais (PAES) da pata dos insetos. Houve uma diminuicao da atividade locomotora, perfil exploratorio e comportamento de grooming para todas as doses administradas do EBMR. Sendo o grooming de pernas modulado pela via octopaminergica, a octopamina induziu o aumento desse parâmetro, que foi novamente diminuido pela administracao previa do EBMR. Todas as doses do EBMR induziram um aumento da amplitude maxima do pico dos (PAES). Esse parâmetro teve uma diminuicao quando a octopamina foi administrada, porem, sofreu um aumento com a administracao previa de EBMR; semelhante a acao da fentolamina, que teve seu efeito complementado pelo EBMR. O numero de eventos (spikes) nao sofreu alteracoes pela acao isolada do EBMR, porem, quando este foi administrado previamente, reverteu o efeito da octopamina e complementou a acao da fentolamina para esse parâmetro. Ambas FAMR e FMMR (10 e 40 µg/g de animal) induziram um aumento na amplitude dos PAES. Porem, apenas a FAMR aumentou a duracao destes eventos. Considerando que a FMMR nao obteve modulacao sobre esse parâmetro, sugere-se que a FAMR seja necessaria para os efeitos do EBMR. Os dados obtidos demonstram o potencial biotecnologico da planta Manilkara rufula, bem como seu efeito entomotoxico em baratas da especie Nauphoeta cinerea. Sugere-se que o EBMR e suas fracoes possuam uma acao equivalente a antagonistas de receptores octopaminergicos, tendo em vista que os resultados obtidos com a administracao da octopamina indicam a atividade dos compostos principalmente nesta via.
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mechanism of the entomotoxic activity induced by araucaria angustifolia methanolic extract in Nauphoeta cinerea lobster cockroaches
Journal of Botany Research, 2017Co-Authors: Thiago Carrazoni, Patricia De Brum Vieira, Patricia Gomes Da Silva, Marines De Avila Heberle, Graziele Daiane Sturmer, Michele Stach Correa, Antonio Batista Pereira, Andreas Sebastian Mendez, Sidnei Moura, Chariston Andre Dal BeloAbstract:Araucaria angustifolia (Bert.) O. Kuntze (Araucariaceae), known as “Parana pine”, is a conifer found in Southern of Brazil and it needles are used traditionally as natural insecticide and acaricide. The aim of this study was to investigate the insecticide activity of A. angustifolia needles Nauphoeta cinerea as behavior model and neuromuscular preparations.
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entomotoxicidade do veneno de sapo rhinella icterica em baratas Nauphoeta cinerea
Anais do Salão Internacional de Ensino Pesquisa e Extensão, 2017Co-Authors: Yuri Correia Barreto, Raquel Soares Oliveira, Lucia Vinade, Chariston Andre Dal Belo, Allan Pinto LealAbstract:INTRODUCAO: Os sapos sao animais venenosos de interesse biotecnologico devido aos compostos bioativos presentes no seu veneno. Rhinella icterica e uma especie de anuro venenoso comum no Brasil, no qual a atividade biologica de seu veneno nunca foi descrita anteriormente. Este trabalho investigou os mecanismos da atividade entomotoxica do veneno do sapo R. icterica (VSRI). METODOLOGIA: O veneno foi extraido de sapos coletados no municipio de Derrubadas (RS), com autorizacao do Sistema de Autorizacao e Informacao em Biodiversidade (SISBIO) licenca de coletor n°: 24041-2. Baratas adultas Nauphoeta cinerea foram utilizadas como modelo experimental. A atividade neuromuscular do VSRI foi avaliada usando a preparacao musculo coxal adutor metatoracico (MCAM) segundo descrito por Martinelli et al. (2014). A Cardiotoxicidade foi avaliada utilizando a preparacao coracao semi-isolada (CSI) de barata in vivo de acordo com Rodrigues et al., (2012), frequencia cardiaca foi contabilizada visualmente durante 30 min. O comportamento de higienizacao (grooming) foi medido conforme descrito em (Carrazoni et al., 2016). Para avaliar a atividade locomotora in vivo, quatro insetos foram filmados durante 10 min e os filmes analisados utilizando softwares conforme Adedara et al. (2015). odos os dados foram expressos como media ± erro (E.P.M), sendo os mesmos analisados pelo teste two-way ANOVA, seguido dos testes Tukey ou Dunnett, sendo considerado significativos quando P
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avaliacao da influencia de neuromoduladores sobre a frequencia cardiaca de baratas da especie Nauphoeta cinerea
Anais do Salão Internacional de Ensino Pesquisa e Extensão, 2016Co-Authors: Fabiola Duarte, Lucia Vinade, Polyana Veloso Rodrigues, Chariston Andre Dal Belo, Douglas Silva Dos SantosAbstract:Os estudos com baratas tem sido motivados pelo interesse no desenvolvimento de novos agentes com atividade inseticida, bem como em ensaios de farmacologia para o desenvolvimento de novos compostos terapeuticos. O uso desse modelo tem sido estimulado pela restricao quanto ao uso de vertebrados em pesquisas cientificas bem como pelo baixo custo de criacao e manutencao desses animais em pequenos ambientes. Nesse sentido, varios neurotransmissores semelhantes aos de mamiferos ja foram identificados em insetos os quais modulam de forma direta ou indireta o sistema cardiovascular desses animais. A proposito, o sistema cardiovascular de insetos corresponde a um tubo vascular dividido em doze segmentos possuindo tanto influencia neurogenica como miogenica, pela autoritmicidade cardiaca. Recentemente, foi evidenciada a participacao do oxido nitrico sobre as respostas do sistema nervoso de insetos. O objetivo desse trabalho foi investigar a influencia de diferentes compostos (dexametasona, octopamina e atropina), sobre a modulacao da frequencia cardiaca de baratas da especie Nauphoeta cinerea usando-se a preparacao in vivo coracao semi-isolado. Nesse trabalho foram usadas baratas de ambos os sexos, adultos da especie Nauphoeta cinerea que foram alojadas em insetario com temperatura controlada (22-24C), e agua e racao a vontade. Para a montagem da preparacao as baratas foram anestesiadas por resfriamento (4C por 10min) e afixadas com alfinetes entomologicos em uma placa recoberta com isopor com a regiao ventral voltada para cima. A cuticula que recobre o abdome foi retirada com o auxilio de uma tesoura oftalmica e os orgaos viscerais removidos cuidadosamente com o auxilio de uma pinca, para a visualizacao do sistema vascular. A seguir o animal foi colocado sob uma lupa com aumento de 60X (Olympus, EUA) e os batimentos cardiacos contabilizados visualmente durante 30min. Os resultados foram expressos como a media ± EPM. Foi usado o teste t de Student como analise estatistica, onde p 0.05). Os dados sugerem que a frequencia cardiaca de baratas da especie Nauphoeta cinerea e modulada positivamente pela acetilcolina que interage com receptores muscarinicos, devido a inibicao da resposta colinergica pela atropina. A inibicao da fosfolipase A2, pelo tratamento com dexametasona, um antiinflamatorio esteroidal, e o consequente aumento da frequencia cardiaca basal na barata, sugere que as ciclooxigenases podem estar envolvidas na modulacao das respostas cronotropicas em insetos, semelhantemente ao que ocorre em mamiferos.
