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Utsunomiya HSM, Ferraz JVC, Fujiwara GH, Gutierres DM, Fernandes IF, de Lacerda Valverde BS, de Oliveira C, Franco-Belussi L, Fernandes MN, Dos Santos Carvalho C. Changes in blood parameters and metabolism in bullfrog tadpoles, Lithobates catesbeianus, (Shaw, 1802) after exposure to the Sorocaba River (São Paulo, Brazil) water. Environ Sci Pollut Res Int 2023; 30:33419-33431. [PMID: 36480144 DOI: 10.1007/s11356-022-24590-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
Abstract
This study evaluated the genetic damage, oxidative stress, neurotoxicity, and energy metabolism in bullfrog tadpoles (Lithobates catesbeianus) exposed to water from two sites of the Sorocaba River, Ibiúna (PI), and Itupararanga reservoir (PIR), in summer and winter. After 96-h exposure, the erythrocyte number decreased in PI and increase in PIR in summer. Bullfrogs show oxidative unbalance (liver, kidney, and muscle), with alterations in the nitric oxide synthase and glucose 6-phosphate dehydrogenase. Cholinesterase increased in the brain in PI and PIR in the summer and decreased in PI in the winter. It also increased in the muscle in both PI and PIR in the winter. Tadpoles show alterations in the activity of the metabolic enzymes (liver, kidney, and muscle), such as phosphofructokinase, pyruvatokinase, malate dehydrogenase, and lactate dehydrogenase; and in the amount of glucose and triglycerides metabolites. Exposure to the Sorocaba River reflected a stressful situation for L. catesbeianus as the changes caused to their metabolism associated with oxidative stress and neurotoxicity may have effects on the development of tadpoles.
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Affiliation(s)
- Heidi Samantha Moraes Utsunomiya
- Laboratório de Bioquímica E Microbiologia (LaBioM), Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme Dos Santos, Km 110, SP-264, Sorocaba, SP, CEP 18052-780, Brazil
| | - João Victor Cassiel Ferraz
- Laboratório de Bioquímica E Microbiologia (LaBioM), Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme Dos Santos, Km 110, SP-264, Sorocaba, SP, CEP 18052-780, Brazil
| | - Gabriel Hiroshi Fujiwara
- Laboratório de Bioquímica E Microbiologia (LaBioM), Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme Dos Santos, Km 110, SP-264, Sorocaba, SP, CEP 18052-780, Brazil
| | - Davi Marques Gutierres
- Laboratório de Bioquímica E Microbiologia (LaBioM), Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme Dos Santos, Km 110, SP-264, Sorocaba, SP, CEP 18052-780, Brazil
| | - Isabela Ferreira Fernandes
- Laboratório de Bioquímica E Microbiologia (LaBioM), Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme Dos Santos, Km 110, SP-264, Sorocaba, SP, CEP 18052-780, Brazil
- Programa de Pós-Graduação Em Biotecnologia E Monitoramento Ambiental, Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme Dos Santos, Km 110, SP-264, Sorocaba, SP, CEP 18052-780, Brazil
| | - Bruno Serra de Lacerda Valverde
- Programa de Pós-Graduação Em Biodiversidade, Universidade Estadual Paulista (UNESP), Campus de São José Do Rio Preto, São José Do Rio Preto, SP, Brazil
| | - Classius de Oliveira
- Departamento de Ciências Biológicas, Universidade Estadual Paulista (UNESP), Campus de São José Do Rio Preto, São José Do Rio Preto, SP, Brazil
| | - Lilian Franco-Belussi
- Laboratório de Patologia Experimental (LAPex), Instituto de Biociências, Universidade Federal de Mato Grosso Do Sul, Campus Campo Grande, Campo Grande, MS, Brazil
| | - Marisa Narciso Fernandes
- Departamento de Ciências Fisiológicas, Universidade Federal de São Carlos, Caixa Postal 676, Rodovia Washington Luís Km 235, São Carlos, SP, CEP 13565-905, Brazil
| | - Cleoni Dos Santos Carvalho
- Laboratório de Bioquímica E Microbiologia (LaBioM), Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme Dos Santos, Km 110, SP-264, Sorocaba, SP, CEP 18052-780, Brazil.
- Programa de Pós-Graduação Em Biotecnologia E Monitoramento Ambiental, Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme Dos Santos, Km 110, SP-264, Sorocaba, SP, CEP 18052-780, Brazil.
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Abstract
Invasive non-native predators negatively affect native species; however, some native species can survive the predation pressures of invasive species by using pre-existing antipredator strategies or evolving defenses against invasive predators. The American bullfrog Lithobates catesbeianus (Anura: Ranidae) has been intentionally introduced to many countries and regions, and has impacted native animals through direct predation. Bombardier beetles (Coleoptera: Carabidae: Brachininae: Brachinini) discharge chemicals at a temperature of approximately 100 °C from the tip of the abdomen when they are attacked by predators. This "bombing" can successfully repel predators. However, adults of a native bombardier beetle Pheropsophus (Stenaptinus) occipitalis jessoensis have been reportedly found in the gut contents of the introduced bullfrog L. catesbeianus in Japan. These records suggest that the invasive bullfrog L. catesbeianus attacks the native bombardier beetle P. occipitalis jessoensis under field conditions in Japan; however, the effectiveness of the bombing defense against invasive bullfrogs is unclear. To test the effectiveness of the bombing defense against bullfrogs, we investigated the behavioral responses of L. catesbeianus juveniles to P. occipitalis jessoensis adults under laboratory conditions. Contrary to previous gut content results, almost all the bullfrogs (96.3%) rejected bombardier beetles before swallowing them; 88.9% rejected the beetles after being bombed, and 7.4% stopped attacking the beetles before being bombed. Only 3.7% successfully swallowed and digested the beetle. All of the beetles collected from non-bullfrog-invaded sites could deter bullfrogs, suggesting that the pre-existing defenses of bombardier beetles played an essential role in repelling bullfrogs. When treated beetles that were unable to discharge hot chemicals were provided, 77.8% of bullfrogs successfully swallowed and digested the treated beetles. These results indicate that bombing is important for the successful defense of P. occipitalis jessoensis against invasive bullfrogs. Although invasive bullfrogs have reportedly impacted native insect species, P. occipitalis jessoensis has an existing defense mechanism strong enough to repel the invasive predators.
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Moreno-de-Lima PL, Lambertini C, Becker CG, Rebouças R, Toledo LF. Presence of invasive American bullfrogs may reduce infectious disease in a native frog species. Dis Aquat Organ 2022; 149:53-58. [PMID: 35510821 DOI: 10.3354/dao03653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Amphibians breeding in aquatic environments may encounter a myriad of threats during their life cycle. One species known to prey on native amphibians in aquatic habitats is the invasive North American bullfrog Lithobates catesbeianus, which, besides being a voracious predator and competitor, often acts as a pathogen carrier and disease superspreader because it tolerates high infection loads of the frog-killing fungus Batrachochytrium dendrobatidis (Bd). Here, we hypothesized that the presence of the bullfrogs in microcosms should either (1) decrease Bd disease severity in native frog species by discouraging them from using the aquatic environment, or (2) increase the mortality of the native species. We tested these 2 mutually exclusive hypotheses by co-housing the snouted treefrog Scinax x-signatus (native to our study area) with L. catesbeianus in the laboratory, exposing them to Bd, and using qPCR analysis to quantify the resulting Bd infection loads in the native frogs. Our experiment had the following replicated treatments: (1) native-only treatment (3 individuals of S. x-signatus), (2) native-predominant treatment (2 S. x-signatus + 1 L. catesbeianus), and (3) exotic-predominant treatment (1 S. x-signatus + 2 L. catesbeianus). We found that Bd infection loads in the native S. x-signatus were highest in the native-only treatment, and lowest in the exotic-predominant treatment, indicating that bullfrogs may discourage native frogs from occupying the aquatic habitat, thus reducing encounter rates between native frogs and the waterborne pathogen. This effect could be driven by the bullfrogs' predatory behavior and their high philopatry to aquatic habitats. Our results highlight that predation risk adds to the complexity of host-species interactions in Bd epidemiology.
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Affiliation(s)
- Psiquê Laís Moreno-de-Lima
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo 13083-862, Brazil
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Adams S, Zubov T, Bueschke N, Santin JM. Neuromodulation or energy failure? Metabolic limitations silence network output in the hypoxic amphibian brainstem. Am J Physiol Regul Integr Comp Physiol 2021; 320:R105-R116. [PMID: 33175586 PMCID: PMC7948128 DOI: 10.1152/ajpregu.00209.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/10/2020] [Accepted: 11/02/2020] [Indexed: 11/22/2022]
Abstract
Hypoxia tolerance in the vertebrate brain often involves chemical modulators that arrest neuronal activity to conserve energy. However, in intact networks, it can be difficult to determine whether hypoxia triggers modulators to stop activity in a protective manner or whether activity stops because rates of ATP synthesis are insufficient to support network function. Here, we assessed the extent to which neuromodulation or metabolic limitations arrest activity in the respiratory network of bullfrogs-a circuit that survives moderate periods of oxygen deprivation, presumably, by activating an inhibitory noradrenergic pathway. We confirmed that hypoxia and norepinephrine (NE) reduce network output, consistent with the view that hypoxia may cause the release of NE to inhibit activity. However, these responses differed qualitatively; hypoxia, but not NE, elicited a large motor burst and silenced the network. The stereotyped response to hypoxia persisted in the presence of both NE and an adrenergic receptor blocker that eliminates sensitivity to NE, indicating that noradrenergic signaling does not cause the arrest. Pharmacological inhibition of glycolysis and mitochondrial respiration recapitulated all features of hypoxia on network activity, implying that reduced ATP synthesis underlies the effects of hypoxia. Finally, activating modulatory mechanisms that dampen neuronal excitability when ATP levels fall, KATP channels and AMP-dependent protein kinase, did not resemble the hypoxic response. These results suggest that energy failure-rather than inhibitory modulation-silences the respiratory network during hypoxia and emphasize the need to account for metabolic limitations before concluding that modulators arrest activity as an adaptation for energy conservation in the nervous system.
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Affiliation(s)
- Sasha Adams
- Department of Biology, The University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Tanya Zubov
- Department of Biology, The University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Nikolaus Bueschke
- Department of Biology, The University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Joseph M Santin
- Department of Biology, The University of North Carolina at Greensboro, Greensboro, North Carolina
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Pinto Vidal FA, Abdalla FC, Carvalho CDS, Moraes Utsunomiya HS, Teixeira Oliveira LA, Salla RF, Jones-Costa M. Metamorphic acceleration following the exposure to lithium and selenium on American bullfrog tadpoles (Lithobates catesbeianus). Ecotoxicol Environ Saf 2021; 207:111101. [PMID: 32905937 DOI: 10.1016/j.ecoenv.2020.111101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 07/24/2020] [Accepted: 07/29/2020] [Indexed: 06/11/2023]
Abstract
To regulate the presence of contaminants in Brazilian water, the Brazilian Environmental Council (CONAMA) promulgates regulations regarding the concentrations of given compounds that are supposed to be safe for aquatic life. Considering these regulations, this study tested the effects of considered safe levels of lithium (2.5 mgL-1) and selenium (0.01 mgL-1), isolated and mixed, on the American bullfrog (Lithobates catesbeianus) tadpoles. The evaluation was done through the use of biomarkers of larval development as total wet weight (TWW), snout-vent-length (SVL), hind-limb-length (HLL), activity level (AL), histologic evaluation of the thyroid gland and the mortality rate. The tadpoles were allocated into four groups (n = 20 each): a control group (CT); a group exposed to lithium (LI), a group exposed to selenium (SE), and a group exposed to both lithium and selenium (SELI). The whole assay was carried out over 21 days, with two rounds of data collection (on 7th and 21st day) to evaluate the responses over time. A statistical reduction in the AL was observed in the tadpoles from the LI and SELI groups after 7 days of exposure, the same pattern was observed after 21 days. Histological analyses of the thyroid gland showed signs of up-regulation (i.e. statistic reduction in number and area of the follicles, as well a significant reduction in the area of the gland) in all exposed groups, which represents an endocrine response as an adaptative strategy to deal with polluted aquatic environment. The stress triggered by the polluted medium is discussed.
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Affiliation(s)
- Felipe Augusto Pinto Vidal
- Laboratory of Conservation Physiology (LaFisC), Federal University of São Carlos, Brazil; Graduate Program of Biotechnology and Environmental Monitoring, Federal University of SãoCarlos, Brazil
| | - Fábio Camargo Abdalla
- Laboratory of Structural and Functional Biology (LaBEF), Federal University of São Carlos, Brazil
| | | | | | | | - Raquel Fernanda Salla
- Laboratory of Natural History of Brazilian Amphibians (LaHNAB), State University of Campinas, Brazil
| | - Monica Jones-Costa
- Laboratory of Conservation Physiology (LaFisC), Federal University of São Carlos, Brazil.
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Boiarski DR, Toigo CM, Sobjak TM, Santos AFP, Romão S, Guimarães ATB. Assessment of antioxidant system, cholinesterase activity and histopathology in Lithobates catesbeianus tadpoles exposed to water from an urban stream. Ecotoxicology 2020; 29:314-326. [PMID: 32107698 DOI: 10.1007/s10646-020-02176-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/12/2020] [Indexed: 06/10/2023]
Abstract
Anthropogenic activities promote changes in community structure and decrease the species abundance of amphibians. The aim of this study was to assess potential alterations in the antioxidant system and cholinesterase activity, histopathological and oxidative damage in Lithobates catesbeianus tadpoles exposed to water from the Cascavel River, in Southern Brazil. Water samples (140 L each) were collected from the headwater, urban and rural areas of the river. Tadpoles were acclimated for seven days. After acclimatization tadpoles were reared in water from the river, except for the control aquarium. After seven days, a portion of the liver was removed and prepared for cholinesterase (ChE), superoxide dismutase (SOD), catalase (CAT) and lipid peroxidation (LPO) analysis; another part of the tissue was prepared for histological examination. An elevation of CAT activity was observed for water from both urban and rural environments. A decrease in LPO reaction was detected, mainly among the tadpoles exposed to water from the rural area. These alternations can cause delay the metamorphosis and lead to metabolic dysfunction, interfering in survival capacity and diminishing, not only individual fitness, but that of the whole population.
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Affiliation(s)
- Diego Romagna Boiarski
- Undergraduate Program in Biological Sciences, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brazil
| | - Camila Maria Toigo
- Graduate Program in Conservation and Management of Natural Resources Postgraduate Program, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brazil
| | - Thaís Maylin Sobjak
- Undergraduate Program in Biological Sciences, Universidade Tecnológica Federal do Paraná-UTFPR, Dois Vizinhos, PR, Brazil.
| | | | - Silvia Romão
- Graduate Program in Agroecology and Sustainable Development, Universidade Federal da Fronteira Sul, Laranjeiras do Sul, PR, Brazil
| | - Ana Tereza Bittencourt Guimarães
- Undergraduate Program in Biological Sciences, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brazil
- Graduate Program in Biosciences and Health, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brazil
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Oliveira CR, Garcia TD, Franco-Belussi L, Salla RF, Souza BFS, de Melo NFS, Irazusta SP, Jones-Costa M, Silva-Zacarin ECM, Fraceto LF. Pyrethrum extract encapsulated in nanoparticles: Toxicity studies based on genotoxic and hematological effects in bullfrog tadpoles. Environ Pollut 2019; 253:1009-1020. [PMID: 31434178 DOI: 10.1016/j.envpol.2019.07.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 06/14/2019] [Accepted: 07/08/2019] [Indexed: 06/10/2023]
Abstract
The environment receives about 2.7 kg.ha-1 annually of pesticides, used in crop production. Pesticides may have a negative impact on environmental biodiversity and potentially induce physiological effects on non-target species. Advances in technology and nanocarrier systems for agrochemicals led to new alternatives to minimize these impacts, such as nanopesticides, considered more efficient, safe and sustainable. However, it is important to evaluate the risk potential, action and toxicity of nanopesticides in aquatic and terrestrial organisms. This study aims to evaluate genotoxic and hematological biomarkers in bullfrog tadpoles (Lithobates catesbeianus) submitted to acute exposure (48 h) to pyrethrum extract (PYR) and solid lipid nanoparticles loaded with PYR. Results showed increased number of leukocytes during acute exposure, specifically eosinophils in nanoparticle-exposed groups, and basophil in PYR-exposed group. Hematological analysis showed that PYR encapsulated in nanoparticles significantly increased the erythrocyte number compared to the other exposed groups. Data from the comet assay indicated an increase in frequency of the classes that correspond to more severe DNA damages in exposed groups, being that the PYR-exposed group showed a high frequency of class-4 DNA damage. Moreover, erythrocyte nuclear abnormalities were triggered by short-time exposure in all treatments, which showed effects significantly higher than the control group. These results showed genotoxic responses in tadpoles, which could trigger cell death pathways. Concluding, these analyses are important for applications in assessment of contaminated aquatic environments and their biomonitoring, which will evaluate the potential toxicity of xenobiotics, for example, the nanoparticles and pyrethrum extract in frog species. However, further studies are needed to better understand the effects of nanopesticides and botanical insecticides on non-target organisms, in order to contribute to regulatory aspects of future uses for these systems.
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Affiliation(s)
- C R Oliveira
- Universidade Estadual Paulista (UNESP), Instituto de Ciência e Tecnologia de Sorocaba, Laboratório de Nanotecnologia Ambiental, Av. Três de Março, 511, Alto da Boa Vista, 18087-180, Sorocaba, SP, Brazil; Universidade Federal de São Carlos (UFSCar), Campus Sorocaba, Departamento de Biologia, Laboratório de Fisiologia da Conservação e Laboratório de Ecotoxicologia e Biomarcadores em Animais, Rodovia João Leme dos Santos km 110, Itinga, 18052-780, Sorocaba, SP, Brazil
| | - T D Garcia
- Universidade Federal de São Carlos (UFSCar), Campus Sorocaba, Programa de Pós-Graduação em Biotecnologia e Monitoramento Ambiental, Rodovia João Leme dos Santos km 110, Itinga, 18052-780, Sorocaba, SP, Brazil
| | - L Franco-Belussi
- Universidade Federal de Mato Grosso do Sul (UFMS), Instituto de Biociências, Laboratório de Patologia Experimental, Avenida Costa e Silva, s/n, Bairro Universitário, 79002-970, Campo Grande, MS, Brazil
| | - R F Salla
- Universidade Estadual de Campinas (UNICAMP), Instituto de Biologia, Departamento de Biologia Animal, R. Monteiro Lobato, 255, Cidade Universitária, 13083-862, Campinas, SP, Brazil
| | - B F S Souza
- Universidade Federal de São Carlos (UFSCar), Campus Sorocaba, Programa de Pós-Graduação em Biotecnologia e Monitoramento Ambiental, Rodovia João Leme dos Santos km 110, Itinga, 18052-780, Sorocaba, SP, Brazil; Universidade Federal de São Carlos (UFSCar), Campus Sorocaba, Departamento de Biologia, Laboratório de Fisiologia da Conservação e Laboratório de Ecotoxicologia e Biomarcadores em Animais, Rodovia João Leme dos Santos km 110, Itinga, 18052-780, Sorocaba, SP, Brazil
| | - N F S de Melo
- Faculdade de Medicina São Leopoldo Mandic, Campus Araras, Av. Dona Renata, 71, Santa Cândida, 13600-001, Araras, SP, Brazil
| | - S P Irazusta
- Faculdade de Tecnologia de Sorocaba (FATEC), Centro Estadual de Educação Tecnológica Paula Souza, Campus Sorocaba, Laboratório de Ecotoxicologia, Av. Eng. Carlos R. Mendes, 2015, Além Ponte, 18013-280, Sorocaba, SP, Brazil
| | - M Jones-Costa
- Universidade Federal de São Carlos (UFSCar), Campus Sorocaba, Programa de Pós-Graduação em Biotecnologia e Monitoramento Ambiental, Rodovia João Leme dos Santos km 110, Itinga, 18052-780, Sorocaba, SP, Brazil; Universidade Federal de São Carlos (UFSCar), Campus Sorocaba, Departamento de Biologia, Laboratório de Fisiologia da Conservação e Laboratório de Ecotoxicologia e Biomarcadores em Animais, Rodovia João Leme dos Santos km 110, Itinga, 18052-780, Sorocaba, SP, Brazil.
| | - E C M Silva-Zacarin
- Universidade Federal de São Carlos (UFSCar), Campus Sorocaba, Programa de Pós-Graduação em Biotecnologia e Monitoramento Ambiental, Rodovia João Leme dos Santos km 110, Itinga, 18052-780, Sorocaba, SP, Brazil; Universidade Federal de São Carlos (UFSCar), Campus Sorocaba, Departamento de Biologia, Laboratório de Fisiologia da Conservação e Laboratório de Ecotoxicologia e Biomarcadores em Animais, Rodovia João Leme dos Santos km 110, Itinga, 18052-780, Sorocaba, SP, Brazil
| | - L F Fraceto
- Universidade Estadual Paulista (UNESP), Instituto de Ciência e Tecnologia de Sorocaba, Laboratório de Nanotecnologia Ambiental, Av. Três de Março, 511, Alto da Boa Vista, 18087-180, Sorocaba, SP, Brazil.
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Reed MD, Iceman KE, Harris MB, Taylor BE. Buccal rhythmogenesis and CO 2 sensitivity in Lithobates catesbeianus tadpole brainstems across metamorphosis. Respir Physiol Neurobiol 2019; 268:103251. [PMID: 31279052 DOI: 10.1016/j.resp.2019.103251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 06/19/2019] [Accepted: 07/02/2019] [Indexed: 11/19/2022]
Abstract
Bullfrog tadpoles ventilate both the buccal cavity and lung. In isolated brainstems, the midbrain/pons influences CO2 responsiveness and timing of lung ventilatory bursting, depending on larval development. However, little is known about midbrain/pons influences on buccal burst patterns. As such, we investigated how removal of this region affects buccal burst shape and CO2 responsiveness across development. We measured facial nerve activity in brainstems isolated from tadpoles during early and late developmental stages, under normal and elevated levels of CO2. Brainstems were either left intact or transected by removing the midbrain/pons. In late stage preparations, buccal burst pattern differed between intact and reduced preparations, and bursts were responsive to elevated CO2 in these reduced preparations. These results suggest the midbrain/pons affects tadpole buccal burst pattern and CO2 responsiveness, perhaps similar to its influences on lung ventilation.
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Affiliation(s)
- Mitchell D Reed
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, 99775, United States.
| | - Kimberly E Iceman
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, 99775, United States; Department of Biology, Valparaiso University, Valparaiso, IN, 46383, United States
| | - Michael B Harris
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, 99775, United States; Department of Biology, California State University Long Beach, Long Beach, CA, 90840, United States
| | - Barbara E Taylor
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, 99775, United States; Department of Biology, California State University Long Beach, Long Beach, CA, 90840, United States
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do Amaral DF, Montalvão MF, de Oliveira Mendes B, da Costa Araújo AP, de Lima Rodrigues AS, Malafaia G. Sub-lethal effects induced by a mixture of different pharmaceutical drugs in predicted environmentally relevant concentrations on Lithobates catesbeianus (Shaw, 1802) (Anura, ranidae) tadpoles. Environ Sci Pollut Res Int 2019; 26:600-616. [PMID: 30411290 DOI: 10.1007/s11356-018-3656-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 10/31/2018] [Indexed: 06/08/2023]
Abstract
The increasing consumption of medications by humans has negative effects such as the increased disposal of these compounds in the environment. Little is known about how the disposal of a "drug mix" (DM) in aquatic ecosystems can affect their biota. Thus, we evaluated whether the exposure of Lithobates casteibeianus tadpoles to a DM composed of different medication classes (antibiotic, anti-inflammatory, antidepressant, anxiolytic, analgesic, and antacid drugs)-at environmentally relevant concentrations-may change their oral morphology, trigger behavioral disorders, and have mutagenic effects on erythrocyte cells. Based on our data, animals exposed to the DM showed changes in mandibular sheath pigmentation, dentition, and swimming activity, as well as atypical behavior in the social aggregation test [with co-specific and interspecific (Physalaemus cuvieri) individuals] and antipredatory defensive response deficit (chemical stimulus from Odonata larvae), after 15 exposure days. The mutagenic analysis revealed higher frequency of nuclear abnormalities in the erythrocytes of tadpoles exposed to the DM (e.g., multilobulated, blebbed, kidney-shaped, notched nucleus, binuclear, and micronucleated erythrocytes). Given the chemical complexity of the DM, we assumed that several organic functions may have been affected, either by the isolated, synergistic, antagonistic, or additive action of DM compounds. Finally, our study confirms the toxicological potential of DM in L. catesbeianus tadpoles, with emphasis to impacts that can affect the fitness of individuals and their natural populations. Thus, we suggest that more attention should be given to the disposal of medications in the environment and reinforce the need of improving water and sewage treatment systems.
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Affiliation(s)
- Diogo Ferreira do Amaral
- Post-Graduation Program in Conservation of Cerrado Natural Resources - Biological Research Laboratory, Goiano Federal Institute-Urutaí Campus, Urutaí, GO, Brazil
| | - Mateus Flores Montalvão
- Post-Graduation Program in Conservation of Cerrado Natural Resources - Biological Research Laboratory, Goiano Federal Institute-Urutaí Campus, Urutaí, GO, Brazil
| | - Bruna de Oliveira Mendes
- Post-Graduation Program in Conservation of Cerrado Natural Resources - Biological Research Laboratory, Goiano Federal Institute-Urutaí Campus, Urutaí, GO, Brazil
| | - Amanda Pereira da Costa Araújo
- Post-Graduation Program in Conservation of Cerrado Natural Resources - Biological Research Laboratory, Goiano Federal Institute-Urutaí Campus, Urutaí, GO, Brazil
| | - Aline Sueli de Lima Rodrigues
- Post-Graduation Program in Conservation of Cerrado Natural Resources - Biological Research Laboratory, Goiano Federal Institute-Urutaí Campus, Urutaí, GO, Brazil
- Biologigal Sciences Department, Post-Graduation Program in Conservation of Cerrado Natural Resources, Goiano Federal Institute-Urutaí Campus, Urutaí, GO, Brazil
| | - Guilherme Malafaia
- Post-Graduation Program in Conservation of Cerrado Natural Resources - Biological Research Laboratory, Goiano Federal Institute-Urutaí Campus, Urutaí, GO, Brazil.
- Biologigal Sciences Department, Post-Graduation Program in Conservation of Cerrado Natural Resources, Goiano Federal Institute-Urutaí Campus, Urutaí, GO, Brazil.
- Laboratório de Pesquisas Biológicas, Instituto Federal Goiano-Campus Urutaí, Rodovia Geraldo Silva Nascimento, 2,5 km, Zona Rural, Urutaí, GO, Brazil.
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10
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Jones-Costa M, Franco-Belussi L, Vidal FAP, Gongora NP, Castanho LM, Dos Santos Carvalho C, Silva-Zacarin ECM, Abdalla FC, Duarte ICS, Oliveira CD, de Oliveira CR, Salla RF. Cardiac biomarkers as sensitive tools to evaluate the impact of xenobiotics on amphibians: the effects of anionic surfactant linear alkylbenzene sulfonate (LAS). Ecotoxicol Environ Saf 2018; 151:184-190. [PMID: 29351853 DOI: 10.1016/j.ecoenv.2018.01.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 06/07/2023]
Abstract
Amphibian populations have been experiencing a drastic decline worldwide. Aquatic contaminants are among the main factors responsible for this decline, especially in the aquatic environment. The linear alkylbenzene sulfonate (LAS) is of particular concern, since it represents 84% of the anionic surfactants' trade. In Brazil, the maximal LAS concentration allowed in fresh waters is 0.5mgL-1, but its potential harmful effects in amphibians remain unknown. Therefore, this study aimed to analyze the effects of a sublethal concentration of LAS (0.5mgL-1) for 96h on sensitive cardiac biomarkers of bullfrog tadpoles, Lithobates catesbeianus (Shaw, 1802). For this, we measured the activity level (AL - % of animals), in situ heart rate (fH - bpm), relative ventricular mass (RVM - % of body mass), in vitro myocardial contractility and cardiac histology of the ventricles. Tadpoles' AL and fH decreased in LAS group. In contrast, the RVM increased, as a result of a hypertrophy of the myocardium, which was corroborated by the enlargement of the nuclear measures and the increase of myocytes' diameters. These cellular effects resulted in an elevation of the in vitro contractile force of ventricle strips. Acceleration in the contraction (TPT - ms) also occurred, although no alterations in the time to relaxation (THR -ms) were observed. Therefore, it can be concluded that even when exposed to an environmentally safe concentration, this surfactant promotes several alterations in the cardiac function of bullfrog tadpoles that can impair their development, making them more susceptible to predators and less competitive in terms of reproduction success. Thus, LAS concentrations that are considered safe by Brazilian by regulatory agencies must be revised in order to minimize a drastic impact over amphibian populations. This study demonstrates the relevance of employing cardiac biomarkers at different levels (e.g., morphological, physiological and cellular) to evaluate effects of xenobiotics in tadpoles.
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Affiliation(s)
- Monica Jones-Costa
- Laboratório de Fisiologia da Conservação, Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil
| | - Lilian Franco-Belussi
- Laboratório de Fisiologia da Conservação, Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil; Programa de Pós-Graduação em Biotecnologia e Monitoramento Ambiental, Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil; Departamento de Biologia, Universidade Estadual Paulista (UNESP), 15054-000 São José do Rio Preto, São Paulo, Brazil.
| | - Felipe Augusto Pinto Vidal
- Laboratório de Fisiologia da Conservação, Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil; Programa de Pós-Graduação em Biotecnologia e Monitoramento Ambiental, Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil
| | - Nathália Penteado Gongora
- Laboratório de Fisiologia da Conservação, Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil
| | - Luciano Mendes Castanho
- Laboratório de Fisiologia da Conservação, Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil
| | - Cleoni Dos Santos Carvalho
- Laboratório de Fisiologia da Conservação, Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil
| | - Elaine Cristina Mathias Silva-Zacarin
- Núcleo de Pesquisa em Ecotoxicologia de Abelhas, Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil
| | - Fabio Camargo Abdalla
- Laboratório de Biologia Estrutural e Funcional, Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil
| | - Iolanda Cristina Silveira Duarte
- Laboratório de Microbiologia Ambiental (LaMA), Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil
| | - Classius De Oliveira
- Departamento de Biologia, Universidade Estadual Paulista (UNESP), 15054-000 São José do Rio Preto, São Paulo, Brazil.
| | - Cristiane Ronchi de Oliveira
- Departamento de Biologia, Universidade Estadual Paulista (UNESP), 15054-000 São José do Rio Preto, São Paulo, Brazil
| | - Raquel Fernanda Salla
- Laboratório de Fisiologia da Conservação, Universidade Federal de São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Bairro do Itinga, Sorocaba, São Paulo 18052-780, Brazil.
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11
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Tashiro N, Nishi S. Short-term facilitation and depression of transmitter release at amphibian sympathetic ganglionic cells - Mathematical/computational modeling. Brain Res 2017; 1672:35-43. [PMID: 28684049 DOI: 10.1016/j.brainres.2017.06.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 03/01/2017] [Accepted: 06/28/2017] [Indexed: 11/19/2022]
Abstract
There have been few investigations of the short-term plasticity of synaptic transmission at amphibian sympathetic ganglionic cells where the frequency of miniature excitatory postsynaptic potentials is too low to measure an accurate quantum size. This has made it difficult to investigate the mechanism of synaptic transmission at the ganglionic cells by quantal analysis. A theoretical equation, therefore, is proposed. This equation is based on the premise that transmitter release is due to the product of two factors: intracellular calcium ([Ca2+]i) and acetylcholine (ACh), which is a readily releasable transmitter. The equation accounts for the mechanism of synaptic facilitation and depression of transmitter release at the ganglionic cells in the paired-pulse experiments. The purpose of the present experiment is to investigate whether the equation accounts for the mechanism of short-term plasticity of synaptic transmission produced by a train of pulses at the ganglionic cells. Trains of excitatory postsynaptic current (EPSC) were recorded, and the ratios of the nth EPSC induced by the nth pulse to the initial EPSC were analyzed by the equation. The results indicated that the mechanism of short-term facilitation and depression was interpreted by the equation, which met the following two requirements: [Ca2+]i consisting of two components of residual Ca2+ and the mobilization rate of ACh which accelerated as stimulus frequencies increased. The findings were consistent with those clarified by the quantal analysis. It is suggested that the theoretical equation is also useful for the investigation of the effect of chemical substances on synaptic transmission.
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Affiliation(s)
- Nobutada Tashiro
- Neurophysiology Laboratory, Departments of Pharmacology and Therapeutics, Loyola University Medical Center, Maywood, IL 60153, USA.
| | - Shogoro Nishi
- Neurophysiology Laboratory, Departments of Pharmacology and Therapeutics, Loyola University Medical Center, Maywood, IL 60153, USA
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12
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Vasconcelos AM, Daam MA, de Resende JC, Casali-Pereira MP, Espíndola ELG. Survival and development of bullfrog tadpoles in microcosms treated with abamectin. Ecotoxicology 2017; 26:729-737. [PMID: 28409414 DOI: 10.1007/s10646-017-1804-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/05/2017] [Indexed: 05/22/2023]
Abstract
As compared to other aquatic taxonomic groups, few studies have been conducted so far evaluating the potential risks of pesticides to amphibians. Furthermore, most existing studies with amphibians consist of acute laboratory toxicity tests that mostly only evaluated single peak pesticide exposure. In the present study, potential chronic effects of single and repeated abamectin applications on the survival and development of L. catesbeianus tadpoles under (semi-) field conditions were evaluated. To this end, tadpoles were housed in microcosms treated with single or repeated applications of abamectin (as the commercial product Vertimec® 18 EC). The single application level corresponded to the previously established laboratory 96 h LC50 of the test organism, whereas the repeated application was based on abamectin concentrations likely to occur in runoff water from agricultural areas where Vertimec® 18 EC is applied. Under semi-field conditions, toxicity after the single application was greater than would be expected from the laboratory toxicity value. Although the repeated application did not exert direct effects on tadpole survival, the observed delay in development may have pronounced effect on the fitness and survival of anuran populations in edge-of-field water bodies.
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Affiliation(s)
- Ana M Vasconcelos
- NEEA/CRHEA/SHS, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, 13.560-970, São Carlos, Brazil
| | - Michiel A Daam
- NEEA/CRHEA/SHS, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, 13.560-970, São Carlos, Brazil.
- CENSE, Department of Environmental Sciences and Engineering, Faculty of Sciences and Technology, New University of Lisbon, Quinta da Torre, Caparica, 2829-516, Portugal.
| | - Juliana C de Resende
- NEEA/CRHEA/SHS, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, 13.560-970, São Carlos, Brazil
| | - Maressa P Casali-Pereira
- NEEA/CRHEA/SHS, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, 13.560-970, São Carlos, Brazil
| | - Evaldo L G Espíndola
- NEEA/CRHEA/SHS, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, 13.560-970, São Carlos, Brazil
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13
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Carvalho CS, Utsunomiya HSM, Pasquoto T, Lima R, Costa MJ, Fernandes MN. Blood cell responses and metallothionein in the liver, kidney and muscles of bullfrog tadpoles, Lithobates catesbeianus, following exposure to different metals. Environ Pollut 2017; 221:445-452. [PMID: 27989390 DOI: 10.1016/j.envpol.2016.12.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 12/01/2016] [Accepted: 12/08/2016] [Indexed: 06/06/2023]
Abstract
The hematological parameters and metallothionein (MT) levels in the liver, kidney and muscles were measured in bullfrog tadpoles, Lithobates catesbeianus, following exposures to 1 μg L-1 of zinc (Zn), copper (Cu) and cadmium (Cd) alone or in combination (1:1 and 1:1:1) for 2 and 16 days. Metal accumulation occurred in all organs, with the highest values found in the kidney, followed by the muscles and liver. After exposure to isolated metals, the accumulation was in the following order: Cd > Zn > Cu in the liver and muscles and Cd > Cu > Zn in the kidney. Exposure to combined metals (Zn + Cu, Zn + Cd, Cu + Cd and Zn + Cu + Cd) revealed complex responses, such as metal accumulation increased or decreased over the exposure periods, suggesting possible competion at the uptake sites and/or metabolization and elimination processes in each organ. The MT concentration increased in the organs of tadpoles following metal exposure alone, mainly in the liver, for both periods. After the combined exposures, the MT levels were higher in the liver and muscles at 16 days, suggesting that the interaction between metals was additive, and the level was decreased in the kidney after 2 and 16 days of exposure. The whole blood hemoglobin content (Hb), red blood cell count (RBCs) and mean corpuscular hemoglobin (MCH) differed from the control groups after 2 and 16 days of exposure, showing changes in the improvement of oxygen transport. The number of lymphocytes increased, and the levels of neutrophils, eosinophils, basophils and monocytes were reduced after exposure to the metals. The changes in blood cells suggested that tadpoles have a mechanism to improve oxygen transport probably because of the increased oxygen demand and a general reduction in defense cells. The exposure of L. catesbeianus to metals during the larval phase can generate long-term dysfunction to a degree, which could lead to alterations in their health status.
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Affiliation(s)
- C S Carvalho
- Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme dos Santos, km 110, SP-264, CEP 18052-780, Sorocaba, São Paulo, Brazil; Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental, Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme dos Santos, km 110, SP-264, CEP 18052-780, Sorocaba, São Paulo, Brazil.
| | - H S M Utsunomiya
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental, Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme dos Santos, km 110, SP-264, CEP 18052-780, Sorocaba, São Paulo, Brazil
| | - T Pasquoto
- Universidade de Sorocaba, Rodovia Raposo Tavares, km 92, 5 - Artura, Sorocaba - SP, 18023-000, SP, Brazil
| | - R Lima
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental, Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme dos Santos, km 110, SP-264, CEP 18052-780, Sorocaba, São Paulo, Brazil; Universidade de Sorocaba, Rodovia Raposo Tavares, km 92, 5 - Artura, Sorocaba - SP, 18023-000, SP, Brazil
| | - M J Costa
- Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme dos Santos, km 110, SP-264, CEP 18052-780, Sorocaba, São Paulo, Brazil; Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental, Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme dos Santos, km 110, SP-264, CEP 18052-780, Sorocaba, São Paulo, Brazil
| | - M N Fernandes
- Universidade Federal de São Carlos, Departamento de Ciências Fisiológicas, Caixa Postal 676, Rodovia Washington Luis, km 235, CEP 13565-905, São Carlos, SP, Brazil
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14
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Veronez ACDS, Salla RV, Baroni VD, Barcarolli IF, Bianchini A, Dos Reis Martinez CB, Chippari-Gomes AR. Genetic and biochemical effects induced by iron ore, Fe and Mn exposure in tadpoles of the bullfrog Lithobates catesbeianus. Aquat Toxicol 2016; 174:101-108. [PMID: 26930479 DOI: 10.1016/j.aquatox.2016.02.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 02/15/2016] [Accepted: 02/16/2016] [Indexed: 06/05/2023]
Abstract
For decades, the extraction of minerals has intensified in order to meet the demand of industry. Iron ore deposits are important sources of metals, such as iron (Fe) and manganese (Mn). The particulate ores can be dispersed during extraction, transport and storage, with potential to induce biological impacts. Amphibians are very sensitive to environmental stressors. Therefore, the present study aimed to assess the effects of iron ore, Fe and Mn exposure during the metamorphosis of Lithobates catesbeianus. Endpoints analyzed included morphological (biometrical and developmental analyses), whole body Fe and Mn concentration in, plasma ferritin concentration, erythrocyte DNA damage (measured through comet assay and micronucleus test) and liver activity of enzymes involved in oxidative status [glutathione S-transferase (GST) and catalase (CAT)]. Tadpoles were kept under control condition (no contaminant addition) or exposed to iron ore (3.79mg/L as fine particulate matter); Fe (nominal concentration: 0.51mg/L Fe as C10H12FeN2NaO8; Fe-EDTA); and Mn (nominal concentration: 5.23mg/L Mn as 4H2O.MnCl2) for 30 days. Virtually, no mortality was observed, except for one tadpole found dead in the iron ore treatment. However, tadpoles exposed to iron ore had longer tail than those kept under control conditions while tadpoles exposed to manganese chloride showed higher body length than control ones. Exposure to Fe and Mn induced a delay in tadpole metamorphosis, especially when these metals are presented not as a mixture (iron ore). Tadpoles exposed to iron ore had increased whole body Fe and Mn while those exposed to Fe and Mn accumulated each metal individually. Tadpoles exposed to any of the contaminants tested showed a significant increase in erythrocyte DNA damage and frequency of micronuclei. In addition, they showed higher liver GST activity respect with those kept under control conditions. Plasma ferritin concentration and liver CAT activity were higher only in tadpoles exposed to iron ore. These findings indicated that tadpoles accumulated Fe and Mn at the whole body level after exposure to the single metals or to their mixture as iron ore. In addition, they indicate that Fe and Mn accumulation can induce oxidative stress with consequent significant developmental, genotoxic and biochemical effects in L. catesbeianus tadpoles.
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Affiliation(s)
- Alexandra Caroline da Silva Veronez
- Universidade Vila Velha-UVV, Laboratório de Ictiologia Aplicada (LAB PEIXE), Rua Comissário José Dantas de Melo no 21, Boa Vista, 29102-770 Vila Velha, ES, Brazil.
| | - Rômulo Victor Salla
- Universidade Vila Velha-UVV, Laboratório de Ictiologia Aplicada (LAB PEIXE), Rua Comissário José Dantas de Melo no 21, Boa Vista, 29102-770 Vila Velha, ES, Brazil.
| | - Vinícius Dadalto Baroni
- Universidade Vila Velha-UVV, Laboratório de Ictiologia Aplicada (LAB PEIXE), Rua Comissário José Dantas de Melo no 21, Boa Vista, 29102-770 Vila Velha, ES, Brazil.
| | - Indianara Fernanda Barcarolli
- Universidade do Estado de Santa Catarina-UDESC, Av. Madre Benvenuta, 2007-Itacorubi, 88035-001 Florianópolis, SC, Brazil.
| | - Adalto Bianchini
- Universidade Federal do Rio Grande-FURG, Instituto de Ciências Biológicas, Av. Itália km 8, Carreiros, 96, 203-900 Rio Grande, RS, Brazil.
| | - Claudia Bueno Dos Reis Martinez
- Universidade Estadual de Londrina - UEL, Departamento de Ciências Fisiológicas, Laboratório de Ecofisiologia Animal, Caixa-postal: 10011, 86057-970 Londrina, PR, Brazil.
| | - Adriana Regina Chippari-Gomes
- Universidade Vila Velha-UVV, Laboratório de Ictiologia Aplicada (LAB PEIXE), Rua Comissário José Dantas de Melo no 21, Boa Vista, 29102-770 Vila Velha, ES, Brazil.
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15
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Vasconcelos AM, Daam MA, dos Santos LRA, Sanches ALM, Araújo CVM, Espíndola ELG. Acute and chronic sensitivity, avoidance behavior and sensitive life stages of bullfrog tadpoles exposed to the biopesticide abamectin. Ecotoxicology 2016; 25:500-509. [PMID: 26758616 DOI: 10.1007/s10646-015-1608-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/28/2015] [Indexed: 06/05/2023]
Abstract
As compared to other aquatic organism groups, relatively few studies have been conducted so far evaluating the toxicity of pesticides to amphibians. This may at least partly be due to the fact that regulations for registering pesticides usually do not require testing amphibians. The sensitivity of amphibians is generally considered to be covered by that based on toxicity tests with other aquatic organisms (e.g. fish) although the impact of a pesticide on amphibians may be very different. In the present study, acute and chronic laboratory tests were conducted to evaluate the acute and chronic toxicity of abamectin (as Vertimec(®) 18EC) to bullfrog (Lithobates catesbeianus) tadpoles. Acute tests were conducted at two tadpole stages (Gosner stage 21G and 25G) and avoidance tests were also conducted with stage Gosner stage 21G tadpoles. Calculated acute toxicity values were greater than those reported for standard fish test species, hence supporting the use of fish toxicity data as surrogates for amphibians in acute risk assessments. Given the limited number and extent of available amphibian toxicity studies, however, research needs to increase our understanding of pesticide toxicity to amphibians are discussed.
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Affiliation(s)
- Ana M Vasconcelos
- NEEA/CRHEA, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, São Carlos, 13.560-970, Brazil
| | - Michiel A Daam
- NEEA/CRHEA, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, São Carlos, 13.560-970, Brazil.
- CESAM and Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-191, Aveiro, Portugal.
| | - Liliana R A dos Santos
- Instituto Superior de Agronomia, University of Lisbon, Tapada da Ajuda, 1349-017, Lisbon, Portugal
| | - Ana L M Sanches
- NEEA/CRHEA, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, São Carlos, 13.560-970, Brazil
| | - Cristiano V M Araújo
- Central Department of Research (DCI), Ecuadorian Aquatic Ecotoxicology (ECUACTOX) Group, Universidad Laica Eloy Alfaro de Manabí (ULEAM), Manta, Ecuador
- Centre of Functional Ecology (CFE), Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - Evaldo L G Espíndola
- NEEA/CRHEA, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, São Carlos, 13.560-970, Brazil
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16
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Salla RF, Gamero FU, Rissoli RZ, Dal-Medico SE, Castanho LM, Carvalho CDS, Silva-Zacarin ECM, Kalinin AL, Abdalla FC, Costa MJ. Impact of an environmental relevant concentration of 17α-ethinylestradiol on the cardiac function of bullfrog tadpoles. Chemosphere 2016; 144:1862-1868. [PMID: 26539711 DOI: 10.1016/j.chemosphere.2015.10.042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 09/30/2015] [Accepted: 10/10/2015] [Indexed: 06/05/2023]
Abstract
This study evaluated if a concentration of 17α-ethinylestradiol (EE2 - 10 ng L(-1) for 96 h) normally found in Brazilian surface waters exerts any impact on cardiac function of bullfrog tadpoles (25 Gosner stage), Lithobates catesbeianus. During exposure, the animals' activity level (AL -% of active individuals) was monitored twice a day. Then, the in loco heart rate (f(H) - bpm) was determined, as well as the relative ventricular mass (RVM - % of body mass). Afterwards, cardiac ventricles were mounted for isometric force recordings (CS - mN mm(-2)), and determination of the cardiac pumping capacity (CPC - mN mm(-2) min(-1)). EE2 did not affect tadpoles' AL, although it resulted in a tachycardia in animals exposed to EE2 (f(H) = 66 bpm) when compared to controls (f(H) = 52 bpm), suggesting that EE2 acts directly on the cardiac muscle of tadpoles, rather than being a result of an increased cardiac demand due to a higher activity level (i.e., avoidance response). Additionally, EE2 exerted a positive inotropic response, which resulted in a higher CPC, which occurred independently of an increase in the number of myofibrils of EE2-exposed animals, since RVM remained similar between experimental groups. Thus, the increase on cardiac demand induced by the exposure to EE2 elevates considerably the animal energy expenditure, diverting a large amount of energy that tadpoles could use for their growth and development. These alterations can make amphibians more susceptible to predators and reduce the likelihood to reach reproductive stage.
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Affiliation(s)
- Raquel F Salla
- Laboratory of Conservation Physiology, Department of Biology, Federal University of São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Sorocaba, São Paulo, Brazil
| | - Fernando U Gamero
- Laboratory of Conservation Physiology, Department of Biology, Federal University of São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Sorocaba, São Paulo, Brazil
| | - Rafael Z Rissoli
- Laboratory of Conservation Physiology, Department of Biology, Federal University of São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Sorocaba, São Paulo, Brazil
| | - Samuel E Dal-Medico
- Laboratory of Conservation Physiology, Department of Biology, Federal University of São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Sorocaba, São Paulo, Brazil
| | - Luciano Mendes Castanho
- Department of Morphology and Pathology, Pontifical Catholic University of São Paulo, Rua Joubert Wey, 290, Sorocaba, São Paulo, Brazil
| | - Cleoni dos Santos Carvalho
- Laboratory of Conservation Physiology, Department of Biology, Federal University of São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Sorocaba, São Paulo, Brazil
| | - Elaine C M Silva-Zacarin
- Laboratory of Structural and Functional Biology, Department of Biology, Federal University of São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Sorocaba, São Paulo, Brazil
| | - Ana L Kalinin
- Laboratory of Comparative Physiology and Biochemistry, Department of Physiology, Federal University of São Carlos, Rodovia Washington Luís (SP-310), km 235, São Carlos, São Paulo, Brazil
| | - Fabio C Abdalla
- Laboratory of Structural and Functional Biology, Department of Biology, Federal University of São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Sorocaba, São Paulo, Brazil
| | - Monica J Costa
- Laboratory of Conservation Physiology, Department of Biology, Federal University of São Carlos, Rodovia João Leme dos Santos (SP-264), Km 110, Sorocaba, São Paulo, Brazil.
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Robertson BD, Sawicki GS. Unconstrained muscle-tendon workloops indicate resonance tuning as a mechanism for elastic limb behavior during terrestrial locomotion. Proc Natl Acad Sci U S A 2015; 112:E5891-8. [PMID: 26460038 PMCID: PMC4629365 DOI: 10.1073/pnas.1500702112] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In terrestrial locomotion, there is a missing link between observed spring-like limb mechanics and the physiological systems driving their emergence. Previous modeling and experimental studies of bouncing gait (e.g., walking, running, hopping) identified muscle-tendon interactions that cycle large amounts of energy in series tendon as a source of elastic limb behavior. The neural, biomechanical, and environmental origins of these tuned mechanics, however, have remained elusive. To examine the dynamic interplay between these factors, we developed an experimental platform comprised of a feedback-controlled servo-motor coupled to a biological muscle-tendon. Our novel motor controller mimicked in vivo inertial/gravitational loading experienced by muscles during terrestrial locomotion, and rhythmic patterns of muscle activation were applied via stimulation of intact nerve. This approach was based on classical workloop studies, but avoided predetermined patterns of muscle strain and activation-constraints not imposed during real-world locomotion. Our unconstrained approach to position control allowed observation of emergent muscle-tendon mechanics resulting from dynamic interaction of neural control, active muscle, and system material/inertial properties. This study demonstrated that, despite the complex nonlinear nature of musculotendon systems, cyclic muscle contractions at the passive natural frequency of the underlying biomechanical system yielded maximal forces and fractions of mechanical work recovered from previously stored elastic energy in series-compliant tissues. By matching movement frequency to the natural frequency of the passive biomechanical system (i.e., resonance tuning), muscle-tendon interactions resulting in spring-like behavior emerged naturally, without closed-loop neural control. This conceptual framework may explain the basis for elastic limb behavior during terrestrial locomotion.
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Affiliation(s)
- Benjamin D Robertson
- Joint Department of Biomedical Engineering, University of North Carolina-Chapel Hill and North Carolina State University, Raleigh, NC 27695
| | - Gregory S Sawicki
- Joint Department of Biomedical Engineering, University of North Carolina-Chapel Hill and North Carolina State University, Raleigh, NC 27695
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Sawicki GS, Robertson BD, Azizi E, Roberts TJ. Timing matters: tuning the mechanics of a muscle-tendon unit by adjusting stimulation phase during cyclic contractions. J Exp Biol 2015; 218:3150-9. [PMID: 26232413 PMCID: PMC4631775 DOI: 10.1242/jeb.121673] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 07/17/2015] [Indexed: 11/20/2022]
Abstract
A growing body of research on the mechanics and energetics of terrestrial locomotion has demonstrated that elastic elements acting in series with contracting muscle are critical components of sustained, stable and efficient gait. Far fewer studies have examined how the nervous system modulates muscle-tendon interaction dynamics to optimize 'tuning' or meet varying locomotor demands. To explore the fundamental neuromechanical rules that govern the interactions between series elastic elements (SEEs) and contractile elements (CEs) within a compliant muscle-tendon unit (MTU), we used a novel work loop approach that included implanted sonomicrometry crystals along muscle fascicles. This enabled us to decouple CE and SEE length trajectories when cyclic strain patterns were applied to an isolated plantaris MTU from the bullfrog (Lithobates catesbeianus). Using this approach, we demonstrate that the onset timing of muscle stimulation (i.e. stimulation phase) that involves a symmetrical MTU stretch-shorten cycle during active force production results in net zero mechanical power output, and maximal decoupling of CE and MTU length trajectories. We found it difficult to 'tune' the muscle-tendon system for strut-like isometric force production by adjusting stimulation phase only, as the zero power output condition involved significant positive and negative mechanical work by the CE. A simple neural mechanism - adjusting muscle stimulation phase - could shift an MTU from performing net zero to net positive (energy producing) or net negative (energy absorbing) mechanical work under conditions of changing locomotor demand. Finally, we show that modifications to the classical work loop paradigm better represent in vivo muscle-tendon function during locomotion.
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Affiliation(s)
- Gregory S Sawicki
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill, Raleigh, NC 27695, USA
| | - Benjamin D Robertson
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill, Raleigh, NC 27695, USA
| | - Emanuel Azizi
- Department of Ecology and Evolutionary Biology, School of Biological Sciences, University of California, Irvine, CA 92697, USA
| | - Thomas J Roberts
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912-G, USA
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Wolff SE, Veldhoen N, Helbing CC, Ramirez CA, Malpas JM, Propper CR. Estrogenic environmental contaminants alter the mRNA abundance profiles of genes involved in gonadal differentiation of the American bullfrog. Sci Total Environ 2015; 521-522:380-7. [PMID: 25863316 PMCID: PMC4440455 DOI: 10.1016/j.scitotenv.2015.02.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 02/06/2015] [Accepted: 02/09/2015] [Indexed: 05/08/2023]
Abstract
Wildlife and human populations are exposed to anthropogenic mixtures of chemicals in the environment that may adversely influence normal reproductive function and development. We determined the effects of exposure to estrogenic chemicals and wastewater effluent (WWE) on developing gonads of the American bullfrog, Rana (Lithobates) catesbeiana, a species whose widespread distribution make it an ideal model for environmental monitoring of endocrine effects of chemical contaminants. Premetamorphic bullfrog tadpoles were exposed to treatment vehicle, 17β-estradiol (E2; 10(-9)M) or 4-tert-octylphenol (OP; 10(-9)M, 10(-8)M, and 10(-7)M). Additionally, gonadal differentiation was evaluated in bullfrog tadpoles from a WWE-containing site versus those from a reference location receiving no WWE. In both studies, phenotypic sex, steroidogenic factor-1 (nr5a1), and aromatase (cyp19a1) mRNA levels using quantitative real-time PCR were determined. Exposure to E2 or OP did not alter sex ratios. In controls, both nr5a1 and cyp19a1 transcript levels exhibited sexual dimorphism, with males demonstrating higher levels of nr5a1 and females greater abundance of cyp19a1. However, E2 exposure increased cyp19a1 mRNA abundance in testes and decreased levels in ovaries, eliminating the sexual dimorphism observed in controls. E2-exposed males exhibited increased nr5a1 transcript levels in the testes compared to controls, while females demonstrated no E2 effect. OP treatment had no effect on female cyp19a1 mRNA abundance, but exposure to 10(-7)M OP increased testicular transcript levels. Treatment with 10(-9) and 10(-8)M OP, but not 10(-7)M, resulted in decreased abundance of nr5a1 transcript in both ovaries and testes. Animals from the field had sexually dimorphic gonadal levels of cyp19a1, but both sexes from the WWE site exhibited elevated cyp19a1 transcript abundance compared to the reference location. Individual chemical compounds and anthropogenic wastewater effluent dispersed within the environment influence the levels of gonadal mRNA encoding key proteins involved in gonadal differentiation.
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Affiliation(s)
- Stephanie E Wolff
- Department of Biological Sciences, S. Beaver St., Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Nik Veldhoen
- Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 1700, STN CSC, Victoria, British Columbia V8W 2Y2, Canada
| | - Caren C Helbing
- Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 1700, STN CSC, Victoria, British Columbia V8W 2Y2, Canada
| | - Claire A Ramirez
- Department of Biological Sciences, S. Beaver St., Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Janae M Malpas
- Department of Biological Sciences, S. Beaver St., Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Catherine R Propper
- Department of Biological Sciences, S. Beaver St., Northern Arizona University, Flagstaff, AZ 86011, USA.
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Murugan K, Priyanka V, Dinesh D, Madhiyazhagan P, Panneerselvam C, Subramaniam J, Suresh U, Chandramohan B, Roni M, Nicoletti M, Alarfaj AA, Higuchi A, Munusamy MA, Khater HF, Messing RH, Benelli G. Predation by Asian bullfrog tadpoles, Hoplobatrachus tigerinus, against the dengue vector, Aedes aegypti, in an aquatic environment treated with mosquitocidal nanoparticles. Parasitol Res 2015; 114:3601-10. [PMID: 26091763 DOI: 10.1007/s00436-015-4582-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 06/11/2015] [Indexed: 12/21/2022]
Abstract
Aedes aegypti is a primary vector of dengue and chikungunya. The use of synthetic insecticides to control Aedes populations often leads to high operational costs and adverse non-target effects. Botanical extracts have been proposed for rapid extracellular synthesis of mosquitocidal nanoparticles, but their impact against predators of mosquito larvae has not been well studied. We propose a single-step method for the biosynthesis of silver nanoparticles (AgNP) using the extract of Artemisia vulgaris leaves as a reducing and stabilizing agent. AgNP were characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). SEM and XRD showed that AgNP were polydispersed, crystalline, irregularly shaped, with a mean size of 30-70 nm. EDX confirmed the presence of elemental silver. FTIR highlighted that the functional groups from plant metabolites capped AgNP, stabilizing them over time. We investigated the mosquitocidal properties of A. vulgaris leaf extract and green-synthesized AgNP against larvae and pupae of Ae. aegypti. We also evaluated the predatory efficiency of Asian bullfrog tadpoles, Hoplobatrachus tigerinus, against larvae of Ae. aegypti, under laboratory conditions and in an aquatic environment treated with ultra-low doses of AgNP. AgNP were highly toxic to Ae. aegypti larval instars (I-IV) and pupae, with LC50 ranging from 4.4 (I) to 13.1 ppm (pupae). In the lab, the mean number of prey consumed per tadpole per day was 29.0 (I), 26.0 (II), 21.4 (III), and 16.7 (IV). After treatment with AgNP, the mean number of mosquito prey per tadpole per day increased to 34.2 (I), 32.4 (II), 27.4 (III), and 22.6 (IV). Overall, this study highlights the importance of a synergistic approach based on biocontrol agents and botanical nano-insecticides for mosquito control.
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Affiliation(s)
- Kadarkarai Murugan
- Division of Entomology, Department of Zoology, School of Life sciences, Bharathiar University, Coimbatore, 641 046, Tamil Nadu, India
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21
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Falso PG, Noble CA, Diaz JM, Hayes TB. The effect of long-term corticosterone treatment on blood cell differentials and function in laboratory and wild-caught amphibian models. Gen Comp Endocrinol 2015; 212:73-83. [PMID: 25616196 DOI: 10.1016/j.ygcen.2015.01.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Revised: 01/10/2015] [Accepted: 01/13/2015] [Indexed: 02/05/2023]
Abstract
The effect of long-term stress on amphibian immunity is not well understood. We modeled a long-term endocrine stress scenario by elevating plasma corticosterone in two species of amphibians and examined effects on white blood cell differentials and innate immune activity. Plasma corticosterone was elevated in American bullfrogs (Lithobates catesbeianus) by surgically implanting corticosterone capsules and in African clawed frogs (Xenopus laevis) by immersion in corticosterone-treated water. To provide a context for our results within endogenous corticosterone fluctuations, diurnal plasma corticosterone cycles were determined. A daily low of corticosterone was observed in X. laevis at 12:00, while a significant pattern was not observed in L. catesbeianus. Elevated plasma corticosterone levels increased the ratio of peripheral neutrophils to lymphocytes, in both species, and decreased eosinophil concentrations in L. catesbeianus over a long-term period. Whole blood oxidative burst generally correlated with neutrophil concentrations, and thus was increased with corticosterone treatment, significantly in L. catesbeianus. In L. catesbeianus, an endogenous response of eosinophils and lymphocytes to implanted empty (sham) capsules was observed, but this effect was attenuated by corticosterone. Peripheral monocyte and basophil concentrations were not significantly altered by corticosterone treatment in either species. Our results show that long-term stress can alter amphibian immune parameters for extended periods and may play a role in susceptibility to disease.
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Affiliation(s)
- Paul G Falso
- Department of Biology, Slippery Rock University, Slippery Rock, PA 16057, USA.
| | - Christopher A Noble
- Laboratory for Integrative Studies in Amphibian Biology, Molecular Toxicology Group, and Integrative Biology Department, University of California, Berkeley, CA 94720-3140, USA.
| | - Jesus M Diaz
- Laboratory for Integrative Studies in Amphibian Biology, Molecular Toxicology Group, and Integrative Biology Department, University of California, Berkeley, CA 94720-3140, USA.
| | - Tyrone B Hayes
- Laboratory for Integrative Studies in Amphibian Biology, Molecular Toxicology Group, and Integrative Biology Department, University of California, Berkeley, CA 94720-3140, USA.
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22
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França FM, De Paiva TCB, Marcantônio AS, Teixeira PC, Ferreira CM. Acute toxicity and ecotoxicological risk assessment of rice pesticides to Lithobates catesbeianus tadpoles. J Environ Sci Health B 2015; 50:406-410. [PMID: 25844861 DOI: 10.1080/03601234.2015.1011950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The objective of this study was to determine the acute toxicity of some pesticides used in irrigated rice farming to Lithobates catesbeianus tadpoles. The LC 50-96h for commercial formulations containing bentazon, penoxsulam, vegetable oil, permethrin and carbofuran, separately and their mixtures, were determined at the proportions commonly used in the field. The limits of risk concentrations of these products for the studied species were also established. The LC 50-96h for tadpoles was 4,530 mg L(-1) for bentazon; 7.52 mg L(-1) for penoxsulam + 145.66 mg L(-1) of vegetable oil; 81.57 mg L(-1) for vegetable oil; 0.10 mg L(-1) for permethrin; 29.90 mg L(-1) for carbofuran (active ingredients), and 38.79 times the dose used in the field for the mixture of these products. The environmental risk was determined only for permethrin, and care should be taken when using the vegetable oil.
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Atobe T, Osada Y, Takeda H, Kuroe M, Miyashita T. Habitat connectivity and resident shared predators determine the impact of invasive bullfrogs on native frogs in farm ponds. Proc Biol Sci 2014; 281:20132621. [PMID: 24827433 PMCID: PMC4046391 DOI: 10.1098/rspb.2013.2621] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Accepted: 04/10/2014] [Indexed: 11/12/2022] Open
Abstract
Habitat connectivity is considered to have an important role on the persistence of populations in the face of habitat fragmentation, in particular, for species with conservation concern. However, it can also impose indirect negative effects on native species through the spread of invasive species. Here, we investigated direct and indirect effects of habitat connectivity on populations of invasive bullfrogs and native wrinkled frogs and how these effects are modified by the presence of common carp, a resident shared predator, in a farm pond system in Japan. The distribution pattern analysis using a hierarchical Bayesian modelling indicated that bullfrogs had negative effects on wrinkled frogs, and that these negative effects were enhanced with increasing habitat connectivity owing to the metapopulation structure of bullfrogs. The analysis also suggested that common carp mitigated these impacts, presumably owing to a top-down trophic cascade through preferential predation on bullfrog tadpoles. These presumed interspecific interactions were supported by evidence from laboratory experiments, i.e. predation by carp was more intense on bullfrog tadpoles than on wrinkled frog tadpoles owing to the difference in refuge use. Our results indicate that metacommunity perspectives could provide useful insights for establishing effective management strategies of invasive species living in patchy habitats.
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Affiliation(s)
- Takashi Atobe
- Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yutaka Osada
- Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Hayato Takeda
- Faculty of Medicine, Tsukuba University, Ibaraki, Japan
| | - Misako Kuroe
- Graduate School of Science, Kyushu University, Fukuoka, Japan
| | - Tadashi Miyashita
- Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
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Dal-Medico SE, Rissoli RZ, Gamero FU, Victório JA, Salla RF, Abdalla FC, Silva-Zacarin ECM, Carvalho CS, Costa MJ. Negative impact of a cadmium concentration considered environmentally safe in Brazil on the cardiac performance of bullfrog tadpoles. Ecotoxicol Environ Saf 2014; 104:168-174. [PMID: 24681445 DOI: 10.1016/j.ecoenv.2014.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 02/28/2014] [Accepted: 03/06/2014] [Indexed: 06/03/2023]
Abstract
A drastic amphibian decline has been observed worldwide, which can be attributed (among other factors) to exposure to pollutants. Considering that cadmium corresponds to the most rapidly increasing trace metal in the environment, the aim of this work was to evaluate whether the exposure (2 and 16 days) of bullfrog tadpoles to this trace metal, at the concentration currently considered environmentally safe (at 1ppb) in class 1 and 2 waters by the Brazilian Environmental Council, can affect the cardiac performance of these animals. The acute exposure (2 days) of tadpoles to cadmium resulted in a marked bradycardic response, which was correlated with an incomplete cardiac relaxation, without any compensation by improved cardiac twitch force (Fc) or contraction velocity (TPT), nor even by cardiac hypertrophy. Indeed, after 16 days of exposure, the cardiac function of tadpoles became even more depressed due to a marked decrease in Fc, a prolongation of TPT, and also incomplete relaxation (i.e. increases in the ventricle resting tension), without changes in ventricle relative mass. Altogether, the cardiodepressive effects of cadmium (especially after more prolonged exposure periods) impose negative alterations on a tadpole׳s development and also impede adequate homeostatic adjustments to respond appropriately to the exposure to cadmium with increase in energetic demand to counteract the deleterious effects of the xenobiotic. These disturbances can impair tadpoles׳ growth, development and reproduction. It is a fact that allows us to strongly suggest that cadmium concentrations, which are currently considered environmentally safe in Brazil, should be revised.
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Affiliation(s)
- S E Dal-Medico
- Universidade Federal de São Carlos, Departamento de Biologia, Rodovia João Leme dos Santos (SP-264), Km 110, 18052-780 Sorocaba, SP, Brazil
| | - R Z Rissoli
- Universidade Federal de São Carlos, Departamento de Biologia, Rodovia João Leme dos Santos (SP-264), Km 110, 18052-780 Sorocaba, SP, Brazil
| | - F U Gamero
- Universidade Federal de São Carlos, Departamento de Biologia, Rodovia João Leme dos Santos (SP-264), Km 110, 18052-780 Sorocaba, SP, Brazil
| | - J A Victório
- Universidade Federal de São Carlos, Departamento de Biologia, Rodovia João Leme dos Santos (SP-264), Km 110, 18052-780 Sorocaba, SP, Brazil
| | - R F Salla
- Universidade Federal de São Carlos, Departamento de Biologia, Rodovia João Leme dos Santos (SP-264), Km 110, 18052-780 Sorocaba, SP, Brazil
| | - F C Abdalla
- Universidade Federal de São Carlos, Departamento de Biologia, Rodovia João Leme dos Santos (SP-264), Km 110, 18052-780 Sorocaba, SP, Brazil
| | - E C M Silva-Zacarin
- Universidade Federal de São Carlos, Departamento de Biologia, Rodovia João Leme dos Santos (SP-264), Km 110, 18052-780 Sorocaba, SP, Brazil
| | - C S Carvalho
- Universidade Federal de São Carlos, Departamento de Biologia, Rodovia João Leme dos Santos (SP-264), Km 110, 18052-780 Sorocaba, SP, Brazil
| | - M J Costa
- Universidade Federal de São Carlos, Departamento de Biologia, Rodovia João Leme dos Santos (SP-264), Km 110, 18052-780 Sorocaba, SP, Brazil.
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Stead N. Motivating your frogs, Calaveras County can help. J Exp Biol 2013; 216:i. [PMID: 24298638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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Li H, Liu WZ, Liang PJ. Adaptation-dependent synchronous activity contributes to receptive field size change of bullfrog retinal ganglion cell. PLoS One 2012; 7:e34336. [PMID: 22479604 PMCID: PMC3313981 DOI: 10.1371/journal.pone.0034336] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 03/01/2012] [Indexed: 11/18/2022] Open
Abstract
Nearby retinal ganglion cells of similar functional subtype have a tendency to discharge spikes in synchrony. The synchronized activity is involved in encoding some aspects of visual input. On the other hand, neurons always continuously adjust their activities in adaptation to some features of visual stimulation, including mean ambient light, contrast level, etc. Previous studies on adaptation were primarily focused on single neuronal activity, however, it is also intriguing to investigate the adaptation process in population neuronal activities. In the present study, by using multi-electrode recording system, we simultaneously recorded spike discharges from a group of dimming detectors (OFF-sustained type ganglion cells) in bullfrog retina. The changes in receptive field properties and synchronization strength during contrast adaptation were analyzed. It was found that, when perfused using normal Ringer's solution, single neuronal receptive field size was reduced during contrast adaptation, which was accompanied by weakening in synchronization strength between adjacent neurons' activities. When dopamine (1 µM) was applied, the adaptation-related receptive field area shrinkage and synchronization weakening were both eliminated. The activation of D1 receptor was involved in the adaptation-related modulation of synchronization and receptive field. Our results thus suggest that the size of single neuron's receptive field is positively related to the strength of its synchronized activity with its neighboring neurons, and the dopaminergic pathway is responsible for the modulation of receptive field property and synchronous activity of the ganglion cells during the adaptation process.
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Affiliation(s)
| | | | - Pei-Ji Liang
- Department of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
- * E-mail:
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Wahid F, Jung H, Khan T, Hwang KH, Park JS, Chang SC, Khan MA, Kim YY. Effects of Rubus coreanus extract on visual processes in bullfrog's eye. J Ethnopharmacol 2011; 138:333-339. [PMID: 21787855 DOI: 10.1016/j.jep.2011.07.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 07/07/2011] [Accepted: 07/07/2011] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The fruit of Rubus coreanus (Rosaceae) is traditionally used as an aphrodisiac, astringent, restorative and tonic in Asian countries. It is advised for treating diseases related to liver, kidney and urinary dysfunction, premature greying, blurred vision, infertility, impotence and premature ejaculation. Additionally, there is a long history of different parts of the plants being used in the treatment of ophthalmic diseases. However, no scientific studies have been undertaken to determine the effects of Rubus coreanus in visual processes of the vertebrate retina. AIM OF STUDY The purpose of the present study was to investigate the positive effects of Rubus coreanus extracts on visual processes in the vertebrate's eye. MATERIALS AND METHODS Electroretinogram (ERG) techniques were used to record the responses from a bullfrog's eye cup preparations. Active pharmacological agents were used to block specific receptors in the retina and to leave others unaffected. Lipid peroxidation in the retina was generated by adding FeSO(4)+Na-ascorbate. RESULTS It was observed that both dark- and light-adapted ERG b-wave peak amplitude significantly increases with Rubus coreanus treatment. It was found that Rubus coreanus acts as a retinal neural antagonist but not as GABA receptor antagonist. Rubus coreanus treatment lowered the duration of rhodopsin regeneration. The results obtained indicated that Rubus coreanus protects against lipid peroxidation drop off ERG amplitude in retina. CONCLUSION Based on results obtained, it is suggested that Rubus coreanus can potentially improve visual sensitivity and can be used to treat pathophysiological conditions of eye.
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Affiliation(s)
- Fazli Wahid
- School of Life Sciences and Biotechnology, College of Natural Sciences, Kyungpook National University, 1370 Sangeok-dong, Buk-ku, Taegu 702-701, Republic of Korea
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Nori J, Urbina-Cardona JN, Loyola RD, Lescano JN, Leynaud GC. Climate change and American Bullfrog invasion: what could we expect in South America? PLoS One 2011; 6:e25718. [PMID: 21991339 PMCID: PMC3185029 DOI: 10.1371/journal.pone.0025718] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 09/08/2011] [Indexed: 12/02/2022] Open
Abstract
Background Biological invasion and climate change pose challenges to biodiversity conservation in the 21st century. Invasive species modify ecosystem structure and functioning and climatic changes are likely to produce invasive species' range shifts pushing some populations into protected areas. The American Bullfrog (Lithobates catesbeianus) is one of the hundred worst invasive species in the world. Native from the southeast of USA, it has colonized more than 75% of South America where it has been reported as a highly effective predator, competitor and vector of amphibian diseases. Methodology/Principal Findings We modeled the potential distribution of the bullfrog in its native range based on different climate models and green-house gases emission scenarios, and projected the results onto South America for the years of 2050 and 2080. We also overlaid projected models onto the South American network of protected areas. Our results indicate a slight decrease in potential suitable area for bullfrog invasion, although protected areas will become more climatically suitable. Therefore, invasion of these sites is forecasted. Conclusion/Significance We provide new evidence supporting the vulnerability of the Atlantic Forest Biodiversity Hotspot to bullfrog invasion and call attention to optimal future climatic conditions of the Andean-Patagonian forest, eastern Paraguay, and northwestern Bolivia, where invasive populations have not been found yet. We recommend several management and policy strategies to control bullfrog invasion and argue that these would be possible if based on appropriate articulation among government agencies, NGOs, research institutions and civil society.
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Affiliation(s)
- Javier Nori
- Centro de Zoología Aplicada, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba, Argentina.
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Morimoto N, Hashimoto K, Okada R, Mochida H, Uchiyama M, Kikuyama S, Matsuda K. Inhibitory effect of corticotropin-releasing factor on food intake in the bullfrog, Aquarana catesbeiana. Peptides 2011; 32:1872-5. [PMID: 21864603 DOI: 10.1016/j.peptides.2011.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 08/08/2011] [Accepted: 08/08/2011] [Indexed: 11/19/2022]
Abstract
Corticotropin-releasing factor (CRF) and CRF-related peptides exert hypophysiotropic and anorexigenic effects in mammals and teleost fish. In anuran amphibians, CRF acts as a potent stimulator of thyrotropin release from the pituitary. According to our recent study, CRF also acts as an anorexigenic factor for the cessation of food intake in the metamorphosing bullfrog larvae. However, the anorexigenic action of CRF has not been confirmed in adult bullfrogs. In this context, we examined the effect of feeding status on the expression level of the CRF transcript in the hypothalamus of the adult bullfrog. Levels of CRF mRNA in the hypothalami from bullfrogs fasted for 7 days were lower than in those from the bullfrogs that had been fed normally. Subsequently, we developed a method for measuring food intake in adult bullfrogs, and then investigated the effect of CRF on their food consumption in these animals. Intracerebroventricular (ICV) administration of CRF at 1 and 10pmol/g body weight (BW) induced a significant decrease of food intake during 60min. The CRF-induced anorexigenic action was blocked by treatment with a CRF receptor 1/CRF receptor 2 antagonist, α-helical CRF((9-41)), at 100pmol/g BW. These results provide direct evidence for the inhibitory effect of CRF on food intake, and suggest the involvement of CRF in the regulation of feeding through a CRF receptor-signaling pathway in the adult bullfrog.
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Affiliation(s)
- Noriaki Morimoto
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, Toyama 930-8555, Japan
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Yamauchi K, Sai G. Characterization of plasma triiodophenol binding proteins in vertebrates and tissue distribution of triiodophenol in Rana catesbeiana tadpoles. Comp Biochem Physiol C Toxicol Pharmacol 2011; 153:328-35. [PMID: 21147258 DOI: 10.1016/j.cbpc.2010.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 11/29/2010] [Accepted: 12/06/2010] [Indexed: 12/22/2022]
Abstract
We investigated the interaction of 2,4,6-triiodophenol (TIP), a potent thyroid hormone disrupting chemical, with serum proteins from rainbow trout (Onchorhynchus mykiss), bullfrog (Rana catesbeiana), chicken (Gallus gallus), pig (Sus scrofa domesticus), and rat (Rattus norvegicus) using a [(125)I]TIP binding assay, gel filtration chromatography, and native polyacrylamide gel electrophoresis. [(125)I]TIP bound non-specifically to proteins in trout serum, specifically but weakly to proteins in bullfrog serum, and specifically and strongly to proteins in chicken, pig, and rat serum samples. Candidate TIP-binding proteins included lipoproteins (220-320kDa) in trout, albumin in bullfrog, albumin and transthyretin (TTR) in chicken and pig, and TTR in rat. TTR in the chicken, pig, and rat serum samples was responsible for the high-affinity, low-capacity binding sites for TIP (dissociation constant 2.2-3.5×10(-10)M). In contrast, a weak interaction of [(125)I]TIP with tadpole serum proteins accelerated [(125)I]TIP cellular uptake in vitro. Intraperitoneal injection of [(125)I]TIP in tadpoles revealed that the radioactivity was predominantly accumulated in the gallbladder and the kidney. The differences in the molecular and binding properties of TIP binding proteins among vertebrates would affect in part the cellular availability, tissue distribution and clearance of TIP.
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Affiliation(s)
- Kiyoshi Yamauchi
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan.
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Gunderson MP, Veldhoen N, Skirrow RC, Macnab MK, Ding W, van Aggelen G, Helbing CC. Effect of low dose exposure to the herbicide atrazine and its metabolite on cytochrome P450 aromatase and steroidogenic factor-1 mRNA levels in the brain of premetamorphic bullfrog tadpoles (Rana catesbeiana). Aquat Toxicol 2011; 102:31-8. [PMID: 21371610 PMCID: PMC3065035 DOI: 10.1016/j.aquatox.2010.12.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 12/23/2010] [Accepted: 12/29/2010] [Indexed: 05/22/2023]
Abstract
The transcriptional regulator steroidogenic factor 1 (SF-1) and the enzyme cytochrome P450 aromatase (CYP19) play a central role in modulation of a broad range of tissue-specific developmental processes associated with hormone homeostasis that includes differentiation of the central nervous system. SF-1 and CYP19 expression may be targeted by a variety of endocrine disruptive agents prevalent within the environment. In the present study, we cloned and characterized partial sequences for bullfrog (Rana catesbeiana) SF-1 and CYP19 and examined the effects of a 48h exposure to 1 and 100μg/l of the herbicide atrazine (ATZ) and its major metabolite desethylatrazine (DEA), as well as 5ng/l of the estrogenic chemical, 17α-ethynylestradiol (EE(2)), and 673ng/l of the thyroid hormone, 3,5,3'-triiodothyronine (T(3)), on SF-1 and CYP19 mRNA abundance in the brains of premetamorphic bullfrog tadpoles. Quantitative RT-PCR analysis showed an increase in CYP19 mRNA following a 48h exposure to EE(2) but not T(3) while no significant changes in SF-1 transcript levels occurred. We observed a strong positive correlation between CYP19 and SF-1 transcript abundance in the ATZ-exposed animals which was not evident with DEA- or hormone-exposed tadpoles. Our results are intriguing in light of reported behavioral changes in ATZ-exposed frogs and suggest that further research is warranted to examine the relationship and role of CYP19 and SF-1 in amphibian brain development.
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Affiliation(s)
- Mark P. Gunderson
- Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia, V8W 3P6, Canada
| | - Nik Veldhoen
- Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia, V8W 3P6, Canada
| | - Rachel C. Skirrow
- Pacific Environmental Science Centre, Environment Canada, 2645 Dollarton Highway, North Vancouver, British Columbia, V7H 1V2, Canada
| | - Magnus K. Macnab
- Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia, V8W 3P6, Canada
| | - Wei Ding
- Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia, V8W 3P6, Canada
| | - Graham van Aggelen
- Pacific Environmental Science Centre, Environment Canada, 2645 Dollarton Highway, North Vancouver, British Columbia, V7H 1V2, Canada
| | - Caren C. Helbing
- Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia, V8W 3P6, Canada
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Castellano-Muñoz M, Israel SH, Hudspeth AJ. Efferent control of the electrical and mechanical properties of hair cells in the bullfrog's sacculus. PLoS One 2010; 5:e13777. [PMID: 21048944 PMCID: PMC2966443 DOI: 10.1371/journal.pone.0013777] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 08/25/2010] [Indexed: 11/22/2022] Open
Abstract
Background Hair cells in the auditory, vestibular, and lateral-line systems respond to mechanical stimulation and transmit information to afferent nerve fibers. The sensitivity of mechanoelectrical transduction is modulated by the efferent pathway, whose activity usually reduces the responsiveness of hair cells. The basis of this effect remains unknown. Methodology and Principal Findings We employed immunocytological, electrophysiological, and micromechanical approaches to characterize the anatomy of efferent innervation and the effect of efferent activity on the electrical and mechanical properties of hair cells in the bullfrog's sacculus. We found that efferent fibers form extensive synaptic terminals on all macular and extramacular hair cells. Macular hair cells expressing the Ca2+-buffering protein calretinin contain half as many synaptic ribbons and are innervated by twice as many efferent terminals as calretinin-negative hair cells. Efferent activity elicits inhibitory postsynaptic potentials in hair cells and thus inhibits their electrical resonance. In hair cells that exhibit spiking activity, efferent stimulation suppresses the generation of action potentials. Finally, efferent activity triggers a displacement of the hair bundle's resting position. Conclusions and Significance The hair cells of the bullfrog's sacculus receive a rich efferent innervation with the heaviest projection to calretinin-containing cells. Stimulation of efferent axons desensitizes the hair cells and suppresses their spiking activity. Although efferent activation influences mechanoelectrical transduction, the mechanical effects on hair bundles are inconsistent.
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Affiliation(s)
- Manuel Castellano-Muñoz
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, New York, United States of America
| | - Samuel H. Israel
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, New York, United States of America
| | - A. J. Hudspeth
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, New York, United States of America
- * E-mail:
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Moutou F, Pastoret PP. Invasive reptiles and amphibians. REV SCI TECH OIE 2010; 29:235-233. [PMID: 20919579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Although they are frequently lumped together, reptiles and amphibians belong to two very different zoological groups. Nevertheless, one fact is clear: while numerous reptile and amphibian species on Earth are in decline, others have taken advantage of trade or human movements to become established in new lands, adopting different, and sometimes unusual, strategies. The authors have taken a few examples from these two zoological groups that illustrate the majority of cases. A brief analysis of the causes and effects of their introductions into new areas reveals connections with economic interests, trade in companion animals, medical research and public health.
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Affiliation(s)
- F Moutou
- (1) Agence Française de Sécurité Sanitaire des Aliments (AFSSA), Laboratoire d'Etudes et de Recherches en Pathologie Animale et Zoonoses (LERPAZ), 23 Avenue du Général-de-Gaulle, 94706 Maisons Alfort, France
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Azizi E, Roberts TJ. Muscle performance during frog jumping: influence of elasticity on muscle operating lengths. Proc Biol Sci 2010; 277:1523-30. [PMID: 20106852 PMCID: PMC2871832 DOI: 10.1098/rspb.2009.2051] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Accepted: 01/06/2010] [Indexed: 11/12/2022] Open
Abstract
A fundamental feature of vertebrate muscle is that maximal force can be generated only over a limited range of lengths. It has been proposed that locomotor muscles operate over this range of lengths in order to maximize force production during movement. However, locomotor behaviours like jumping may require muscles to shorten substantially in order to generate the mechanical work necessary to propel the body. Thus, the muscles that power jumping may need to shorten to lengths where force production is submaximal. Here we use direct measurements of muscle length in vivo and muscle force-length relationships in vitro to determine the operating lengths of the plantaris muscle in bullfrogs (Rana catesbeiana) during jumping. We find that the plantaris muscle operates primarily on the descending limb of the force-length curve, resting at long initial lengths (1.3 +/- 0.06 L(o)) before shortening to muscle's optimal length (1.03 +/- 0.05 L(o)). We also compare passive force-length curves from frogs with literature values for mammalian muscle, and demonstrate that frog muscles must be stretched to much longer lengths before generating passive force. The relatively compliant passive properties of frog muscles may be a critical feature of the system, because it allows muscles to operate at long lengths and improves muscles' capacity for force production during a jump.
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Affiliation(s)
- Emanuel Azizi
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, USA.
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Bates ME, Cropp BF, Gonchar M, Knowles J, Simmons JA, Simmons AM. Spatial location influences vocal interactions in bullfrog choruses. J Acoust Soc Am 2010; 127:2664-2677. [PMID: 20370047 PMCID: PMC2865710 DOI: 10.1121/1.3308468] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 12/17/2009] [Accepted: 01/11/2010] [Indexed: 05/29/2023]
Abstract
A multiple sensor array was employed to identify the spatial locations of all vocalizing male bullfrogs (Rana catesbeiana) in five natural choruses. Patterns of vocal activity collected with this array were compared with computer simulations of chorus activity. Bullfrogs were not randomly spaced within choruses, but tended to cluster into closely spaced groups of two to five vocalizing males. There were nonrandom, differing patterns of vocal interactions within clusters of closely spaced males and between different clusters. Bullfrogs located within the same cluster tended to overlap or alternate call notes with two or more other males in that cluster. These near-simultaneous calling bouts produced advertisement calls with more pronounced amplitude modulation than occurred in nonoverlapping notes or calls. Bullfrogs located in different clusters more often alternated entire calls or overlapped only small segments of their calls. They also tended to respond sequentially to calls of their farther neighbors compared to their nearer neighbors. Results of computational analyses showed that the observed patterns of vocal interactions were significantly different than expected based on random activity. The use of a multiple sensor array provides a richer view of the dynamics of choruses than available based on single microphone techniques.
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Affiliation(s)
- Mary E Bates
- Department of Psychology, Brown University, Providence, Rhode Island 02912, USA.
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Cooper S, Fortin C. Metal and metallothionein content in bullfrogs: study of a whole watershed impacted by agricultural activities. Ecotoxicol Environ Saf 2010; 73:391-399. [PMID: 20047761 DOI: 10.1016/j.ecoenv.2009.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 11/27/2009] [Accepted: 12/04/2009] [Indexed: 05/28/2023]
Abstract
Among the various anthropogenic activities potentially affecting amphibian populations, agriculture has often been evoked. Fertilizers used in agriculture are documented sources of metals that may contaminate nearby rivers. Bullfrogs (Rana catesbeiana) were collected within the Yamaska River basin (Quebec, Canada) along a gradient of agricultural land use intensity. Hepatic, renal and intestinal metal content, along with hepatic metallothionein content, were determined. In general, dissolved metal concentrations and accumulated metal concentrations in bullfrogs varied little among sites. Hepatic Cu and Zn concentrations were significantly different among subwatersheds and were in accordance with the gradient in agricultural activities in at least one of the three years studied. Liver metallothionein content did not vary significantly among the subwatersheds, but they were correlated with Cu content within two sites and Cd content at one site. We conclude that R. catesbeiana could be used as a biomonitor for Cu contamination and potentially for other metals.
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Affiliation(s)
- Sophie Cooper
- INRS-Eau, Terre et Environnement, Université du Québec, 490 rue de la Couronne, Québec, QC, Canada
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Spear PA, Boily M, Giroux I, Deblois C, Leclair MH, Levasseur M, Leclair R. Study design, water quality, morphometrics and age of the bullfrog, Rana catesbeiana, in sub-watersheds of the Yamaska River drainage basin, Québec, Canada. Aquat Toxicol 2009; 91:110-117. [PMID: 19027968 DOI: 10.1016/j.aquatox.2008.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 09/16/2008] [Accepted: 09/19/2008] [Indexed: 05/27/2023]
Abstract
The Yamaska River basin is renowned for its poor water quality, which has been attributed to intensive agriculture (corn, soya, high-density pork and poultry production). Six locations within the Yamaska watershed were selected to evaluate the impact of agriculture on water habitats and study the bullfrog as a sentinel species of potential exposure and effects. The selected sub-watersheds were chosen according to the percentage of surface area under cultivation and classified as low (0-19%), moderate (20-59%) or high (>60%). In 2004 and 2005, analysis of surface water samples demonstrated that pesticide concentrations and most water quality parameters increased with increasing agricultural activity. Sixteen adult bullfrogs were sampled from each site. Animals were weighed, measured for length (total, snout-vent, tibia, tympanum), sexed, and evaluated for the colour of the throat. Skeletochronology was used to estimate the growth and age of the frogs. Cross-sections of decalcified phalanges and femurs were treated in order to count LAGs (lines of arrest growth) and for the observations of other parameters related to bone growth. The bullfrogs from highly contaminated sites had the lowest mean age and the smallest snout-vent length compared to sites of low contamination.
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Affiliation(s)
- Philip A Spear
- TOXEN Research Centre, Université du Québec at Montréal, Case Postale 8888, Succursale Centre-ville, Montréal, Québec H3C 3P8, Canada
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Abstract
Duodenum is exposed to potential damage from acidopeptic secretions emptied from the stomach. In several mammalian species the duodenal mucosa was shown some 50 years ago to be better able to resist acid gastric juice than mucosa in more distal small intestine. Recent studies have identified HCO3- secretion originating from the surface epithelium, together with the ability of this epithelium to respond to intraluminal acid with a rise in HCO3- secretion, as important components of duodenal mucosal protection. Whether duodenal (Brunner's) glands also secrete some HCO3- is at present unknown. Secretion of HCO3- is stimulated up to 10-fold by the presence of luminal acid and is quantitatively sufficient to maintain neutrality at the mucosal cell surface at the lowest pH values encountered in the duodenum (approximately pH 2.0). Stimulation is mediated by mucosal production of prostaglandins, humoral factors and possibly neural mechanisms. The mucus gel adherent to the mucosa provides a physical basis for the standing pH gradient generated by epithelial HCO3- secretion. In vivo, mucosal blood flow supplies HCO3- to the epithelial cells and is particularly important at high (stimulated) rates of secretion.
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Clausznitzer D, Lindner B, Jülicher F, Martin P. Two-state approach to stochastic hair bundle dynamics. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 77:041901. [PMID: 18517650 DOI: 10.1103/physreve.77.041901] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Indexed: 05/26/2023]
Abstract
Hair cells perform the mechanoelectrical transduction of sound signals in the auditory and vestibular systems of vertebrates. The part of the hair cell essential for this transduction is the so-called hair bundle. In vitro experiments on hair cells from the sacculus of the American bullfrog have shown that the hair bundle comprises active elements capable of producing periodic deflections like a relaxation oscillator. Recently, a continuous nonlinear stochastic model of the hair bundle motion [Nadrowski, Proc. Natl. Acad. Sci. U.S.A. 101, 12195 (2004)] has been shown to reproduce the experimental data in stochastic simulations faithfully. Here, we demonstrate that a binary filtering of the hair bundle's deflection (experimental data and continuous hair bundle model) does not change significantly the spectral statistics of the spontaneous as well as the periodically driven hair bundle motion. We map the continuous hair bundle model to the FitzHugh-Nagumo model of neural excitability and discuss the bifurcations between different regimes of the system in terms of the latter model. Linearizing the nullclines and assuming perfect time-scale separation between the variables we can map the FitzHugh-Nagumo system to a simple two-state model in which each of the states corresponds to the two possible values of the binary-filtered hair bundle trajectory. For the two-state model, analytical expressions for the power spectrum and the susceptibility can be calculated [Lindner and Schimansky-Geier, Phys. Rev. E 61, 6103 (2000)] and show the same features as seen in the experimental data as well as in simulations of the continuous hair bundle model.
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Affiliation(s)
- Diana Clausznitzer
- Max-Planck-Institut für Physik Komplexer Systeme, Nöthnitzer Strasse 38, Dresden, Germany
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Puglis HJ, Boone MD. Effects of a fertilizer, an insecticide, and a pathogenic fungus on hatching and survival of bullfrog (Rana catesbeiana) tadpoles. Environ Toxicol Chem 2007; 26:2198-201. [PMID: 17867893 DOI: 10.1897/07-237r.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Accepted: 05/15/2007] [Indexed: 05/17/2023]
Abstract
We assessed the single and interactive effects of ammonium nitrate fertilizer, the insecticide carbaryl, and a widespread waterborne pathogen Saprolegnia ferax on the hatching and survival of bullfrog (Rana catesbeiana) tadpoles in the laboratory. Carbaryl significantly reduced tadpole survival and hatching rate, but no interactive effects were found among stressors.
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Affiliation(s)
- Holly J Puglis
- Miami University, Department of Zoology, 212 Pearson Hall, Oxford, Ohio 45056, USA
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Simmons AM, Horowitz SS, Brown RA. Cell proliferation in the forebrain and midbrain of the adult bullfrog, Rana catesbeiana. Brain Behav Evol 2007; 71:41-53. [PMID: 17878717 PMCID: PMC3256745 DOI: 10.1159/000108610] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2007] [Accepted: 03/30/2007] [Indexed: 12/22/2022]
Abstract
The distribution of proliferating cells in the midbrain, thalamus, and telencephalon of adult bullfrogs (Rana catesbeiana) was examined using immunohistochemistry for the thymidine analog 5-bromo-2'-deoxyuridine (BrdU) and DNA dot-blotting. At all time points examined (2 to 28 days post-injection), BrdU-labeled cells were located in ventricular zones at all levels of the neuraxis, but with relatively more label around the telencephalic ventricles. Labeled cells, some showing profiles indicative of dividing and migrating cells, were present in brain parenchyma from 7 to 28 days post-injection. These labeled cells were particularly numerous in the dorsal and ventral hypothalamus, preoptic area, optic tectum, and laminar and principal nuclei of the torus semicircularis, with label also present, but at qualitatively reduced levels, in thalamic and telencephalic nuclei. Double-label immunohistochemistry using glial and early neural markers indicated that gliogenesis and neurogenesis both occurred, with new neurons observed particularly in the hypothalamus, optic tectum, and torus semicircularis. In all brain areas, many cells not labeled with BrdU were nonetheless labeled with the early neural marker TOAD-64, indicating that these cells were postmitotic. Incorporation of DNA measured by dot-blotting confirms the presence of DNA synthesis in the forebrain and brainstem at all time points measured. The pattern of BrdU label confirms previous experiments based on labeling with (3)H-thymidine and proliferating cell nuclear antigen showing cell proliferation in the adult ranid brain, particularly in hypothalamic nuclei. The consistent appearance of new cells in the hypothalamus of adult frogs suggests that proliferative activity may be important in mediating reproductive behaviors in these animals.
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Abstract
OBJECTIVE A few investigations have been reported about pretectal suppressive influences on the optic tectum of frog, but characteristics of tectal activity to pretectal input are left unknown. We made intracellular recordings to demonstrate the unexpected complexity in synaptic mechanisms involved in the suppressive influences of pretecal stimulation on the tectal cells. METHODS In the present study, we investigated the neuronal activity evoked by pretectal (Lpd/P) nuclei stimulation using intracellular recording technique. RESULTS The pretectal stimulation mainly elicited two types of responses in the ipsilateral tectum: an excitatory postsynaptic potential (EPSP) followed by an inhibitory postsynaptic potential (IPSP) and a pure IPSP. The latter predominated in the tectal cells responding to pretectal stimulation. In a few cells, biphasic hyperpolarization appeared under stronger stimulus intensities. The spikes of tecto-pretectal projecting cells elicited by antidromical stimulation were recorded in the ipsilateral tectum, which revealed reciprocal connections between the tectum and particular pretectal nuclei. The synaptic natures underlying pretecto-tectal information transformation have also been demonstrated. EPSPs with short latencies were concluded to be monosynaptic. Most IPSPs were generated through polysynaptic paths, but monosynaptic IPSPs were also recorded in the tectum. Nearly 98% of impaled tectal cells (except for antidromically projecting cells) showed inhibitory responses to pretectal stimulation. CONCLUSION The results provide strong evidence that pretectal cells broadly inhibit tectal neurons as that has suggested by behavioral and extracellular recording studies.
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Affiliation(s)
- Hong-Jian Kang
- Kyushu Institute of Technology, Graduate School of Life Science and Systems Engineering, Department of Brain Science and Engineering, Fukuoka 808-0196, Japan.
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Okada Y, Imendra KG, Miyazaki T, Hotokezaka H, Fujiyama R, Zeredo JL, Toda K. A Calcium-Receptor Agonist Induces Gustatory Neural Responses in Bullfrogs. Cell Mol Neurobiol 2007; 27:771-81. [PMID: 17636404 DOI: 10.1007/s10571-007-9171-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Accepted: 06/18/2007] [Indexed: 10/23/2022]
Abstract
The effect of calcium-sensing receptor (CaR) agonists on frog gustatory responses was studied using glossopharyngeal nerve recording and whole-cell patch-clamp recording of isolated taste disc cells. Calcimimetic NPS R-467 dissolved in normal saline solution elicited a large transient response in the nerve. The less active enantiomer of the compound, NPS S-467 induced only a small neural response. The EC(50) for NPS R-467 was about 20 microM. Cross-adaptation experiments were performed to examine the effect of 30 microM NPS R-467 and 100 microM quinine on the gustatory neural response. The magnitude of the R-467-induced response after adaptation to quinine was approximately equal to that after adaptation to normal saline solution, indicating that the receptor site for NPS R-467 is different from the site for quinine. NPS R-467 (100 microM) also induced an inward current accompanied with conductance increase and large depolarization in two (13%) of 15 rod cells, and a sustained decrease in outward current and small depolarization in six (40%) other rod cells. NPS S-467 (100 microM) induced a sustained decrease in outward current and depolarization in five (50%) of 10 rod cells. Another calcimimetic cinacalcet (100 microM) induced an inward current accompanied with conductance increase in three (27%) of 11 rod cells. The results suggest that NPS R-467 induces neural responses through cell responses unrelated to a resting K(+) conductance decrease.
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Affiliation(s)
- Yukio Okada
- Integrative Sensory Physiology, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki, Nagasaki 852-8588, Japan.
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Belzile O, Gulemetova R, Kinkead R. Effects of medullary Raphé stimulation on fictive lung ventilation during development in Rana catesbeiana. J Exp Biol 2007; 210:2046-56. [PMID: 17562878 DOI: 10.1242/jeb.003202] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
To better understand serotonergic modulation of air breathing during bullfrog development, we measured changes in fictive lung ventilation frequency associated with focal stimulation of the rostral region of the medullary Raphé neurons. Electrical (3 to 33 Hz) and chemical(glutamate microinjections; 0.5 mol l–1, 0.3–10 nl)activation of Raphé neurons was performed in brainstem preparations from three developmental stages (pre- and metamorphic tadpoles and adult frogs). Fictive lung ventilation was recorded extracelluarly from the Vth and Xth cranial nerves. Electrical stimulation of Raphé neurons caused a frequency-dependent increase in lung burst frequency in pre-metamorphic tadpoles only. In metamorphic tadpoles, an increase in fictive lung ventilation was observed at 20 Hz only. Electrical stimulation had no effect in preparations from adult frogs. Glutamate microinjections elicited similar responses as a lung burst frequency increase was observed in the pre-metamorphic group only. Regardless of the stimulation technique used, the increase in fictive lung ventilation was attenuated by the selective 5-HT3 antagonist tropisetron (5–20 μmol l–1). Results from immunohistochemical analysis of the Raphé region stimulated do not correlate with functional data as the number of 5-HT immunoreactive neurons within this region increases during development. We conclude that, in this preparation, stimulation of lung ventilation by the medullary Raphé is restricted to early(pre-metamorphic) stages.
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Affiliation(s)
- Olivier Belzile
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9039, USA
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Abstract
SUMMARYWe characterized carbohydrate metabolism following activity in the American bullfrog, Rana catesbeiana, and compared whole body metabolic profiles between two seasons. Forty-eight adult male Rana catesbeianawere chronically cannulated and injected with[U-14C]l-lactic acid sodium salt in either summer (June)or winter (January) after acclimation for 2 weeks at 15°C with a 12 h:12 h L:D photoperiod. Following injection with [14C]lactate, frogs were either allowed to rest for 240 min (REST), hopped for 2 min on a treadmill and immediately sacrificed (PE), or hopped for 2 min on a treadmill and allowed to recover for 240 min (REC 4). Exercise caused a significant increase in blood lactate level from 2.7±0.1 mmol l–1 at rest to 17.0±2.1 mmol l–1 immediately following exercise. This increase persisted throughout the recovery period, with average blood lactate level only reduced to 13.7±1.1 mmol l–1 after 240 min of recovery, despite complete recovery of intramuscular lactate levels. Lactate levels were not significantly different between seasons in any treatment (REST, PE, REC4), in either gastrocnemius muscle or blood. The vast majority of [14C]lactate was recovered in the muscle, in both winter (86.3%) and summer (87.5%). Season had no effect on total amount of 14C label recovered. [14C]Lactate was measured in the forms of lactate, glucose and glycogen, in the liver and the muscle sampled. The most robust difference found in seasonal metabolism was that both the liver and the gastrocnemius contained significantly higher levels of intracellular free glucose under all treatments in winter. These data suggest that, overall, bullfrogs accumulate and slowly clear lactate in a manner quite similar to findings in fish, other amphibians and lizards. Additionally, our findings indicate that lactate metabolism is not highly influenced by season alone, but that intracellular glucose levels may be sensitive to annual patterns.
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Affiliation(s)
- A M Petersen
- Department of Integrative Physiology University of Colorado, Boulder, CO 80309-0354, USA
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46
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Skirrow RC, Helbing CC. Decreased cyclin-dependent kinase activity promotes thyroid hormone-dependent tail regression in Rana catesbeiana. Cell Tissue Res 2007; 328:281-9. [PMID: 17225171 DOI: 10.1007/s00441-006-0362-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2006] [Accepted: 11/13/2006] [Indexed: 11/26/2022]
Abstract
The thyroid hormone (TH), 3,5,3'-triiodothyronine (T(3)), is an important regulator of diverse cellular processes including cell proliferation, differentiation, and apoptosis, with increasing evidence that the modulation of the phosphoproteome is an important factor in the TH-mediated response. However, little is understood regarding the mechanisms whereby phosphorylation may contribute to T(3)-mediated cellular outcomes during development. The cyclin-dependent kinases (Cdks) and mitogen-activated protein kinases (MAPK/ERK) have been implicated in TH signaling in mammalian cells. In this study, we have investigated, in frogs, the possible role that these kinases may have in the promotion of tail regression during tadpole metamorphosis, an important postembryonic process that is completely TH-dependent. Cdk2 steady state levels and activity increase in the tail concurrent with progression through the growth phase of metamorphosis, followed by a precipitous decrease coinciding with tail regression. Cyclin-A-associated kinase activity also follows a similar trend except that its associated kinase activity is maintained longer before a decrease in activity. Protein steady state levels of ERK1 and ERK2 remain relatively constant, and their kinase activities do not decrease until much later during tail regression. Tail tips cultured in serum-free medium in the presence of T(3) undergo regression, which is accelerated by coincubation with a specific Cdk2 inhibitor. Coincubation with PD098059, a MAPK inhibitor, has no effect. Thus, T(3)-dependent tail regression does not require MAPKs, but a decrease in Cdk2 activity promotes tail regression.
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Affiliation(s)
- Rachel C Skirrow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
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Garner TWJ, Perkins MW, Govindarajulu P, Seglie D, Walker S, Cunningham AA, Fisher MC. The emerging amphibian pathogen Batrachochytrium dendrobatidis globally infects introduced populations of the North American bullfrog, Rana catesbeiana. Biol Lett 2007; 2:455-9. [PMID: 17148429 PMCID: PMC1686185 DOI: 10.1098/rsbl.2006.0494] [Citation(s) in RCA: 209] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Batrachochytrium dendrobatidis is the chytridiomycete fungus which has been implicated in global amphibian declines and numerous species extinctions. Here, we show that introduced North American bullfrogs (Rana catesbeiana) consistently carry this emerging pathogenic fungus. We detected infections by this fungus on introduced bullfrogs from seven of eight countries using both PCR and microscopic techniques. Only native bullfrogs from eastern Canada and introduced bullfrogs from Japan showed no sign of infection. The bullfrog is the most commonly farmed amphibian, and escapes and subsequent establishment of feral populations regularly occur. These factors taken together with our study suggest that the global threat of B. dendrobatidis disease transmission posed by bullfrogs is significant.
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Affiliation(s)
- Trenton W J Garner
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK.
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Fournier S, Kinkead R. Noradrenergic modulation of respiratory motor output during tadpole development: Role of alpha-adrenoceptors. ACTA ACUST UNITED AC 2006; 209:3685-94. [PMID: 16943508 DOI: 10.1242/jeb.02418] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Noradrenaline (NA) is an important modulator of respiratory activity. Results from in vitro studies using immature rodents suggest that the effects exerted by NA change during development, but these investigations have been limited to neonatal stages. To address this issue, we used in vitro brainstem preparations of an ectotherm, Rana catesbeiana, at three developmental stages: pre-metamorphic tadpoles, metamorphic tadpoles and fully mature adult bullfrogs. We first compared the effects of NA bath application (0.02-10 micromol l(-1)) on brainstem preparations from both pre-metamorphic (Taylor-Köllros stages VII-XI) and metamorphic tadpoles (TK stages XVIII-XXIII) and adult frogs. The fictive lung ventilation frequency response to NA application was both dose- and stage-dependent. Although no net change was observed in the pre-metamorphic group, NA application decreased fictive lung burst frequency in preparations from more mature animals. These effects were attenuated by application of alpha-adrenoceptor antagonists. Conversely, NA application elicited dose- and stage-dependent increases in fictive buccal ventilation frequency. We then assessed the contribution of alpha-adrenoceptors towards these responses by applying specific agonists (alpha1: phenylephrine; alpha2: clonidine; concentration range from 10 to 200 micromol l(-1) for both). Of the two agonists used, only phenylephrine application consistently mimicked the lung burst frequency response observed during NA application in each stage group. However, both agonists decreased buccal burst frequency, thus suggesting that other (beta) adrenoceptor types mediate this response. We conclude that modulation of both buccal and lung-related motor outputs change during development. NA modulation affects both types of respiratory activities in a distinct fashion, owing to the different adrenoceptor type involved.
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Affiliation(s)
- Stéphanie Fournier
- Department of Pediatrics, Université Laval, Centre de Recherche du Centre Hospitalier Universitaire de Québec, 10 rue de l'Espinay, Québec City, QC G1L 3L5, Canada
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Veldhoen N, Skirrow RC, Osachoff H, Wigmore H, Clapson DJ, Gunderson MP, Van Aggelen G, Helbing CC. The bactericidal agent triclosan modulates thyroid hormone-associated gene expression and disrupts postembryonic anuran development. Aquat Toxicol 2006; 80:217-27. [PMID: 17011055 DOI: 10.1016/j.aquatox.2006.08.010] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 08/17/2006] [Accepted: 08/30/2006] [Indexed: 05/12/2023]
Abstract
We investigated whether exposure to environmentally relevant concentrations of the bactericidal agent, triclosan, induces changes in the thyroid hormone-mediated process of metamorphosis of the North American bullfrog, Rana catesbeiana and alters the expression profile of thyroid hormone receptor (TR) alpha and beta, basic transcription element binding protein (BTEB) and proliferating nuclear cell antigen (PCNA) gene transcripts. Premetamorphic tadpoles were immersed in environmentally relevant concentrations of triclosan and injected with 1 x 10(-11)mol/g body weight 3,5,3'-triiodothyronine (T3) or vehicle control. Morphometric measurements and steady-state mRNA levels obtained by quantitative polymerase chain reaction were determined. mRNA abundance was also examined in Xenopus laevis XTC-2 cells treated with triclosan and/or 10nM T3. Tadpoles pretreated with triclosan concentrations as low as 0.15+/-0.03 microg/L for 4 days showed increased hindlimb development and a decrease in total body weight following T3 administration. Triclosan exposure also resulted in decreased T3-mediated TRbeta mRNA expression in the tadpole tail fin and increased levels of PCNA transcript in the brain within 48 h of T3 treatment whereas TRalpha was unaffected [corrected] Triclosan alone altered thyroid hormone receptor alpha transcript levels in the brain of premetamorphic tadpoles and induced a transient weight loss. In XTC-2 cells, exposure to T3 plus nominal concentrations of triclosan as low as 0.03 microg/L for 24h resulted in altered thyroid hormone receptor mRNA expression. Exposure to low levels of triclosan disrupts thyroid hormone-associated gene expression and can alter the rate of thyroid hormone-mediated postembryonic anuran development.
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Affiliation(s)
- Nik Veldhoen
- Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
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Helbing CC, Ovaska K, Ji L. Evaluation of the effect of acetochlor on thyroid hormone receptor gene expression in the brain and behavior of Rana catesbeiana tadpoles. Aquat Toxicol 2006; 80:42-51. [PMID: 16949162 DOI: 10.1016/j.aquatox.2006.07.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Revised: 07/12/2006] [Accepted: 07/12/2006] [Indexed: 05/11/2023]
Abstract
The thyroid hormones (THs) including 3,5,3'-triiodothyronine (T3), are important regulators of growth and development of the brain in vertebrates. Previous studies showed that acetochlor, a widely used herbicide, accelerates T3 -induced frog tadpole metamorphosis and elevates the T3 -dependent accumulation of the mRNAs encoding the TH receptors, TRalpha and beta, in the tail. Here we show that acetochlor affects the expression of these TR isoforms in the brain of Rana catesbeiana tadpoles. Premetamorphic tadpoles exposed to 10 nM acetochlor with and without 100 nM T(3) for 4 days showed substantial increases in TRalpha and TRbeta transcript levels and significant decreases in the TRalpha/TRbeta ratios in their brains. This change in TR ratios is recapitulated with 10 nM acetochlor in R. catesbeiana tadpole brains during prometamorphosis, a period in which THs are endogenously produced. Tail fin biopsies revealed an elevation in TRalpha and beta mRNA levels compared to control animals when exposed to 1 and 10 nM acetochlor for 6 days. When subsequently reared in clean water for 59 days, no alterations in metamorphic hallmarks (forelimb emergence, mouth development, tail regression) were noted compared to the controls. Since alterations in TR ratios/levels may impact brain development, we tested the escape behavior in premetamorphic tadpoles exposed to 10 nM acetochlor for 4 days. We did not detect any statistically significant differences that would indicate that acetochlor affects escape behavior. However, since the gene expression data suggest that brain function may be affected, additional studies examining different behaviors upon acetochlor exposure at environmentally-relevant concentrations are warranted.
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Affiliation(s)
- Caren C Helbing
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada.
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