Chronic hypoxia attenuates central respiratory-related pH/CO2 chemosensitivity in the cane toad

McAneney, Jessica; Reid, Scott D.

doi:10.1016/j.resp.2006.10.002

Cited by 5 publications

(6 citation statements)

References 47 publications

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“…The decrease in lung burst duration allows for subsequent breaths to follow at a quicker rate, thus increasing absolute frequency. In anurans, lung burst area has been associated with respiratory tidal volume (McAneney and Reid 2007). The increase in area during SP treatment despite the decrease in lung burst duration is attributed to the increase in lung burst amplitude.…”

Section: Discussionmentioning

confidence: 99%

Lung respiratory rhythm and pattern generation in the bullfrog: role of neurokinin-1 and μ-opioid receptors

et al. 2009

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Location of the lung respiratory rhythm generator (RRG) in the bullfrog brainstem was investigated by examining neurokinin-1 and µ-opioid receptor (NK1R, µOR) colocalization by immunohistochemistry and characterizing the role of these receptors in lung rhythm and episodic pattern generation. NK1R and µOR occurred in brainstems from all developmental stages. In juvenile bullfrogs a distinct area of colocalization was coincident with high-intensity fluorescent labeling of µOR; high-intensity labeling of µOR was not distinctly and consistently localized in tadpole brainstems. NK1R labeling intensity did not change with development. Similarity in colocalization is consistent with similarity in responses to substance P (SP, NK1R agonist) and DAMGO (µOR agonist) when bath applied to bullfrog brainstems of different developmental stages. In early stage tadpoles and juvenile bullfrogs, SP increased and DAMGO decreased lung burst frequency. In juvenile bullfrogs, SP increased lung burst frequency, episode frequency, but decreased number of lung bursts per episode and lung burst duration. In contrast, DAMGO decreased lung burst frequency and burst cycle frequency, episode frequency, and number of lung bursts per episode but increased all other lung burst parameters. Based on these results, we hypothesize that NK1R and µOR colocalization together with a metamorphosis-related increase in µOR intensity marks the location of the lung RRG but not necessarily the lung episodic pattern generator.

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Section: Discussionmentioning

confidence: 99%

Lung respiratory rhythm and pattern generation in the bullfrog: role of neurokinin-1 and μ-opioid receptors

et al. 2009

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“…Neuroepithelial bodies, containing putative oxygen-sensing cells, have also been found in the lungs of amphibians, suggesting that the oxygen composition of respiratory gas may also be monitored (Goniakowska-Witalinska et al 2009). More recently, it has been suggested that central O 2 sensitive chemoreceptors may also be involved in this response (see next section) (Reid 2006; McAneney and Reid 2007). …”

Section: Amphibiansmentioning

confidence: 99%

“…Blood gases were not measured in this study, however, making it difficult to establish whether similar changes occurred in and as in control animals. However, isolated brainstems from these animals also showed a blunted response to hypoxia as well as to changes in pH/CO 2 (McAneney and Reid 2007). The latter was abolished by midbrain transection, again illustrating a descending inhibitory role of higher brain structures on ventilatory activity produced by the medulla (McAneney and Reid 2007).…”

Section: Amphibiansmentioning

confidence: 99%

“…However, isolated brainstems from these animals also showed a blunted response to hypoxia as well as to changes in pH/CO 2 (McAneney and Reid 2007). The latter was abolished by midbrain transection, again illustrating a descending inhibitory role of higher brain structures on ventilatory activity produced by the medulla (McAneney and Reid 2007). Chronic exposure to hypoxic hypercapnia (10% O 2 /3.5% CO 2 ), also blunted the ventilatory response to hypoxia in intact animals (Srivaratharajah et al 2008).…”

Section: Amphibiansmentioning

confidence: 99%

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Time domains of the hypoxic ventilatory response in ectothermic vertebrates

et al. 2011

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Over a decade has passed since Powell et al. (Respir Physiol 112:123–134, 1998) described and defined the time domains of the hypoxic ventilatory response (HVR) in adult mammals. These time domains, however, have yet to receive much attention in other vertebrate groups. The initial, acute HVR of fish, amphibians and reptiles serves to minimize the imbalance between oxygen supply and demand. If the hypoxia is sustained, a suite of secondary adjustments occur giving rise to a more long-term balance (acclimatization) that allows the behaviors of normal life. These secondary responses can change over time as a function of the nature of the stimulus (the pattern and intensity of the hypoxic exposure). To add to the complexity of this process, hypoxia can also lead to metabolic suppression (the hypoxic metabolic response) and the magnitude of this is also time dependent. Unlike the original review of Powell et al. (Respir Physiol 112:123–134, 1998) that only considered the HVR in adult animals, we also consider relevant developmental time points where information is available. Finally, in amphibians and reptiles with incompletely divided hearts the magnitude of the ventilatory response will be modulated by hypoxia-induced changes in intra-cardiac shunting that also improve the match between O2 supply and demand, and these too change in a time-dependent fashion. While the current literature on this topic is reviewed here, it is noted that this area has received little attention. We attempt to redefine time domains in a more ‘holistic’ fashion that better accommodates research on ectotherms. If we are to distinguish between the genetic, developmental and environmental influences underlying the various ventilatory responses to hypoxia, however, we must design future experiments with time domains in mind.

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“…O fluxo pulmocutâneo muda sua distribuição relativa entre a pele e o pulmão, favorecendo a circulação cutânea (BURGGREN e DOYLE, 1986). Wang et al (1994) e Andersen et al (2003) (MCANENEY et al, 2006;MCANENEY et al, 2007). A transecção do mesencéfalo restaura a resposta, o que sugere que estruturas mesencefálicas exercem uma modulação inibitória sobre a quimiossensibilidade central durante a hipóxia crônica (MCANENEY et al, 2007).…”

Section: Sistema Cardiovascularunclassified

Participação dos núcleos da rafe nas respostas cardiorespiratórias à hipóxia e hipercarbia em sapos

Souza¹

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À minha orientadora, Profa. Dra. Luciane Helena Gargaglioni Batalhão, por me abrir as portas do mundo científico. Agradeço a confiança e respeito que sempre demonstrou por minhas decisões, permitindo a autonomia necessária para o meu amadurecimento, mas sem nunca deixar que me perdesse ao longo do caminho. Agradeço também a amizade durante estes 5 anos de convivência. Ao Prof. Luiz Guilherme de Siqueira Branco, pela colaboração. Agradeço por ter me recebido em seu laboratório e possibilitado que desenvolvesse meu trabalho da melhor maneira possível. À prof. Dra. Kênia Cardoso Bícego, por estar também presente na execução deste trabalho e pela companhia em tantos momentos. Aos colegas de laboratório, alunos tanto da profa. Luciane Gargaglioni quanto do prof. Luis Guilherme Branco e da profa. Kênia Bícego. Agradeço não só a convivência divertida, como também a ajuda nos trabalhos práticos e nas discussões. À Elisa por confiar que lhe auxiliasse em seu trabalho de iniciação científica, sempre disposta a ouvir conselhos e discutir suas dúvidas. À Aretuza, pela amizade e assistência técnica. Aos colegas da 39ª turma de Ciência Biológicas da Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (USP-Ribeirão Preto), por tudo. É um prazer, e um incentivo para me superar sempre, conviver com pessoas tão especiais. Às colegas de república: Mariela, Clara, Mônica e Preta pela companhia e pelos ouvidos, cansados de tanto me escutar. E aos amigos de mais longa data, de São José dos Campos. Ao Iuri por "abraçar" minhas idéias e ajudar no que fosse preciso: figuras, textos, problemas com o computador, desabafos. Agradeço por estar sempre presente, se esforçando em me manter longe de qualquer problema para que pudesse trabalhar tranquilamente. E claro, agradeço por todo o amor. A meus pais pelo apoio presente ou remoto em todos os momentos: felizes, tristes, fáceis ou difíceis, e pelo valor imensurável que dão aos estudos. Agradeço também pela revisão de linguagem desta dissertação. À FAPESP pelo suporte financeiro, concedendo a bolsa de mestrado que possibilitou que me dedicasse integralmente a este trabalho (processo número 2007/53118-8). E a Deus por prover condições que permitem me dedicar inteiramente a minha formação; privilégio perante tantos outros milhões de brasileiros. RESUMO NORONHA-DE-SOUZA, C.R.N. Participação dos núcleos da rafe nas respostas cardiorrespiratórias à hipóxia e hipercarbia em sapos. 2009. Dissertação (Mestrado)

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Chronic hypoxia attenuates central respiratory-related pH/CO2 chemosensitivity in the cane toad

Cited by 5 publications

References 47 publications

Lung respiratory rhythm and pattern generation in the bullfrog: role of neurokinin-1 and μ-opioid receptors

Lung respiratory rhythm and pattern generation in the bullfrog: role of neurokinin-1 and μ-opioid receptors

Time domains of the hypoxic ventilatory response in ectothermic vertebrates

Participação dos núcleos da rafe nas respostas cardiorespiratórias à hipóxia e hipercarbia em sapos

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