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Pesquisa : B01.050.150.200.400.380 [Categoria DeCS]
Referências encontradas : 537 [refinar]
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[PMID]:28515081
[Au] Autor:Clifford AM; Weinrauch AM; Edwards SL; Wilkie MP; Goss GG
[Ad] Endereço:Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada; alex.clifford@ualberta.ca.
[Ti] Título:Flexible ammonia handling strategies using both cutaneous and branchial epithelia in the highly ammonia-tolerant Pacific hagfish.
[So] Source:Am J Physiol Regul Integr Comp Physiol;313(2):R78-R90, 2017 Aug 01.
[Is] ISSN:1522-1490
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Hagfish consume carrion, potentially exposing them to hypoxia, hypercapnia, and high environmental ammonia (HEA). We investigated branchial and cutaneous ammonia handling strategies by which Pacific hagfish ( ) tolerate and recover from high ammonia loading. Hagfish were exposed to HEA (20 mmol/l) for 48 h to elevate plasma total ammonia (T ) levels before placement into divided chambers for a 4-h recovery period in ammonia-free seawater where ammonia excretion ( ) was measured independently in the anterior and posterior compartments. Localized HEA exposures were also conducted by subjecting hagfish to HEA in either the anterior or posterior compartments. During recovery, HEA-exposed animals increased in both compartments, with the posterior compartment comprising ~20% of the total compared with ~11% in non-HEA-exposed fish. Plasma T increased substantially when whole hagfish and the posterior regions were exposed to HEA. Alternatively, plasma T did not elevate after anterior localized HEA exposure. was concentration dependent (0.05-5 mmol/l) across excised skin patches at up to eightfold greater rates than in skin sections that were excised from HEA-exposed hagfish. Skin excised from more posterior regions displayed greater than those from more anterior regions. Immunohistochemistry with hagfish-specific anti-rhesus glycoprotein type c (α-hRhcg; ammonia transporter) antibody was characterized by staining on the basal aspect of hagfish epidermis while Western blotting demonstrated greater expression of Rhcg in more posterior skin sections. We conclude that cutaneous Rhcg proteins are involved in cutaneous ammonia excretion by Pacific hagfish and that this mechanism could be particularly important during feeding.
[Mh] Termos MeSH primário: Adaptação Fisiológica/fisiologia
Amônia/farmacocinética
Eliminação Cutânea/fisiologia
Brânquias/metabolismo
Feiticeiras (Peixe)/fisiologia
Pele/metabolismo
[Mh] Termos MeSH secundário: Animais
Tolerância a Medicamentos/fisiologia
Epitélio/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
7664-41-7 (Ammonia)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170907
[Lr] Data última revisão:
170907
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170519
[St] Status:MEDLINE
[do] DOI:10.1152/ajpregu.00351.2016


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[PMID]:28242306
[Au] Autor:Suzuki S; Kasai K; Nishiyama N; Ishihara A; Yamauchi K
[Ad] Endereço:Department of Biological Science, Graduate School of Science, Shizuoka University, Shizuoka 422-8529, Japan.
[Ti] Título:Characteristics of the brown hagfish Paramyxine atami transthyretin: Metal ion-dependent thyroid hormone binding.
[So] Source:Gen Comp Endocrinol;249:1-14, 2017 Aug 01.
[Is] ISSN:1095-6840
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Transthyretin (TTR) is a vertebrate-specific protein involved in thyroid hormone distribution in plasma, and its gene is thought to have emerged by gene duplication from the gene for the ancient TTR-related protein, 5-hydroxyisourate hydrolase, at some early stage of chordate evolution. We investigated the molecular and hormone-binding properties of the brown hagfish Paramyxine atami TTR. The amino acid sequence deduced from the cloned hagfish TTR cDNA shared 33-50% identities with those of other vertebrate TTRs but less than 24% identities with those of vertebrate and deuterostome invertebrate 5-hydroxyisourate hydrolases. Hagfish TTR, as well as lamprey and little skate TTRs, had an N-terminal histidine-rich segment, allowing purification by metal-affinity chromatography. The affinity of hagfish TTR for 3,3',5-triiodo-L-thyronine (T3) was 190 times higher than that for L-thyroxine, with a dissociation constant of 1.5-3.9nM at 4°C. The high-affinity binding sites were strongly sensitive to metal ions. Zn and Cu decreased the dissociation constant to one-order of magnitude, whereas a chelator, o-phenanthroline, increased it four times. The number of metal ions (mainly Zn and Cu ) was approximately 12/TTR (mol/mol). TTR was also a major T3-binding protein in adult hagfish sera and its serum concentration was approximately 8µM. These results suggest that metal ions and the acquisition of N-terminal histidine-rich segment may cooperatively contribute to the evolution toward an ancient TTR with high T3 binding activity from either 5-hydroxyisourate hydrolase after gene duplication.
[Mh] Termos MeSH primário: Feiticeiras (Peixe)/metabolismo
Metais/farmacologia
Pré-Albumina/metabolismo
Hormônios Tireóideos/metabolismo
[Mh] Termos MeSH secundário: Amidoidrolases/metabolismo
Sequência de Aminoácidos
Animais
Cátions Bivalentes/farmacologia
DNA Complementar/genética
Perfilação da Expressão Gênica
Hidrólise
Cinética
Filogenia
Pré-Albumina/química
Pré-Albumina/genética
Pré-Albumina/isolamento & purificação
Ligação Proteica/efeitos dos fármacos
RNA Mensageiro/genética
RNA Mensageiro/metabolismo
Proteínas Recombinantes/metabolismo
Soro/metabolismo
Fatores de Tempo
Tri-Iodotironina/metabolismo
Ácido Úrico/análogos & derivados
Ácido Úrico/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (5-hydroxyisourate); 0 (Cations, Divalent); 0 (DNA, Complementary); 0 (Metals); 0 (Prealbumin); 0 (RNA, Messenger); 0 (Recombinant Proteins); 0 (Thyroid Hormones); 06LU7C9H1V (Triiodothyronine); 268B43MJ25 (Uric Acid); EC 3.5.- (Amidohydrolases); EC 3.5.2.- (hydroxyisourate hydrolase)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171106
[Lr] Data última revisão:
171106
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170301
[St] Status:MEDLINE


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[PMID]:28214856
[Au] Autor:Salas CA; Yopak KE; Lisney TJ; Potter IC; Collin SP
[Ad] Endereço:School of Animal Biology, The University of Western Australia, Crawley, WA, Australia.
[Ti] Título:The Central Nervous System of Jawless Vertebrates: Encephalization in Lampreys and Hagfishes.
[So] Source:Brain Behav Evol;89(1):33-47, 2017.
[Is] ISSN:1421-9743
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:Lampreys and hagfishes are the sole surviving representatives of the early agnathan (jawless) stage in vertebrate evolution, which has previously been regarded as the least encephalized group of all vertebrates. Very little is known, however, about the extent of interspecific variation in relative brain size in these fishes, as previous studies have focused on only a few species, even though lampreys exhibit a variety of life history traits. While some species are parasitic as adults, with varying feeding behaviors, others (nonparasitic species) do not feed after completing their macrophagous freshwater larval phase. In addition, some parasitic species remain in freshwater, while others undergo an anadromous migration. On the basis of data for postmetamorphic individuals representing approximately 40% of all lamprey species, with representatives from each of the three families, the aforementioned differences in life history traits are reflected in variations in relative brain size. Across all lampreys, brain mass increases with body mass with a scaling factor or slope (α) of 0.35, which is less than those calculated for different groups of gnathostomatous (jawed) vertebrates (α = 0.43-0.62). When parasitic and nonparasitic species are analyzed separately, with phylogeny taken into account, the scaling factors of both groups (parasitic α = 0.43, nonparasitic α = 0.45) approach those of gnathostomes. The relative brain size in fully grown adults of parasitic species is, however, less than that of the adults of nonparasitic species, paralleling differences between fully grown adults and recently metamorphosed individuals of anadromous species. The average degree of encephalization is found in anadromous parasitic lampreys and might thus represent the ancestral condition for extant lampreys. These results suggest that the degree of encephalization in lampreys varies according to both life history traits and phylogenetic relationships.
[Mh] Termos MeSH primário: Evolução Biológica
Encéfalo/anatomia & histologia
Comportamento Alimentar/fisiologia
Feiticeiras (Peixe)
Lampreias
Filogenia
[Mh] Termos MeSH secundário: Animais
Tamanho Corporal
Feiticeiras (Peixe)/anatomia & histologia
Feiticeiras (Peixe)/fisiologia
Lampreias/anatomia & histologia
Lampreias/fisiologia
Tamanho do Órgão
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170719
[Lr] Data última revisão:
170719
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170220
[St] Status:MEDLINE
[do] DOI:10.1159/000455183


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[PMID]:28126345
[Au] Autor:Clifford AM; Bury NR; Schultz AG; Ede JD; Goss BL; Goss GG
[Ad] Endereço:Bamfield Marine Sciences Centre, Bamfield, BC, Canada; Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.
[Ti] Título:Regulation of plasma glucose and sulfate excretion in Pacific hagfish, Eptatretus stoutii is not mediated by 11-deoxycortisol.
[So] Source:Gen Comp Endocrinol;247:107-115, 2017 Jun 01.
[Is] ISSN:1095-6840
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The goal of this study was to identify whether Pacific hagfish (Eptatretus stoutii) possess glucocorticoid and mineralocorticoid responses and to examine the potential role(s) of four key steroids in these responses. Pacific hagfish were injected with varying amounts of cortisol, corticosterone or 11-deoxycorticosterone (DOC) using coconut oil implants and plasma glucose and gill total-ATPase activity were monitored as indices of glucocorticoid and mineralocorticoid responses. Furthermore, we also monitored plasma glucose and 11-deoxycortisol (11-DOC) levels following exhaustive stress (30 min of agitation) or following repeated infusion with SO . There were no changes in gill total-ATPase following implantation with any steroid, with only very small statistical increases in plasma glucose noted in hagfish implanted with either DOC (at 20 and 200mgkg at 7 and 4days post-injection, respectively) or corticosterone (at 100mgkg at 7days post-injection). Following exhaustive stress, hagfish displayed a large and sustained increase in plasma glucose. Repeated infusion of SO into hagfish caused increases in both plasma glucose levels and SO excretion rate suggesting a regulated glucocorticoid and mineralocorticoid response. However, animals under either condition did not show any significant increases in plasma 11-DOC concentrations. Our results suggest that while there are active glucocorticoid and mineralocorticoid responses in hagfish, 11-DOC does not appear to be involved and the identity and primary function of the steroid in hagfish remains to be elucidated.
[Mh] Termos MeSH primário: Glicemia/metabolismo
Cortodoxona/metabolismo
Feiticeiras (Peixe)/fisiologia
Sulfatos/metabolismo
[Mh] Termos MeSH secundário: Animais
Vias Biossintéticas
Óleo de Coco
Corticosterona/biossíntese
Óleos Vegetais/farmacologia
Estresse Fisiológico
Sulfatos/sangue
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Blood Glucose); 0 (Plant Oils); 0 (Sulfates); Q9L0O73W7L (Coconut Oil); W980KJ009P (Corticosterone); WDT5SLP0HQ (Cortodoxone)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170128
[St] Status:MEDLINE


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[PMID]:28087655
[Au] Autor:Freedman CR; Fudge DS
[Ad] Endereço:Dept. of Integrative Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
[Ti] Título:Hagfish Houdinis: biomechanics and behavior of squeezing through small openings.
[So] Source:J Exp Biol;220(Pt 5):822-827, 2017 Mar 01.
[Is] ISSN:1477-9145
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Hagfishes are able to squeeze through small openings to gain entry to crevices, burrows, hagfish traps and carcasses, but little is known about how they do this, or what the limits of this ability are. The purpose of this study was to describe this ability, and to investigate possible mechanisms by which it is accomplished. We investigated the hypothesis that the passive movement of blood within a hagfish's flaccid subcutaneous sinus allows it to squeeze through narrow apertures that it would not be able to if it were turgid. To test this hypothesis, we analyzed videos of Atlantic hagfish ( ) and Pacific hagfish ( ) moving through narrow apertures in the lab. We measured changes in body width as the animals moved through these openings and documented the behaviors associated with this ability. We found that hagfishes are able to pass through narrow slits that are less than one half the width of their bodies. Our results are consistent with the idea that a flaccid subcutaneous sinus allows hagfish to squeeze through narrow apertures by facilitating a rapid redistribution of venous blood. In addition, we describe nine distinct behaviors associated with this ability, including a form of non-undulatory locomotion also seen in snakes and lampreys. Our results illuminate a behavior that may be a critical component of the hagfish niche, as a result of its likely importance in feeding and avoiding predators.
[Mh] Termos MeSH primário: Feiticeiras (Peixe)/fisiologia
[Mh] Termos MeSH secundário: Animais
Comportamento Animal
Fenômenos Biomecânicos
Tamanho Corporal
Feiticeiras (Peixe)/anatomia & histologia
Locomoção
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170829
[Lr] Data última revisão:
170829
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170115
[St] Status:MEDLINE
[do] DOI:10.1242/jeb.151233


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[PMID]:27915150
[Au] Autor:Glover CN; Blewett TA; Wood CM
[Ad] Endereço:Athabasca River Basin Research Institute and Faculty of Science and Technology, Athabasca University, Athabasca, Alberta T9S 3A3, Canada; Bamfield Marine Sciences Centre, Bamfield, British Columbia V0R 1B0, Canada; Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2R3, Canada. Electronic address: cglover@athabascau.ca.
[Ti] Título:Effect of environmental salinity manipulation on uptake rates and distribution patterns of waterborne amino acids in the Pacific hagfish.
[So] Source:Comp Biochem Physiol A Mol Integr Physiol;204:164-168, 2017 Feb.
[Is] ISSN:1531-4332
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Among vertebrates, hagfish are the only known iono- and osmoconformers, and the only species thus far documented to absorb amino acids directly across the skin. In the current study, short-term (6h) manipulations of exposure salinities (75-125% seawater) were conducted to determine whether changes in osmotic demands influenced the uptake and tissue distribution of waterborne amino acids (alanine, glycine and phenylalanine), in the Pacific hagfish, Eptatretus stoutii. No changes in erythrocyte or muscle amino acid accumulation rates were noted, but the patterns of plasma amino acid accumulation were suggestive of regulation. Contrary to expectations, glycine transport across the skin in vitro was enhanced in the lowest exposure salinity, but no other salinity-dependent changes were demonstrated. Overall, this study indicates that uptake and distribution of amino acids varies with salinity, but not in a manner that is consistent with a role for the studied amino acids in maintaining osmotic balance in hagfish.
[Mh] Termos MeSH primário: Aminoácidos/metabolismo
Feiticeiras (Peixe)/metabolismo
Salinidade
Água do Mar
[Mh] Termos MeSH secundário: Animais
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amino Acids)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170907
[Lr] Data última revisão:
170907
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161205
[St] Status:MEDLINE


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[PMID]:27746317
[Au] Autor:Suzuki A; Komata H; Iwashita S; Seto S; Ikeya H; Tabata M; Kitano T
[Ad] Endereço:Department of Biomolecular Functional Engineering, College of Engineering, Ibaraki University, 4-12-1 Nakanarusawa-cho, Hitachi 316-8511, Japan.
[Ti] Título:Evolution of the RH gene family in vertebrates revealed by brown hagfish (Eptatretus atami) genome sequences.
[So] Source:Mol Phylogenet Evol;107:1-9, 2017 Feb.
[Is] ISSN:1095-9513
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In vertebrates, there are four major genes in the RH (Rhesus) gene family, RH, RHAG, RHBG, and RHCG. These genes are thought to have been formed by the two rounds of whole-genome duplication (2R-WGD) in the common ancestor of all vertebrates. In our previous work, where we analyzed details of the gene duplications process of this gene family, three nucleotide sequences belonging to this family were identified in Far Eastern brook lamprey (Lethenteron reissneri), and the phylogenetic positions of the genes were determined. Lampreys, along with hagfishes, are cyclostomata (jawless fishes), which is a sister group of gnathostomata (jawed vertebrates). Although those results suggested that one gene was orthologous to the gnathostome RHCG genes, we did not identify clear orthologues for other genes. In this study, therefore, we identified three novel cDNA sequences that belong to the RH gene family using de novo transcriptome analysis of another cyclostome: the brown hagfish (Eptatretus atami). We also determined the nucleotide sequences for the RHBG and RHCG genes in a red stingray (Dasyatis akajei), which belongs to the cartilaginous fishes. The phylogenetic tree showed that two brown hagfish genes, which were probably duplicated in the cyclostome lineage, formed a cluster with the gnathostome RHAG genes, whereas another brown hagfish gene formed a cluster with the gnathostome RHCG genes. We estimated that the RH genes had a higher evolutionary rate than the RHAG, RHBG, and RHCG genes. Interestingly, in the RHBG genes, only the bird lineage showed a higher rate of nonsynonymous substitutions. It is likely that this higher rate was caused by a state of relaxed functional constraints rather than positive selection nor by pseudogenization.
[Mh] Termos MeSH primário: Evolução Molecular
Genoma
Feiticeiras (Peixe)/genética
Sistema do Grupo Sanguíneo Rh-Hr/genética
[Mh] Termos MeSH secundário: Animais
DNA Mitocondrial/química
DNA Mitocondrial/classificação
DNA Mitocondrial/metabolismo
Perfilação da Expressão Gênica
Feiticeiras (Peixe)/classificação
Filogenia
RNA Ribossômico 16S/classificação
RNA Ribossômico 16S/genética
Sistema do Grupo Sanguíneo Rh-Hr/classificação
Análise de Sequência de DNA
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Mitochondrial); 0 (RNA, Ribosomal, 16S); 0 (Rh-Hr Blood-Group System)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170927
[Lr] Data última revisão:
170927
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161107
[St] Status:MEDLINE


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[PMID]:27287934
[Au] Autor:Nishimiya O; Katsu Y; Inagawa H; Hiramatsu N; Todo T; Hara A
[Ad] Endereço:Laboratory of Fish Reproductive Physiology and Biochemistry, Division of Marine Life Sciences, Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido, 041-8611, Japan.
[Ti] Título:Molecular cloning and characterization of hagfish estrogen receptors.
[So] Source:J Steroid Biochem Mol Biol;165(Pt B):190-201, 2017 Jan.
[Is] ISSN:1879-1220
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:One or more distinct forms of the nuclear estrogen receptor (ER) have been isolated from many vertebrates to date. To better understand the molecular evolution of ERs, we cloned and characterized er cDNAs from the inshore hagfish, Eptatretus burgeri, a modern representative of the most primitive vertebrates, the agnathans. Two er cDNAs, er1 and er2, were isolated from the liver of a reproductive female hagfish. A phylogenetic analysis placed hagfish ER1 into a position prior to the divergence of vertebrate ERs. Conversely, hagfish ER2 was placed at the base of the vertebrate ERß clade. The tissue distribution patterns of both ER subtype mRNAs appeared to be different, suggesting that each subtype has different physiological roles associated with estrogen actions. An estrogen responsive-luciferase reporter assay using mammalian HEK293 cells was used to functionally characterize these hagfish ERs. Both ER proteins displayed estrogen-dependent activation of transcription. These results clearly demonstrate that the hagfish has two functional ER subtypes.
[Mh] Termos MeSH primário: Estrogênios/metabolismo
Proteínas de Peixes/metabolismo
Feiticeiras (Peixe)/genética
Receptores Estrogênicos/metabolismo
[Mh] Termos MeSH secundário: Animais
Clonagem Molecular
DNA Complementar/metabolismo
Relação Dose-Resposta a Droga
Receptor alfa de Estrogênio/genética
Receptor beta de Estrogênio/genética
Evolução Molecular
Feminino
Proteínas de Peixes/genética
Células HEK293
Feiticeiras (Peixe)/metabolismo
Seres Humanos
Ligantes
Masculino
Filogenia
Receptores Estrogênicos/genética
Transdução de Sinais
Especificidade da Espécie
Distribuição Tecidual
Ativação Transcricional
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Complementary); 0 (ESR2 protein, human); 0 (Estrogen Receptor alpha); 0 (Estrogen Receptor beta); 0 (Estrogens); 0 (Fish Proteins); 0 (Ligands); 0 (Receptors, Estrogen); 0 (estrogen receptor alpha, human)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170706
[Lr] Data última revisão:
170706
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160612
[St] Status:MEDLINE


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[PMID]:27732626
[Au] Autor:Chatzievangelou D; Doya C; Thomsen L; Purser A; Aguzzi J
[Ad] Endereço:Jacobs University Bremen, Bremen, Germany.
[Ti] Título:High-Frequency Patterns in the Abundance of Benthic Species near a Cold-Seep - An Internet Operated Vehicle Application.
[So] Source:PLoS One;11(10):e0163808, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Three benthic megafaunal species (i.e. sablefish Anoplopoma fimbria; pacific hagfish Eptatretus stoutii and a group of juvenile crabs) were tested for diel behavioral patterns at the methane hydrates site of Barkley Canyon (890 m depth), off Vancouver Island (BC, Canada). Fluctuations of animal counts in linear video-transects conducted with the Internet Operated Deep-Sea Crawler "Wally" in June, July and December of 2013, were used as proxy of population activity rhythms. Count time series and environmental parameters were analyzed under the hypothesis that the environmental conditioning of activity rhythms depends on the life habits of particular species (i.e. movement type and trophic level). Non-linear least squares modeling of biological time series revealed significant diel periods for sablefish in summer and for hagfish and crabs in December. Combined cross-correlation and redundancy (RDA) analyses showed strong relationships among environmental fluctuations and detected megafauna. In particular, sablefish presence during summer months was related to flow magnitude, while the activity of pacific hagfish and juvenile crabs in December correlated with change in chemical parameters (i.e. chlorophyll and oxygen concentrations, respectively). Waveform analyses of animal counts and environmental variables confirmed the phase delay during the 24 h cycle. The timing of detection of sablefish occurred under low flow velocities, a possible behavioral adaptation to the general hypoxic conditions. The proposed effect of chlorophyll concentrations on hagfish counts highlights the potential role of phytodetritus as an alternative food source for this opportunistic feeder. The juvenile crabs seemed to display a cryptic behavior, possibly to avoid predation, though this was suppressed when oxygen levels were at a minimum. Our results highlight the potential advantages such mobile observation platforms offer in multiparametric deep-sea monitoring in terms of both spatial and temporal resolution and add to the vastly understudied field of diel rhythms of deep-sea megafauna.
[Mh] Termos MeSH primário: Cordados não Vertebrados/fisiologia
[Mh] Termos MeSH secundário: Animais
Braquiúros/fisiologia
Canadá
Feiticeiras (Peixe)/fisiologia
Estações do Ano
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170509
[Lr] Data última revisão:
170509
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161013
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0163808


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[PMID]:27510962
[Au] Autor:Wilson CM; Roa JN; Cox GK; Tresguerres M; Farrell AP
[Ad] Endereço:Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4 cwilson@larrea.cl.
[Ti] Título:Introducing a novel mechanism to control heart rate in the ancestral Pacific hagfish.
[So] Source:J Exp Biol;219(Pt 20):3227-3236, 2016 Oct 15.
[Is] ISSN:1477-9145
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Although neural modulation of heart rate is well established among chordate animals, the Pacific hagfish (Eptatretus stoutii) lacks any cardiac innervation, yet it can increase its heart rate from the steady, depressed heart rate seen in prolonged anoxia to almost double its normal normoxic heart rate, an almost fourfold overall change during the 1-h recovery from anoxia. The present study sought mechanistic explanations for these regulatory changes in heart rate. We provide evidence for a bicarbonate-activated, soluble adenylyl cyclase (sAC)-dependent mechanism to control heart rate, a mechanism never previously implicated in chordate cardiac control.
[Mh] Termos MeSH primário: Feiticeiras (Peixe)/fisiologia
Frequência Cardíaca/fisiologia
[Mh] Termos MeSH secundário: Adenilil Ciclases/metabolismo
Animais
Membrana Celular/enzimologia
AMP Cíclico/metabolismo
Feminino
Hipóxia/metabolismo
Hipóxia/fisiopatologia
Masculino
Miocárdio/enzimologia
Receptores Adrenérgicos beta/metabolismo
Simportadores de Sódio-Bicarbonato/metabolismo
Solubilidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Receptors, Adrenergic, beta); 0 (Sodium-Bicarbonate Symporters); E0399OZS9N (Cyclic AMP); EC 4.6.1.1 (Adenylyl Cyclases)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170809
[Lr] Data última revisão:
170809
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160812
[St] Status:MEDLINE



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