Hypoxic cardiorespiratory reflexes in the facultative air-breathing fish jeju (Hoplerythrinus unitaeniatus): role of branchial O2 chemoreceptors

This study analyzed the physiological role of the cardiac sarcoplasmic reticulum (SR) of two neotropical teleosts, the jeju, Hoplerythrinus unitaeniatus (Erythrinidae), and the acara, Geophagus brasiliensis (Cichlidae). While the in vivo heart frequency (fH - bpm) of acara (79.6 ± 6.6) was higher than that of the jeju (50.3 ± 2.7), the opposite was observed for the ventricular inotropism (Fc - mN/mm²) at 12 bpm (acara = 28.66 ± 1.86 vs. jeju = 36.09 ± 1.67). A 5 min diastolic pause resulted in a strong potentiation of Fc (≅ 90%) of strips from jeju, which was completely abolished by ryanodine. Ryanodine also resulted in a ≅ 20% decrease in the Fc developed by strips from jeju at both subphysiological (12 bpm) and physiological (in vivo) frequencies. However, this effect of ryanodine reducing the Fc from jeju was completely compensated by adrenaline increments (10-9 and 10-6 M). In contrast, strips from acara were irresponsive to ryanodine, irrespective of the stimulation frequency, and increases in adrenaline concentration (to 10-9 and 10-6 M) further increased Fc. These results reinforce the hypothesis of the functionality of the SR as a common trait in neotropical ostariophysian (as jeju), while in acanthopterygians (as acara) it seems to be functional mainly in 'athletic' species.

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The Effects of Branchial Denervation and Pseudobranch Ablation on Cardioventilatory Control in an Air-Breathing Fish

Journal of Experimental Biology ◽

10.1242/jeb.161.1.347 ◽

1991 ◽

Vol 161 (1) ◽

pp. 347-365 ◽

Cited By ~ 6

Author(s):

DAVID J. McKENZIE ◽

MARK L. BURLESON ◽

DAVID J. RANDALL

Keyword(s):

Cardiovascular Responses ◽

Sodium Cyanide ◽

Air Breathing ◽

Ventilatory Responses ◽

Reflex Bradycardia ◽

Afferent Information ◽

Gill Ventilation ◽

Air Ventilation ◽

Amia Calva

Present address and address for reprint requests: Istituto di Scienze Farmacologiche, via Balzaretti 9, Università di Milano, Milano 20133, Italy. The role of sensory afferent information from the gills of Amia calva in cardiovascular and ventilatory control was investigated by bilateral branchial denervation and pseudobranch ablation. Aquatic hypoxia or 1 mg of sodium cyanide (NaCN) in the water flowing over the gills stimulated bradycardia, and gill and air ventilation in sham-operated fish. Sodium cyanide, noradrenaline (NA) and adrenaline (A) infusion into the dorsal aorta increased gill ventilation, and NA and A infusion also stimulated tachycardia and an increase in blood pressure. Following denervation and pseudobranch ablation, O2 consumption (V·OO2), airbreathing frequency (fAB) and arterial O2 tension (PaOO2) declined, and circulating NA levels increased, as compared with sham-operated fish. Cardiovascular and air-breathing responses to hypoxia were abolished and gill ventilatory responses attenuated. All ventilatory and cardiovascular responses to NaCN were abolished and gill ventilatory responses to NA and A were attenuated in animals following denervation and pseudobranch ablation. These results demonstrate that O2-sensitive chemoreceptors in the gills and pseudobranch control reflex bradycardia and air-breathing responses in Amia, but that gill ventilatory responses to hypoxia, NA and A are partially mediated by extrabranchial mechanisms. Plasma NA levels increased during hypoxia in shamoperated and denervated animals, indicating that circulating NA may have mediated gill ventilatory responses in denervated animals.

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Role of Taurine in Cellular Volume Regulation in Erythrocytes of Air-Breathing Catfish (Clarias magur) Under Osmotic Stress

Proceedings of the National Academy of Sciences India Section B Biological Sciences ◽

10.1007/s40011-018-01067-5 ◽

2019 ◽

Vol 89 (4) ◽

pp. 1389-1397

Author(s):

Bodhisattwa Banerjee ◽

Debaprasad Koner ◽

Priyanka Lal ◽

Suman Kumari ◽

Rubaiya Hasan ◽

...

Keyword(s):

Osmotic Stress ◽

Volume Regulation ◽

Air Breathing ◽

Cellular Volume

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Development of central respiratory control in anurans: The role of neurochemicals in the emergence of air-breathing and the hypoxic response

Respiratory Physiology & Neurobiology ◽

10.1016/j.resp.2019.103266 ◽

2019 ◽

Vol 270 ◽

pp. 103266 ◽

Cited By ~ 2

Author(s):

Tara A. Janes ◽

Jean-Philippe Rousseau ◽

Stéphanie Fournier ◽

Elizabeth A. Kiernan ◽

Michael B. Harris ◽

...

Keyword(s):

Respiratory Control ◽

Hypoxic Response ◽

Air Breathing

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The role of TASK-2 channels in CO2 sensing in zebrafish (Danio rerio)

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00132.2020 ◽

2020 ◽

Vol 319 (3) ◽

pp. R329-R342

Author(s):

N. Koudrina ◽

S. F. Perry ◽

K. M. Gilmour

Keyword(s):

Danio Rerio ◽

Ventilatory Response ◽

Indirect Evidence ◽

Adult Zebrafish ◽

Larval Zebrafish ◽

Neuroepithelial Cells ◽

Cardiorespiratory Reflexes ◽

Or Task ◽

And Task

Peripheral chemosensitivity in fishes is thought to be mediated by serotonin-enriched neuroepithelial cells (NECs) that are localized to the gills of adults and the integument of larvae. In adult zebrafish ( Danio rerio), branchial NECs are presumed to mediate the cardiorespiratory reflexes associated with hypoxia or hypercapnia, whereas in larvae, there is indirect evidence linking cutaneous NECs to hypoxic hyperventilation and hypercapnic tachycardia. No study yet has examined the ventilatory response of larval zebrafish to hypercapnia, and regardless of developmental stage, the signaling pathways involved in CO2 sensing remain unclear. In the mouse, a background potassium channel (TASK-2) contributes to the sensitivity of chemoreceptor cells to CO2. Zebrafish possess two TASK-2 channel paralogs, TASK-2 and TASK-2b, encoded by kcnk5a and kcnk5b, respectively. The present study aimed to determine whether TASK-2 channels are expressed in NECs of larval zebrafish and whether they are involved in CO2 sensing. Using immunohistochemical approaches, TASK-2 protein was observed on the surface of NECs in larvae. Exposure of larvae to hypercapnia caused cardiac and breathing frequencies to increase, and these responses were blunted in fish experiencing TASK-2 and/or TASK-2b knockdown. The results of these experiments suggest that TASK-2 channels are involved in CO2 sensing by NECs and contribute to the initiation of reflex cardiorespiratory responses during exposure of larvae to hypercapnia.

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Adrenaline and triiodothyronine modify the iron handling in the freshwater air-breathing fish Anabas testudineus Bloch: Role of ferric reductase in iron acquisition

General and Comparative Endocrinology ◽

10.1016/j.ygcen.2012.11.008 ◽

2013 ◽

Vol 181 ◽

pp. 130-138 ◽

Cited By ~ 1

Author(s):

V. Rejitha ◽

M.C. Subhash Peter

Keyword(s):

Iron Acquisition ◽

Ferric Reductase ◽

Anabas Testudineus ◽

Air Breathing

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Role of ureogenesis in tackling problems of ammonia toxicity during exposure to higher ambient ammonia in the air-breathing walking catfishclarias batrachus

Journal of Biosciences ◽

10.1007/bf02708434 ◽

2003 ◽

Vol 28 (6) ◽

pp. 733-742 ◽

Cited By ~ 13

Author(s):

Nirmalendu Saha ◽

Shritapa Datta ◽

Kuheli Biswas ◽

Zaiba Y. Kharbuli

Keyword(s):

Ammonia Toxicity ◽

Air Breathing

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Air-breathing mechanics in two Amazonian teleosts, Arapaima gigas and Hoplerythrinus unitaeniatus

Canadian Journal of Zoology ◽

10.1139/z78-129 ◽

1978 ◽

Vol 56 (4) ◽

pp. 939-945 ◽

Cited By ~ 28

Author(s):

A. P. Farrell ◽

D. J. Randall

Keyword(s):

Gas Pressure ◽

Breathing Patterns ◽

Air Breathing ◽

Arapaima Gigas ◽

Breathing Mechanics ◽

Replacement Technique ◽

Hoplerythrinus Unitaeniatus

The mechanics of air breathing in pirarucu, Arapaima gigas, and jeju, Hoplerythrinus unitaeniatus, were studied by simultaneous monitoring of air bladder gas pressure and buccal pressure. Also the effect of alterations in air bladder gas tensions on air-breathing patterns was examined by a gas replacement technique. Pirarucu surface every 4.2 min to make a single ventilation of the air bladder, whilst jeju usually make two or three ventilations at an air breath every 3.0 min. Pirarucu exhale first, then inhale, but in jeju buccal filling occurred before lung emptying. Inhalation in pirarucu is a result of air bladder aspiration combined with the action of a buccal pump; however, lung filling in jeju is achieved by a buccal pump only. The significance of aspiration breathing in pirarucu is discussed. Both fish respond similarly to alterations in air bladder gas tensions. Hyperoxia prolongs the interval between air breaths and hypercapnia reduces this interval.

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Some kinetic properties of skeletal muscle pyruvate kinase from air-breathing and water-breathing fish of the Amazon

Canadian Journal of Zoology ◽

10.1139/z78-104 ◽

1978 ◽

Vol 56 (4) ◽

pp. 751-758 ◽

Cited By ~ 15

Author(s):

J. H. A. Fields ◽

W. R. Driedzic ◽

C. J. French ◽

P. W. Hochachka

Keyword(s):

Skeletal Muscle ◽

Pyruvate Kinase ◽

Adenosine Diphosphate ◽

Kinetic Properties ◽

Air Breathing ◽

Hoplias Malabaricus ◽

Arapaima Gigas ◽

Saturation Kinetics ◽

Muscle Pyruvate Kinase ◽

Hoplerythrinus Unitaeniatus

The kinetic properties of pyruvate kinase from skeletal muscle were studied in two species of air-breathing fish, Hoplerythrinus unitaeniatus and Arapaima gigas, and two species of water-breathing fish, Hoplias malabaricus and Osteoglossum bicirrhosum. It was found that the enzymes from Hoplias and Hoplerythrinus showed hyperbolic saturation kinetics for all substrates, were activated slightly by fructose 1,6-diphosphate, and were inhibited by phosphocreatine and citrate. The enzyme from Hoplias was inhibited by alanine, whereas the enzyme from Hoplerythrinus was not. The enzymes from Arapaima and Osteoglossum showed hyperbolic saturation kinetics for adenosine diphosphate, but the saturation kinetics for phusphoenol-pyruvate were sigmoidal. These enzymes were strongly activated by fructose 1,6-diphosphate and strongly inhibited by alanine, the former completely reversing the inhibition by the latter. Phosphocreatine and citrate were also found to be inhibitors of these enzymes, but the inhibition by phosphocreatine was not reversed by additions of fructose 1,6-diphosphate. The enzymes from the water-breathing fish were more sensitive to inhibition by alanine than were those from the air-breathing fish, but in other respects the enzymes were very similar.

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