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Enhanced oxygen unloading in two marine percomorph teleosts.
Shu, Jacelyn J; Heuer, Rachael M; Hannan, Kelly D; Stieglitz, John D; Benetti, Daniel D; Rummer, Jodie L; Grosell, Martin; Brauner, Colin J.
Afiliação
  • Shu JJ; University of British Columbia, Department of Zoology, Canada. Electronic address: jacelyn@zoology.ubc.ca.
  • Heuer RM; University of Miami, Rosenstiel School of Marine and Atmospheric Science, Marine Biology and Ecology Department, USA.
  • Hannan KD; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, 4811 QLD, Australia.
  • Stieglitz JD; University of Miami, Rosenstiel School of Marine and Atmospheric Science, Marine Biology and Ecology Department, USA.
  • Benetti DD; University of Miami, Rosenstiel School of Marine and Atmospheric Science, Marine Biology and Ecology Department, USA.
  • Rummer JL; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, 4811 QLD, Australia; College of Science and Engineering, James Cook University, Townsville, 4811, QLD, Australia.
  • Grosell M; University of Miami, Rosenstiel School of Marine and Atmospheric Science, Marine Biology and Ecology Department, USA.
  • Brauner CJ; University of British Columbia, Department of Zoology, Canada.
Article em En | MEDLINE | ID: mdl-34755650
ABSTRACT
Teleost fishes are diverse and successful, comprising almost half of all extant vertebrate species. It has been suggested that their success as a group is related, in part, to their unique O2 transport system, which includes pH-sensitive hemoglobin, a red blood cell ß-adrenergic Na+/H+ exchanger (RBC ß-NHE) that protects red blood cell pH, and plasma accessible carbonic anhydrase which is absent at the gills but present in some tissues, that short-circuits the ß-NHE to enhance O2 unloading during periods of stress. However, direct support for this has only been examined in a few species of salmonids. Here, we expand the knowledge of this system to two warm-water, highly active marine percomorph fish, cobia (Rachycentron canadum) and mahi-mahi (Coryphaena hippurus). We show evidence for RBC ß-NHE activity in both species, and characterize the Hb-O2 transport system in one of those species, cobia. We found significant RBC swelling following ß-adrenergic stimulation in both species, providing evidence for the presence of a rapid, active RBC ß-NHE in both cobia and mahi-mahi, with a time-course similar to that of salmonids. We generated oxygen equilibrium curves (OECs) for cobia blood and determined the P50, Hill, and Bohr coefficients, and used these data to model the potential for enhanced O2 unloading. We determined that there was potential for up to a 61% increase in O2 unloading associated with RBC ß-NHE short-circuiting, assuming a - 0.2 ∆pHa-v in the blood. Thus, despite phylogenetic and life history differences between cobia and the salmonids, we found few differences between their Hb-O2 transport systems, suggesting conservation of this physiological trait across diverse teleost taxa.
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Texto completo: 1 Base de dados: MEDLINE Assunto principal: Oxigênio / Perciformes / Peixes Tipo de estudo: Prognostic_studies Limite: Animals Idioma: En Ano de publicação: 2022 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Oxigênio / Perciformes / Peixes Tipo de estudo: Prognostic_studies Limite: Animals Idioma: En Ano de publicação: 2022 Tipo de documento: Article