A successful spawning migration in salmon depends on their athletic ability, and thus on efficient cardiovascular oxygen (O-2) transport. Most teleost fishes have highly pH-sensitive haemoglobins (Hb) that can release large amounts of O-2 when the blood is acidified at the tissues. We hypothesized that plasma-accessible carbonic anhydrase (paCA; the enzyme that catalyses proton production from CO2) is required to acidify the blood at the tissues and promote tissue O-2 extraction. Previous studies have reported an elevated tissue O-2 extraction in hypoxia-acclimated teleosts that may also be facilitated by paCA. Thus, to create experimental contrasts in tissue O-2 extraction, Atlantic salmon were acclimated to normoxia or hypoxia (40% air saturation for more than six weeks), and the role of paCA in enhancing tissue O-2 extraction was tested by inhibiting paCA at rest and during sub-maximal exercise. Our results show that: (i) in both acclimation groups, the inhibition of paCA increased cardiac output by one-third, indicating a role of paCA in promoting tissue O-2 extraction during exercise, recovery and at rest; (ii) the recruitment of paCA was plastic and increased following hypoxic acclimation; and (iii) maximal exercise performance in salmon, and thus a successful spawning migration, may not be possible without paCA.

Functional support for a novel mechanism that enhances tissue oxygen extraction in a teleost fish / Harter, T S; Zanuzzo, F S; Supuran, C T; Gamperl, A K; Brauner, C J. - In: PROCEEDINGS - ROYAL SOCIETY. BIOLOGICAL SCIENCES. - ISSN 0962-8452. - ELETTRONICO. - 286:(2019), pp. 0-0. [10.1098/rspb.2019.0339]

Functional support for a novel mechanism that enhances tissue oxygen extraction in a teleost fish

Supuran, C T;
2019

Abstract

A successful spawning migration in salmon depends on their athletic ability, and thus on efficient cardiovascular oxygen (O-2) transport. Most teleost fishes have highly pH-sensitive haemoglobins (Hb) that can release large amounts of O-2 when the blood is acidified at the tissues. We hypothesized that plasma-accessible carbonic anhydrase (paCA; the enzyme that catalyses proton production from CO2) is required to acidify the blood at the tissues and promote tissue O-2 extraction. Previous studies have reported an elevated tissue O-2 extraction in hypoxia-acclimated teleosts that may also be facilitated by paCA. Thus, to create experimental contrasts in tissue O-2 extraction, Atlantic salmon were acclimated to normoxia or hypoxia (40% air saturation for more than six weeks), and the role of paCA in enhancing tissue O-2 extraction was tested by inhibiting paCA at rest and during sub-maximal exercise. Our results show that: (i) in both acclimation groups, the inhibition of paCA increased cardiac output by one-third, indicating a role of paCA in promoting tissue O-2 extraction during exercise, recovery and at rest; (ii) the recruitment of paCA was plastic and increased following hypoxic acclimation; and (iii) maximal exercise performance in salmon, and thus a successful spawning migration, may not be possible without paCA.
2019
286
0
0
Harter, T S; Zanuzzo, F S; Supuran, C T; Gamperl, A K; Brauner, C J
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/1307851
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 31
  • ???jsp.display-item.citation.isi??? 32
social impact