Effet combiné de la température et de la disponibilité en oméga 3 dans la nourriture sur la fonction cardio-respiratoire du mulet doré - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2019

Ocean warming combined with lower omega-3 nutritional availability impairs thecardio-respiratory function of a marine fish

Effet combiné de la température et de la disponibilité en oméga 3 dans la nourriture sur la fonction cardio-respiratoire du mulet doré

Résumé

Highly unsaturated fatty acids of the omega-3 series (HUFA) are major constituents of cell membranes, yet poorly synthesized de novo by consumers. Their production, mainly supported by aquatic microalgae, has been decreasing with global change. Understanding the consequences of such reductions is essential for ectotherm consumers, since temperature tightly regulates the HUFA content in cell membranes, maintaining their functionality. Integrating individual,tissue and molecular approaches, we examined the consequences of the combined effects of temperature and HUFA depletion on the key cardio-respiratory functions of the golden grey mullet, an ectotherm grazer of high ecological importance. For four months, fish were exposed to two contrasting HUFA diets (4.8% ecosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) on dry matter (DM) vs. 0.2% EPA+DHA on DM) at 12°C and 20°C. Ventricular force development coupled with gene expression profiles measured on cardiac muscle suggest that combining HUFA depletion with warmer temperatures leads to (1) a proliferation of sarcolemmal and SR Ca2+ channels and (2) a higher force-generating ability by increasing extracellular Ca2+ influx via sarcolemmal channels when the heart has to sustain excessive effort due to stress and/or exercise. At the individual scale, these responses were associated with a relatively greater aerobic scope, maximum metabolic rate and net cost of locomotion, suggesting the higher energycost of this strategy. These impaired cardiac performances could have wider consequences on other physiological performances such as growth,reproduction or migration, all greatly depending on heart function.
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Dates et versions

hal-02409190 , version 1 (15-11-2021)

Identifiants

  • HAL Id : hal-02409190 , version 1

Citer

Marie Vagner, Eric Pante, Amelia Viricel, Thomas Lacoue-Labarthe, Jose-Luis Zambonino-Infante, et al.. Effet combiné de la température et de la disponibilité en oméga 3 dans la nourriture sur la fonction cardio-respiratoire du mulet doré. Colloque d'Ecophysiologie Animale, Oct 2019, Rennes, France. ⟨hal-02409190⟩
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