Taurine depletion impairs cardiac function and affects tolerance to hypoxia and high temperatures in brook char (Salvelinus fontinalis)

• DOI: 10.1242/jeb.245092
• Publication Date: 2023-02-02T14:33:43Z
• Authors: Toni-Anne M. Dixon; Emma-Lee M. Rhyno; Nir El; Samuel P. McGaw; Nathan A. Otley; Katya S. Parker; Elena C. Buldo; Claire M. Pabody; Mireille Savoie; Amanda Cockshutt; Andrea J. Morash; Simon G. Lamarre; Tyson J. MacCormack
• Keywords: Fontinalis; Arctic char; Hypoxia

Physiological and environmental stressors can cause osmotic stress in fish hearts, leading to a reduction intracellular taurine concentration. Taurine is β-amino acid known regulate cardiac function other animal models but its role has not been well characterized. We generated model of deficiency (TD) by feeding brook char (Salvelinus fontinalis) diet enriched β-alanine, which inhibits cardiomyocyte uptake. Cardiac levels were reduced 21% stress-induced changes normal handling observed TD char. Responses exhaustive exercise acute thermal hypoxia tolerance then assessed using combination vivo, vitro biochemical approaches. Critical maximum was higher despite significant reductions heart rate. In exhibited lower resting rate, blunted hypoxic bradycardia severe time loss equilibrium under hypoxia. similar between control hearts oxygenated conditions, stroke volume output severely compromised Aspects mitochondrial structure also impacted permeabilized cardiomyocytes, overall effects modest. High are required achieve efflux may be necessary support stress. appears play vital, previously unrecognized supporting cardiovascular fish.