Cardiac injury and purine metabolic remodeling in Carassius auratus under environmentally relevant carbonate alkalinity exposure.

Carbonate alkalinity exposure causes significant cardiac injury in Carassius auratus, with mitochondrial damage and disrupted energy metabolism at 20 and 40 mM levels.

• Why it matters: Understanding how environmental carbonate alkalinity affects fish hearts is crucial as freshwater systems become more salinized and alkalized due to climate change and human activities, threatening aquatic health.
• What they did: Researchers exposed C. auratus to 0, 20, or 40 mM NaHCO3, then assessed cardiac tissue for injury, mitochondrial function, redox balance, and metabolic changes using histology, biochemical assays, and untargeted metabolomics.
• The result: Findings reveal that alkalinity induces cardiac injury linked to mitochondrial dysfunction, altered purine metabolism, and oxidative stress, highlighting potential mechanisms of environmental stress impacts on fish health.