Differential regulation of glucolipid metabolism by acute hypoxia in gibel carp (Carassius gibelio) strains

This study investigated the responses of glucolipid metabolism in gibel carp, the CAS III strain (A strain, 7.14 ± 0.23 g) and the Dongting strain (DT strain, 7.72 ± 0.54 g), following acute hypoxia/reoxygenation. The effects of hypoxia (0.39 ± 0.02 mg/L) and reoxygenation (8.30 ± 0.30 mg/L) were examined in both strains after exposure for 2 h. The results revealed significantly enhanced PI3K/AKT pathway and AMPK/HIF-1α pathways, along with upregulated expression of glucose-6-phosphatase ( g6pase ) and lipid synthesis-related genes ( acc and fas ) in both gibel carp strains following acute hypoxia ( P < 0.05). The observed increase in plasma glucose levels during acute hypoxia may be related to elevated expression of g6pase ( P < 0.05). Regarding the genotype, the A strain exhibited significantly higher expression of glucose metabolism-related genes ( pk and pepck ) in the liver compared to the DT strain ( P < 0.05). Conversely, the expression of lipid metabolism-related genes ( hsl , lpl , pparα , cpt1a , and aco3 ) were significantly lower in the A strain compared to the DT strain ( P < 0.05). In both strains of gibel carp, reoxygenation resulted in significant activation of the PI3K/AKT and AMPK/mTOR pathways, accompanied by upregulated expression of glucose metabolism-related genes ( gk , 6pfk, foxo1a , fbpase , and pepck ) and lipid synthesis-related genes ( srebp-1 , acly, and acc ) ( P < 0.05). Notably, the A strain exhibited increased transcripts of glucose metabolism-related genes ( gk , pk , foxo1a , g6pase , and pepck ) and lipid metabolism-related genes ( acly , fas , and cpt1a ) compared to the DT strain ( P < 0.05). Overall, this study revealed distinct regulation patterns of glucolipid metabolism in the gibel carp with different genotype under acute hypoxia/reoxygenation. • PI3K/AKT pathway was significantly enhanced in gibel carp following acute hypoxia. • AMPK/HIF-1α pathway was significantly induced by acute hypoxia in both gibel carp strains. • AMPK/mTOR pathway was activated during reoxygenation in gibel carp. • Different regulation of glycolipid metabolism between the two strains of gibel carp under acute hypoxic stress.