Postmortem grass carp (Ctenopharyngodon idella) muscle towards the disruption of integrity: a likely cause of abnormal regulation of tight junction and decreased antioxidant capacity

Abstract

Summary The disruption of structural integrity could affect flesh quality changes. This study investigated the disruption of muscle integrity and the affecting factors in postmortem fish at 4 °C for 5 days storage. Haematoxylin–eosin staining indicated that profound disruption of structural integrity was observed for the changes of dissolved nucleus, irregular shape of myofibrils and loose attachment. The increased activities of β‐N‐acetyl‐glucosaminidase (NAG) and α‐Glucosidase (AG) enzymes confirmed the profound disruption of integrity in postmortem muscle. The abnormal up‐regulated gene expressions of claudin‐11, claudin‐12, claudin‐15a, claudin‐15b and myosin light chain kinase (MLCK) implied the disrupted intercellular integrity. The impaired cellular integrity and the increased oxidative damage was due to the decreased antioxidant capacity, which was regulated by the decreased transcriptional levels of antioxidant enzymes. Collectively, this study provided a partial molecular mechanisms for the disruption of structural integrity and the changes of flesh quality in postmortem fish muscle.

Dietary copper improves intestinal structural integrity in juvenile grass carp (Ctenopharyngodon idella) probably related to its increased intestinal antioxidant capacity and apical junction complex

“…Malondialdehyde (MDA) and protein carbonyl (PC) reflect a state of oxidative damage to lipids ( Burcham and Kuhan, 1996 ) and proteins ( Van Montfort et al., 2003 ), respectively, resulting in oxidative stress in the organism. Oxidative stress causes damage to cellular integrity and decreases the antioxidant capacity in the organism ( Tie et al., 2022 ). Superoxide dismutase (SOD) ( Harris, 1992 ) and glutathione peroxidase (GPx) are antioxidant enzymes that play a vital role in antioxidation ( Gu and Zhao, 2015 ).…”