Background Environmental hypoxia is a common phenomenon in aquaculture,which causes gill tissue injury in fish.Glutathione(GSH)is a vital antioxidant in animal tissues,and its levels decrease under hypoxic conditions....Background Environmental hypoxia is a common phenomenon in aquaculture,which causes gill tissue injury in fish.Glutathione(GSH)is a vital antioxidant in animal tissues,and its levels decrease under hypoxic conditions.However,the effects of glutathione on fish under hypoxic stress remain poorly understood.This study aimed to investigate the impact of glutathione on gill tissue damage in fish under hypoxic stress and explore the underlying mechanisms.Methods Six experimental diets with varying glutathione concentrations.The actual glutathione levels in these diets,measured by high-performance liquid chromatography,were 0.00,145.95,291.90,437.85,583.80,and 729.75 mg/kg,respectively.Fish were fed these diets for 70 d,after which a 96-h hypoxic stress experiment was conducted.The experiment was set up with normoxic and hypoxic groups,in which the dissolved oxygen in the group was 6 mg/L,and that in the group was 1 mg/L.Results This research revealed that glutathione could enhance the growth performance and antioxidant capability of juvenile grass carp while mitigating the structural damage to gill tissues induced by hypoxia stress.Mechanistic investigations further indicated that glutathione mitigated hypoxia-induced oxidative injury in gill tissues and improved their antioxidant capacity.In addition,glutathione attenuated gill apoptosis induced by hypoxia stress.Glutathione also inhibited the initiation,nucleation,elongation,and degradation phases of autophagy,thereby attenuating hypoxia-induced gill autophagy.Moreover,glutathione was found to alleviate hypoxia-induced endoplasmic reticulum stress(ERS)in gills,a response potentially linked to the suppression of PERK,IRE1,and ATF6 signaling pathways.Finally,based on the ROS and PC contents in gill tissue,the optimum glutathione supplementation levels for juvenile grass carp under hypoxia stress were 437.10 and 495.00 mg/kg,respectively.Conclusions In conclusion,our experimental results demonstrated the effectiveness of glutathione in alleviating gill tissue damage caused by hypoxic stress.This study confirms the feasibility and effectiveness of dietary glutathione addition to alleviate hypoxic stress in fish.展开更多
Background As living standards improve,consumers are placing greater emphasis on the enhancement of fish flesh quality,making its improvement increasingly critical.Plant-derived polysaccharides positively affect the i...Background As living standards improve,consumers are placing greater emphasis on the enhancement of fish flesh quality,making its improvement increasingly critical.Plant-derived polysaccharides positively affect the improvement of animal flesh quality.Panax ginseng leaf polysaccharides(PGLP)have a similar composition and lower cost compared with Panax ginseng root polysaccharides.However,its function and application effects in grass carp(Ctenopharyngodon idella)are unclear.Methods A total of 540 sub-adult grass carp(679±1.29 g),one of the important economic fish species,were used as experimental models and fed diets supplemented with 0,100,200,300,400,or 500 mg/kg PGLP for 60 d.After 60 d,grass carp were weighed,and their muscles were collected to explore the effects of PGLP on the growth and development of myofibers and energy metabolism-related parameters.Results Our study found that PGLP increased the growth performance and muscle nutritional composition as well as improved muscle hardness,springiness,cohesiveness,chewiness,and hyperplasia of myofibers of sub-adult grass carp.Besides,PGLP promoted muscle energy metabolism by increasing creatine,glycogen,pyruvate,and acetyl-CoA contents and creatine kinase(CK),pyruvate kinase(PK),phosphofructokinase(PFK),and hexokinase(HK)activities,while decreasing lactate dehydrogenase(LDH)activity and lactate content in fish muscle.Finally,our study found that PGLP enhanced mitochondrial function by increasing the protein expression of mitochondrial complexes I–V,biogenesis,and fusion and decreasing autophagy and fission in fish muscle.Conclusions PGLP improved growth performance and flesh quality of sub-adult grass carp,which may be related to enhancing hyperplasia of myofibers by promoting energy metabolism.We concluded that the recommended amount of PGLP in sub-adult grass carp feed to optimize growth performance is 100–200 mg/kg.This study provides a theoretical basis for the application of PGLP in fish feed and for the analysis of the mechanism of nutrition and feed regulating fish flesh quality,which is of great significance.展开更多
基金financially supported by the Sichuan Science and Technology Program(2024YFNH0016,2024NSFSC2072)the earmarked fund for CARS(CARS-45)+2 种基金the National Science Fund for Distinguished Young Scholars of China(32425056)the National Key Research and Development Program of China(2023YFD2400600)Sichuan Innovation Team of National Modern Agricultural Industry Technology System(SCCXTD-2024-15)。
文摘Background Environmental hypoxia is a common phenomenon in aquaculture,which causes gill tissue injury in fish.Glutathione(GSH)is a vital antioxidant in animal tissues,and its levels decrease under hypoxic conditions.However,the effects of glutathione on fish under hypoxic stress remain poorly understood.This study aimed to investigate the impact of glutathione on gill tissue damage in fish under hypoxic stress and explore the underlying mechanisms.Methods Six experimental diets with varying glutathione concentrations.The actual glutathione levels in these diets,measured by high-performance liquid chromatography,were 0.00,145.95,291.90,437.85,583.80,and 729.75 mg/kg,respectively.Fish were fed these diets for 70 d,after which a 96-h hypoxic stress experiment was conducted.The experiment was set up with normoxic and hypoxic groups,in which the dissolved oxygen in the group was 6 mg/L,and that in the group was 1 mg/L.Results This research revealed that glutathione could enhance the growth performance and antioxidant capability of juvenile grass carp while mitigating the structural damage to gill tissues induced by hypoxia stress.Mechanistic investigations further indicated that glutathione mitigated hypoxia-induced oxidative injury in gill tissues and improved their antioxidant capacity.In addition,glutathione attenuated gill apoptosis induced by hypoxia stress.Glutathione also inhibited the initiation,nucleation,elongation,and degradation phases of autophagy,thereby attenuating hypoxia-induced gill autophagy.Moreover,glutathione was found to alleviate hypoxia-induced endoplasmic reticulum stress(ERS)in gills,a response potentially linked to the suppression of PERK,IRE1,and ATF6 signaling pathways.Finally,based on the ROS and PC contents in gill tissue,the optimum glutathione supplementation levels for juvenile grass carp under hypoxia stress were 437.10 and 495.00 mg/kg,respectively.Conclusions In conclusion,our experimental results demonstrated the effectiveness of glutathione in alleviating gill tissue damage caused by hypoxic stress.This study confirms the feasibility and effectiveness of dietary glutathione addition to alleviate hypoxic stress in fish.
基金supported by National Natural Science Foundation of China(U23A20250)the earmarked fund for CARS(CARS-45)+2 种基金the National Key R&D Program of China(2023YFD2400600)Sichuan Provincial Science and Technology Innovation Talent Project(2023JDRC0043)Sichuan Innovation Team of National Modern Agricultural Industry Technology System(SCCXTD-2024-15)。
文摘Background As living standards improve,consumers are placing greater emphasis on the enhancement of fish flesh quality,making its improvement increasingly critical.Plant-derived polysaccharides positively affect the improvement of animal flesh quality.Panax ginseng leaf polysaccharides(PGLP)have a similar composition and lower cost compared with Panax ginseng root polysaccharides.However,its function and application effects in grass carp(Ctenopharyngodon idella)are unclear.Methods A total of 540 sub-adult grass carp(679±1.29 g),one of the important economic fish species,were used as experimental models and fed diets supplemented with 0,100,200,300,400,or 500 mg/kg PGLP for 60 d.After 60 d,grass carp were weighed,and their muscles were collected to explore the effects of PGLP on the growth and development of myofibers and energy metabolism-related parameters.Results Our study found that PGLP increased the growth performance and muscle nutritional composition as well as improved muscle hardness,springiness,cohesiveness,chewiness,and hyperplasia of myofibers of sub-adult grass carp.Besides,PGLP promoted muscle energy metabolism by increasing creatine,glycogen,pyruvate,and acetyl-CoA contents and creatine kinase(CK),pyruvate kinase(PK),phosphofructokinase(PFK),and hexokinase(HK)activities,while decreasing lactate dehydrogenase(LDH)activity and lactate content in fish muscle.Finally,our study found that PGLP enhanced mitochondrial function by increasing the protein expression of mitochondrial complexes I–V,biogenesis,and fusion and decreasing autophagy and fission in fish muscle.Conclusions PGLP improved growth performance and flesh quality of sub-adult grass carp,which may be related to enhancing hyperplasia of myofibers by promoting energy metabolism.We concluded that the recommended amount of PGLP in sub-adult grass carp feed to optimize growth performance is 100–200 mg/kg.This study provides a theoretical basis for the application of PGLP in fish feed and for the analysis of the mechanism of nutrition and feed regulating fish flesh quality,which is of great significance.
