Anaerobic Exercise-induced Metabolism And Related Enzyme Adaptive Changes In Zebrafish (Danio Rerio)

To explore anaerobic exercise metabolic characteristics and adaption changes to anaerobic exercise training of zebrafish (Danio rerio) and supply basic data for future molecular mechanism research of adaption to anaerobic exercise training of fish, zebrafish was used to measure the muscle glycogen and lactate concentration changes in 8 h after 10 min anaerobic exercise. And also the influence of 4 weeks anaerobic exercise training on behavior, morphology, growth, biochemical components of muscle, muscle glycogen and lactate concentration following exercise and muscle metabolic enzyme activity were investigated.Muscle glycogen concentration of zebrafish reduced 76.90%, but no exhaustive behavior was observed following 10 min anaerobic chasing-exercise. Muscle glycogen concentration recovered regularly in 8 h, reached 66.27% of pre-exercise. Muscle lactate concentration increased sharply following exercise and reached 16.43±1.39μmol/g wet wt, it was 2.62 fold of pre-exercise. Muscle lactate concentration reduced regularly in 8 h and there was no significant difference at 4h and 8h compared to pre-exercise. The lactate clearance rate (LCR) is 1.16μmol/h·g and the lactate produce coefficient (LPC) is 1.50.The death rate of control and trained-group were 8.0%,11.3% respectively following 4 weeks anaerobic exercise training. The daily level of activity was less low in trained group than control, the trained zebrafish usually liked swimming together more than control.The training caused no significant increase in length and weight of trained group, but control zebrafish increased both the length and weight significantly. The condition factor of control increased significantly, but the trained group's condition factor was reduced significantly following training.4 weeks training induced significant increase in muscle glycogen of zebrafish, but training were no effects on protein and moisture of muscle. Muscle lactate concentration of control was significantly higher than trained group following 10 min anaerobic exercise and both groups of muscle glycogen were reduced, the decrease values of control and trained group were 8.51μmol/g wet wt and 10.33μmol/g wet wt respectively.4 weeks training significantly increased the activity of lactate dehydrogenase (LDH) in muscle, but decreased the activity of citrate synthase (CS). There were no effects on activity of hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), cytochrome c oxidase (COX) in muscle.Results above indicate:10 min anaerobic exercise isn't able to cause exhaustion of zebrafish. Zebrafish is able to bear some degree concentration of lactate and belongs to"the lactate releaser". Though the recovery time of post-exercise of zebrafish is short, the clearance rate is normal. The daily level of activity was declined by 4 weeks anaerobic training and they swim together more. The growth is inhibited significantly and zebrafish change slimmer adapted to locomotion. Training causes the increase of glycogen in muscle and enhances the exercise endurance and the ability of bearing lactate. And also the anaerobic metabolism is enhanced. The ability of anaerobic exercise of zebrafish is enhanced in general.