Effects Of Hypoxia Stress On Energy Metabolism, Respiratory Metabolism And Antioxidant Metabolism Of Eriocheir Sinensis

The objective of the present research was to investigate the effects of hypoxia stress onenergy metabolism, respiratory metabolism and antioxidant metabolism in defferent tissues ofEriocheir sinensis, in order to offerring the healthy culture reference of E. sinensis. Duringthe experiment, the E. sinensis in normoxia (DO7.0±0.2mg/L,27h) was counted as controlgroup, while the E. sinensis in hypoxia (DO2.0±0.2mg/L,24h) and in normoxia (DO7.0±0.2mg/L,3h) was considered as the experiment group. The hepatopancreas, muscle, anteriorand posterior gills were removed in0,3,6,12,18,24,24.5,25.5and27h from two groups,which was used to determine the biochemical parameters. The results are as follows:1Effects of hypoxia stress on the energy metabolism in the tissues of E. sinensis. Duringhypoxia, glycogen content, pyruvic acid content and Arginine kinase (AK) activities weresignificantly decreased (P<0.05), and the glycogen levels were significantly increased,gradually, but still had significant difference after3h of reoxygenation (P<0.05),while thepyruvic acid content and AK activities were significantly increased and had no significantdifference after3h of reoxygenation (P>0.05). The statistics show that: the glycogen andpyruvic acid of E. sinensis were disassembled, the phosphoarginine (PA) may play a role ofATP buffer.durig hypoxia stress. when afforded adequate oxygen，the pyruvic acid and PAwere recruited，while the glycogen synthesize, but some glycogen were broken down byaerobic oxidation, which result that the glycogen content could not restore to the controllevels.2Effects of hypoxia stress on the respiration metabolism in the tissues of E. sinensis.Under the hypoxia, the succinate dehydrogenase (SDH) and cytochrome oxidase (CCO)activities were significantly decreased (P<0.05), on the contrary, the fumarate reductase (FRD)and muscle lactate dehydrogenase (LDH) activities were significantly increased (P<0.05).SDH, CCO, FRD and muscle LDH activities gradually returned after3h of reoxygenationand had no significant difference with control levels(P>0.05). Statistics show that aerobicmetabolism weakened and anaerobic metabolism strengthened of E. sinensis after hpyoxia; in reoxygenation, the respiratory metabolism is gradually restored to control levels.3Effects of hypoxia stress on the antioxidant metabolism in the tissues of E. sinensis. Innormoxia, The total antioxidant capacity (T-AOC), catalase (CAT) and glutathioneS-transferase (GST) activities were significantly increased(P<0.05), SOD activities weresignificantly decreased (P<0.05).Dduring reoxygenation, CAT, GST, and T-AOC activitiesgradually decreased and approach to control levels,and no significant difference in thecontrol group (P>0.05), hepatopancreas SOD activities were increased and had no significantdifference in the control group (P>0.05), muscle,anterior gills and posterior gills SODactivities were increased for one thing, and then decreased, increased again, posterior gillsSOD activities had no significant difference in the control group after3h of reoxygenation(P>0.05), muscle and anterior gills SOD activities still had significant difference after3h ofreoxygenation (P<0.05) The results showed that: hypoxia and reoxygenation may activate theantioxidation system of E. sinensis, which could protect the body from ROS.As previously stated, the physiological and biochemical reactions of E. sinensis wereaffected in hypoxia: aerobic metabolism was restrained and ATP synthesis was blocked dueto lacking of the oxygen, the PA may release ATP and play a role of ATP buffer. With theanaerobic metabolism enhancement, pyruvic acid came into anaerobic metabolic pathwayand was used to engender energy, the large consumption of pyruvic acid could accelerate thedecomposition of glycogen in order to supplement the deficiencies of the pyruvic acid in thehemolymph, the purpose of which were ensure the energy supply of the body, at the sametime, hypoxia activated the antioxidant system. In short, change in metabolism may be vitalto avoid damnification and assure E. sinensis to survive in hypoxia.