Biochemphysiological Parameters Of Juvenile Catfish (Silurus Asotus Linnaeus) In Response To Exhaustive Exercise

The exhaustive exercise or the burst type exercise of the vertebrates is a kind of to takehaving anaerobic metabolism as the main exercise method, and it will cause a great deal ofaccumulation of the lactate and the quickly depletion of the glycogen, so a lot of relatedresearches already the important experiment means that the exhaustive exercise is toannounce to public the machine body anaerobic metabolism mechanism, but importantindex sign of the lactate conduct and actions reflection body anaerobic metabolism ability.The biochemphysiological parameters of carnivorous and economic juvenile catfish(Silurus asotus Linnaeus) were measured at rest (resting controls)and during differentrecovery periods (0, 0.5, 1, 2, 4, 8, 16h) after exhaustive exercise at 25±1℃ atdecontamination circularly control sink in Laboratory of Evolutionary Physiologyand Behavior of Chongqing Normal University in this study. The aim was to investigate thechanges of lactate, glycogen and glucose levels in white muscle, blood and liver,respiratory rates and red blood cells counts (RBC). Meanwhile it was in order to clarifythe relationship between levels of lactate and glycogen.The results as follows:1. The lactate levels in muscle and blood of juvenile catfish (Silurus asotusLinnaeus) increased to peak value immediately after exhaustive exercise, reaching 12.13±0.19μmol/g and 4.57±0.23mmol/l, respectively. The increase in muscle lactate levelsafter exercise agreed well with the decrease in its glycogen levels, whereas concentration ofglucose remained relatively unchanged during this period. Muscle lactate returned toresting levels within 8 h of recovery and its lactate clearance rate was 0.9μmol/h/g. Therecovery of lactate in muscle approximated an exponential decay:Y=9.403e-0.0949x(r=0.779,P﹤0.01,N=36).2. According to the bio-chemical equivalent relation that the 1 mol glycogen producesthe 2 mol lactates, if the muscular tissue is placed in for the completely closing, state,thenthe lactate produce coefficient(LPC) is 2.0.If muscular tissue exist"lactate leaking"phenomenon, that value then should be lower than 2.0.The lactate produce coefficient ofthis study showed that it was 0.7.3. The glycogen levels in muscle and liver trended to decline in juvenile catfish(Silurus asotus Linnaeus) after exhaustive exercise, then rised again, but content ofglucose then with it contrary. The change of the blood glucose was different from glycogenand glucose in muscle and liver, it descended to rise again first then again descend of trend.4. The RBC within the juvenile catfish (Silurus asotus Linnaeus)blood presents torise the variety trend descend behind first after exhaustive exercise. The RBC was 132.83±4.28 104/mm3.After recovery 0.5h, it was increased, and then arrives to peak value(225.67±13.97 104/mm3). Subsequently, it was returned to resting levels within 8h of recovery.5. The respiratory rates of juvenile catfish (Silurus asotus Linnaeus) were increasedimmediately after exhaustive exercise, then returned to resting levels within differenttime of recovery(P﹤0.05).In conclusion:1. This study showed that lactate in muscle was increased immediately afterexhaustive exercise, and compared with other fish, its Lacmax was lower. According to thisstandard for evaluation analysis, its anaerobic metabolism ability maybe weaker thanothers.2. This study showed that the change of lactate in blood agreed well with the changeof lactate in muscle of Silurus asotus Linnaeus.From this, it is concluded that lactate canenter the blood through the muscle fiber cell membrane. So it is clear suggested that Silurusasotus Linnaeus belongs to" the lactate releaser".Then it really exists" lactate leaking"phenomenon. The ability of its anaerobic metabolism also would be higher than the resultthat calculates to gain with the peak value of lactate in the part.3. This study showed that the decrease increase in muscle lactate levels after exerciseagreed well with the increase in its glucose levels, whereas concentration of glycogenremained relatively unchanged during in 1h recovery. It suggested that glycogen is used asthe main fuel source for anaerobic metabolism, and the lactate's clearance may exist thepath of synthesize the glucose.4. Compared with other related datum, the lactate in muscle of juvenile catfish(Silurus asotus Linnaeus)was cleared that needed more time, and lactate clearance ratewas lower than others. Meanwhile, the recovery time of lactate in liver was more than16h,it was slowest, so glycogen is used as the main fuel source for anaerobic metabolism;the liver may act as a temporary sink for lactate.