LACTATE, GLYCOGEN AND GLUCOSE LEVELS OF JUVENILE CATFISH (SILURUS ASOTUS LINNAEUS) IN RESPONSE TO EXHAUSTIVE EXERCISE

The lactate, glycogen and glucose levels in whitemuscle, blood and liver of juvenile catfish (Silurus asotus Linnaeus) were measured at rest(rest ing controls) and during different recovery periods (0、0. 5、1、2、4、8、16h) after exhaustive exercise at (25±1) e in this study. The results showed that lactate levels in muscle and blood increased to peak value immediately, reaching (12. 13±0. 19) Lmol/g and (4.57±0. 23) mmol/L, respectively. While the liver lactate reached to the maximum(9. 78±0. 69) Lmol/g during recovery at 1h post exercise. The increase in muscle lactate levels after exercise agreed well with the decrease in its glycogen levels, whereas concentrat ion of glucose remained relatively unchanged during this period. Muscle lactate returned to resting levels within 8h of recovery and its lactate clearance rate was 0.9Lmol/h·g. These results of our study suggest that -lactate leaking.-phenomenon actually exists in catfish after exhaustive exercise, glycogen is used as themain fuel source for anaerobic metabolism; the liver may act as a temporary sink for lactate.