Changes of enzyme activity in blood and liver of juvenile Chinese sturgeon(Acipenser sinensis) during starvation

The effects of starvation on the enzyme activity in blood and liver of juvenile Chinese sturgeon(Acipenser sinensis) were studied.Blood and liver were sampled every six days during 43 days of starvation.The activity of alanine aminotransferase decreased significantly after 13 and 37 days of starvation.The levels ranged from 42.1 to 134.6 U/L.The activity of aspartate aminotransferase decreased after 19 days of starvation.The levels ranged from 310.1±52.4 to 420.8±83.4 U/L.The activity of lysozyme increased generally and there were significant differences between 43-day starvation group and 4 starvation groups of 1-19 days.Total antioxidative capacity remained low level after 19-day starvation and the level in 13-day starvation group was significantly higher than that of 37-day starvation group.The activity of Na+-K+-ATPase decreased first and then increased significantly.There were significant differences between 37-day starvation group and 4 starvation groups of 1-19 days.The activity of lactate dehydrogenase decreased significantly after 13 days of starvation,ranging from 5.101 to 3.154 U/g.The activity of alkaline phosphatase increased generally.The levels in 5 starvation groups of 19-43 days were significantly higher than that of 1-day starvation group.In general,physiological parameters of juvenile Chinese sturgeon changed after 19-25 days of starvation.These results indicated that the level of metabolism and energy supply of juveniles decreased after starvation.