Tissue Distribution Of The AMP-activated Protein Kinase And The Effect Of Stress On The Kinase Activity In Layers

This study was performed to evaluate tissue distribution of the AMP-activated protein kinase in layers, and the effect of starvation or heat stress on serum parameters, laying rates, feed intake and the AMP-activated protein kinase and acetyl-CoA carboxylase activities in liver, skeletal muscle, cardiac muscle and duodenum. Three groups of six layers each were control group(CG), starvation group(FG), and heat stress group(HG).The control group feed ad libitum in ambient temperature of 18±2℃.The FG were fasted for 48 hours as the same ambient temperature as CG.The HG lived ad libitum in 38±2℃enviroment with humidity of 40%-50%. When experiment finished, five hens in every group were killed and liver,skeletal muscle,cardiac muscle and duodenum sample were excised and frozen in liquid nitrogen to assay the activities of AMPK and ACC. Blood samples were collected at slaughter. The activity of AMPK were assayed by determining the rate of [ Y -32P] ATP incorporated into SAMS peptide.The activity of ACC were assayed by determining the rate of [MC]HCO3- incorporated into malonyl-CoA.Data indicated that heat or starvation stress resulted laying rates declined. Heat stress resulted feed intake per day markedly decrease. Starvation stress resulted the serum ALP and LDH significant increase. ALP and LDH were also improved in Heat-Stress-Layers. Stress resulted triacyl glycerol remarkable drops, but cholesterol esterase and glucose slightly declined.There were different activities of AMPK in liver, skeletal muscle, cardiac muscle and duodenum in Layers. The skeletal and cardiac muscle had higher AMPK activities than liver and duodenum. Liver had the lowest activity of AMPK.In comparision to control, starvation stress increased the activitiy of AMPK in liver by 3.35%, and decreased ACC activity by 8.15%. The AMPK activity in Duodenum improved 14.61%, and the ACC activity decreased 25. 30%(p<0. 01). The AMPK activity in skeletalmuscle increased 6.29%, but the ACC activity didn't change. Starvation stress had no effect on AMPK and ACC activities.In comparision to control, the AMPK activity in liver of heat stress group increased 16.27%, and the ACC activity markedly declined with 22.46%. The AMPK activity in skeletal muscle increased 20.61%, but the ACC activity didn't change. The AMPK activity in cardiac muscle increased 7.32%, and the ACC activity decreased 26.16%. The AMPK activity in Duodenum improved 11.36%, and the ACC activity only decreased 4.19%.In conclusion, (1) There were AMPK in liver, skeletal muscle, cardiac muscle and duodenum of Layers. The activities of APMK had some difference in these tissues, (2) Starvation. or heat stress resulted the AMPK activated in some tissues. Starvation or heat stress also resulted the activity of ACC, serum triacyl glycerol and cholesterol decreases. The results implied that AMPK might be related to nutritional metabolism of stress in layers.