葡萄糖调控因子对肉鸡血糖浓度及GLUT4表达的影响OA

[Objective]This study investigated the effects of glucose regulatory factors(insulin,glucose treatment,and nutrient restriction)on blood glucose concentration and glucose transporter 4(GLUT4)expression in broilers,aiming to provide a theoretical basis for further elucidating the regulatory mecha-nisms of glucose homeostasis in poultry,and to offer potential targets for improving broiler growth perfor-mance and muscle quality.[Method]At the in vivo level,Arbor Acres(AA)broiler chickens were administered with intraperitoneal injections of insulin(5 IU·kg-1)or glucose(2 g·kg-1),subjected to different levels of feed restriction(15%energy restriction,15%protein restriction,30%energy restric-tion),or fasted for 24 hours.Blood glucose was measured at specific time points,and GLUT4 gene expression in various tissues was determined using qRT-PCR.At the cellular level,primary chicken skeletal myoblasts were treated with different concentrations of insulin(0,0.02,0.10,0.50,2.50 µmol·L-1)for 120 min or glucose(0,0.5,1.0,1.5,2.5 g·L-1)for 12 h.In a separate experiment,cells were subjected to glucose or serum starvation for 18 h,after which GLUT4 gene expression was mea-sured.[Result]1)In vivo:At 120 min post-insulin injection,blood glucose was significantly decreased,while GLUT4 gene expression was significantly increased in pectoral muscle and an extremely significant increase in the leg muscle,both returning to basal levels by 240 min;No significant changes were observed in the liver.At 10 min post-glucose injection,blood glucose was significantly elevated,and GLUT4 gene expression in pectoral muscle and liver was extremely significantly decreased,recove-ring by 60 min,with no significant change in leg muscle.Feed restriction(30%energy,15%energy,or 15%protein)had no significant effect on GLUT4 gene expression in pectoral muscle,whereas 24 h fas-ting significantly reduced its expression.2)In vitro:In chicken primary myoblasts,GLUT4 gene expre-ssion exhibited a concentration-dependent response to both insulin and glucose.The most significant increase was observed with 0.10 µmol·L-1 insulin treatment.Expression peaked in the 0.5-1.0 g·L-1 glucose treatment groups and was significantly higher than in the 2.5 g·L-1 high-glucose group.Glucose starvation had no significant effect on its expression,whereas serum starvation significantly upregulated its expression.3)A significant negative correlation was found between GLUT4 gene expression in pecto-ral muscle and blood glucose concentration,while no such correlation was observed for leg muscle or liver.[Conclusion]Chicken GLUT4 gene expression is regulated by insulin,glucose,and nutritional status(notably fasting)and is closely associated with blood glucose homeostasis.