调控家禽肌肉和肝脏代谢的胰岛素信号

The regulation of insulin signaling in muscle and liver metabolism of poultry

本文综述了胰岛素通过受体对鸡肝脏和肌肉的一般代谢和基因表达的调控作用。与哺乳动物相比,家禽血液循环中具有相似的胰岛素浓度,但仍然可以维持高血糖水平,这可能是家禽对外源性胰岛素敏感性低的结果。为了确定这种低敏感性是否是家禽与哺乳动物之间胰岛素受体信号差异的结果,家禽组织中的胰岛素受体已经得到了验证,并在肝脏和肌肉组织发现了两种胰岛素受体底物(胰岛素受体底物-1和结构域蛋白C)。与哺乳动物相比,目前我们对家禽胰岛素信号传导的认识还不全面。当考虑到参与胰岛素级联反应的成分异构体数量时,这一点尤其明显,许多异构体可能尚未在家禽中得到验证。尽管现有数据存在一些不足,但鸡肝脏中的胰岛素信号与哺乳动物相似,但肌肉与哺乳动物不同。在腿部肌肉中,鸡与哺乳动物在胰岛素信号级联的早期阶段不同,其中,鸡的磷脂酰肌醇-3激酶(PI3K)活性大约是大鼠的30倍,这种肌肉PI3K的高活性可能过度刺激鸡的反馈抑制通路,从而使鸡肌肉对胰岛素不敏感。

This article reviews the role of insulin through receptor in the regulation of general metabolism and gene expression in chicken liver and muscle. Compared with mammals,the circulating insulin in chickens has a similar concentration,but still can maintain high blood glucose levels,which may be the result of the low sensitivity of chickens to exogenous insulin. To determine whether this low sensitivity is the result of differences in insulin receptor signaling between mammals,insulin receptors have been validated in some chicken tissues and two insulin receptor substrates(insulin receptor substrates -1 and domain protein C)have been found in liver and muscle. Current understanding of insulin signaling in poultry is incomplete compared to that in mammals. This is particularly true when considering the number of component isomers involved in the insulin cascade,many of which may not have been verified in poultry. Despite these shortcomings in the available data,the insulin signals in the chicken liver are similar to those in mammals but different from those in their muscles. In leg muscles,chickens differ from mammals in the early stages of the insulin cascade,in that chickens have about 30 times the activity of phosphatidylinositol kinase(PI3K)as do rats. This high PI3K activity in muscle may overstimulate the feedback inhibitory pathway described in mammals,thereby making chicken muscles insensitive to insulin.