Insulin action regulates the metabolic functions of the classically insulin-responsive tissues: liver, adipose, and skeletal muscle. Evidence also suggests that insulin acts on neural tissue and can modulate neural metabolism, synapse activity, and feeding behaviors. Insulin receptors are expressed on both the vasculature and neurons of the retina, but their functions are not completely defined. Insulin action stimulates neuronal development, differentiation, growth, and survival, rather than stimulating nutrient metabolism, e.g., glucose uptake as in skeletal muscle. Insulin receptors from retinal neurons and blood vessels share many similar properties with insulin receptors from other peripheral tissues, and retinal neurons express numerous proteins that are attributed to the insulin signaling cascade as in other tissues. However, undefined neuron-specific signals downstream of the insulin receptor are likely to also exist. This review compares retinal insulin action to that of peripheral tissues, and demonstrates that the retina is an insulin-sensitive tissue. The review also addresses the hypothesis that dysfunctional insulin receptor signaling in the retina contributes to cell dysfunction and death in retinal diseases.

中文翻译：

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视网膜中胰岛素和胰岛素受体信号传导的功能：对糖尿病性视网膜病的可能影响。

胰岛素作用调节经典的胰岛素反应组织的代谢功能：肝脏，脂肪和骨骼肌。证据还表明，胰岛素作用于神经组织，并且可以调节神经代谢，突触活性和进食行为。胰岛素受体在视网膜的脉管系统和神经元上均有表达，但其功能尚未完全确定。胰岛素作用刺激神经元的发育，分化，生长和存活，而不是刺激营养代谢，例如骨骼肌中的葡萄糖摄取。来自视网膜神经元和血管的胰岛素受体与来自其他周围组织的胰岛素受体具有许多相似的特性，并且视网膜神经元像在其他组织中一样表达多种归因于胰岛素信号级联的蛋白质。然而，胰岛素受体下游的不确定的神经元特异性信号也可能存在。这项审查比较视网膜胰岛素的作用与周围组织，并证明视网膜是胰岛素敏感的组织。这篇综述还提出了一个假设，即视网膜中功能障碍的胰岛素受体信号传导会导致视网膜疾病中的细胞功能障碍和死亡。