Agouti-related Protein (AGRP) (25-82), human

刺鼠相关蛋白（刺鼠相关肽AgRP）是大脑内AgRP/NPY神经元产生的神经肽。刺鼠相关肽只在下丘脑中弓状核的腹内侧部分含有NPY的细胞体中合成。刺鼠相关蛋白主要在肾上腺、丘脑底核和下丘脑中表达，在睾丸、肾和肺中的表达水平相对较低(1)。AgRP具有刺激食欲的作用，这种作用可以被瘦素抑制，被生长素激活。脂肪细胞响应于食物摄取，分泌瘦素。这种激素作用于弓状核，抑制AgRP / NPY神经元释放开胃肽(2)。NPY / AgRP神经元中含有生长素受体，可以刺激NPY和AgRP的分泌，增进食欲。AgRP存储在细胞内的分泌颗粒中，通过可调节的通路进行分泌。AgRP的转录和分泌作用可由炎症信号调节。在禁食期间，AgRP的表达增加。研究发现，AgRP刺激下丘脑-垂体-肾上腺皮质轴释放促肾上腺皮质激素、皮质醇和催乳素。它还增强促肾上腺皮质激素对IL-1β的应答，表明AgRP可能在神经内分泌对炎症的响应中发挥调节作用(3)。

Figure1  the structures of Agouti-related Protein (AGRP)

Figure2  the Agouti-related Protein (AGRP) pathway

参考文献：

1. Bäckberg M, Madjid N, Ogren SO, Meister B (June 2004). "Down-regulated expression of agouti-related protein (AGRP) mRNA in the hypothalamic arcuate nucleus of hyperphagic and obese tub/tub mice". Brain Res. Mol. Brain Res. 125 (1-2): 129–39.

2. Enriori PJ, Evans AE, Sinnayah P, Jobst EE, Tonelli-Lemos L, Billes SK, Glavas MM, Grayson BE, Perello M, Nillni EA, Grove KL, Cowley MA (March 2007). "Diet-induced obesity causes severe but reversible leptin resistance in arcuate melanocortin neurons". Cell Metabolism 5 (3): 181–94.

3. Xiao E, Xia-Zhang L, Vulliémoz NR, Ferin M, Wardlaw SL (May 2003). "Agouti-related protein stimulates the hypothalamic-pituitary-adrenal (HPA) axis and enhances the HPA response to interleukin-1 inthe primate". Endocrinology 144 (5): 1736–41.