载脂蛋白A-Ⅳ对摄食的调节作用

Role of apolipoprotein A-Ⅳ in the regulation of food intake

尽管载脂蛋白A Ⅳ (apo AⅣ )表现出许多重要的生理功能 ,但本文重点综述其对摄食的短期与长期调节作用 ,其中包括作者领导的实验室所进行的大量研究工作。apo AⅣ是由人体肠道合成的一种糖蛋白。啮齿类动物的小肠和肝脏均可分泌apo AⅣ ,但循环中的apo AⅣ主要来自于小肠 ,脂肪的吸收可明显刺激apo AⅣ的合成。值得一提的是作者的实验室最近发现在大鼠的下丘脑可以合成apo AⅣ。乳糜微粒的形成是肠道apo AⅣ形成的诱导信号。来自回肠的一种可能是酪氨酸 酪氨酸肽 (PPY)的因子同样也可增加肠道apo AⅣ的合成。apo AⅣ对食物摄入的抑制作用是通过神经中枢而介导的。脂肪的吸收可在短时间内刺激肠道apo AⅣ合成与分泌。因此apo AⅣ可能对食物摄入的短期调节发挥作用。另有研究表明apo AⅣ也涉及到对摄食和体重的长期调节作用。长期摄入高脂肪膳食可使肠道apo AⅣ对脂肪的摄入反应迟钝 。

Although many exciting functions of Apolipoprotein A Ⅳ(apo AⅣ) have been proposed, this review focuses on its unique role in regulating food intake. Apo AⅣ is a glycoprotein produced by human intestine and rodent intestine and liver, but the small intestine is the major organ responsible for the circulating apo A Ⅳ. Our Laboratory recently demonstrated that apo AⅣ protein and apo AⅣ mRNA were present in rat hypothalamus. Intestinal apo AⅣ synthesis is markedly stimulated by fat absorption and the formation of chylomicrons. Intestinal apo AⅣ synthesis is also enhanced by the peptide tyrosine tyrosine. The inhibition of food intake by apo AⅣ is mediated centrally. Apo AⅣ likely plays a role in the short term regulation of food intake. Other evidence suggests that apo AⅣ may also be involved in the long term regulation of food intake and body weight. Reduction of apo AⅣ in response to lipid feeding in both animal and humans that chronically consume a high fat diet may explain in part why the chronic ingestion of a high fat diet predisposes to obesity.