脂肪消化和吸收
中文名称
通路描述
脂肪是食物中的重要能量来源。超过95%的膳食脂肪是长链三酰甘油（TAG），其余为磷脂（4.5%）和固醇。在小肠腔内，膳食TAG由胰脂肪酶水解为脂肪酸（FA）和单酰甘油（MAG）。这些产物在磷脂（PL）和胆汁酸（BA）的帮助下，与存在于胆汁中的磷脂和胆汁酸形成微胶粒。游离FA和MAG被肠上皮细胞摄取，在那里它们迅速在内质网（ER）中重新合成形成TAG。来自饮食的磷脂以及胆汁 - 主要是LPA - 也被肠上皮细胞吸收，并酰化形成磷脂酰肌醇（PA），PA也被转化为TAG。吸收的胆固醇（CL）酰化形成胆固醇酯（CE）。在内质网中，TAG与胆固醇酯（CE）和载脂蛋白B（ApoB）结合形成乳糜微粒，然后通过淋巴进入血液循环。
英文描述
Fat is an important energy source from food. More than 95% of dietary fat is long-chain triacylglycerols (TAG), the remaining being phospholipids (4.5%) and sterols. In the small intestine lumen, dietary TAG is hydrolyzed to fatty acids (FA) and monoacylglycerols (MAG) by pancreatic lipase. These products are then emulsified with the help of phospholipids (PL) and bile acids (BA) present in bile to form micelles. Free FAs and MAGs are taken up by the enterocyte where they are rapidly resynthesized in endoplasmic reticulum (ER) to form TAG. PLs from the diet as well as bile - mainly LPA - too are absorbed by the enterocyte and are acylated to form phosphatidic acid (PA), which is also converted into TAG. Absorbed cholesterol (CL) is acylated to cholesterol esters (CE). Within the ER, TAG joins CE and apolipoprotein B (ApoB) to form chylomicrons that enter circulation through the lymph.
所含基因
43 个基因