Lutton C, Champarnaud G
Laboratoire de Physiologie de la Nutrition, Université Paris Sud, France.
Gut. 1994 Mar;35(3):343-6. doi: 10.1136/gut.35.3.343.
The rates of high density lipoprotein HDL uptake and cholesterol synthesis were compared in the normocholesterolaemic (SW) and genetically hypercholesterolaemic (RICO) rat intestine. The RICO rat has a hyperintestinal cholesterol synthesis. 14C sucrose, a marker which becomes irreversibly entrapped within the cells, was used to measure total rat HDL uptake over 24 hours in the various cells of the small intestinal mucosa. The rates of sterol synthesis were estimated in vivo with 1-14C acetate, as previously validated. The rates of HDL uptake in the upper villus cells were similar along the length of the small intestine in both types of rat, but the rates of sterol synthesis varied up to eightfold. When the mucosal epithelium was divided along the villus/crypt axis, HDL uptake increased two to threefold and cholesterol synthesis two to fivefold in the upper villus compared with the crypt cells in both SW and RICO rats. The high cholesterogenesis in the mucosal cells of the RICO rat is not related to a modified HDL cholesterol uptake. Thus, cholesterol synthesis and HDL uptake seem to be regulated independently in the rat small intestinal mucosa.
在正常胆固醇血症（SW）大鼠和遗传性高胆固醇血症（RICO）大鼠的肠道中，对高密度脂蛋白（HDL）摄取率和胆固醇合成率进行了比较。RICO大鼠存在肠道胆固醇合成亢进的情况。14C蔗糖是一种会不可逆地滞留在细胞内的标记物，用于测定24小时内大鼠小肠黏膜各种细胞对HDL的总摄取量。如之前所验证的，用1-14C乙酸盐在体内估算固醇合成率。在两种类型的大鼠中，小肠上段绒毛细胞的HDL摄取率沿小肠长度相似，但固醇合成率变化高达八倍。当沿绒毛/隐窝轴将黏膜上皮分开时，与隐窝细胞相比，SW大鼠和RICO大鼠上段绒毛中的HDL摄取增加了两到三倍，胆固醇合成增加了两到五倍。RICO大鼠黏膜细胞中高胆固醇生成与HDL胆固醇摄取的改变无关。因此，在大鼠小肠黏膜中，胆固醇合成和HDL摄取似乎是独立调节的。
