Malavolti M, Fromm H, Ceryak S, Shehan K L
Department of Medicine, George Washington University Medical Center, Washington, DC.
Biochim Biophys Acta. 1991 Jan 4;1081(1):106-8. doi: 10.1016/0005-2760(91)90257-i.
Although the cholesterol pool in the central nervous system is considered to be relatively stable, few studies have tested this assumption. The aim of the study was to gain further information on the communication between the extracerebral organs and the brain as far as cholesterol and lipoprotein transport are concerned. Receptor-dependent as well as receptor-independent LDL uptake in the brain were measured, by established methods, after constant 1-h intravenous infusions of [14C]sucrose-labelled hamster LDL and methylated human LDL, both in hamsters with an acute bile fistula and in control animals with an intact enterohepatic circulation. The receptor-dependent LDL uptake in the brain promptly showed a significant increase after the construction of the bile fistula. However, there was no difference in the receptor-independent LDL uptake between the bile fistula and control animals. The studies indicate the presence of close communications between extracerebral and brain cholesterol. Changes in the extracerebral compartments of cholesterol are, apparently, readily sensed by the LDL receptor in the brain and promptly evoke appropriate modifications in its activity.
尽管中枢神经系统中的胆固醇池被认为相对稳定，但很少有研究验证这一假设。本研究的目的是获取有关脑外器官与大脑之间在胆固醇和脂蛋白运输方面通讯的更多信息。通过既定方法，在急性胆瘘仓鼠和肠肝循环完整的对照动物中，持续1小时静脉输注[14C]蔗糖标记的仓鼠低密度脂蛋白（LDL）和甲基化人LDL后，测量大脑中依赖受体和不依赖受体的LDL摄取。胆瘘构建后，大脑中依赖受体的LDL摄取迅速显著增加。然而，胆瘘动物和对照动物之间不依赖受体的LDL摄取没有差异。这些研究表明脑外和脑内胆固醇之间存在密切通讯。显然，胆固醇脑外区室的变化很容易被大脑中的LDL受体感知，并迅速引起其活性的适当改变。
