Holzbach R T
Gastrointestinal Research Unit, Cleveland Clinic Foundation, Ohio 44195-5218.
Hepatology. 1990 Sep;12(3 Pt 2):26S-31S; discussion 31S-32S.
The presence of vesicles in human bile probably accounts almost entirely for the frequently observed, but hitherto unexplained, phenomenon of metastable cholesterol supersaturation. This, in turn, largely explains the prolonged stability of cholesterol solubilized in supersaturated human bile. Under certain overall compositional conditions for a supersaturated native bile, the vesicular phase in its contribution to total cholesterol transport also becomes supersaturated in cholesterol. Because of this, the vesicles also become unstable, leading to formation of cholesterol crystals. A simple but common example of one factor affecting composition in this way is concentration of total solutes, especially the biliary lipids. Conversely, dilution of bile (e.g., hepatic bile) markedly reduces the cholesterol saturation level in biliary vesicles. The result is that such vesicles become much more stable. Under these conditions, cholesterol crystal formation becomes unlikely and rarely, if ever, occurs.
人胆汁中囊泡的存在可能几乎完全解释了经常观察到但迄今尚未得到解释的亚稳胆固醇过饱和现象。反过来，这在很大程度上解释了溶解在过饱和人胆汁中的胆固醇的长期稳定性。在过饱和天然胆汁的某些总体组成条件下，囊泡相在总胆固醇转运中的贡献也会在胆固醇中变得过饱和。因此，囊泡也变得不稳定，导致胆固醇晶体的形成。以这种方式影响成分的一个简单但常见的因素例子是总溶质的浓度，尤其是胆汁脂质。相反，胆汁（例如肝胆汁）的稀释会显著降低胆汁囊泡中的胆固醇饱和水平。结果是这些囊泡变得更加稳定。在这些条件下，胆固醇晶体形成不太可能发生，而且很少（如果有的话）发生。
