Gregg R E, Connor W E, Lin D S, Brewer H B
J Clin Invest. 1986 Jun;77(6):1864-72. doi: 10.1172/JCI112513.
Sitosterolemia and xanthomatosis together are a disease characterized by premature cardiovascular disease, and by elevated plasma concentrations of total sterols and of plant sterols, especially sitosterol which is hyperabsorbed. In order to determine whether this abnormal metabolism also involved other sterols, a patient with sitosterolemia was fed a diet high in shellfish that contain significant quantities of noncholesterol sterols, some of which are less well absorbed than cholesterol in humans. Compared with control subjects (n = 8), the sitosterolemic subject had an increased absorption of 22-dehydrocholesterol (71.5% vs. 43.8 +/- 11.4%, mean +/- SD), C-26 sterol (80.6% vs. 49.3 +/- 11.4%), brassicasterol (51.8% vs. 4.8 +/- 4.2%), and 24-methylene cholesterol (60.5% vs. 16.0 +/- 8.3%). This enhanced absorption was associated with an increased plasma total shellfish sterol level (13.1 mg/dl vs. 1.9 +/- 0.7 mg/dl in normals). In the sitosterolemic subject, as in normals, the shellfish sterols were not preferentially concentrated in any lipoprotein class, and 50-65% of these sterols were in the esterified form in plasma. Bile acids and neutral sterols were quantitated in bile obtained by duodenal aspiration. The bile acid composition did not differ significantly in the sitosterolemic subject compared with the normal controls. The sitosterolemic subject, though, was unable to concentrate normally the neutral shellfish sterols in bile. The normal controls concentrated the shellfish sterols in bile 6.3 +/- 1.7-fold relative to the plasma shellfish sterol concentration whereas the study subject was only able to concentrate them 2.1-fold. We propose that sitosterolemia and xanthomatosis occur from a generalized abnormality in the usual ability of the gut mucosa and other tissues of the body to discriminate among many different sterols. This has important implications for the understanding of the pathophysiology of this disease and for therapeutic recommendations.
谷甾醇血症和黄瘤病共同构成一种疾病，其特征为心血管疾病发病过早，血浆总甾醇和植物甾醇浓度升高，尤其是谷甾醇吸收过多。为了确定这种异常代谢是否还涉及其他甾醇，我们让一名谷甾醇血症患者食用富含贝类的饮食，贝类含有大量非胆固醇甾醇，其中一些在人体中的吸收率低于胆固醇。与对照组受试者（n = 8）相比，谷甾醇血症受试者对22 - 脱氢胆固醇的吸收率增加（71.5% 对43.8 +/- 11.4%，均值 +/- 标准差），C - 26甾醇（80.6% 对49.3 +/- 11.4%），油菜甾醇（51.8% 对4.8 +/- 4.2%），以及24 - 亚甲基胆固醇（60.5% 对16.0 +/- 8.3%）。这种吸收增强与血浆总贝类甾醇水平升高有关（13.1 mg/dl 对正常人的1.9 +/- 0.7 mg/dl）。在谷甾醇血症受试者中，与正常人一样，贝类甾醇并非优先集中在任何一种脂蛋白类别中，并且这些甾醇的血浆中有50 - 65% 呈酯化形式。通过十二指肠抽吸获取胆汁，对胆汁酸和中性甾醇进行定量分析。与正常对照组相比，谷甾醇血症受试者的胆汁酸组成没有显著差异。然而，谷甾醇血症受试者无法正常地将中性贝类甾醇浓缩在胆汁中。正常对照组胆汁中贝类甾醇相对于血浆贝类甾醇浓度的浓缩倍数为6.3 +/- 1.7倍，而研究对象仅能浓缩2.1倍。我们提出，谷甾醇血症和黄瘤病是由于肠道黏膜和身体其他组织区分多种不同甾醇的正常能力出现普遍异常所致。这对于理解该疾病的病理生理学以及治疗建议具有重要意义。
