Bile acid synthesis in man: assay of hepatic microsomal cholesterol 7 alpha-hydroxylase activity by isotope dilution-mass spectrometry.
Bile acid synthesis in man: assay of hepatic microsomal cholesterol 7 alpha-hydroxylase activity by isotope dilution-mass spectrometry.
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人体胆汁酸合成：同位素稀释质谱法测定肝微粒体胆固醇 7 α-羟化酶活性。
DOI：
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发表时间：
1986
影响因子：
6.5
通讯作者：
I. Björkhem
中科院分区：
文献类型：
--
作者：
K. Einarsson;B. Angelin;S. Ewerth;K. Nilsell;I. Björkhem
本工作描述了一种对人体肝脏中胆汁酸合成的限速酶--胆固醇7α-羟基酶的准确测定。该分析基于同位素稀释-质谱法，内源微粒体胆固醇是该酶的唯一底物。手术肝活检取自在高度标准化条件下接受择期胆囊切除术的患者。在10例胆结石患者中，微粒体组分的酶活性平均为9.6+/-1.4(平均值+/-扫描电子显微镜)pmoXmin-1X mg蛋白-1，相当于每天合成约0.5 mmol的胆汁酸。三名接受胆碱胺治疗的患者显示出四倍的酶活性。没有证据支持胆固醇7α-羟基酶受磷酸化-去磷酸化调控的观点。
The present work describes an accurate assay of the rate-limiting enzyme in bile acid synthesis, the cholesterol 7 alpha-hydroxylase, in human liver. The assay is based on isotope dilution-mass spectrometry, and endogenous microsomal cholesterol is used as the only substrate for the enzyme. Operative liver biopsies were obtained from patients undergoing elective cholecystectomy under highly standardized conditions. In ten gallstone patients, the enzyme activity of the microsomal fraction averaged 9.6 +/- 1.4 (mean +/- SEM) pmol X min-1 X mg protein-1 corresponding to a daily synthesis of about 0.5 mmol of bile acids. Three cholestyramine-treated patients displayed a four-fold higher enzyme activity. No evidence was obtained supporting the concept that the cholesterol 7 alpha-hydroxylase is modulated by phosphorylation-dephosphorylation.
影响因子：
15.9
作者：
DUANE, WC;LEVITT, DG;BEHRENS, JC
通讯作者：
BEHRENS, JC
影响因子：
6.5
作者：
S. Shefer;F. Cheng;S. Hauser;A. Batta;G. Salen
通讯作者：
S. Shefer;F. Cheng;S. Hauser;A. Batta;G. Salen