Mechanisms of Bile Acid Biosynthesis Studied with 3α-3H- and 4β-3H-Cholesterol
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منابع مشابه
Unreliability of tritiated cholesterol: studies with [1,2-3H]-cholesterol and [24,25-3H]cholesterol in humans.
Over the past 18 months different lots of [1,2-3H]cholesterol and [24,25-3H]cholesterol were found to be radiochemically acceptable by conventional chemical and other in vitro tests, yet, when co-administered with [4-14C]cholesterol to human subjects, an abrupt fall in the 3H/14C specific activity ratio in plasma cholesterol was discovered in every case. We have concluded that all batches of [3...
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Bile acid production has been quantitated in seven subjects by methods that compare the results of two independent approaches, namely, quantitation of cholesterol side-chain oxidation and fecal bile acid excretion. Six hypertriglyceridemic (HT) subjects and one normolipidemic control were studied by both techniques. A further control subject was studied by the cholesterol side-chain oxidation m...
متن کاملPreparation of [24,25-3H] cholesterol. Oxidation in man as a measure of bile acid formation.
In order to devise a convenient method for measuring the rate of formation of bile acids from cholesterol in man, [24,25-3H] cholesterol was prepared by catalytic tritiation of desmosterol where the delta5-unsaturation was protected by conversion to the 3 alpha, 5 alpha-cyclosterol-6-methyl ether. It was shown that tritium in the purified labeled sterol was located exclusively in the side chain...
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Under most experimental conditions, the activities of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA reductase) and cholesterol 7 alpha-hydroxylase, change together in parallel directions. It has been suggested that newly synthesized cholesterol may be the preferred substrate for cholesterol 7 alpha-hydroxylase, which may account for the observed synchronous behavior of the two enzymes. To test...
متن کاملDeposition of [3H]cocaine, [3H]nicotine, and [3H]flunitrazepam in mouse hair melanosomes after systemic administration.
Microautoradiography was employed to show that association of drugs from the serum directly with forming hair pigment is a primary pathway of deposition into the hair. After systemic administration of [3H]flunitrazepam, [3H]nicotine, and [3H]cocaine, association of all three drugs with melanin in the forming hair was observed within minutes of dosage. Sebum was determined to be an insignificant...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1964
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)93817-2