Journal ArticleDOI
On metabolic degradations of squalene, lanosterol and cholesterol in rat liver in vivo. Evidence for recycling of metabolites for the synthesis of isoprene compounds.
Oswald,Verena Wiss +1 more
TLDR
It appears therefore, that the squalene which escapes incorporation into cholesterol is degraded to metabolite(s) suited for the synthesis of isoprene compounds.Abstract:
(1) Radioactivity of biosynthetically labeled squalene, injected in tracer amounts in rats is incorporated to about equal parts into cholesterol and component(s) of the fatty acid fraction of the liver. The ubiquinones isolated from the liver are radioactive and show about the same specific radioactivity as the cholesterol. It appears therefore, that the squalene which escapes incorporation into cholesterol is degraded to metabolite(s) suited for the synthesis of isoprene compounds.
(2) Radioactivity of injected biosynthetically and chemically labeled cholesterol is traced in the ubiquinones and the squalene of rat liver indicating that a degradation of cholesterol and a recycling of the metabolite(s) occurs.
(3) A recycling of metabolite(s) of squalene and of cholesterol can explain the observation that after labeled mevalonate or acetate as precursor, radioactivity can be traced in the squalene of the liver many hours after the injection and maintains a constant value during a period of several hours.
(4) Radioactivity of biosynthetically labeled lanosterol is not only incorporated into cholesterol but a considerable part of it into component(s) of the bile acid fraction of the liver. Evidence is obtained that this transformation occurs by circumventing cholesterol as intermediate.read more
Citations
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Journal ArticleDOI
The effects of BM 15.766, an inhibitor of 7-dehydrocholesterol δ7-reductase∗, on cholesterol biosynthesis in primary rat hepatocytes
TL;DR: The effect of the piperazine derivative BM 15.766 on the biosynthesis of sterols was investigated in adult rat hepatocytes in primary monolayer culture, which led to a dose-dependent reduction of cholesterol in the serum of various species of animals such as rat, dog and marmoset.
Journal ArticleDOI
The influence of fasting on the synthesis of cholesterol, squalene, fatty acids, and ubiquinones in liver, small intestine, and kidney of rats in vivo.
Oswald,Verena Wiss +1 more
TL;DR: It could be shown, that the cholesterol synthesis in the kidneys is regulated by the same mechanism as in liver, whereas such a regulation could be excluded in the small intestine.
Journal ArticleDOI
The degradation of labelled lanosterol by homogenate of rat liver: evidence for the formation of lithocholic acid from lanosterol without cholesterol as intermediate.
Oswald,Verena Wiss +1 more
TL;DR: In contrast to labelled cholesterol, labelled lanosterol is rapidly degraded by rat liver homogenate leading to metabolites which behave like bile acids by characterization with thin layer chromatography, which could be traced after injection of labelled cholesterol in rat liver in vivo.
Journal ArticleDOI
On the Influence of Cholesterol Feeding and of a Lipogenic Diet on the Cholesterogenesis in Rat Liver in vivo
Oswald,Verena Wiss +1 more
TL;DR: It is shown that the isoprenic synthesis is inhibited between squalene and Lanosterol but that other regulation site(s) after the lanosterol formation must exist, and another regulating site controlling the utilization of acetylcoenzyme A for the synthesis of mevalonate is also shown to exist.
References
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Journal ArticleDOI
Studies of the In Vivo Metabolism of Mevalonic Acid in the Normal Rat
TL;DR: The most unexpected finding of this study was that both in vivo and in vitro the kidneys rather than the liver are the primary site of the metabolism of circulating mevalonate.
Journal ArticleDOI
The biosynthesis of ubiquinone
TL;DR: Vitamin E, however, is no precursor of ubiquinone and it is suggested that the ring component is essential for animals and that the isoprene side chain is at least partly built up by mevalonic acid.
Journal ArticleDOI
Influence of fasting and cholesterol feeding on the cholesterol synthesis in rats in vivo.
TL;DR: An inhibition of the cholesterol synthesis located between lanosterol and cholesterol could be shown in fasting rats in vivo with glucose, palmitate, acetate, and mevalonate as tracer substances.
Journal ArticleDOI
Die Beteiligung der Mevalonsäure an der Biosynthese der Ubichinone in der Ratte
TL;DR: It is concluded that mevalonic acid is used for the biosynthesis of the whole side-chain of ubiquinone and no radioactivity has been detected in the quinone ring.