Triparanol (/3-L-diethylaminoethoxyphenyl-l-[-ptolyl]-2-p-chlorophenyl)* is an efficient inhibitor of endogenous cholesterol biosynthesis (Blohm and MacKenzie, 1959). It seems to prevent the conversion of 24-dehydrocholesterol (desmotserol) to cholesterol (Avigan, Steinberg, Thompson, and Mosettig, 1960; Frantz, Mobberley, and Schroepfer, 1960). Recently, it has been shown that triparanol, in d...

The universally recognised action spectrum for the UV-induced conversion of 7-dehydrocholesterol to previtamin D(3) in human skin was published in 1982, and indicates a maximum at about 297 nm with essentially no production above 315 nm. This work represents a milestone in research on vitamin D, but limitations in the original data should be recognised. Various findings have arisen in recent ye...

This article is available online at http://www.jlr.org Smith-Lemli-Opitz syndrome (SLOS) is a metabolic disorder resulting from mutations in the gene encoding 7-dehydrocholesterol reductase (DHCR7), the enzyme that catalyzes the reduction of 7-dehydrocholesterol (7-DHC) to cholesterol (Chol) ( 1–7 ). Elevated levels of 7-DHC and reduced levels of Chol are observed in tissues and fl uids of pati...

Hepatic and adrenal cholesterol biosynthesis were investigated in the human fetus in vitro by measuring the incorporation of acetate2-14C into cholesterol by slices of liver and adrenals from the same fetus. To differentiate neutral lipids from cholesterol biosynthesis, the radioactivity was measured in the nonsaponifiable neutral lipid fraction and in cholesterol isolated and purified as its c...

Calcitriol [1alpha,25(OH)2D3], the hormonally active form of vitamin D3 (D3) is produced in both renal and extrarenal tissues. Our findings demonstrate that physiological doses of UVB radiation at 300 nm induce the conversion of 7-dehydrocholesterol (7-DHC) via preD3 and D3 into calcitriol in the pmol range in epidermal keratinocytes. The hydroxylation of photosynthesized D3 to calcitriol is st...

IN a recent communication (2), it was demonstrated that in human subjects receiving triparanol therapy, 24-dehydrocholesterol (desmosterol) could serve as a direct precursor of several physiologically important compounds normally derived from cholesterol. The results indicated the direct conversion of desmosterol to both bile acids and to steroid hormones in these patients, and suggested that d...

Desmosterol (24-dehydrocholesterol), a precursor of cho lesterol, represents 5 to 20% of the total sterols of the brain during maturation, although it is practically absent in normal adult brain. The desmosterol content is increased to a small extent in human glial tumors and in some transplantable experimental tumors. In the present experiments it has been shown that desmo sterol accumulates i...

Desmosterol (24-dehydrocholesterol), a precursor of cho lesterol, represents 5 to 20% of the total sterols of the brain during maturation, although it is practically absent in normal adult brain. The desmosterol content is increased to a small extent in human glial tumors and in some transplantable experimental tumors. In the present experiments it has been shown that desmo sterol accumulates i...