The administration to rats of cholesta-3:5-dien-7-one.

Biosynthesis of cholestanol from intestinal 7 alpha-hydroxy-4-cholesten-3-one.

Using isotope dilution-mass spectrometry, it was shown that human bile contains significant amount of 7 alpha-hydroxy-4-cholesten-3-one, an intermediate in the major pathway for bile acid biosynthesis. In bile from 14 healthy subjects, the concentration was 0.14 +/- 0.01 micrograms/ml (mean +/- S.E.). Four bile samples collected from two patients with cerebrotendinous xanthomatosis contained co...

Metabolism of Cholesta-4,7-dien-3-one and Cholesta-4,6-dien-3-one by Mouse Liver Microsomes.

Oxysterols from human bile induce apoptosis of canine gallbladder epithelial cells in monolayer culture.

Oxysterols have been detected in various mammalian organs and blood. Biliary epithelium is exposed to high concentrations of cholesterol, and we have identified three keto-oxysterols (cholest-4-en-3-one, cholesta-4,6-dien-3-one, cholesta-3,5-dien-7-one) in human bile and gallstones. Because the effects of oxysterols on biliary physiology are not well defined, we investigated their biological ef...

Stability of Cholesterol; Cholesterol-5β,6β-Epoxide; Cholesta-3,5-Dien-7-One, and 5α-Cholestane in Solution During Short-Term Storage

Because cholesterol and its oxide products (COPs) are used as standards during analysis, their stability and autoxidation were assessed under typical storage conditions. Individual toluene solutions of cholesterol; cholesterol5β, 6β-epoxide; cholesta-3,5-dien-7-one; and 5α-cholestane were prepared and aliquots were stored at 23 ± 2°C, 4°C, and -20°C for 7 days. Samples were removed from storage...

Inhibitors of ergosterol biosynthesis and growth of the trypanosomatid protozoan Crithidia fasciculata.

Six nitrogen-, sulfur- and cyclopropane-containing derivatives of cholestanol were examined as inhibitors of growth and sterol biosynthesis in the trypanosomatid protozoan Crithidia fasciculata. The concentrations of inhibitors in the culture medium required for 50% inhibition of growth were 0.32 microM for 24-thia-5 alpha,20 xi-cholestan-3 beta-ol (2), 0.009 microM for 24-methyl-24-aza-5 alpha...