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Ruan B, Gerst N, Emmons GT, Shey J, Schroepfer GJ. Sterol synthesis. A timely look at the capabilities of conventional and silver ion high performance liquid chromatography for the separation of C27 sterols related to cholesterol biosynthesis. J Lipid Res 1997. [DOI: 10.1016/s0022-2275(20)30045-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Izumi A, Pinkerton F, Nelson S, Pyrek J, Neill P, Smith JH, Schroepfer G. Inhibitors of sterol synthesis. Submicromolar 14 alpha-ethyl-5 alpha-cholest-7-ene-3 beta, 15 alpha-diol causes a major modification of the sterol composition of CHO-K1 cells and a marked change in cell morphology. J Lipid Res 1994. [DOI: 10.1016/s0022-2275(20)39968-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Pajewski TN, Brabson JS, Kisic A, Wang KS, Hylarides MD, Jackson EM, Schroepfer GJ. Inhibitors of sterol synthesis. Metabolism of [2,4-3H]5 alpha-cholest-8(14)-en-3 beta-ol-15-one after oral administration to a nonhuman primate. Chem Phys Lipids 1989; 49:243-63. [PMID: 2720860 DOI: 10.1016/0009-3084(89)90072-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
5 alpha-Cholest-8(14)-en-3 beta-ol-15-one is a potent inhibitor of cholesterol biosynthesis which has significant hypocholesterolemic activity upon oral administration to rodents and nonhuman primates. In the present study the metabolism of the 15-ketosterol has been investigated after the oral administration of a mixture of [2,4-3H]5 alpha-cholest-8(14)-en-3 beta-ol-15-one and [4-14C]cholesterol to 8 baboons. Blood samples were obtained at 4, 8, 12, 16, and 24 h after administration of the labeled sterols. Clear differences in the time courses of the levels of 3H and 14C in plasma were observed. 3H in plasma showed maximum values at 4 to 8 h, whereas maximum values for the levels of 14C were observed much later. 3H in plasma was shown to be primarily in the form of its metabolites, i.e. esters of the 15-ketosterol, cholesterol, and cholesteryl esters. The levels of the 15-ketosterol and of each of these metabolites showed different changes with time. The labeled cholesterol (and the cholesterol moiety of the cholesteryl esters), formed from the [2,4-3H]-15-ketosterol, was characterized by chromatography and by purification by way of its dibromide derivative. At 24 h after the administration of the labeled sterols, the distribution of 3H in plasma lipoprotein fractions paralleled that of 14C, with most of the 3H and 14C in high density lipoprotiens (HDL) and low density lipoproteins (LDL). Almost all of the 3H in HDL and in LDL was found as cholesterol, cholesteryl esters and esters of the 15-ketosterol. The distribution of 3H in HDL and in LDL of the free 15-ketosterol, esters of the 15-ketosterol, cholesterol, and cholesteryl esters was similar to that of plasma, thereby indicating no unusual concentration of any of the 3H labeled components in HDL or LDL.
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Affiliation(s)
- T N Pajewski
- Department of Biochemistry, Rice University, Houston, TX 77251
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Brabson JS, Schroepfer GJ. Inhibitors of sterol synthesis. Studies of the distribution and metabolism of 5 alpha-[2,4-3H]cholest-8(14)-en-3 beta-ol-15-one after intragastric administration to rats. Steroids 1988; 52:51-68. [PMID: 3247671 DOI: 10.1016/0039-128x(88)90217-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
5 alpha-[2,4-3H]Cholest-8(14)-en-3 beta-ol-15-one was administered to a series of male Sprague-Dawley rats by intragastric intubation in the form of an emulsion in a mixture of triolein, sodium taurocholate, bovine serum albumin, and glucose. [4-14C]Cholesterol was similarly administered to a second series of rats. The distribution of 3H and 14C was studied at 12 and 48 h after the administration of the sterols. The results demonstrated that the 15-ketosterol is absorbed and metabolized to material with the chromatographic properties of fatty acid esters of the 15-ketosterol, to cholesterol, and to fatty acid esters of cholesterol. The [3H]cholesterol formed from the 15-ketosterol was characterized by its behavior on silicic acid-Super Cel column chromatography, by the chromatographic behavior of its acetate derivative on alumina-AgNO3 column chromatography, and by purification by way of its dibromide derivative without significant change in specific activity. The general distribution of 3H was similar to that of 14C. No unusual concentration of 3H in any of the organs studied was observed.
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Affiliation(s)
- J S Brabson
- Department of Biochemistry, Rice University, Houston, TX 77251
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Monger DJ, Schroepfer GJ. Inhibitors of cholesterol biosynthesis. Further studies of the metabolism of 5 alpha-cholest-8(14)-en-3 beta-ol-15-one in rat liver preparations. Chem Phys Lipids 1988; 47:21-46. [PMID: 3396133 DOI: 10.1016/0009-3084(88)90030-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
5 alpha-Cholest-8(14)-en-3 beta-ol-15-one is a potent inhibitor of sterol biosynthesis in mammalian cells in culture and has significant hypocholesterolemic activity upon oral administration to rodents and non-human primates. The conversion of the 15-ketosterol to cholesterol upon incubation with the 10,000 x g supernatant fraction of rat liver homogenate preparations under aerobic conditions has been reported (D.J. Monger, E.J. Parish and G.J. Schroepfer, Jr. (1980) J. Biol. Chem. 255, 11122-11129). Presented herein are results of studies of the metabolism of [2,4-3H]5 alpha-cholest-8(14)-en-3 beta-ol-15-one obtained upon incubation with the microsomal, cytosolic and the 10,000 x g supernatant fractions of liver homogenates of female rats under a variety of conditions. The results of these studies indicated metabolism of the 15-ketosterol to materials with the chromatographic properties of fatty acid esters of the 15-ketosterol, fatty acid esters of C27-monohydroxysterols, a component similar to the 15-ketosterol (possibly an isomer of the delta 8(14)-15-ketosterol), and a polar component. Detailed studies of the C27-monohydroxysterols obtained from incubation of the 15-ketosterol under anaerobic conditions indicated the formation of labeled 5 alpha-cholesta-8,14-dien-3 beta-ol and 5 alpha-cholest-7-en-3 beta-ol which were characterized by their behavior on silicic acid column chromatography, by the behavior of their acetate derivatives on medium pressure liquid chromatography on alumina-AgNO3 columns, and by co-crystallization of the labeled sterols with authentic unlabeled standards. The identification of 5 alpha-cholesta-8,14-dien-3 beta-ol and 5 alpha-cholest-7-en-3 beta-ol as metabolites of the 15-ketesterol, coupled with previous studies of the metabolism of 5 alpha-cholesta-8,14-dien-3 beta-ol and of 5 alpha-cholest-8(14)-ene-3 beta, 15 alpha-diol and 5 alpha-cholest-8(14)-ene-3 beta, 15 beta-diol has permitted the formulation of a scheme for the overall metabolism of the 15-ketosterol to cholesterol.
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Affiliation(s)
- D J Monger
- Department of Biochemistry, Rice University, Houston, TX 77251
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Schroepfer GJ, Kisic A, Izumi A, Wang KS, Carey KD, Chu AJ. Inhibitors of sterol synthesis. Metabolism of [2,4-3H]5 alpha-cholest-8(14-)-en-3 beta-ol-15-one after intravenous administration to a nonhuman primate. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68896-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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7
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Inhibitors of sterol synthesis. Metabolism of 5 alpha-cholest-8(14)-en-3 beta-ol-15-one after intravenous administration to bile duct-cannulated rats. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68897-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Schroepfer GJ, Pajewski TN, Hylarides M, Kisic A. 5 alpha-Cholest-8(14)-en-3 beta-ol-15-one. In vivo conversion to cholesterol upon oral administration to a nonhuman primate. Biochem Biophys Res Commun 1987; 146:1027-32. [PMID: 3619912 DOI: 10.1016/0006-291x(87)90750-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The metabolism of 5 alpha-cholest-8(14)-en-3 beta-ol-15-one (I), a potent inhibitor of cholesterol synthesis with marked hypocholesteremic activity, has been studied in a nonhuman primate. A mixture of [2,4-3H]-I and [4-14C]-cholesterol was administered to a male baboon in the form of a feedball. Blood was samples at 4, 8, 12, 16, and 24 hr. Detailed analyses of the plasma lipids indicated very rapid absorption of I (relative to cholesterol) and metabolism to cholesterol, cholesteryl esters, and esters of I. The labeled cholesterol was characterized by chromatographic techniques and by purification by way of its dibromide derivative. The levels of 3H in plasma associated with I, esters of I, cholesterol, and cholesteryl esters each showed a different time course. By 24 hr after the administration of [2,4-3H]-I, most of the 3H in plasma was associated with cholesterol and cholesteryl esters. The levels of total 3H and 14C in plasma at various times after the administration of the mixture of [2,4-3H]-I and [4-14C]-cholesterol differed markedly with 3H showing a maximum value at 4 hr and 14C showing a maximum value at 24 hr.
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Miller LR, Pajewski TN, Schroepfer GJ. Inhibitors of sterol synthesis. Studies of in vitro effects of C27 15-oxygenated sterols on sterol synthesis in cell free homogenates of rat liver. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)34939-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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14 alpha-Ethyl-5 alpha-cholest-7-ene-3 beta,15 alpha-diol, a potent inhibitor of sterol biosynthesis, has two sites of action in cultured mammalian cells. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(19)68128-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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12
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Rip J, Rupar C, Chaudhary N, Carroll K. Localization of a dolichyl phosphate phosphatase in plasma membranes of rat liver. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)69896-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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13
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Monger D, Parish E, Schroepfer G. 15-Oxygenated sterols. Enzymatic conversion of [2,4]3H]5 alpha-cholest-8(14)-en-3 beta-ol-15-one to cholesterol in rat liver homogenate preparations. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)70264-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Pascal RA, Farris CL, Schroepfer GJ. Sterol synthesis: medium-pressure chromatography of C27 sterol precursors of cholesterol on alumina-silver nitrate columns. Anal Biochem 1980; 101:15-22. [PMID: 7356123 DOI: 10.1016/0003-2697(80)90033-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Chan JT, Spike TE, Trowbridge ST, Schroepfer GJ. Sterol synthesis: studies of the metabolism of 14 alpha-methyl-5 alpha-cholest-7-en-3 beta-ol. J Lipid Res 1979. [DOI: 10.1016/s0022-2275(20)40003-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Thowsen JR, Schroepfer GJ. Sterol synthesis. High-pressure liquid chromatography of C27 sterol precursors of cholesterol. J Lipid Res 1979. [DOI: 10.1016/s0022-2275(20)40594-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Huntoon S, Fourcans B, Lutsky B, Parish E, Emery H, Knapp F, Schroepfer G. Sterol Synthesis. Chemical syntheses, spectral properties, and metabolism of 5alpha-cholest-8(14)-en-3beta,15beta-diol and 5alpha-cholest-8(14)-en-3beta,15alpha-diol. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)38170-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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18
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Chemical Synthesis of Δ7,24-[3α-3H]Cholestadien-3β-ol and Its Conversion to Cholesterol in the Rat. J Biol Chem 1973. [DOI: 10.1016/s0021-9258(19)43409-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Lutsky BN, Schroepfer GJ. Enzymatic conversion of 5alpha-cholest-8(14)-en-3beta-o1 to 5alpha-cholesta-8,14-dien-3beta-o1. Lipids 1971; 6:957-9. [PMID: 5163761 DOI: 10.1007/bf02531180] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Lutsky BN, Martin J, Schroepfer G. Studies of the Metabolism of 5α-Cholesta-8,14-dien-3β-ol and 5α-Cholesta-7,14-dien-3β-ol in Rat Liver Homogenate Preparations. J Biol Chem 1971. [DOI: 10.1016/s0021-9258(19)45907-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Cavina G, Moretti G, Mollica A, Moretta L, Siniscalchi P. Analytical and preparative column chromatography of neutral lipids with continuous monitoring of the eluate by a flame ionization detector. J Chromatogr A 1969; 44:493-508. [PMID: 4311407 DOI: 10.1016/s0021-9673(01)92573-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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22
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Studies on the Mechanism of the Enzymatic Conversion of Δ8-Cholesten-3β-ol to Δ7-Cholesten-3β-ol. J Biol Chem 1969. [DOI: 10.1016/s0021-9258(18)94363-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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23
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Lutsky BN, Schroepfer GJ. Enzymatic conversion of delta8, 14-cholestadien-3beta-ol to cholesterol. Biochem Biophys Res Commun 1968; 33:492-6. [PMID: 5722242 DOI: 10.1016/0006-291x(68)90602-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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24
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Lee WH, Schroepfer GJ. Enzymatic conversion of delta-8(14)-cholesten-3-beta-ol to cholesterol. Biochem Biophys Res Commun 1968; 32:635-8. [PMID: 5682286 DOI: 10.1016/0006-291x(68)90285-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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