title: Identification of intermediates after inhibition of cholesterol synthesis by aminotriazole treatment in vivo.
abstract: Cholesterol synthesis from mevalonate is inhibited by aminotriazole treatment in vivo. We tried to identify intermediates accumulated in liver of aminotriazole-treated rats. At 6 h after the aminotriazole treatment, the liver was excised. Sterols were extracted from it, and subjected to capillary gas-liquid chromatography, high-performance liquid chromatography, gas-liquid chromatography linked to mass spectrometry and gas-liquid chromatography linked to Fourier-transform infrared spectrometry. It was found that 4 alpha-methyl-5 alpha-cholest-7-en-3 beta-ol and 4,4-dimethyl-5 alpha-cholest- 8-en-3 beta-ol were accumulated in the liver, mainly as the free forms. The contents of the former and the latter were increased to 25- and 64-times the control values, respectively. In another experiment, [2-13C]mevalonate was injected at 2 h after aminotriazole treatment, and 4 h later the liver was excised. The sterols extracted from the liver were subjected to gas-liquid chromatography linked to mass spectrometry. Specific fragment ions reflecting the incorporation of [13C] mevalonate were detected in the mass spectra of the intermediate sterols. Accumulation of 4 alpha-methyl-5 alpha-cholest-7-en-3 beta-ol and 4,4-dimethyl-5 alpha-cholest-8-en-3 beta-ol after aminotriazole treatment suggests that elimination of the 4 alpha-methyl group from 4-methyl intermediate sterols is inhibited by aminotriazole.
authors.affiliation: Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Josai University, Saitama, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Hashimoto
authors.forename: H
authors.initials: H
authors.lastname: Hayashi
mesh_terms: D000640:Amitrole / Q000494:pharmacology*; D000818:Animals; D002374:Catalase / Q000037:antagonists & inhibitors*; D002775:Cholestadienols / Q000378:metabolism; D002782:Cholestenes / Q000378:metabolism; D002784:Cholesterol / Q000096:biosynthesis*; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D008401:Gas Chromatography-Mass Spectrometry; D007810:Lanosterol / Q000031:analogs & derivatives / Q000096:biosynthesis; D008099:Liver / Q000378:metabolism*; D008297:Male; D008798:Mevalonic Acid / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D002775:Cholestadienols; D002782:Cholestenes; C071868:4,4-dimethylcholesta-8,14-dien-3-ol; D007810:Lanosterol; C024372:4,4-dimethyl-delta(8)-cholestenol; D002784:Cholesterol; D002374:Catalase; D008798:Mevalonic Acid; C008421:4-methylcholest-7-en-3-ol; D000640:Amitrole