title: Determination method for steroid 5alpha-reductase activity using liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry.
abstract: A determination method for steroid 5alpha-reductase activity using liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS) in the positive-ion mode has been developed. The rat prostatic enzyme source was used and the enzymatically formed 5alpha-dihydrotestosterone and 5a-androstane-3alpha,17beta-diol were determined by LC/APCI-MS using absolute calibration curve method. The sum of the formed products was used as a measurement of the enzyme activity. This method was applied to kinetic study of this enzyme and inhibitory experiments using Finasteride as a model inhibitor.
authors.affiliation: Division of Pharmaceutical Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
authors.forename: Kuniko
authors.initials: K
authors.lastname: Mitamura
authors.forename: Chie
authors.initials: C
authors.lastname: Ogasawara
authors.forename: Asami
authors.initials: A
authors.lastname: Shiozawa
authors.forename: Erika
authors.initials: E
authors.lastname: Terayama
authors.forename: Kazutake
authors.initials: K
authors.lastname: Shimada
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000032:analysis* / Q000378:metabolism; D058891:5-alpha Reductase Inhibitors; D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D004789:Enzyme Activation / Q000187:drug effects; D018120:Finasteride / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D011467:Prostate / Q000201:enzymology; D051381:Rats; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D058891:5-alpha Reductase Inhibitors; D018120:Finasteride; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase