Analytical Sciences


Abstract − Analytical Sciences, 21(10), 1241 (2005).

Determination Method for Steroid 5 α-Reductase Activity Using Liquid Chromatography/Atmospheric Pressure Chemical Ionization-Mass Spectrometry
Kuniko MITAMURA, Chie OGASAWARA, Asami SHIOZAWA, Erika TERAYAMA, and Kazutake SHIMADA
Division of Pharmaceutical Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
A determination method for steroid 5 α-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 5 α-dihydrotestosterone and 5 α-androstane-3 α,17 β-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.