title: Simultaneous determination of salivary testosterone and dehydroepiandrosterone using LC-MS/MS: Method development and evaluation of applicability for diagnosis and medication for late-onset hypogonadism.
abstract: Late-onset hypogonadism (LOH) is a male-specific disorder caused by the age-related decline in androgens, such as testosterone (T). A sensitive liquid chromatography-electrospray ionization-tandem mass spectrometric (LC-ESI-MS/MS) method for the simultaneous quantification of T and its precursor, dehydroepiandrosterone (DHEA), in human saliva has been developed and validated. The saliva was deprotenized with acetonitrile, purified using a Strata-X cartridge, derivatized with 2-hydrazino-1-methylpyridine, and subjected to LC-MS/MS. The recovery rates of the steroids during the pretreatment were about 90%. Quantification was based on selected reaction monitoring using characteristic transitions, and deuterated T and DHEA were used as internal standards. This method allowed the reproducible (inter- and intra-assay precisions, <2.9%) and accurate (accuracy, 98.5-101.8%) quantification of the salivary androgens using a 500-microl sample and the limits of quantification for both androgens were 10 pg/ml. As preliminary steps in the practical application of the developed method in diagnosis and medication for LOH, the diurnal rhythms, inter-day alternations and age differences in the salivary T and DHEA were examined; the method found that the salivary T and DHEA show specific diurnal rhythms, significant alternations in early morning and pronouncedly decline with age. The method also enabled the determination of the changes in the individual T and DHEA levels after the DHEA supplementation, which is expected to be a new and easy medication for LOH. Thus, the developed method has satisfactory applicability in the diagnosis and medication for LOH.
authors.affiliation: Division of Pharmaceutical Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Shibayama
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Higashi
authors.forename: Kazutake
authors.initials: K
authors.lastname: Shimada
authors.forename: Akira
authors.initials: A
authors.lastname: Odani
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mizokami
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Konaka
authors.forename: Eitetsu
authors.initials: E
authors.lastname: Koh
authors.forename: Mikio
authors.initials: M
authors.lastname: Namiki
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D002853:Chromatography, Liquid / Q000379:methods*; D003687:Dehydroepiandrosterone / Q000032:analysis* / Q000627:therapeutic use; D006801:Humans; D007006:Hypogonadism / Q000175:diagnosis* / Q000188:drug therapy* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013739:Testosterone / Q000032:analysis*; D055815:Young Adult
chemical_list: D013739:Testosterone; D003687:Dehydroepiandrosterone