title: Microscopic visualization of testosterone in mouse testis by use of imaging mass spectrometry.
abstract: Testosterone is one of the androgens synthesized from cholesterol as a precursor in the Leydig cells of testes. Since the ionization efficiency of testosterone in matrix-assisted laser desorption ionization (MALDI) is quite low, visualization of testosterone by using MALDI-imaging mass spectrometry (MALDI-IMS) has been considered difficult. To overcome this problem, we used two types of on-tissue derivatization techniques, which were achieved by pyridine sulfur trioxide and Girard's T (GT) reagent, to introduce a polar group into testosterone molecule with the aim to increase the sensitivity. Derivatization by use of GT reagent provided excellent results, superior to those obtained with pyridine sulfur trioxide, in terms of ionization efficiency, molecular specificity, and tissue damage. In GT derivatized testis tissues of mice treated with human chorionic gonadotropin (hCG), testosterone was broadly observed both inside and outside the seminiferous tubules by using an iMScope. To evaluate our imaging results, we performed quantification experiments of underivatized testosterone extracted from hCG-treated testes and control testes using LC-MS/MS. We confirmed the 256-fold concentration change between hCG-treated tissues and control tissues. We also confirmed the 228-fold change in detected peak intensities between hCG-treated tissue sections and control tissue sections in imaging results. We consider our tissue preparation methods for IMS provide high sensitivity with high precision. In addition, high-spatial definition IMS was also available, and we confirmed testosterone had mainly accumulated on the surface of the Leydig cells. Graphical abstract Girard's T-testosterone (GT-Ts) provides the fragment ion at m/z 343.24. Clear GT-Ts signal was detected in hCG treated mouse testis not only as spectra but also as a mass image.
authors.affiliation: Division of Advanced Science and Biotechnology, Graduate School of Engineering of Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Shimma
authors.affiliation: Department of Medical Chemistry, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan.
authors.forename: Henri-Obadja
authors.initials: HO
authors.lastname: Kumada
authors.affiliation: Department of Medical Chemistry, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan.|Department of Urology and Andrology, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan.
authors.forename: Hisanori
authors.initials: H
authors.lastname: Taniguchi
authors.affiliation: Department of Optical Imaging, Institute for Medical Photonics Research, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka, 431-3192, Japan.|JST, ERATO, Sato project, Tokyo, 160-8582, Japan.
authors.forename: Alu
authors.initials: A
authors.lastname: Konno
authors.affiliation: Department of Medical Chemistry, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan.|Department of Optical Imaging, Institute for Medical Photonics Research, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka, 431-3192, Japan.|JST, ERATO, Sato project, Tokyo, 160-8582, Japan.
authors.forename: Ikuko
authors.initials: I
authors.lastname: Yao
authors.affiliation: Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, Yanagido 1-1, Gifu, Gifu, 501-1193, Japan.
authors.forename: Kyoji
authors.initials: K
authors.lastname: Furuta
authors.affiliation: Department of Urology and Andrology, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsuda
authors.affiliation: Department of Medical Chemistry, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan. ito@hirakata.kmu.ac.jp.
authors.forename: Seiji
authors.initials: S
authors.lastname: Ito
mesh_terms: D000818:Animals; D001622:Betaine / Q000031:analogs & derivatives* / Q000737:chemistry; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D006801:Humans; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D051379:Mice; D057054:Molecular Imaging / Q000295:instrumentation / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods*; D013463:Sulfuric Acid Esters / Q000737:chemistry; D013739:Testosterone / Q000737:chemistry* / Q000378:metabolism
chemical_list: D006063:Chorionic Gonadotropin; D013463:Sulfuric Acid Esters; D001622:Betaine; D013739:Testosterone; C012332:Girard's reagent T
keywords: Derivatization; Girard’s T reagent; Imaging mass spectrometry; Testis; Testosterone; iMScope