Tandem Mass Spectrometry Imaging Reveals Distinct Accumulation Patterns of Steroid Structural Isomers in Human Adrenal Glands

Abstract

) to distinguish a mineralcorticoid aldosterone (Aldo) and a glucocorticoid cortisol (F), from their structural isomers. Our method is also useful to detect hybrid steroids (18-hydroxycortisol [18-OHF] and 18-oxocortisol) with sufficient signal-to-noise ratio. The clinical applicability of the tandem MS method was evaluated by analyzing F, Aldo, and 18-OHF distributions in human adrenal glands. In such clinical specimens, small Aldo-producing cell clusters (APCCs) were identified and were first found to produce a high level of Aldo and not to contain F. Moreover, a part of APCCs produced 18-OHF, presumably converted from F by APCC-specific CYP11B2 activity. Catecholamine species were also visualized with another derivatization reagent (TAHS), and those profiling successfully discriminated pheochromocytoma species. These tandem MSI-methods, coupled with on-tissue chemical derivatization has proven to be useful for detecting low-abundance steroids, including Aldo and hybrid steroids and thus identifying steroid hormone-producing lesions.