Metabolic changes in serum steroids induced by total-body irradiation of female C57B/6 mice

Abstract

The short- and long-term effects of a single exposure to gamma radiation on steroid metabolism were investigated in mice. Gas chromatography-mass spectrometry was used to generate quantitative profiles of serum steroid levels in mice that had undergone total-body irradiation (TBI) at doses of 0Gy, 1Gy, and 4Gy. Following TBI, serum samples were collected at the pre-dose time point and 1, 3, 6, and 9 months after TBI. Serum levels of progestins, progesterone, 5β-DHP, 5α-DHP, and 20α-DHP showed a significant down-regulation following short-term exposure to 4Gy, with the exception of 20α-DHP, which was significantly decreased at each of the time points measured. The corticosteroids 5α-THDOC and 5α-DHB were significantly elevated at each of the time points measured after exposure to either 1 or 4Gy. Among the sterols, 24S-OH-cholestoerol showed a dose-related elevation after irradiation that reached significance in the high dose group at the 6- and 9-month time points.

Keywords: Aging; Gas chromatography–mass spectrometry; Steroid metabolism; Steroid signatures; Total-body irradiation.