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

• Changes in circulating steroids by total-body irradiation (TBI) were investigated.
• Androgens were slightly decreased in Cs-137 exposure female mice.
• Stress hormones were significantly increased after TBI.
• The TBI decreased age-protective 20α-dihydroprogesterone in serum.
• The biomarkers may be useful for suspecting the radiation exposure.

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 0 Gy, 1 Gy, and 4 Gy. 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 4 Gy, 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 4 Gy. 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.