Thiol disulfide homeostasis in ionizing radiation and chemotherapeutic drug exposure.

Objective: This study aims to reveal the oxidant and antioxidant status in nurses with chemotheropathic drug exposure and radiology unit workers exposed to ionizing radiation (IR).

Methods: Nineteen radiology unit workers, 14 nurses, and 15 controls were included the study. All of the participants using antioxidants, vitamin supplements, smokers, any therapeutic drugs, and exposed therapeutic or diagnostic X-ray or chemotherapeutic drugs in 12 months were excluded from the study. Total and native thiols, disulfide/native thiol percent ratios (SS/SH), disulfide/total thiol percent ratios, disulfide amounts, and native thiol/total thiol percent ratios, ischemia-modified albumin (IMA) were determined.

Results: Disulfide levels, disulfide/total thiol ratio, and disulfide/native thiol ratio of serum samples of both radiology unit workers and nurses were significantly higher and ratio of native thiol/total thiol was lower than the control group. The radiation dose in radiology unit workers was mean±SD: 0.02±0.009, median (min-max): 0.02 (0.001-0.04). Thiol-disulfide homeostasis was disturbed and the balance shifted in the direction of oxidant damage, even at low-dose IR exposure and normal range.

Conclusion: As far as we know, the current findings first demonstrate an apparent chronic oxidative stress in the subjects who were occupationally exposed to antineoplastic drugs and radiation even if annual radiation exposure dose measurements are normal.