Different damaging effects of volatile anaesthetics alone or in combination with 1 and 2 Gy gamma-irradiation in vivo on mouse liver DNA: a preliminary study

As the number of radiotherapy and radiology diagnostic procedures increases from year to year, so does the use of general volatile anaesthesia (VA). Although considered safe, VA exposure can cause different adverse effects and, in combination with ionising radiation (IR), can also cause synergistic effects. However, little is known about DNA damage incurred by this combination at doses applied in a single radiotherapy treatment. To learn more about it, we assessed DNA damage and repair response in the liver tissue of Swiss albino male mice following exposure to isoflurane (I), sevoflurane (S), or halothane (H) alone or in combination with 1 or 2 Gy irradiation using the comet assay. Samples were taken immediately (0 h) and 2, 6, and 24 h after exposure. Compared to control, the highest DNA damage was found in mice receiving halothane alone or in combination with 1 or 2 Gy IR treatments. Sevoflurane and isoflurane displayed protective effects against 1 Gy IR, while with 2 Gy IR the first adverse effects appeared at 24 h post-exposure. Although VA effects depend on liver metabolism, the detection of unrepaired DNA damage 24 h after combined exposure with 2 Gy IR indicates that we need to look further into the combined effects of VA and IR on genome stability and include a longer time frame than 24 h for single exposure as well as repeated exposure as a more realistic scenario in radiotherapy treatment.

Automated summary

With the increasing use of general volatile anaesthesia (VA) in radiotherapy and radiology diagnostic procedures, there is a need to understand the combined effects of VA and ionising radiation (IR) on DNA damage and repair. This study evaluated DNA damage in liver tissue of mice exposed to different VA agents alone or in combination with IR using the comet assay. The results showed that halothane alone or in combination with IR caused the highest DNA damage, while sevoflurane and isoflurane had protective effects against lower doses of IR.