Hyperbaric Oxygen Modulators Gene Expression in the Ischaemic Gerbil Brain

摘要

Interruption of blood supply (ischaemia) results in tissue injury. However, most damage occurs as blood rapidly returns (reperfusion), generating reactive oxygen species (e.g. superoxide) and causing damage to DNA and other cellular components. Along with superoxide, increased nitric oxide (NO) levels ensue. NO, normally present in low concentrations, at higher concentrations may cause cellular damage. Hyperbaric oxygen (HBO) treatment suppresses NO production in vivo. Mongolian gerbils underwent transient global ischaemia via bilateral carotid ligation with, or without, FIBO (2 atm) and allowed to recover for 2 or 24 hrs. Brain tissue was analyzed for heat shock protein 70 (HSP7O), ornithine decarboxylase (ODC), and inducible NO synthase (iNOS) mRNAs. ODC mRNA levels decreased 50% when HBO was given before ischaemia, compared to ischaemia alone. iNOS mRNA was lower when HBO was provided before, versus after, ischaemia insult. HSP7O mRNA was increased for all treatments, compared to the sham control. HBO appears to impact the mRNA levels of ischaemia-related genes and likely the production of NO and radical species. These results are relevant to cases of ischaemic injury, as well as to operational exposures of personnel to radical producing chemicals in non-isobaric conditions.