Objective Resuscitation with 100% compared with 21% O₂ increases inflammatory responses in the lungs and the brain. We have previously shown that the transcription factor NF-κB is elevated in adult hypoxic mice resuscitated with 100% O₂.

Methods Seven-day-old transgenic mice expressing luciferase as reporter of NF-κB activity were divided into two groups, which were either injected (n = 140) or not injected (n = 148) with nicotine subcutaneously, 2.4 mg/kg of nicotine base dissolved in 9% saline. They were then exposed to 40 min FiO₂ of 0.08 and further randomized to be resuscitated with either 21% or 100% O₂ for 30 min. Light produced by the luciferase reaction which reflects NF-κB activity were detected by the IVIS Imaging system 100 series. The whole body (Total) and the brain area were measured. NF-κB activity at maximal velocity of the reaction are reported.

Results There were no effects of nicotine (Nic) on the groups. Mean and SD for NF-κB activities are given (see table).

Conclusions Nicotine in the doses used in this study had no effect on NF-κB activity. Resuscitation with 100% O₂ reduced NF-κB when comparing with use of 21% O₂. This is the opposite result to what we have previously reported regarding adult mice.