Quantitative reverse transcription-polymerase chain reaction for inflammatory mediators and transcripts in lung tissues with mechanical ventilation with higher tidal volume (30 mL/kg). The levels of mRNAs for early growth response-1 (Egr-1) (a), tumor necrosis factor-alpha (TNFα) (b), interleukin-1-beta (IL-1β) (c), and CCL-2 (d) significantly increased after mechanical ventilation with either with 2% nitrogen in air (VILI/N2) or 2% hydrogen in air (VILI/H2). However, mRNA expression was significantly less in the VILI/H2 group compared with the VILI/N2 group. All values are reported as percentage of β-actin with normalization to β-actin mRNA expression. N = 8 for each group. *P < 0.05 versus sham/N2 and sham/H2; #P < 0.05 versus VILI/N2. CCL2, chemokine (CC motif) ligand 2; VILI, ventilator-induced lung injury.