Fig. 2. Dose–response effect of intravenous sodium nitrite on ventilator-induced lung injury. (A ) Mean arterial pressure in rats ventilated with either low tidal volume (LV^T) or high tidal volume (HV^T) ventilation with and without IV administration of sodium nitrite. HV^T+ sodium nitrite (0.25, 2.5, and 25) groups were given IV sodium nitrite at 0.25, 2.5, and 25 μmol/kilogram body weight, respectively. Values are means ± SD; P < 0.05 and *versus  LV^T. (B ) Time course of PaO²and PaCO²in animals ventilated with LV^Tor untreated HV^Tinjurious ventilation as compared with animals subjected to HV^Tventilation with IV sodium nitrite pretreatment (0.25, 2.5, and 25 μmol/kilogram body weight). Values are means ± SEM; P < 0.05 and *versus  LV^T, †versus  baseline, #versus  HV^T. HV^T= high-tidal volume; LV^T= low-tidal volume; MAP = mean arterial pressure; NaNO²= sodium nitrite; ns = not significant.