Figure 4.

Effects of regional hypoxia induced by LMBO on the systemic arterial partial pressure of oxygen (PaO₂) in endotoxin-treated wild-type mice (thick line) and endotoxin-treated NOS2-deficient mice (narrow line). Endotoxin was administered 22 hours before study by an intraperitoneal injection of 10 mg/kg E. coli endotoxin. Continuous recordings of PaO₂ were obtained with a Clark-type oxygen electrode located in the aortic arch. Data are the mean of independent experiments with wild-type mice (n = 5) and NOS2-deficient mice (n = 3). Note that LMBO decreased the PaO₂ in both groups, but the decrease of PaO₂ was more marked in wild-type mice than in NOS2-deficient mice (P < 0.05; 5 minutes after LMBO).