Fig. 5

Hypoxic pulmonary vasoconstriction and arterial oxygenation. Panel A: Mice were challenged with saline (control) or endotoxin (LPS). After 21 h, the animals were treated with normal saline (NS) or the arginase inhibitor norNOHA (20 mg/kg or 40 mg/kg). HPV was assessed as the left pulmonary vascular resistance (LPVR) in response to left mainstem bronchus occlusion (LMBO). Treatment with the arginase inhibitor norNOHA (40 mg/kg) restored HPV in endotoxemic mice. Panel B: Arterial blood gas tensions were measured during LMBO at the end of the experiments. The restoration of HPV was associated with improved arterial oxygenation (PaO₂) in endotoxemic mice treated with 40 mg/kg norNOHA compared to saline treatment. N = 7 per group; data presented as mean ± SD; * P < 0.05 vs. control group treated with NS, § P < 0.05 vs. LPS group treated with normal saline, † LPS group treated with 20 mg/kg norNOHA