Figure 4. Activation of soluble guanylyl cyclase is required for the protective effect of inhaled nitric oxide (INO). Values displayed represent capillary filtration coefficients (Kfc) after 30 min of reperfusion. (A) Inhaled NO at 50 ppm attenuates ischemia-reperfusion-induced increases in pulmonary microvascular leak (n = 22). (B) Inhibition of soluble guanylyl cyclase has no effect on baseline Kfc over time (baseline values not shown). Treatment with 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one prevented the protective effect of 50 ppm INO after ischemia-reperfusion (n = 22). P < 0.05 from time-control and labeled comparison.