Fig. 4.

Experiments on ventilated, isolated and perfused whole lungs from young (n = 5), aged vehicle (n = 5) and PF-04447943 (PF-04)-treated (n = 6) animals used to test the vasodilator action on the perfusion pressure in preconstricted pulmonary vasculature. A Representative traces recorded from the lung experiments in response to increasing concentrations of the vasodilator drugs in all assigned experimental groups. B Summary graphs of the pulmonary artery perfusion pressure decrease in response to a increasing concentrations of bradykinin in a whole lung vasculature, preconstricted with U46619 (10^–6 M). C Summary graphs of the pulmonary artery perfusion pressure decrease in response to a increasing concentrations of sodium nitroprusside (SNP, 10^–6.5) in a whole lung vasculature, preconstricted with U46619 (10^–6 M). Data presented as means ± SEM and analyzed using two-way ANOVA with mixed effects and Tukey’s multiple comparison test was used. *—p < 0.05, **—p < 0.01, ***—p < 0.001; in B and C *—young vs aged veh, &—young vs aged PDE9I, §—aged veh vs aged PDE9I