Comparison of the effect of IP polyP on perfusion and fibrin deposition in the lungs of wild-type (WT) or HRG-deficient mice. (A) Evans blue dye was injected into the right ventricle of WT or HRG^−/− mice administered IP saline or polyP. Images of the lungs were taken to examine the extent of dye perfusion into the lungs. Representative images from 6 mice per group are shown. (B) Evans blue dye extracted from lungs with formamide was quantified by measuring absorbance at 605 nm and calculating the amount of dye per microgram of tissue by comparison with a standard curve. N = 6 mice per group; bars represent mean ± standard deviation. (C) Fibrin deposition (red) in lung sections was detected by immunofluorescence with 4′,6-diamidino-2-phenylindole (blue) serving as a nuclear stain. Scale bars represent 50 μm. Representative images from six mice per treatment group are shown. (D) Fibrin intensity was scored in a blinded manner by using a scale of 0 to 4, with 4 representing the greatest intensity. N = 6 mice per group; bars represent mean ± standard deviation. *P < .05, **P < .01, ***P < .001 comparison between saline- or polyP-treated WT or HRG^−/− mice as indicated by the lines (analysis of variance, Holm-Šídákmethod).