Mice deficient for P-Rex1 are protected from renal ischemia-reperfusion injury. (A) Mean numbers of neutrophils per kidney 24 hours after ischemia-reperfusion injury or sham operation as determined by flow cytometry analysis ± SEM in WT mice (n = 5), P-Rex1^−/− mice (n = 4), and WT mice pretreated with a blocking antibody against LFA-1 (n = 3) or Mac-1 (n = 3). (B) Serum creatinine levels in the blood of WT mice (n = 5), P-Rex1^−/− mice (n = 4), and WT mice pretreated with a blocking antibody against LFA-1 (n = 3) or Mac-1 (n = 3) subjected to ischemia-reperfusion injury and sham operation (n = 3 each) 24 hours after the intervention ± SEM. (C) Representative hematoxylin and eosin stainings of kidney outer medulla from WT mice and P-Rex1^−/− mice were assessed 24 hours after sham operation or renal IRI. Bar represents 50 μm. (D) Rolling velocities of labeled WT (n = 3) and P-Rex1^−/− (n = 3) neutrophils 4 hours after ischemia reperfusion in cortical venules of the kidney. Bars are means ± SEM. (E) Mean numbers of labeled adherent cells per square millimeter in cortical kidney venules 4 hours after ischemia-reperfusion injury in WT mice injected with either labeled WT (n = 3) or P-Rex1^−/− (n = 3) bone marrow ± SEM. (F) Representative image of renal cortical venules 4 hours after ischemia-reperfusion injury in mice injected with labeled WT (above) or P-Rex1^−/− (below) bone marrow. (G) Permeability of kidney vessels as measured by quantification of extravasated Evans blue in WT mice and P-Rex1^−/− mice after sham operation or ischemia-reperfusion injury ± SEM. ^#P < .05.