Fig. 1.

Paw edema is markedly reduced in Akt1^−/− mice in both early and late phases of inflammation. (A) Akt1^−/− mice display reduced edema in the first phase (0–6 h) and in the second phase (>24 h) (n = 6 per group). (B) Myeloperoxidase (MPO) activity, an index of the neutrophil influx into the paw 2 and 4 h after subplantar injection of carrageenan (2% wt/vol) into the paw. Akt1^−/− mice display a reduction in tissue MPO levels at 2 and 4 h time points (n = 5 per group). (C) Hematoxylin and eosin staining of carrageenan-injected paws at 4 (left) and 72 h (center) time points. Immunostaining of WT and Akt1^−/− histological paw sections for CD68, a monocyte/macrophage marker, at 72 h after carrageenan injection (right). The Akt1^−/− mice show a marked reduction in leukocyte infiltration in both early and late phases of paw edema compared with those of WT and Akt2^−/− mice. Data are expressed as mean ± SEM. *, P < 0.05; **, P < 0.01; ***, P < 0.001. (Magnification, 10×.)