Figure 5. Photomicrographs of hypoxia-inducible factor-1α (HIF-1α) immunohistochemistry in skeletal muscle tissue. The thickness of skeletal muscle containing HIF-1α-positive skeletal muscle cells was determined at 3 h. Scale bar: 5 μm. A, Weak staining of skeletal muscle cytoplasm and nucleus, of vascular endothelial cytoplasm and nucleus, and of inflammatory cytoplasm and nucleus, in sham-operated control (C) group skeletal muscle. B, Strong staining of skeletal muscle cytoplasm and nucleus, of vascular endothelial cytoplasm and nucleus, and of inflammatory cytoplasm and nucleus, in ischemia-reperfusion (IR) group skeletal muscle. C, Moderate staining of skeletal muscle cytoplasm and nucleus, of vascular endothelial cytoplasm, and of inflammatory cytoplasm and nucleus, in ischemic postconditioning (IPO) group skeletal muscle. Note that there were significant differences in the expression of HIF-1α between sham-operated, IR, and IPO groups. D, SUM IOD (integrated absorbance value) of HIF-1α protein level in sham-operated, IR, and IPO groups of skeletal muscle tissue (n=36). Data are reported as means±SD. ^★P<0.01 vs sham-operated group; ^▾P<0.01 vs IR group (one-way ANOVA).