Figure 3 CIH resulted in the dysfunction of vascular endothelial cells. (A) Immunohistochemistry staining of CD31 (red) on the soft palate of the control group and the CIH group. The arrow shows vascular vessels in the connective tissues of the soft palate, and CIH exposure resulted in the enlarged vessels. (B) Western blotting demonstrates the expression of caveolin-1 in the control group and the CIH group. (C) The right bar showing the relative expression level. The relative protein expression was calculated based on the control group which was considered equal to 1. (D) Immunohistochemistry staining for caveolin-1 in the rat soft palate exposed CIH group and the control group. All values presented as mean±standard deviation. ** Significantly different from the control group, P<0.01. Scale bar is 100 μm.