Fig. 1

Generation of carotid artery injury model and the effect of lack of NPY on neointima formation. a Representative H&E staining of carotid artery sections from wild-type and NPY^−/− mice, 21 days after artery injury. The bar represents 100 μm. b–e The bar graphs show the results of morphometric analysis. The neointimal area (b), neointima/media ratio (d) and lumen stenosis (e) were significantly reduced in NPY^−/− mice compared to those in the WT control (n = 15 mice/group). f Expression of NPY in carotid arteries 21 days after injury. Representative NPY immunohistochemical staining micrographs are shown. The dotted line indicates the area of neointima. The arrowheads indicate the NPY-positive areas in the neointima, media, and perivascular tissue in the injured carotid artery of the WT mice. The bar represents 100 μm. g Quantification of NPY immunostaining in carotid arteries of WT and NPY^−/− mice 21 days after FeCl₃ induced injury. Differences between groups were assessed by Student’s t-test, *p < 0.05