Smooth muscle cell and collagen content of atherosclerotic lesions. Representative photomicrographs showing atherosclerotic lesions in the aortic sinus of control (A,C) or CD2-dnTGFBRII (B,D) LDLr KO mice. Smooth-muscle cell content was detected by staining with anti-α-actin antibody (black staining; A-B). Collagen content in the lesions was detected by staining with Sirius red (red staining; C-D). ^* Indicates the intima; L, the lumen of the vessel. Original magnification, × 400. (E) Quantitative analysis of α-actin and Sirius red staining was performed using Histolab Microvision software. Four to 5 sections per animal were analyzed for each immunostaining; n = 7 to 8 per group. Results (means ± SE) are expressed as percentage of positive surface area. P = .03 for actin and P = .01 for Sirius red. Mean values are shown above bars.