Figure 2.

Histologic appearance of TGF-β and β-gal arteries. (A) In a 2-week TGF-β artery, increases in medial proteoglycans (green) and collagen (yellow) are apparent. (B) In a 4-week TGF-β artery, asymmetric increases in intimal and medial thickness are seen. (C) In a 4-week β-gal artery, the intima and media appear essentially normal. (D–F) In 4-week TGF-β arteries, a cellular and matrix-rich intima is present with both medial and intimal cartilaginous metaplasia. Numerous cells appear in lacunae, surrounded by a proteoglycan and collagen-rich matrix. In F, S-100 immunostain identifies chondrocytes. (G) In an 8-week β-gal artery, the intima and media appear essentially normal. (H–I) In an 8-week TGF-β artery, a small area of neointima is present. Arrows in B, D, E, F, and I indicate internal elastic lamina; arrowheads in F indicate some of the cells staining for S-100 antigen; arrowheads in H and I indicate small remaining neointima and an area of proteoglycan accumulation, respectively. Sections were stained with hematoxylin and eosin (B–D, G, H), Movat’s pentachrome (A and E), S-100 immunostain (F), or Alcian Blue (I). Original magnifications: (E) ×20; (B, C, G, and H) ×25; (A, F, and I) ×65; (D) ×80.