Figure 2.

Process of de novo adipogenesis by injection of Matrigel and bFGF. Matrigel was s.c. injected together with 1 μg/ml bFGF over the chests of 6-week-old mice, and well defined plugs between skin and muscle were excised for histological staining with hematoxylin and eosin. Neovascularization in Matrigel is completed within 1 week, and blood vessels with a clear endothelium lining are formed (A). The neovascularization was accompanied by invasion of fibroblast-like cells that differentiate into adipocytes within 2 weeks (B). The population and size of the adipocytes increased until 5 weeks after injection (C). The fat plugs formed de novo by injection of Matrigel and bFGF were preserved for 10 weeks (D) whereas the plugs formed by injecting Matrigel alone lacked many cells (E). (Bar = 100 μm.)