In vivo and in vitro models of Mammalian angiogenesis.

Angiogenesis is a complex process involving the organization of proliferating endothelial cells into new blood vessels. Both in vivo models and in vitro models are important for investigating angiogenesis and for defining the involvement of specific molecules. This chapter describes a basic mouse model of vascular endothelial growth factor-driven angiogenesis in mouse skin together with a modified version of this model in which retrovirus-packaging cells are included as a means to efficiently achieve retroviral transduction in vivo. With this approach, the contributions of specific proteins to angiogenesis can be defined. In addition, we describe a model of capillary morphogenesis in vitro that uses microvascular endothelial cells transduced with retrovirus in culture. This in vitro model provides a complementary strategy for investigating the importance of specific molecules for angiogenesis.