Dorsal vessel formation

Implantation of polymer matrices that contain angiogenic factors requires quantification of the extent of vessel ingrowth. This can either be analysed immunohistochemically or by haemoglobin/red blood cell count in the tissue. These models generally do not allow analysis of the time course of vascularization since this would require the sacrifice of animals. Application in a dorsal skin fold chamber circumvents this experimental problem, as it provides the opportunity to monitor vessel formation at various time points during the experiment. 

In this section, we discuss the genetic networks that control lumen formation of the Drosophila dorsal vessel. In particular, we discuss the necessary changes in cell shape and cell-cell adhesion that occur during lumen formation, and the requirement of G-protein signaling for maintenance of the cardiac tube. 

Formation of the dorsal vessel lumen also depends on the transmembrane receptor. Uncoordinated 5 (Unc5). Unc5 represents the single Drosophila homolog of a conserved... 

In this chapter, we have reviewed our current imderstanding of how lumens form and are maintained in the dorsal vessel, salivary gland and trachea of the Drosophila embryo. Lumen formation in the Drosophila embryonic salivary gland and primary branches of the trachea occurs concomitantly with invagination of the salivary gland and tracheal cells from the embryo surface. Thus, it is not entirely surprising that lumen size control in these two epithelial-based organs share similar cellular and molecular mechanisms, such as the roles... 

Although the structure and function of the Drosophila embryonic dorsal vessel, salivary gland and trachea may differ from mote complex organs of other organisms, it is dear that there are conserved mechanisms for lumen formation. Thus, the study of tube and lumen... 

Fig. 1. Microcirculation of a human colon carcinoma grown in the dorsal skin chamber in a severe-combined immunodeficient mouse. (Adapted from Leunig et al., 1992b.) Note that angiogenesis leads to formation of numerous blood vessels. Such a transparent preparation can permit noninvasive, continuous measurement of transport processes in normal and tumor tissues (Jain, 1985b). Parameters we can measure include hemodynamic (e.g., blood flow, vasomotion) metabolic (e.g., pH, p02, Ca2+) transport (e.g., permeability, diffusion, binding), and cell-cell interactions (e.g., adhesion, deformability).

Thrombophlebitis of the deep dorsal vein, also known as penile Mondor s phlebitis, is an inflammatory reaction of the involved vessel associated with thrombus formation. Other causes of thrombosis of the deep superficial vein have been illustrated elsewhere. 

Switch to fluorescent lighting and investigate formation of vasculature on the green channel. Secondary vessels, ISV (inter-segmental vessels), and DLAV (dorsal longitudinal anastomotic vessel) should be formed at this stage. 

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