Microcirculatory characterization of cerebral angiogenesis in mice using intravital videomicroscopy

The present study investigated microcirculatory characteristics of the cerebral neovasculature induced in mice, using basic fibroblast growth factor (bFGF) and platelet derived growth factor (PDGF). The nylon-mesh sandwich (collagen gel/growth factor in bovine serum albumin embedded in between two nylon-mesh pieces) was used to induce angiogenesis. After different days of incubation, the observations of neocapillaries were done on the upper surface of the nylon-mesh, using fluorescence video-microscopy. The neocapillary diameter, red cell velocity, and the neocapillary density were evaluated based on the video-image. The neocapillaries were visible on the upper surface of the mesh on the 6th day after the incubation, and red cells started to flow from the day 7. The neocapillary red cell velocity increased with days after incubation, but its level was less than that of the pre-existing capillaries. The neocapillary diameter decreased as the neocapillaries got matured. The neocapillary density was dependent on the doses of bFGF and PDGF. The neocapillary diameter did not alter with the higher concentration as well as with different growth factors. Both bFGF and PDGF showed an increase in red cell velocity at high concentration.