Developmental expression of vascular endothelial growth factor in the masseter muscle of rats

Developmental changes in vascular endothelial growth factor (VEGF) in rat masseter after birth were investigated. VEGF was extracted efficiently and reproducibly from muscle homogenate with low concentrations of non-ionic detergents, such as Triton X-100, Nonidet P-40, and Tween 20. The amount of VEGF measured by enzyme-linked immunosorbent assay (ELISA) increased markedly by approximately 9-fold, from day 8 to 35 after birth. The increase in VEGF was closely correlated with the development of the capillary network, as shown by the capillary to muscle fibre ratio (C/F ratio). Immunoblotting revealed that the predominant molecular species of VEGF concentrated with heparin–sepharose beads was VEGF188. These results suggest that VEGF plays an important part in the development and maintenance of the capillary network in the rat masseter.