Immunolocalization of vascular endothelial growth factor in the GH(3) cellline

The question of whether vascular endothelial growth factor (VEGF) is expres sed in the GH(3) cell line was investigated using immunocytochemistry, immu noelectron microscopy, and Western blotting. Using immunocytochemistry, VEG F was demonstrated in approximately 90% of the cells, Immunopositivity was localized mainly in the paranuclear Golgi region, In a small minority of ce lls, diffuse cytoplasmic immunostaining was also noted. By immunoelectron m icroscopy VEGF was evident in the secretary granules, cytoplasmic vesicles, rough endoplasmic reticulum, and the Golgi apparatus. Western blotting con firmed the results of the morphologic studies. It can be concluded that VEG F which is know to induce angiogenesis and to increase vascular permeabilit y, is produced in the prolactin- and growth hormone (GH)-secreting GH(3) ce ll line. The functional role of VEGF in the GH(3) cells is unknown, It is p ossible that this growth factor affects endocrine activity of GH, cells by a paracrine mechanism.