Rat Vascular Endothelial Growth Factor A (VEGF-A) is a member of the vascular endothelial growth factor (VEGF) family, which includes VEGF-A, VEGF-B, VEGF-C, VEGF-D, and placental growth factor (PlGF)—key regulators of angiogenesis, vascular permeability, and endothelial cell growth. In rats (Rattus norvegicus), VEGF-A is produced by a wide variety of cells including endothelial cells, macrophages, fibroblasts, epithelial cells, smooth muscle cells, and tumor cells, particularly in response to hypoxia, inflammation, and tissue injury. VEGF-A exerts its biological effects primarily through binding to VEGF receptor-1 (VEGFR-1/Flt-1) and VEGF receptor-2 (VEGFR-2/KDR) on endothelial cells, activating intracellular signaling pathways such as MAPK/ERK, PI3K/AKT, and PLCγ, which promote endothelial cell proliferation, migration, vascular permeability, and new blood vessel formation. In rats, VEGF-A plays essential roles in embryonic vascular development, wound healing, tissue regeneration, and organ repair following injury or ischemia. Rat VEGF-A has been widely studied in experimental models of cardiovascular disease, ischemia, cancer, diabetic complications, and retinal disorders, where VEGF-mediated angiogenesis contributes to both tissue repair and pathological vascular growth. Because rats are commonly used in vascular biology, pharmacology, and disease modeling, characterization of rat VEGF-A has provided important insights into angiogenic signaling and therapeutic strategies targeting VEGF pathways.