Vascular permeability factor, also known as vascular endothelial growth factor (VPF/VEGF), is a disulfide-linked dimeric glycoprotein of about 40 kDa that enhances vascular permeability, induces chemotaxis and activation of monocytes/macrophages, and promotes growth of vascular endothelial cells. It has been reported that several tumor cell lines and normal cells produce VPF/VEGF. To examine the possibility of VPF/VEGF mRNA expression in human peripheral T cells and its mechanism(s) of regulation, we developed a non-radioisotopic semiquantitative reverse transcription-polymerase chain reaction (RT-PCR; VPF/VEGF, GAPDH co-amplification) assay which detects all species of VPF/VEGF mRNA alternative splicing products. T cells expressed negligible VPF/VEGF mRNA in the resting state. However, TPA markedly enhanced the expression of 121-, 165- and 189-amino-acid-containing isoforms of VPF/VEGF mRNA in T cells. Both CD4+ and CD8+ T cells expressed VPF/VEGF mRNA in response to TPA treatment. Moreover, T cell receptor stimulation with monoclonal anti-CD3 antibody with or without IL-1 beta enhanced VPF/VEGF mRNA expression in T cells. These findings suggest that T cell activation induces VPF/VEGF expression in the cells, resulting in induction of its biological activities.