TP508 TFA is a nonproteolytic thrombin peptide. TP508 TFA activates endothelial NO synthase (eNOS) and stimulates the production of NO in human endothelial cells. It activates endothelial cells and stem cells to revascularize and regenerates tissues.

TP508 mitigates the effects of nuclear radiation on human endothelial cells in culture restoring endothelial NO production, tube formation, and accelerating repair of radiation-induced DNA double-strand breaks. TP508 (50 μg/mL; 24 hours; HCAEC) treatment reverses radiation-induced endothelial dysfunction (ED) and loss of NO signaling by attenuating the downregulation of eNOS expression [1]. TP508 acts as an antagonist for the effects of thrombin. TP508 peptide inhibits these thrombin-induced effects through an RGD and αvβ3-related mechanism [3].

In male CD-1 mice, the treatment of TP508 (10 mg/kg; i.v.) mitigates radiation-induced endothelial cell damage, also significantly increases survival of CD-1 mice when injected 24 h after 8.5 Gy exposure [1].