PAR Cell Surface Receptors
Protease Activated Receptors (PAR) are found on the outer surface of all eukaryotic cells. Five types have been identified thus far. The numbers and combinations of PAR determine how cells react to thrombin, which activates the PAR, and energizes cell activities. Cells vary their PAR during embryological development, tissue repair and malignancy, but mature cells are characterized by specific combinations of PAR that determine their response to thrombin.