EFFECTS OF HIRUDIN (THROMBIN SPECIFIC INHIBITOR) IN ZEBRAFISH EMBRYOS- A DEVELOPMENTAL ROLE FOR THROMBIN

To address the role of thrombin in early embryogenesis, hirudin, a thr ombin specific inhibitor was microinjected into developing zebrafish e mbryos to inhibit the temporal activity of thrombin during early embry onic development. We found that the fibrin forming activity is inhibit ed by the presence of hirudin. We also found that hirudin affects deve lopment in zebrafish embryos suggesting thrombin's role in early embry ogenesis. This ability to inhibit thrombin activity in developing embr yos should facilitate studies on identifying signal transduction pathw ays affected by thrombin during embryogenesis.