Hypertension Associated with Reduced Plasma Thrombomodulin Levels and a Hypercoagulable State in Rats

The plasma thrombomodulin (TM) level, an indicator of systemic endothelial cell damage, was measured in spontaneously hypertensive rats (SHR), deoxycorticosteron acetate (DOCA)‐induced hypertensive rats and normotensive Wistar–Kyoto (WKY) rats to clarify its changes in hypertension. Plasma TM levels, measured by enzyme‐linked immuno‐sorbent assay, decreased with aging (5–20‐weeks‐old) in both SHR and WKY, and they were lower in SHR than age‐matched WKY in all ages examined. Deoxycorticosteron acetate‐induced hypertensive WKY also showed decreased TM levels compared with normotensive WKY. Accelerated coagulation and fibrinolysis shown by the increases in thrombin–antithrombin complex (TAT) and D‐dimer levels were observed in both groups of hypertensive rats. These results suggest that hypertension may decrease plasma TM levels and induce a hypercoagulable state in rats.