Fibrinolytic activity and platelet release reaction in essential hypertension.

The incidence of atherosclerotic and thromboembolic complications is quite high in hypertensive patients. Blood platelets and fibrinolytic activity may play an important role in the development of these complications. We investigated fibrinolytic activity and in vivo platelet release reaction in essential hypertension. Plasma levels of beta thromboglobulin (BTG), platelet factor-4 (PF4), tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1) and plasminogen were determined in 36 essential hypertensive and 20 age and sex-matched control subjects. Plasma BTG levels were significantly higher in the hypertensive subjects than in controls (p < 0.05), whereas PF4 levels were similar for both groups suggesting an increase of in vivo platelet activity. PAI-1 antigen levels were found to be significantly higher in the hypertensive patients as compared to the control subjects (p < 0.01). On the other hand significant variations of t-PA antigen and plasminogen values were not observed in the two groups. These results suggest that essential hypertension is associated with decreased fibrinolytic activity and enhanced platelet activity as evidenced by high plasma levels of PAI-1 and BTG.