The blood coagulation factor XII which brings about the activation of the intrinsic coagulation system has more intricate significance in hemostatic balance than other clot promoting factors, because the factor is closely associated with kinin release and activation of the fibrinolytic system which inversely relates to the coagulation system in thrombus formation.
In this study the significance of contact factors, which include factor XII and XI, were observed clinically by assessment of the activity in plasma of cerebrovascular patients.
Contact activity was determined in plasma of 89 cerebrovascular patients without acute infection and hepatic disorders, and of 20 healthy controls following Waalar's method using exhausted plasma prepared by adding 30mg of celite 503 to 1.0ml of plasma at the same time.
The mean values and standard deviations of activity in 89 patients and 20 controls were 140±39.0 and 106±22.0%, significantly higher activity was indicated in patients than in controls. The activity in patients with normal ECG findings was 153±38.1%, and 131±40.2% in those with abnormal EGG findings, this difference was significant. In patients with normal ECG findings the activity of the hypertensives was higher than that of the normotensives, in patients elapsed over 4 months after their admission it was higher than that in one month, in patients with good marks in the test of activities of daily livings (ADL-T) it was higher than that with poor marks.
The activity was not associated with other clinical findings. In normotensive patients with abnormal ECG findings the activity was inversely proportional to serum cholesterol and β-lipoprotein fraction levels respectively.
The high activity in patients with normal ECG findings, and few marked atherosclerotic changes in contrast to patient with abnormal ECG findings, and the inverse correlations between the activity and two lipids are unresonable, considering only the participation of the coagulation system triggered by factor XII.
Few articles on the effect of long-term physical exercise on the fibrinolytic system have been published, except our previous study which demonstrated the lower serum α1-antitrypsin level in cerebrovascular patients with good ADL-T marks than in those with poor marks. However, activation of the fibrinolytic system by exercise of short duration has been reported frequently. Therefore, the high activity must be regared as the result of a participation of the fibrinolytic system activated by factor XII. Although the high activity in patients with normal ECG findings and hypertension may be regarded as the protective effect of the fibrinolytic system to development of atherosclerosis induced by hypertension, and may be apperciated as the direct effect of kinin release by factor XII in hypertension.
These results indicated the complex association of the contact factors with three different systems, which are closely related to the pathophysiolosic status of cerebrovascular disorders, and the necessity of further intensive investigation of contact factors, especially of factor XII.
