[Dynamic changes of the plasma prekallikrein activity in patients with acute myocardial infarction].

The activity of the plasma prekallikrein was assayed by using dextran sulfate as activator and chromogenic compound substance Na-benzoyl-DL-arginine-4-nitroanilid-hydrochloride (BAPNA) as substrate. The dynamic changes of the plasma prekallikrein activity were observed in 22 patients with acute myocardial infarction (AMI) at different period. The correlation between plasma prekallikrein activity and serum CPK activity were analysed in part of the patients. The results indicate that the plasma prekallikrein activity decreased significantly in AMI, especially on the third day after onset. The decrease of plasma prekallikrein and increase of serum CPK were correlated negatively. The results indicate that the chromogenic compound substance BAPNA can be used to determine the activity of plasma prekallikrein. The kinin system was activated by certain factors in AMI, causing the decrease of plasma prekallikrein and increase of bradykinin.

[The significance of the kallikrein-kinin system in the pathogenesis of essential hypertension].

The levels of plasma kininase II (ACE), a high molecular weight-kininogen (HMW), alpha 2-mega-globular protein (alpha 2M), prekallikrein (PK), alpha 1-antitrypsin (alpha 1 AT) were determined in essential hypertension and control groups. The results showed that there is significant increase of ACE and PK activity and HMW content in patients with essential hypertension than in control group (P less than 0.001). No changes in alpha 2M and alpha 1AT were found. These results suggest that human plasma kallikrein system was inhibited in patients with essential hypertension.