Malignant hypertension: a syndrome associated with low plasma kininogen and kinin potentiating factor.

Plasma levels of kininogen, kallikrein, and prekallikrein were determined in patients with malignant hypertension (MH) and compared to normotensive controls (NC) and patients with mild to moderate essential hypertension (EH). Also, a recently described kinin potentiating factor (KPF) was estimated by dividing the value of kininogen determined by trypsin (Kgn-Try) by that of kininogen determined by human urinary kallikrein (Kgn-HuUk). No significant alterations were detected among plasma values of pre-kallikrein and kallikrein of MH as compared to NC. However, Kgn-HuUK values were significantly lower in MH (1.9 +/- 0.3 micron gLBK/ml) as compared to EH and NC (2.7 +/- 0.1 micron gLBK/ml and 3.0 +/- 0.2 micron gLBK/ml respectively, p less than 0.05). Furthermore, KPF values were also low (p less than 0.05) in MH (1.6 +/- 0.3) when compared with similar values obtained in EH and NC (3.0 +/- 0.2 and 2.8 +/- 0.1, respectively). Adequate control of blood pressure levels for 90 days in MH group caused no significant alterations in plasma levels of kininogen and KPF. It is suggested that diminished kininogen levels as well as a decrease in a kinin potentiation KPF that is generated in plasma by trypsin may be involved in the pathogenesis of human malignant hypertension.