[Characteristics of changes in the kinin system of blood in hypertensive disease]

The state of the kinin system of blood was studied in terms of its content of kininogen, prekallikrein, kallikrein inhibitor and the spontaneous esterase activity. The examination was conducted in 10 normal individuals and in 81 hypertensive patients with labile and stable arterial pressure and an uncomplicated course. The studies were conducted at rest, during the transfer into an orthostatic position, and after 15 or 60 minutes of walking. The normals demonstrated an activation of the kinin system that ensued in orthostasis, but was more distinct at walking. A significant correlation was noted between the content of prekallikrein and kininogen in all the states under examination. In cases of labile arterial hypertension an increased activation of the blood kinin system was observed at rest, a lack of its activation at walking, and disorders in the correlation between the content of prekallikrein and kininogen. The observed changes in the kinin system may affect the central haemodynamics and the formation of the hyperkinetic type of circulation.