THE INFLUENCE OF BRADYKININ ON THE FIBRINOLYTIC ENZYME SYSTEMS IN THE URINE, BLOOD AND KIDNEY TISSUES

Particularly, correlation with Renal Bleeding

Abstract

The author has been discussing the relation between the fibrinolytic enzyme system and the capillary permeability promoting action in serum (CPP action) in the case of so-called idiopathic renal bleeding, and reporting the correlation between the fibrinolytic enzyme system and CPP action and the experimental renal bleeding in Reilly's phenomenon, serotonin administration and stimulation of nervus ischiadicus.
In this report, 250 γ of bradykinin, a representative kinin of vasoactive peptide, were administered to the matured rabbit, and the changes of urine and fibrinolytic enzyme system (in kidney tissue, blood and urine) were observed and the following results were obtained.
1) After 10-15 seconds of intravenous injection of bradykinin, anaphylaxy shock-like symptom was induced, and after 2-2.5 minutes, the symptom disappeared.
The excretion of urine stopped as soon as the shock-like symptom was induced, but it was re-excreted after 4-4.5 minutes. There was no change in protein, pH and sugar in the urine.
2) The fibrinolytic activity of urine increased gradually until 25 minutes after the administration and rapidly thenceforce, and simultaneously renal bleeding was increased.
The inhibitory action of urine for the urokinase (UK) and plasmin (PL) was temporarily decreased after the injection, but increased after 25 minutes.
3. The inhibitor (Inh) for UK and PL presented in the normal blood plasma of rabbit.
Administration of a large dose of bradykinin effected on the inhibitory system of UK in blood in relatively early stage and it activated fibrinolytic enzyme system in blood after 20-30 minutes of the administration.
Blood fibrinogen changed on the UK-Inh system in parallel with but slightly behind in the fibrinolytic activating system, and the renal bleeding paralleled with the fibrinolytic activating system in the blood.
4. The activator (Act) presented richly in the renal medulla of normal rabbit, and it was able to be extracted with physiological saline.
The proactivator (Proact) could also be extracted by the physiological saline, and it presented more richly in the order of renal cortex and renal medulla, and it did not present in renal pelvic membrane.
A large amount of bradykinin activated a large amount of the Proact in the renal cortex in early stage, and the Act was not extracted by physiological saline. Since then, Proact in the renal cortex was gradually activated and consumed.
The Act in the renal medulla was reduced and then the Proact was gradually activated to maintain the activity in the renal medulla constantly.
The Act in the renal pelvic membrane was activated slightly in early stage, but the Act was different from that in the renal cortex and renal medulla in nature and inactivated relatively in early stage, but Proact was in slightly increased stage thenceforth.
5. From these results, it may be concluded that a large amount of bradykinin activates fibrinolytic enzymes as the secondary reaction after several steps of reactions, and induces renal bleeding.
The induction of the renal bleeding is supposed to be caused in the renal medulla.