Bradykininogen and bradykinin in the cardiovascular shock produced by proteolytic enzymes

The bradykinin B1 receptor antagonist R-954 inhibits Ehrlich tumor growth in rodents

The present study investigated the effects of a new bradykinin B(1) receptor antagonist, R-954, on the development of Ehrlich ascitic tumor (EAT) induced by the intraperitoneal inoculation of EAT cells in mice and the formation of a solid tumor by the subcutaneous injection of the cells in rat paw. The development of the tumor was associated with an increase in mouse total cell counts in bone marrow (10.8-fold), ascitic fluid (14.6-fold), and blood (12.6-fold). R-954 (2mg/kg, s.c.) significantly reduced the ascitic fluid volume (63.7%) and the mouse weight gain (30.5%) after 10 consecutive days of treatment. The B(1) antagonist as well as the anti-neoplasic drug vincristine also significantly inhibited the increase in total cell count in bone marrow, ascitic fluid, and blood. R-954 reduced significantly the total protein extravasation (57.3%), the production of nitric oxide (56%), PGE(2) production (82%), and TNFα release (85.7%) in mice peritoneal cavity whereas vincristine reduced the release of these inflammatory mediators by 84-94%. The increase in paw edema after intraplantar injection of EAT cells was reduced by approximately 52% by either R-954 or vincristine treatment. In conclusion, this study presents for the first time the antitumoral activity of a new bradykinin B(1) receptor antagonist on ascitic and solid tumors induced by Ehrlich cell inoculation in mice and rats.

The effects of intravenously administered chlorophyll-A on naturally occurring serum protease inhibitors in rabbits

Effects of intravenously administered protease inhibitors on naturally occurring serum inhibitors were investigated in rabbits. Water-dispersed chlorophyll-a, trasylol and leupeptin were tested as exogenous protease inhibitors in the experiments. From the results of experiments, it was concluded that: 1) Pretreatment with chlorophyll-a infusion into rabbits, most effectively prevented the rapid consumption of naturally occurring serum protease inhibitors after successive trypsin infusion, and the duration of its action was observed longest when compared with other exogenous inhibitors, such as trasylol or leupeptin. 2) Final therapeutic effects of these exogenous protease inhibitors seem to have depended upon the disappearing way of the administered inhibitors from the blood in certain period of time, as well as upon biochemical potency of their inhibiting activity.

The role of kininogenases, kinin formation and kininogenase inhibition in post traumatic shock and related conditions

The kinin system has for a long time been considered to play a role in the pathophysiology of trauma, particularly in blood pressure changes and in inflammatory effects. Recent findings necessitate a revision of this view. It is now necessary to differentiate between two kinin systems: 1. the plasma kallikrein-HMW kininogen-kinin-system, which besides forming kinin acts decisively in Hageman Factor activation, clotting and fibrinolysis; 2. the glandular and tissue kallikrein-LMW kininogen-kinin-system which is to our present day knowledge primarily involved in kinin formation. Kinins exert a variety of actions. By interfering with angiotensin II formation, kinins may contribute to blood pressure regulation. By enhancing cellular glucose uptake and/or metabolism, they regulate partly energy production. In post traumatic states death is preceded by a severe depletion of various factors of the system and an almost total loss of kinin forming capacity. Severity and time course of these phenomena suggest that early institution of direct (Trasylol) or indirect (heparins, cortocosteroids) proteinase inhibition, and if necessary a replacement of the lost factors, should be considered.

Irreversible shock in rats after injection of microspheres into the renal artery

After injection of microspheres into both renal arteries of rats, an irreversible shock syndrome develops, resulting in death within 4-12 h. Ligation of both renal pedicles after injection of microspheres prevents the shock. It is presumed that kininogenases released from the kidneys participate in the pathogenesis of the shock syndrome.

Is there a place for proteinase inhibition? A review of the literature

The evidence demonstrating excessive proteinase activity in states of shock is reviewed. The capacity of extrinsic inhibitors to control such activity is indicated and the literature showing the value of inhibitors in treating shock is summarized. Three principles to be observed in the use of exogenous inhibitors are proposed.

Liberation of a bradykinin-like substance in the circulating blood of dogs by trypsin, chymotrypsin and nagarse

1. Using the blood-bathed organ technique with cat jejunum as the test organ, it was shown that kinin was regularly released by infusions of trypsin, chymotrypsin and nagarse into the blood superfusing the tissue or into the jugular vein of dogs.2. Intravenous injections of the three enzymes, in doses which did not change plasma bradykininogen (BKG) level, induced generation of kinin in the circulating blood.3. Nagarse in kinin-liberating concentrations did not liberate angiotensin in the circulating blood.4. The responses of the cat jejunum strip, and the systemic hypotension induced by the three enzymes, were enhanced by treatment of the dog with a bradykinin potentiator.5. Injection of the enzymes in the blood perfused hind leg of the dog caused a fall in the vascular resistance. In this preparation, bradykinin potentiating factor (BPF) potentiated trypsin, but not the effects of chymotrypsin and nagarse injections.6. It is suggested that the blood pressure lowering effect of low doses of trypsin is due mainly to kinin release. Chymotrypsin and nagarse, in addition to having a direct action on the vascular smooth muscles, also have indirect hypotensive effects due to the liberation of kinin.