Essential role of kallikrein-kinin system in suppression of blood pressure rise during the developmental stage of hypertension induced by deoxycorticosterone acetate-salt in rats.

Deoxycorticosterone acetate (DOCA)-salt hypertension was induced in Brown Norway (BN) kininogen-deficient rats (BN-Ka) and normal rats from the same strain (BN-Ki) after nephrectomy. Systolic blood pressure, which was determined by the tail-cuff method, of BN-Ki increased gradually during this treatment. In contrast, the blood pressure of mutant BN-Ka increased rapidly 2 weeks after the onset of the treatment. Urinary excretion of active kallikrein and prokallikrein increased at the same degree in rats of both strains during this treatment. Significant increase in urinary sodium excretion was observed with a tendency to increase in urine volume during the treatment in normal BN-Ki rats, whereas both parameters were essentially not increased in mutant BN-Ka rats, which could not generate urinary kinin. Aprotinin infusion by osmotic minipump to normal BN-Ki rats during the DOCA-salt treatment resulted in significant further increase in the systolic blood pressure.