[Changes of components in the kinin system and plasma renin activity during different stages of hypertension in patients treated with captopril].

The authors aim was to evaluate if the changes in the components of the plasma kinin system on PRA, determined during 3-weeks period of treatment with captopril in daily doses of 150 mg, depend on the stage of arterial hypertension. Investigations were carried out in 40 patients with primary hypertension; 6 patients were in I, 20 in II and 14 in III WHO stage. The control group consisted of 18 healthy persons. All the parameters were examined 3 times: before therapy, after 24 h and after 3 weeks of therapy. It was proved that captopril as monotherapy, was effective in every stage of hypertension, however the normalisation of blood pressure was observed only in I and II WHO stage. The normalisation of the prekallikrein levels appeared after 3 weeks of treatment in all periods of hypertension, while the normalisation of the kininogen levels occurred only in patients of I and II WHO stage. Since changes of kininogen level in plasma occurred along with changes in blood pressure, therefore the estimation of kininogen seems to be better criterium of effectiveness of captorpil than the determination of prekallikrein. The changes of PRA were similar in all stages of hypertension, but they were significant only in the group of patients of II WHO stage and only after 24 h. Presented studies indicate that renin-angiotensin-aldosterone system as well as kinin system, participate in the mechanism of antihypertensive effect of captopril in every stage of hypertension.