Background The aim of the study was to compare the serum activity of angiotensin convertase in healthy subjects and in hypertensive patients with or without advanced heart failure.
Methods Three groups were studied: A - 69 healthy subjects, B - 55 hypertensive patients without advanced heart failure (I-II NYHA stage) and C - 13 hypertensive patients with advanced heart failure (III-IV NYHA stage). The activity of angiotensin convertase in serum was determined by spectrofluorometric method (Friedland and Silverstein).
Results In healthy subjects the mean activity of angiotensin convertase in serum was 38,6 ± 8,1, in the group B - 42,0 ± 15,0 and in the group
C - 30,8 ± 10,5 nmol/ml/min. In the group B angiotensin convertase values shows nongaussian distribu- tion, and frequency of high values (40 nmol/ml/min) was greater than in group A (54 vs 36%,p.). In the group C high values of angiotensin convertase were not so frequent as in the group A (15% vs 36 %) and B (s 15% vs 54%).
Conclusions The distribution of serum angiotensin convertase activity has twomodal character. The percentage of persons with high values of angiotensin convertase ( > 40 nmol /ml/min) is higher in hypertensive patients without significant heart failure than in healthy subjects. When hypertension is associated with advanced heart failure (III-IV NYHA stage), then the percentage of high values of enzyme in serum is low.