Serum angiotensin converting enzyme activity in patients with chronic renal failure on long term hemodialysis.

Serum angiotensin converting enzyme activity was assayed by a spectrofluorometric method in 19 patients with chronic renal failure on long term hemodialysis and 19 control subjects. Converting enzyme activity was increased in 11 of 19 (58%) patients compared with the controls (p less than 0.005). There was no correlation between serum converting enzyme activity and plasma renin activity or blood pressure in the patients. Possible mechanisms responsible for the increased converting enzyme activity are discussed.