To assess the status of renin-angiotensin axis in various types of renal failure, plasma renin activity was studied in 44 patients with acute renal failure, chronic renal failure or postrenal failure by Cohn´s bioassay method modified from the technique of Regoli and Vane using the isolated rat ascending colon.
The results obtained were as follows:
1. Mean recumbent plasma renin activity obtained in 10 healthy subjects was 6. 0±2. 0 ng/ml(range 3.0-10.0 ng/ml).
2. During the oliguric phase of acute renal failure, mean value of plasma renin activity was 24.1± 11. 2 ng/ml and was significantly as compared with those of the control group.
3. Mean value of plasma renin activity during the oliguric phase of Korean Hemorrhagic Fever was 25.8±13.4ng/ml and was stastically insignificant from those of acute renal failure due to other causes. There was no correlation between plasma renin activity and the causes of oliguria of acute renal failure.
The averageplasma renin activity was higher in patients who died than in those who survived the episode of acute renal failure.
4. The mean plasma renin activity in diuretic phase was 10.0±3.8 ng/ml and exceeds significantly, the mean value of the control group although its value was significantly lower in this period than in the oliguric phase of acute renal failure.
5. During the course of acute renal failure, plasma renin activity was pronounced at an early stage of acute renal failure and was not significantly related to arterial blood pressure, concentration of sodium, potassium, urea or creatinine in the same sample of blood.
6. In patients with chronic renal failure, mean plasma renin activity was 7.2±2.7 ng/ml and was not significant by, differently from; that of the control group.
7. In patients with postrenal failure, mean plasma renin activity was 7.8±3.5 ng/ml and stastically in significant as compared with that of the control group or that of the, chronic renal failure group.
These results suggest that the cause of the elevated , plasma, renin activity is located is the kidneys themselves, that different factors inducing acute renal failure, may activate the juxtaglomerular apparatus by a similar mechanism and that renin-angiotensin axis may serve at least a permissible role in inducing oliguria of acute renal failure.
The estimation of plasma renin activity seems to be of diagnostic value in the differentation of acute renal failure from the exacerbated chronic renal failure or postrenal failure.
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