Plasma renin activity (PRA) and aldosterone were measured to evaluate various status of clinical conditions in normal controls and patients with essential hypertension.

Fourteen controls and 45 essential hypertensive patients for PRA, and 10 controls and 28 patients with essential hypertension for plasma aldosterone were studied.

The results obtained are summarizing as follows.

1. Mean value of PRA of normal subjects was 2.9±1.4ng/ml/hr at rest, and 5.9±2.3ng/ml/hr by double stimulation, respectively, the latter elevated up to twice the former.

2. Mean value of PRA in the patients with essential hypertension was 3.37±3.0ng/ml/hr at rest, and 5.99±4.9ng/ml/hr by double stimulation. The latter have increased to 1.8 times the former.

3. The patients with low PRA observed in 33.3%, the normal in 42.2%, and the high in 22.5%, at rest. After double stimulation, the low group was observed in 22.2%, the normal in 60.0%, and the high in 17.8%.

4. Mean age of the patietns with low PRA was 57.2±2.6 years. Though it was higher than those of normal and high PRA groups(52.0±10.1 years), statistical significances were observed (0.05<p<0.1).

5. Significant difference of PRA in relation to blood pressure was not observed, but the diastolic blood pressure were significantly higher (p<0.05) in high PRA group than those of low PRA group after furosemide and physical activity.

6. In relation between the PRA and optic fundus findings, PRA was high in Keith-Wagner III group, however, no statistical difference was found.

7. PRA was significantly elevated (p<0.01) in patients with marked proteinuria (⫵), as compared to the patients with negative proteinuria.

8. PRA was significantly higher in the patients with 20.1 mg% or more of VUN, than those of below 15mg% (p<0.01). There were seven patients who had more than (+) proteinuria and more than 20.1mg% of BUN. Five patietns showed high PRA (71.4%) and two patients normal PRA (28.6%). No low PRA was found in this group.

9. Significantly frequent findings of left ventricular hypertrophy on ECG were disclosed in high PRA group than low PRA group (p<0.05) after furosemide and physical activity.

10. Cerebral vascular accidents were noted more in normal or high PRA groups than low PRA group, but the difference was not statistically significant. Cardiac failures were seen less frequently in low PRA group than high PRA group, and the difference was significant (p<0.05).

11. There were no differences of serum sodium, potassium, cholesterol and triglycerides between three groups of PRA in essential hypertensive patients.

12. Mean value of plasma aldosterone of normal subjects was 17.6±2.3ng/100ml at rest, and it had elevated to 30.2±11.3ng/100ml by double stimulation of furosemide and physical activity.

13. Mean value of plasma aldosterone of essential hypertensive patients was 18.5±7.1ng/100ml at rest, and elevated to 30.2±11.3ng/100ml by double stimulation. There were no differences between normal subjects and hypertensive patients.

14. Correlation coefficients between PRA and plasma aldosterone at rest and after double stimulation in controls were 0.821 and 0.809, respectively, however those of essential hypertensive group were 0.308 and 0.483.

15. The plasma aldosterone were either low (57.1%) or normal (42.9%) in 7cases of low PRA group after double stimulation. In normal PRA group, the plasma aldosterone were normal in 15 cases, high in 2 cases, and in high PRA group two cases were normal and two cases high.

16. There were no differences of serum sodium or potassium whether the plasma aldosterone were low, normal or high. Also no significant differences of plasma aldosterone values were found in the patients with complications. Although the plasma aldosterone was elevated in cases increased BUN, the difference was not significant.