Reduced responses of renin release to three different stimuli in essential hypertensive patients of stage II (WHO stage classification).

The responses of renin release to three different stimuli, such as 1) head-up tilt, 2) administration of loop diuretics(bumetanide) and 3) low sodium diet + administration of bumetanide + ambulation were examined in essential hypertensive patients and normotensive subjects. Essential hypertensive patients were classified as stage I and II according to WHO stage classification. Groups studied were age-matched. The responses of renin release to three stimuli did not significantly differ in normotensive subjects (n = 13, 42 +/- 2(SEM) years old) and essential hypertensive patients of stage I (n = 15, 44 +/- 2). However, essential hypertensive patients of stage II (n = 20, 44 +/- 1) showed significantly lower responses of renin release to all three stimuli than essential hypertensive patients of stage I and normotensive subjects. The results suggest that the suppression of renin release is related in part to the development of hypertension.