The Effects of Intravenous Infusions of Valine-5 Angiotensin Ii and Other Pressor Agents on Urinary Electrolytes and Corticosteroids, including Aldosterone.

Previous studies from this laboratory (1-4) have shown that: 1) there is a statistically significant increase in the mean urinary aldosterone excretion from groups of patients with essential, renal or malignant hypertension, as compared with that of normal subjects similarly studied; 2) 43 per cent of patients with essential hypertension have urinary aldosterone values above normal limits; 3) there is an excessive fluctuation of daily urinary aldosterone in hypertensive patients, from normal to above normal levels, which is most prominent in the early phase of the disease; and 4) mean urinary preglnanetriol is significantly decreased (p < 0.001) in the same groups of hypertensive patients, and the pregnanetriol/aldosterone ratio is below the lower limits of normal range in 92 per cent of all patients studied with arterial hypertension. The findings of a mean increase in urinary aldosterone and of its excessive daily fluctuation in hypertensive patients have recently been confirmed by Romanelli, Biancalona and Matterazzi (5), Venning, Dyrenfurth, Dossetor and Beck (6) and Schwartz (7). However, Laragh and co-workers (8), using a method devised by Ulick, Laragh and Lieberman (9) for the measurement of aldosterone secretion rate, found normal values in 8 patients with benign essential hypertension and significantly increased secretion rates in 5 of 8 pa-