Effect of metoprolol on 24-hour urinary excretion of adrenal steroids and kallikrein in patients with essential hypertension

Urinary kallikrein excretion following chronic sinoaortic denervation in conscious dogs

Urinary kallikrein excretion (UKE) was investigated in neurogenic hypertensive dogs for a period of 8 months. The animals were made hypertensive by sinoaortic denervation (SAD). Plasma catecholamine levels (PC), plasma renin activity (PRA), plasma aldosterone concentration (PAC) and urinary sodium excretion (UNa) were also measured. The onset of hypertension was associated with an increase in PC. UKE, measured by amidolytic and kininogenase activities, exhibited a very significant transient increase two and four weeks after SAD. Progressively, UKE significantly decreased below control values at the 16th and 32nd week. Since the month following SAD is characterized by an increase in sympathetic tone (as shown by high PC levels), the transient increase of UKE can be related to this high PC level; although this hypothesis is only supported by a positive relationship between these two parameters. The subsequent decrease in UKE appeared linked to diminished mineralocorticoid activity. Thus, the biphasic pattern of UKE observed in the study suggests that variations of UKE are more a consequence of hypertension than a pathogenic factor. Because UKE, which is of renal origin, is reduced at the end of the study period, this may also suggest possible renal dysfunctions in this model of hypertension.

Renal kallikrein in diabetic patients with hypertension accompanied by nephropathy

We measured the 24-h excretion of urinary kallikrein in 27 patients with Type 2 (non-insulin-dependent) diabetes and in 10 normal control subjects. Mean (+/- SD) kallikrein excretion in diabetic patients with nephropathy (6.2 +/- 2.4 naphthyl units (NU)/day, n = 13) was significantly lower than in control subjects (12.8 +/- 3.4 NU/day, p less than 0.01) and in diabetic patients without nephropathy (9.4 +/- 3.4 NU/day, n = 14, p less than 0.05). Kallikrein excretion in hypertensive diabetic patients with nephropathy (5.1 +/- 1.6 NU/day, n = 8) was significantly lower (p less than 0.05) than in normotensive patients with nephropathy (8.3 +/- 2.1 NU/day, n = 5). There were no significant differences in kallikrein excretion rate (24-h excretion of urinary kallikrein/24-h creatinine clearance) among control subjects (9.9 +/- 4.3 NU/ml), diabetic patients with (9.0 +/- 3.2 NU/ml) and without (9.3 +/- 3.5 NU/ml) nephropathy. However, kallikrein excretion rate in hypertensive diabetic patients with nephropathy (7.7 +/- 3.3 NU/ml) was significantly lower (p less than 0.05) than in normotensive diabetic patients with nephropathy (11.8 +/- 2.0 NU/ml, n = 10). Respective basal and post-stimulated (with intravenous furosemide 40 mg plus 60 min ambulation) plasma aldosterone concentrations measured in control subjects and in hypertensive diabetic patients with nephropathy were similar and increased to the same extent in the 2 groups (5.5 +/- 3.2 versus 5.3 +/- 3.2 and 9.3 +/- 2.6 versus 10.5 +/- 3.4 ng/ml), although the respective plasma renin activity tended to be lower in diabetic patients than in control subjects (0.7 +/- 0.6 versus 1.3 +/- 0.9 and 1.8 +/- 1.8 versus 3.0 +/- 2.6 ng-1 . ml-1 . h-1).(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of tetracosactide and adrenal steroids on renal kallikrein activity and urinary kallikrein excretion in rats

The effect of adrenal steroids (mineralo- and glucocorticoids) as well as that of the adrenocorticotrophic peptide tetracosactide (beta 1-24 corticotropin) on the renal kallikrein activity and on the urinary kallikrein excretion of rats was investigated. After the animals had been adapted to metabolic cages, they were injected with deoxycorticosterone acetate (15 mg/kg day), corticosterone (40 mg/kg day), both steroids combined or the vehicle (sesame oil). Additional groups of rats received tetracosactide (0.05, 0.1 or 0.2 mg/day) or the vehicle (100 microliter of 38 X 10(-3) M ZnCl2). After four days of treatment the urinary kallikrein excretion was higher in deoxycorticosterone-treated rats than in their controls. This increase was prevented when corticosterone was administered simultaneously. The renal kallikrein activity of corticosterone as well as that of deoxycorticosterone plus corticosterone-treated rats was subnormal. A dose-related reduction of both the renal kallikrein activity and the urinary kallikrein excretion was observed 2 days after starting the tetracosactide administration. It may be concluded that a stimulation of the endogenous release of glucocorticoids in the rat reduces the renal kallikrein activity and that glucocorticoids can prevent the stimulating effect of mineralocorticoids.