The Effect of Mineralocorticoid Administration on Urine Free Dopamine in Man

1980 ◽  
Vol 58 (1) ◽  
pp. 77-82 ◽  
Author(s):  
N. S. Oates ◽  
C. M. Perkins ◽  
M. R. Lee

1. Five normal subjects were studied under metabolic conditions on a controlled sodium and potassium intake. 2. Plasma and urine free dopamine concentrations were measured in these subjects before, during and after 5 days administration of fludrocortisone (0·2 mg twice daily). 3. Urine free dopamine showed a tendency to fall during the early phase of fludrocortisone administration and then rose towards normal. 4. In a patient with primary hyperaldosteronism there was no evidence of increased renal production of dopamine. Urine dopamine fell when plasma renin activity rose as a result of spironolactone administration (200 mg three times a day for 5 days). 5. If renal dopamine has a role in mineralocorticoid ‘escape’ then it may be permissive only. The mechanisms of control of dopamine production could include tubular sodium concentration, tubular chloride concentration and intrarenal renin activity.

1971 ◽  
Vol 67 (1) ◽  
pp. 159-173
Author(s):  
A. Peytremann ◽  
R. Veyrat ◽  
A. F. Muller

ABSTRACT Variations in plasma renin activity and urinary aldosterone excretion were studied in normal subjects submitted to salt restriction and simultaneous inhibition of ACTH production with a new synthetic steroid, 6-dehydro-16-methylene hydrocortisone (STC 407). At a dose of 10 mg t. i. d. this preparation exerts an inhibitory effect on the pituitary comparable to that of 2 mg of dexamethasone. In subjects maintained on a restricted salt intake, STC 407 does not delay the establishment of an equilibrium in sodium balance. The increases in endogenous aldosterone production and in plasma renin activity are also similar to those seen in the control subjects. A possible mineralocorticoid effect of STC 407 can be excluded. Under identical experimental conditions, the administration of dexamethasone yielded results comparable to those obtained with STC 407.


1983 ◽  
Vol 244 (2) ◽  
pp. R244-R248 ◽  
Author(s):  
C. C. Barney ◽  
R. M. Threatte ◽  
M. J. Fregly

The role of angiotensin II in the control of water intake following deprivation of water for varying lengths of time was studied. Male rats were deprived of water for 0, 12, 24, 36, or 48 h. Water intakes were measured with and without pretreatment with the angiotensin I-converting enzyme inhibitor, captopril (50 mg/kg, ip). Captopril had no significant effect on water intake following either 0 or 12 h of water deprivation. However, captopril significantly attenuated water intake following 24-48 h of water deprivation with the magnitude of the attenuation increasing as the length of the period of water deprivation increased. Plasma renin activity was significantly increased over control levels after 24-48 h of water deprivation but not after 12 h of water deprivation. Plasma renin activity tended to increase as the length of the water-deprivation period increased. Serum osmolality and sodium concentration were significantly increased over control levels following 12-48 h of water deprivation. Serum osmolality and sodium concentration failed to show any further increases with increasing length of water deprivation beyond the increases following 12 h of water deprivation. The data indicate that the water intake of water-deprived rats can be divided into an angiotensin II-dependent component and angiotensin II-independent component. The angiotensin II-independent component appears to be more important in the early stages of water deprivation whereas the angiotensin II-dependent component becomes more important as the length of the water-deprivation period increases.


1972 ◽  
Vol 69 (3) ◽  
pp. 531-541 ◽  
Author(s):  
M. Murakami ◽  
R. Takeda ◽  
S. Morimoto ◽  
K. Hirasawa ◽  
K. Uchida ◽  
...  

ABSTRACT The response of plasma renin activity (PRA) to sodium restriction, furosemide and ACTH administration were studied in six patients with panhypopituitarism of various causes and in a patient with Addison's disease. In all the patients with panhypopituitarism, the basal levels of PRA were within normal limits and the responses of PRA and sodium homoeostasis to sodium restriction and furosemide administration were not significantly different from those of normal subjects. On the other hand, in an Addisonian patient the basal level of PRA was very high and this was further increased with a decrease in the serum level of sodium and an increase in the serum level of potassium after one day of sodium restriction. The administration of 1 mg of synthetic β1–24 ACTH every 12 hours for 2 days caused an increased plasma 11-OHCS and urinary 17-OHCS. with a decrease of sodium and an increase of potassium loss in the urine but failed to change PRA in patients with panhypopituitarism. In the Addisonian patient, ACTH did not influence the levels of plasma 11-OHCS, urinary 17-OHCS, PRA as well as serum and urinary electrolytes. From these results it is suggested that ACTH does not directly act on renin secretion and that PRA can adequately respond to various stimuli such as sodium restriction and furosemide administration in a condition of ACTH deficiency.


1980 ◽  
Vol 59 (1) ◽  
pp. 55-62 ◽  
Author(s):  
M. Epstein ◽  
M. D. Lifschitz ◽  
R. Re ◽  
E. Haber

1. The relationship of the renin-angiotensin-aldosterone axis with renal prostaglandin E is complex. Although studies have suggested that these two hormonal systems respond to experimental manipulations in a parallel manner, their interdependence has not been assessed fully during volume expansion. Since studies have demonstrated that in normal man the central hypervolaemia induced by water immersion to the neck produces a prompt and profound suppression of plasma renin activity and plasma aldosterone concentration without concomitant alteration of plasma composition, immersion afforded a unique opportunity to assess simultaneously the effects of central hypervolaemia on plasma renin activity, plasma aldosterone concentration and prostaglandin E excretion. 2. Seven normal subjects were studied twice while in balance on a diet containing 10 mmol of sodium/day, 100 mmol of potassium/day: with indomethacin administration (50 mg given every 6 h for five doses) and without indomethacin. Urinary prostaglandin E excretion was measured hourly and plasma renin activity and plasma aldosterone concentration at 30 min intervals. 3. Immersion was associated with a marked suppression of plasma renin activity (59 ± 7%) and plasma aldosterone concentration (55 ± 3%) with a return to pre-study values during the recovery hour. Concomitantly, urinary prostaglandin E excretion increased from 4.7 to a peak of 10.9 ng/min. Although administration of indomethacin lowered the basal rate of urinary prostaglandin E excretion and plasma renin activity, it did not prevent the subsequent augmentation of urinary prostaglandin E or the suppression of plasma renin activity and plasma aldosterone during the subsequent 4 h of immersion. 4. These results demonstrate a dissociation of renin-aldosterone and prostaglandin E during hypervolaemia and suggest that whereas prostaglandin E may constitute one of the major determinants of renin release clinically and experimentally, these two hormonal systems can be dissociated from each other in response to central volume expansion in man.


1981 ◽  
Vol 60 (4) ◽  
pp. 399-404 ◽  
Author(s):  
C. J. Mathias ◽  
H. L. Frankel ◽  
I. B. Davies ◽  
V. H. T. James ◽  
W. S. Peart

1. The effect of endogenous sympathetic stimulation (induced by urinary bladder stimulation) and intravenous infusion of noradrenaline and isoprenaline on blood pressure, heart rate and levels of plasma renin activity and plasma aldosterone were studied in six tetraplegic patients. Data from infusion studies were compared with data from six normal subjects studied in an identical manner. 2. Bladder stimulation in the tetraplegic patients caused a marked rise in blood pressure and fall in heart rate, but no change in plasma renin activity or plasma aldosterone. 3. Noradrenaline infusion resulted in an enhanced pressor response in the tetraplegic patients when compared with the normal subjects. Heart rate fell in both groups. Plasma renin activity and plasma aldosterone did not change in either group. 4. Isoprenaline infusion caused a fall in both systolic and diastolic blood pressure in the tetraplegic patients, unlike the normal subjects in whom there was a rise in systolic and a fall in diastolic blood pressure. Heart rate and plasma renin activity rose in both groups. Plasma aldosterone did not change in either group. 5. We conclude that in tetraplegic patients neither endogenous sympathetic stimulation by bladder stimulation nor infusion of noradrenaline raises plasma renin activity. Isoprenaline increases plasma renin activity to the same extent as in normal subjects. Renin release mechanisms in tetraplegic patients therefore do not appear to be hypersensitive to catecholamines. Plasma aldosterone is not influenced by any of the stimuli.


1993 ◽  
Vol 85 (4) ◽  
pp. 465-470 ◽  
Author(s):  
M. Sutters ◽  
D. J. S. Carmichael ◽  
S. L. Lightman ◽  
W. S. Peart

1. A diuresis occurs within the first 36 h of salt restriction. A decline in plasma arginine vasopressin concentration may contribute to both the diuresis and antinatriuresis. 2. We have studied six normal human subjects during 36 h of dietary sodium restriction. In one study subjects received an intravenous infusion of D-glucose, and in the other an infusion of arginine vasopressin (6 fmol min−1 kg−1). 3. In the D-glucose phase plasma arginine vasopressin concentration fell (1.77 +034 to 1.02 +0.13 pg/ml), urine flow increased (67.9 +113 to 89.8 + 17.1 ml/h), haemoconcentration occurred (packed cell volume 40.8 +0.3 to 42.8 +03%, protein concentration 71.6 +03 to 74.5 + 0.6 g/l), plasma sodium concentration fell (140 +0.2 to 138 +0.2 mmol/l) and plasma renin activity increased (1600+153 to 3700 + 356 pg of angiotensin I h−1 ml−1). 4. In the arginine vasopressin phase plasma arginine vasopressin concentration remained constant (13 + 0.13 to 134 +0.11 pg/ml), the diuresis was reversed (65.7 +9.9 to 52.1 +8.9 ml/h), plasma sodium concentration fell further (139.8 +0.4 to 136.1 +0.4 mmol/l), the rise in plasma renin activity was reduced (arginine vasopressin 2552 + 292; D-glucose, 3700 + 356 pg of angiotensin I h−1 ml−1) and creatinine clearance was lower in the last 12 h of salt restriction (arginine vasopressin, 96.1 +6.9; D-glucose 116.5 + 6.8 ml/min). Renal sodium excretion was unaffected by arginine vasopressin infusion. 5. We conclude that the fall in plasma arginine vasopressin concentration during dietary salt restriction, whilst not affecting renal sodium excretion, may be important in the regulation of plasma sodium concentration, plasma renin activity and glomerular filtration.


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