Aldosterone regulates salivary sodium secretion in cattle

1986 ◽  
Vol 108 (3) ◽  
pp. 405-411 ◽  
Author(s):  
F. Riad ◽  
J. Lefaivre ◽  
C. Tournaire ◽  
J.-P. Barlet

ABSTRACT Intravenous infusion of aldosterone (10 μg/kg body wt per h for 5 h) in four 2-month-old calves decreased salivary and urinary sodium (Na+) concentration and increased salivary potassium (K+) concentration without modifying salivary flow or urinary K+ concentration. Intravenous angiotensin II infusion (0·3 μg/kg body wt per min for 1 h) in four Na+-replete 16-month-old bulls decreased salivary Na+ concentration and increased that of K+. It also increased plasma cortisol and plasma aldosterone concentrations, and decreased plasma renin activity (PRA). In four 16-month-old bulls Na+ deficiency (induced by chronic cannulation of the righ parotid duct and loss of saliva for 5 days) had similar effects to those observed following aldosterone infusion in calves: a decrease in salivary Na+/K+ ratio. This decrease was associated with an increase in PRA and an increase in plasma aldosterone concentration. In these animals a close positive relationship was observed between PRA and plasma aldosterone concentration (r = 0·91; n = 20; P < 0·01). Thus in cattle, during Na+ deficiency, the effect of aldosterone on parotid glands participates in the regulation of Na+ metabolism. J. Endocr. (1986) 108, 405–411

1977 ◽  
Vol 43 (3) ◽  
pp. 421-424 ◽  
Author(s):  
J. R. Sutton ◽  
G. W. Viol ◽  
G. W. Gray ◽  
M. McFadden ◽  
P. M. Keane

Responses of plasma renin activity, plasma aldosterone, plasma cortisol, and plasma electrolyte concentration and urinary electrolyte and aldosterone excretion were studied in four men during hypoxic decompression to a stimulated altitude of 4,760 m in a pressure chamber. Three of the four subjects developed significant acute mountain sickness. Plasma sodium and potassium concentrations were unchanged. No significant change in plasma renin activity was observed, but values tended to fall. Plasma aldosterone concentration was depressed while plasma cortisol was elevated and diurnal variation lost. Urinary sodium excretion was unchanged, but urinary potassium and aldosterone excretion were decreased. The decrease in plasma and urinary aldosterone and urinary potassium in the absence of change in plasma renin activity or plasma potassium is of uncertain origin. It is unlikely to be due to a decrease in adrenocorticotropin secretion since plasma cortisol rose during the same time. None of the changes could be causally implicated in the development of acute mountain sickness although the increase in plasma cortisol was greatest in the most ill.


1971 ◽  
Vol 16 (3) ◽  
pp. 183-196 ◽  
Author(s):  
J. I. S. Robertson ◽  
R. J. Weir ◽  
G. O. Düsterdieck ◽  
R. Fraser ◽  
M. Tree

Aldosterone secretion is frequently, although not invariably, increased above the normal non-pregnant range in normal pregnancy. Substantial increases in plasma aldosterone concentration have also been demonstrated as early as the sixteenth week. In pregnancy, aldosterone secretion rate responds in the usual way to changes in sodium intake. Plasma renin concentration is frequently, but not invariably, raised above the normal non-pregnant range. Plasma renin-substrate is consistently raised in pregnancy. Plasma angiotensin II has also been shown usually to be raised in a series of pregnant women. A significant positive correlation has been shown between the maternal plasma aldosterone concentration and the product of the concurrent plasma renin and renin-substrate concentrations. This suggests that the increased plasma aldosterone in pregnancy is the consequence of an increase in circulating angiotensin II, which in turn is related to the level of both renin and its substrate in maternal blood. For these reasons, estimations of renin activity in pregnancy are of dubious value. The increased renin, angiotensin and aldosterone concentrations may represent a tendency to maternal sodium depletion, probably mainly a consequence of the increased glomerular filtration rate. It is possible that the nausea and other symptoms of early pregnancy may be a consequence of this tendency to sodium depletion, with its attendant hormonal changes. In ‘pre-eclampsia’, renin and aldosterone values are generally slightly lower than in normal pregnancy. Human chorion can apparently synthesize renin independently of the kidney. The physiological significance of this remains at present obscure, but it seems unlikely that this source contributes much, if at all, to the often elevated maternal plasma renin. Plasma renin, renin-activity and angiotensin II concentrations, and aldosterone secretion are increased in the luteal phase of the menstrual cycle.


Hypertension ◽  
2020 ◽  
Vol 76 (2) ◽  
pp. 488-496 ◽  
Author(s):  
Zeng Guo ◽  
Marko Poglitsch ◽  
Diane Cowley ◽  
Oliver Domenig ◽  
Brett C. McWhinney ◽  
...  

The aldosterone/renin ratio (ARR) is currently considered the most reliable approach for case detection of primary aldosteronism (PA). ACE (Angiotensin-converting enzyme) inhibitors are known to raise renin and lower aldosterone levels, thereby causing false-negative ARR results. Because ACE inhibitors lower angiotensin II levels, we hypothesized that the aldosterone/equilibrium angiotensin II (eqAngII) ratio (AA2R) would remain elevated in PA. Receiver operating characteristic curve analysis involving 60 patients with PA and 40 patients without PA revealed that the AA2R was not inferior to the ARR in screening for PA. When using liquid chromatography-tandem mass spectrometry to measure plasma aldosterone concentration, the predicted optimal AA2R cutoff for PA screening was 8.3 (pmol/L)/(pmol/L). We then compared the diagnostic performance of the AA2R with the ARR among 25 patients with PA administered ramipril (5 mg/day) for 2 weeks. Compared with basally, plasma levels of equilibrium angiotensin I (eqAngI) and direct renin concentration increased significantly ( P <0.01 or P <0.05) after ramipril treatment, whereas eqAngII and ACE activity (eqAngII/eqAngI) decreased significantly ( P <0.01). The changes of plasma renin activity and plasma aldosterone concentration in the current study were not significant. On day 14, 4 patients displayed false-negative results using ARR_direct renin concentration (plasma aldosterone concentration/direct renin concentration), 3 of whom also showed false-negative ARR_plasma renin activity (plasma aldosterone concentration/plasma renin activity). On day 15, 2 patients still demonstrated false-negative ARR_plasma renin activity, one of whom also showed a false-negative ARR_direct renin concentration. No false-negative AA2R results were observed on either day 14 or 15. In conclusion, compared with ARR which can be affected by ACE inhibitors causing false-negative screening results, the AA2R seems to be superior in detecting PA among subjects receiving ACE inhibitors.


1991 ◽  
Vol 124 (3) ◽  
pp. 267-270 ◽  
Author(s):  
Yo Kageyama ◽  
Hiromichi Suzuki ◽  
Takao Saruta

Abstract. Changes in plasma aldosterone, plasma renin activity, plasma cortisol, serum sodium and potassium concentrations were studied in 9 patients with thromboembolic diseases treated with heparin. Heparin was administered at doses of 700-1000 units/h for 7-10 days. Plasma aldosterone decreased from 239±33 to 114±25 pmol/l during heparin therapy and returned to basal levels after discontinuation of the therapy. In addition, responses to a low sodium intake (3 g/day) and ACTH were examined in 5 patients during and 2 weeks after heparin therapy. The increase in plasma aldosterone caused by low sodium intake was significantly attenuated during heparin therapy (124±5% increase from baseline) as compared with that 2 weeks after heparin therapy (148±7%, p<0.05). On the other hand, ACTH stimulated plasma aldosterone similarly during and at 2 weeks after heparin therapy (increase from baseline: 190±20% vs 193±9%). These results suggest that heparin decreased plasma aldosterone owing to attenuation of the angiotensin Il-induced aldosterone production.


1984 ◽  
Vol 246 (4) ◽  
pp. H608-H614 ◽  
Author(s):  
E. L. Schiffrin ◽  
J. Gutkowska ◽  
J. Genest

The effect of angiotensin II (ANG II) and deoxycorticosterone acetate (DOCA) on the density (Bmax) and affinity (Kd) of binding sites for 125I-ANG II was investigated in a particulate fraction prepared from rat mesenteric arteriolar arcades. Rats were infused with ANG II via Alzet osmotic minipumps at a dose of 200 ng X kg-1 X min-1 intraperitoneally or 60 and 200 ng X kg-1 X min-1 intravenously for 5 days. Bmax was 127 +/- 5 fmol/mg protein, and Kd was 0.8 +/- 0.1 nM in controls and was reduced significantly after the intraperitoneal infusion (111 +/- 10 fmol/mg) or the lower intravenous dose (111 +/- 9 fmol/mg), whereas after the higher intravenous dose Bmax did not change (144 +/- 14 fmol/mg). Kd was unaffected in all groups. Plasma renin activity (PRA) was reduced, and plasma ANG II increased in a dose-dependent fashion after ANG II infusion. Plasma aldosterone concentration increased only in the group infused with ANG II at 200 ng X kg-1 X min-1 intravenously (to 33.8 +/- 8.0 ng/dl from 11.6 +/- 3.4). In rats implanted subcutaneously with silicone rubber impregnated with DOCA, Bmax for 125I-ANG II was significantly increased (to 142 +/- 4 fmol/mg), whereas rats receiving 1% NaCl in their drinking water had no change in binding capacity, although PRA was lower in both groups. DOCA infusion, when combined with the intravenous dose of ANG II that reduced Bmax, antagonized this action of ANG II. DOCA infusion into sodium-depleted rats partially corrected the down-regulation of vascular ANG II receptors independent of changes in PRA.(ABSTRACT TRUNCATED AT 250 WORDS)


1984 ◽  
Vol 66 (4) ◽  
pp. 399-406 ◽  
Author(s):  
F. Broughton Pipkin ◽  
J. C. Hunter ◽  
S. R. Turner ◽  
P. M. S. O'Brien

1. The effects of angiotensin II infusion without and with simultaneous infusion of prostaglandin E2 were studied in 25 women in second trimester pregnancy. Twenty received one infusion of angiotensin II alone, followed by its infusion simultaneously with prostaglandin E2; five received two identical infusions of angiotensin II alone as controls. 2. Angiotensin II infusion alone was associated with suppression of plasma renin concentration to levels inversely proportional to the evoked change in diastolic blood pressure. Plasma renin substrate concentration was unchanged, but plasma aldosterone concentration rose markedly. This rise was inversely proportional to the threshold for pressor effect of angiotensin II. 3. Prostaglandin E2 administration alone was associated with increased plasma renin concentrations. 4. The pressor effect of angiotensin II was blunted when given together with prostaglandin E2 and plasma concentrations of angiotensin II reached were lower. 5. Plasma renin concentration was again suppressed during the joint infusion regimen; the degree of suppression was inversely proportional to the change in diastolic pressure. Plasma aldosterone concentration rose, but did not differ in the control and experimental groups. 6. Thus although the renin-angiotensin system is stimulated in normal pregnancy, the normal control mechanisms are still functional, and the capacity for further increases in activity exists.


1984 ◽  
Vol 247 (3) ◽  
pp. E336-E342
Author(s):  
T. Eguchi ◽  
E. L. Bravo

The mechanism(s) by which intracerebroventricularly administered angiotensin II (ANG II) regulates aldosterone production was investigated in dogs with chronically implanted cannula into a lateral cerebroventricle. In salt-replete and salt-depleted dogs, artificial cerebrospinal fluid (CSF) with or without ANG II (1, 10, 100 ng X kg-1 X min-1) was infused intracerebroventricularly for 2 h under pentobarbital anesthesia. Artificial CSF produced no significant humoral changes. Intracerebroventricular ANG II decreased plasma renin activity and increased both ACTH and plasma cortisol in both groups but decreased plasma aldosterone (PA) only in salt-depleted dogs. Dexamethasone pretreatment during intracerebroventricular ANG II decreased PA further in salt-replete but not in salt-depleted dogs. Moreover, the fall in PA during intracerebroventricular ANG II in salt-depleted dogs was prevented when intravenous infusion of ANG II (10 ng X kg-1 X min-1) was given simultaneously to maintain circulating ANG II levels. We conclude that PA response to intracerebroventricular ANG II is mediated primarily through the renin-angiotensin system in the salt-depleted state; however, in the salt-replete state, ACTH assumes a more important role.


1981 ◽  
Vol 61 (s7) ◽  
pp. 441s-444s ◽  
Author(s):  
J. Staessen ◽  
R. Fagard ◽  
P. Lijnen ◽  
L. J. Verschueren ◽  
A. Amery

1. With a double-blind cross-over protocol, 20 hypertensive captopril-treated patients were studied by adding in a variable sequence a placebo and propranolol (80 mg three times a day) to their captopril regimen (200 mg three times a day), during periods each lasting 1 month. During captopril—placebo treatment their diastolic blood pressure remained elevated between 90 and 114 mmHg. 2. The additional administration of propranolol produced a significant hypotensive effect, but no alterations of the plasma angiotensin II and aldosterone concentrations and of the urinary aldosterone excretion occurred. The present data indicate that in captopril-treated patients the hypotensive effect of propranolol is achieved independently of changes in the plasma angiotensin II and aldosterone concentration. 3. The additional administration of propranolol also produced an increase in the serum potassium levels in the absence of any change in the plasma aldosterone concentration or in the urinary aldosterone excretion.


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