Effect of feeding on renin-angiotensin-aldosterone system of the horse

1988 ◽  
Vol 254 (3) ◽  
pp. R524-R530 ◽  
Author(s):  
L. L. Clarke ◽  
V. K. Ganjam ◽  
B. Fichtenbaum ◽  
D. Hatfield ◽  
H. E. Garner
Keyword(s):  
Plasma Renin ◽  
Early Morning ◽  
Strenuous Exercise ◽  
Renin Angiotensin Aldosterone System ◽  
Renin Angiotensin ◽  
Dark Interval ◽  
Feeding Regimen ◽  
Multiple Feeding ◽  
Effect Of Feeding ◽  
Significant Diurnal Variation

The effect of feeding frequency and associated meal size on the renin-angiotensin-aldosterone system (RAAS) in seven horses was examined. A daily maintenance ration of hay-grain pellets was provided either as a multiple feeding regimen (MF), in which the ration was divided into six equal portions fed at 4-h intervals, or as a single large feeding (SF) given from 9 A.M. until 11 A.M. Plasma renin activity (PRA), aldosterone (PAC), cortisol (PCC), protein concentration (TP), packed cell volume (PCV), and serum sodium and potassium were measured serially. To prevent significant RAAS stimulation due to strenuous exercise or by assuming orthostatism after a period of recumbency, the horses were trained to stand in 1 X 4-m tie stalls during the experiments. Changes in Na intake were prevented by disallowing nonration salt sources. A 12:12 light-dark interval was maintained. During the MF experiment, only serum Na changed diurnally, with concentrations lowest in early morning and highest before midday. In contrast, during the SF experiment, PRA was increased at 0.5, 1.0, and 3.0 h and PAC was increased at 3.0, 5.0, and 7.0 h after onset of feeding (P less than 0.005). Increased TP and PCV suggested transient hypovolemia was responsible for renin release. Significant increases in Na and decreases in K occurred while eating; however, K increased postprandially to be coincident with aldosterone. Except for a transient increase during feeding in SF, PCC demonstrated a similar circadian rhythm in both experiments. It was concluded that 1) episodic feeding (SF) causes significant diurnal variation of the RAAS in the horse, and 2) spontaneous circadian activity of the RAAS cannot be demonstrated in this species during a steady-state feeding regimen (MF).

Independence of salt intake induced by calcium deprivation from the renin-angiotensin-aldosterone system

1993 ◽  
Vol 264 (3) ◽  
pp. R492-R499 ◽  
Author(s):  
M. G. Tordoff ◽  
D. M. Pilchak ◽  
R. L. Hughes
Keyword(s):  
Salt Intake ◽  
Plasma Renin ◽  
Calcium Deficiency ◽  
Plasma Aldosterone ◽  
Sodium Balance ◽  
Plasma Sodium ◽  
Receptor Blockade ◽  
Renin Angiotensin Aldosterone System ◽  
Angiotensin System ◽  
Renin Angiotensin

We investigated whether the elevated NaCl intake shown by calcium-deprived rats is mediated by the renin-angiotensin-aldosterone system. First, we looked for manifestations of altered renin-angiotensin-aldosterone system activity during the progression of calcium deficiency. There were no differences between control and calcium-deprived rats in plasma aldosterone concentrations, plasma renin activity, plasma sodium concentrations, sodium balance, or blood pressure. Second, we used selective pharmacological antagonists to examine whether disruption of the renin-aldosterone-angiotensin system influenced salt intake. Blockade of aldosterone receptors with spironolactone (25 mg.kg-1 x day-1 sc for 7 days) had no effect on NaCl intake of control or calcium-deprived rats. Angiotensin AT1 receptor blockade with losartan potassium (0.5-10 mg/kg orally) had no effect on NaCl intake of control or calcium-deprived rats but doses > 0.5 mg/kg decreased NaCl intake of adrenalectomized rats. Taken together, these findings indicate that the renin-angiotensin-aldosterone system does not mediate the increased NaCl intake produced by calcium deficiency. The appetite for salt produced by calcium deficiency involves a different physiological substrate from most other models of NaCl intake.

scholarly journals Effect of renal denervation on catecholamines and the renin–angiotensin–aldosterone system

2020 ◽  
Vol 21 (3) ◽  
pp. 147032032094309
Author(s):  
Lida Feyz ◽  
Sjoerd van den Berg ◽  
Robert Zietse ◽  
Isabella Kardys ◽  
Jorie Versmissen ◽  
...  
Keyword(s):  
Plasma Renin ◽  
Drug Regimen ◽  
Plasma Aldosterone ◽  
Renal Sympathetic Denervation ◽  
Renin Angiotensin Aldosterone System ◽  
Renin Angiotensin ◽  
Post Procedure ◽  
Endogenous Catecholamines ◽  
Significant Change ◽  
Renal Sympathetic

Introduction: The effect of renal sympathetic denervation (RDN) on neurohormonal responses is largely unknown. We aimed to assess the effect of RDN on the renin–angiotensin–aldosterone system (RAAS) and endogenous catecholamines. Methods: A total of 60 patients with hypertension underwent RDN and remained on a stable antihypertensive drug regimen. Samples for plasma aldosterone, plasma renin and urine (nor)metanephrine were collected at baseline and at 6 months post procedure. Ambulatory blood pressure (BP) recordings were obtained at baseline and at 6 months post procedure. Results: Mean age was 64±9 years, and 30/60 patients were male. At 6 months, average daytime systolic and diastolic ambulatory BP decreased by 10 and 6 mmHg, respectively ( p<0.001). No significant change was observed in plasma aldosterone (median=248.0 pmol/L (interquartile range (IQR) 113.3–369.5 pmol/L) vs. median=233.0 pmol/L (IQR 110.3–360.8 pmol/L); p=0.66); renin (median=19.5 µIU/mL (IQR 6.8–119.5 µIU/mL) vs. median=14.3 µIU/mL (IQR 7.2–58.0 µIU/mL); p=0.32), urine metanephrine (median=0.46 µmol/L (IQR 0.24–0.77 µmol/L) vs. median=0.46 µmol/L (IQR 0.22–0.88 µmol/L); p=0.75) and normetanephrine (median=1.41 µmol/L (IQR 0.93–2.00 µmol/L vs. median =1.56 (IQR 0.74–2.50 µmol/L); p=0.58) between baseline and 6 months, respectively. No correlation was found between the decrease in mean systolic daytime BP and changes in RAAS hormones or endogenous catecholamines. Conclusion: Despite significant reductions in ambulatory BP, RDN did not result in a significant change in endogenous catecholamines or in RAAS hormones at 6 months.

Acromegaly and hypertension: role of the renin-angiotensin-aldosterone system

1982 ◽  
Vol 100 (4) ◽  
pp. 581-587 ◽  
Author(s):  
Bengt E. Karlberg ◽  
Anna-Maria Ottosson
Keyword(s):  
Blood Pressure ◽  
High Frequency ◽  
Plasma Renin ◽  
Plasma Aldosterone ◽  
Substantial Part ◽  
Volume Factor ◽  
Renin Angiotensin Aldosterone System ◽  
Renin Angiotensin ◽  
Before And After

Abstract. The incidence of arterial hypertension was evaluated in a partly retrospective study of patients with active acromegaly. Of 37 patients studied, 18 (48%) had hypertension, i.e. a supine blood pressure of > 160/95 mmHg. The type of hypertension was explored further by measuring plasma renin activity and, in some patients plasma aldosterone concentrations before and after stimulation (upright posture or furosemide 80 mg given orally). Urinary 24 h excretion of aldosterone was also determined. About half of the patients with hypertension but also a substantial part of normotensive acromegalics had inappropriately low plasma renin levels both during basal conditions and after stimulation. On the other hand urinary aldosterone excretion was either normal or (in 2 patients) slightly elevated. There was no other evidence of coexistent primary aldosteronism. Our results confirm previous reports of a high frequency of alterations in the renin-angiotensin-aldosterone system in acromegalic patients with growth hormone excess which in some instances may lead to an elevated blood pressure. The biochemical changes have many similarities to low renin essential hypertension. A volume factor may be operating in acromegalic patients with hypertension since in 10 patients treatment with the aldosterone antagonist, spironolactone, with doses between 50–200 mg daily lowered blood pressure to near normal levels. Thus, spironolactone seems to be a worthwhile alternative in the treatment of hypertensive acromegalics.

scholarly journals The Influence of Long Term Hydrochlorothiazide Administration on the Relationship between Renin-Angiotensin-Aldosterone System Activity and Plasma Glucose in Patients with Hypertension

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Xu Xiao ◽  
Hong-jun Du ◽  
Wei-jian Hu ◽  
Peter X. Shaw
Keyword(s):  
Plasma Glucose ◽  
Density Lipoprotein ◽  
Plasma Renin ◽  
Ang Ii ◽  
Elevated Plasma ◽  
Renin Angiotensin Aldosterone System ◽  
Renin Angiotensin ◽  
Glucose Levels ◽  
One Year ◽  
The Relationship

Objective. To observe the relationship between changes in renin-angiotensin-aldosterone system (RAAS) activity and blood plasma glucose after administration of hydrochlorothiazide (HCTZ) for one year in patients with hypertension.Methods. 108 hypertensive patients were given 12.5 mg HCTZ per day for one year. RAAS activity, plasma glucose levels, and other biochemical parameters, as well as plasma oxidized low density lipoprotein (oxLDL) levels, were measured and analyzed at baseline, six weeks, and one year after treatment.Results. After one year of treatment, the reduction in plasma glucose observed between the elevated plasma renin activity (PRA) group (-0.26±0.26 mmol/L) and the nonelevated PRA group (-1.36±0.23 mmol/L) was statistically significant (P<0.05). The decrease of plasma glucose in the elevated Ang II group (-0.17±0.18 mmol/L) compared to the nonelevated Ang II group (-1.07±0.21 mmol/L) was statistically significant (P<0.05). The proportion of patients with elevated plasma glucose in the elevated Ang II group (40.5%) was significantly higher than those in the nonelevated Ang II group (16.3%) (P<0.05). The relative oxLDL level was not affected by the treatment.Conclusions. Changes in RAAS activity were correlated with changes in plasma glucose levels after one year of HCTZ therapy.

Inhibition of the Renin-Angiotensin-Aldosterone System by l-Dopa with and without Inhibition of Extracerebral Dopa Decarboxylase in Man

1981 ◽  
Vol 61 (2) ◽  
pp. 187-190 ◽  
Author(s):  
C. Barbieri ◽  
R. Caldara ◽  
C. Ferrari ◽  
Rosa Maria Crossignani ◽  
M. Recchia
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Plasma Aldosterone ◽  
Renin Angiotensin Aldosterone System ◽  
Plasma Aldosterone Concentration ◽  
Renin Angiotensin ◽  
Drugs Analysis ◽  
Catecholamine Levels

1. The present study was undertaken to investigate the possibility that central nervous system mono-aminergic pathways may play a role in the control of the renin-angiotensin-aldosterone system in man. 2. Eight normal subjects received in a randomized order placebo, l-dopa (500 mg, orally) and l-dopa (100 mg, orally) plus carbidopa (35 mg, orally) after pretreatment with carbidopa (50 mg every 6 h for four doses). 3. l-Dopa administration elicited a significant fall in plasma renin activity (PRA) (P < 0.01 at 120, 150 and 180 min) and in plasma aldosterone levels (P < 0.05 at 90, 120, 150 and 180 min); L-dopa plus carbidopa induced a decrease in PRA (P < 0.05 at 120 and 150 min, P < 0.01 at 180 min) and in plasma aldosterone concentration (P < 0.05 at 30 and 60 min, P < 0.01 at 90 and 120 min), in comparison with placebo administration; between-drugs analysis revealed no difference in the decreases in PRA and plasma aldosterone levels induced by the two regimens. 4. Since l-dopa, as well as l-dopa plus carbidopa, has been shown to augment catecholamine levels in the brain of various animal species, the present data suggest that in man PRA and plasma aldosterone concentration might be inhibited by increased central nervous system catecholamine levels.

scholarly journals RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM IN PATIENTS WITH ABDOMINAL OBESITY AND ARTERIAL HYPERTENSION

2013 ◽  
Vol 19 (5) ◽  
pp. 389-396 ◽  
Author(s):  
E. A. Bazhenova ◽  
O. D. Belyaeva ◽  
A. V. Berezina ◽  
T. L. Karonova ◽  
D. A. Kolodina ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Plasma Renin ◽  
Plasma Aldosterone ◽  
Obese Patients ◽  
Renin Angiotensin Aldosterone System ◽  
Plasma Aldosterone Concentration ◽  
Renin Angiotensin ◽  
Primary Disorder ◽  
Per Se ◽  
Design And Methods

Objective. The activity of renin-angiotensin-aldosterone system (RAAS) is increased in patients with ab-dominal obesity (AO). However, till present time it is unclear whether RAAS activation or hypertension (HTN) found in 50 % patients is the primary disorder.Design and methods. We have studied plasma renin activity (PRA), plasma aldosterone concentration (PAC), their ratio PAC/PRA in patients with AO and related HTN and in subjects without AO.Results. PRA was higher in patients with AO versus people without obesity (2,5 ± 0,2 and 1,7 ± 0,7 ng/ml/hr, p = 0,013), there was a tendency to the reduction of the ratio PAC/PRA in obese patients (14,6 ± 0,9 and 19,7 ± 3,3, p = 0,08). In the subgroup of patients with AO and HTN the PRA was higher, and the ratio PAC/PRA was lower than in obese patients without HTN (PRA: 3,3 ± 0,4 and 1,7±0,2 ng/ml/hr, p = 0,005; PAC/PRA: 11,4 ± 1,1 and 17,4 ± 1,4, p < 0,0001). PRA and systolic blood pressure positively correlated. In patients with morbid obesity (3 degree according to the WHO classiication) obesity may play a signiicant role in the increase of RAAS activity, especially in the absence of concomitant HTN. The ratio PAC/PRA in over weight patients with AO was higher than in patients with AO and body mass index ? 30,0 kg/m (17,2 ± 1,7 and 12,5 ± 1,0 kg/m, p = 0,04). PRA was higher only in patients with AO and co-existing hypertension (3,4 ± 0,7 and 1,1 ± 0,2 ng/ml/hr, p = 0,04).Conclusions. RAAS activity is increased in patients with AO, also due to the co-existing HTN. However, in the absence of elevated blood pressure obesity per se may play a signiicant role in RAAS hyperactivity.

scholarly journals Renin-Angiotensin-Aldosterone System peptide profiles in patients with COVID-19

2021 ◽  
Author(s):  
Alexander Kutz ◽  
Anna Conen ◽  
Claudia Gregoriano ◽  
Sebastian Haubitz ◽  
Daniel Koch ◽  
...  
Keyword(s):  
Respiratory Infections ◽  
Tertiary Care ◽  
Plasma Renin ◽  
Adverse Outcomes ◽  
Care Hospital ◽  
Renin Angiotensin Aldosterone System ◽  
Peptide Profile ◽  
Renin Angiotensin ◽  
Subgroup Analyses ◽  
Raas Inhibitors

Objective While evidence on the interface between severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection and the renin-angiotensin-aldosterone-system (RAAS) is accumulating, clinical data on RAAS peptide alteration among coronavirus disease-19 (COVID-19) patients is missing. Design and Methods In this exploratory study, we prospectively included adult patients (aged ≥18 years) admitted between February 26 and April 30, 2020 to a tertiary care hospital in Switzerland. We assessed the association of an underlying SARS-CoV-2 infection and equilibrium serum levels of RAAS peptides in hospitalized COVID-19 patients 1:1 propensity-score matched with patients suffering from SARS-CoV-2-negative respiratory infections. Subgroup analyses involved stratification for taking RAAS inhibitors. Results COVID-19 patients had about 50% lower equilibrium serum RAAS peptide levels as compared with matched controls (angiotensin I: 31.6 vs. 66.8pmol/l, -52.7% [95%CI -68.5% to -36.9%]; angiotensin II: 37.7 vs. 92.5pmol/l, -59.2% [95%CI -72.1% to -46.3%]; angiotensin (1-5): 3.3 vs. 6.6pmol/l, -49.7% [95%CI -59.2% to -40.2%]; angiotensin (1-7): 4.8 vs. 7.6pmol/l, -64.9% [95%CI -84.5% to -45.3%]). While the plasma renin activity (PRA-S) was lower in COVID-19 patients (88.6 vs. 207.9pmol/l, -58.5% [95%CI -71.4% to -45.6%]), there was no difference of angiotensin-converting enzyme (ACE) and ACE2 plasma activity between the groups. Subgroup analyses revealed a pronounced RAAS peptide profile depression in COVID-19 patients among those not on RAAS inhibitors. Conclusions As compared with SARS-CoV-2-negative patients, we found a downregulated RAAS in presence of a SARS-CoV-2 infection. Whether the lower levels of the protective angiotensin (1-5) and (1-7) are linked to adverse outcomes in COVID-19 warrants further investigation.

Treatment of Renin-Angiotensin-Aldosterone System Dysfunction With Angiotensin II in High-Renin Septic Shock

2020 ◽  
pp. 108925322094907 ◽  
Author(s):  
Jonathan H. Chow ◽  
Marianne Wallis ◽  
Allison S. Lankford ◽  
Zackary Chancer ◽  
Rolf N. Barth ◽  
...  
Keyword(s):  
Septic Shock ◽  
Angiotensin Ii ◽  
Receptor Agonist ◽  
Case Series ◽  
Plasma Renin ◽  
Converting Enzyme ◽  
Renin Angiotensin Aldosterone System ◽  
Renin Angiotensin ◽  
Angiotensin Type

Endothelial dysfunction is common in septic shock and has been shown to impair angiotensin converting enzyme and the renin-angiotensin-aldosterone system (RAAS). Dysregulation of this pathway, which can be measured with plasma renin activity (PRA), is important not only because RAAS dysfunction is associated with increased mortality but also because treatment with angiotensin II (Ang-2) has been shown to decrease mortality. In this case series of 2 patients, serial PRA levels identified septic shock patients with RAAS dysfunction. The patients were treated with Ang-2, an angiotensin type 1 receptor agonist, which resulted in significant improvements in hemodynamics and PRA levels during treatment.

Response of Blood Pressure and the Renin—Angiotensin—Aldosterone System to Chronic Ambulatory Peritoneal Dialysis in Hypertensive End-Stage Renal Failure

1982 ◽  
Vol 63 (s8) ◽  
pp. 207s-209s ◽  
Author(s):  
Ph. Glasson ◽  
H. Favre ◽  
M. B. Vallotton
Keyword(s):  
Blood Pressure ◽  
Peritoneal Dialysis ◽  
Angiotensin Ii ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Renin Activity ◽  
Renin Angiotensin Aldosterone System ◽  
Renin Angiotensin ◽  
End Stage ◽  
Chronic Ambulatory Peritoneal Dialysis

1. Chronic ambulatory peritoneal dialysis allows good control of blood pressure in patients with hypertensive end-stage renal disease. The role of the renin-angiotensin-aldosterone system has therefore been studied in seven patients during the first 6 months of chronic ambulatory peritoneal dialysis treatment. 2. Steady increases in plasma renin activity and aldosterone were observed with a good correlation between these two variables. Plasma electrolytes, renin substrate and body weight did not change significantly. 3. Angiotensin II perfusion tests, performed at the end of the study, showed a relative vascular resistance to angiotensin II. 4. Stimulation of the renin-angiotensin-aldosterone system may be partially explained by this last observation or by removal of an unknown vasopressor substance responsible for the inhibition of the plasma renin activity.

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