EFFECT OF PROSTAGLANDIN SYNTHETASE INHIBITORS ON RENIN AND ALDOSTERONE IN MAN ON A NORMAL OR LOW SODIUM DIET

1978 ◽  
Vol 87 (3) ◽  
pp. 577-588 ◽  
Author(s):  
G. Norbiato ◽  
M. Bevilacqua ◽  
U. Raggi ◽  
P. Micossi ◽  
C. Moroni ◽  
...  

ABSTRACT The effect of two inhibitors of prostaglandin synthetase activity (acetylsalicylic acid (ASA) and diclofenac sodium (DCFS)) on plasma renin activity (PRA) and plasma aldosterone (PA) was studied in normal subjects kept on a diet with constant sodium and potassium intake or on a low-salt diet for 7 days. In 9 subjects, 2 days of treatment with ASA (3 g/day) was followed by a significant decrease of PA in the supine position (after overnight rest); there was no significant decrease of PRA. However, both PA and PRA with the subjects in the upright position were significantly reduced after ASA. In 9 subjects treated with DCFS (200 mg for 2 days), both PA and PRA with the subjects in the supine and upright positions decreased significantly. Similar results were obtained from 4 subjects on a low-sodium diet (15–30 mEq./day) treated with DCFS (150 mg/day for 3 days). In contrast, no significant changes in PA or PRA with the subjects in the supine or upright position were observed in 4 subjects on a very low sodium diet (< 15 mEq./day) treated with DCFS (150 mg/day for 3 days). Covariance analysis (with PRA as independent variable and PA as dependent variable) of the data obtained in the upright position before and after treatment with ASA or DCFS showed that the decrease in PA remained significant after adjustment for the PRA effect. These results suggest a direct effect of prostaglandins on PA. The data obtained from subjects on a low sodium diet indicate that sodium deprivation may counteract the effects of DCFS on PRA and PA.

1987 ◽  
Vol 253 (1) ◽  
pp. R179-R185
Author(s):  
E. Gotoh ◽  
K. Murakami ◽  
T. D. Bahnson ◽  
W. F. Ganong

To investigate the role of brain serotonergic neurons in the regulation of renin secretion, we measured changes in plasma renin activity (PRA), and, in some instances, plasma renin concentration (PRC), plasma angiotensinogen, and plasma adrenocorticotropic hormone (ACTH) in rats with lesions of the dorsal raphe nucleus and lesions of the paraventricular nuclei, dorsomedial nuclei, and ventromedial nuclei of the hypothalamus. We also investigated the effects of p-chloroamphetamine (PCA), immobilization, head-up tilt, and a low-sodium diet in the rats with dorsal raphe, paraventricular, and dorsomedial lesions. Lesions of the dorsal raphe nucleus abolished the increase in PRA produced by PCA but had no effect on the increase produced by immobilization, head-up tilt, and a low-sodium diet. Paraventricular lesions, which abolish the increase in plasma ACTH produced by PCA, immobilization, and head-up tilt, decreased plasma angiotensinogen. The paraventricular lesions abolished the PRA and the PRC responses to PCA and the PRA but not PRC response to immobilization, head-up tilt, and a low-sodium diet. The ventromedial lesions abolished the PRA and PRC responses to PCA and did not reduce plasma angiotensinogen. The data suggest that paraventricular lesions depress angiotensinogen production by the liver and that the paraventricular and ventromedial nuclei are part of the pathway by which serotonergic discharges increase renin secretion. They also suggest that the serotonergic pathway does mediate the increases in renin secretion produced by immobilization, head-up tilt, and a low-sodium diet.


1978 ◽  
Vol 234 (4) ◽  
pp. H447-H453
Author(s):  
H. Munoz-Ramirez ◽  
M. C. Khosla ◽  
F. M. Bumpus ◽  
P. A. Khairallah

Under inactin anesthesia, intravenous infusion of [Sar1,Thr8]angiotensin II produced a hypotensive effect in young spontaneously hypertensive rats (SHR) treated with furosemide and in mature SH rats fed a low-sodium diet. The angiotensin antagonist also lowered blood pressure of young and mature SH rats receiving a normal diet. Deoxycorticosterone acetate (DOCA) plus saline reversed the hypotensive effect of [Saru,Thr8]angiotensin II in young SH rats, but did not do so in mature SH rats. Plasma renin activity (PRA) was not significantly changed by anesthesia. Furosemide or the low-sodium diet significantly increased PRA in young and mature SH rats. In contrast, DOCA plus saline significantly reduced PRA in both young and mature SH rats. However, there was no correlation between PRA and the action of the angiotensin II antagonist. These data suggest that the renin-angiotensin system is involved in genetic hypertension.


1980 ◽  
Vol 238 (6) ◽  
pp. H889-H894 ◽  
Author(s):  
H. Munoz-Ramirez ◽  
R. E. Chatelain ◽  
F. M. Bumpus ◽  
P. A. Khairallah

In Sprague-Dawley rats with unilateral renal artery stenosis and an intact contralateral kidney, administration of a low-sodium diet did not prevent the development of hypertension. Despite an elevated blood pressure, hyponatremia, marked activation of the renin-angiotensin system, and increased hematocrit values, only 10% of the rats showed lesions of malignant hypertension. Systolic blood pressures of one- and two-kidney sham-operated rats fed a low-sodium diet were significantly higher than that of normotensive controls fed a normal diet. Uninephrectomy did not reduce plasma renin activity. The low-sodium diet increased plasma renin activity to about the same level in one- and two-kidney normotensive rats. However, the increase in plasma renin activity elicited by dietary sodium restriction was markedly less in one-kidney Goldblatt hypertension. Systolic blood pressure reached similar levels in one- and two-kidney Goldblatt hypertensive rats fed a low-sodium diet. These data indicate that a decrease in sodium intake does not prevent the development of two-kidney Goldblatt hypertension.


1980 ◽  
Vol 59 (s6) ◽  
pp. 149s-151s ◽  
Author(s):  
C. M. Taquini ◽  
A. Gallo ◽  
N. Basso ◽  
A. C. Taquini

1. Rats on normal sodium diet (group 1) and on chronically maintained low sodium diet (group 2) were studied during a control period, after clipping the renal artery (two-kidney, one-clip hypertension) and after nephrectomy (one-kidney, one-clip hypertension). 2. The low sodium diet neither prevented the development nor changed the severity of two-kidney, one-clip hypertension, and the latter was not accompanied by an increase in plasma renin activity. 3. After nephrectomy arterial pressure further increased and plasma renin activity decreased in group 1, and both remained unchanged in group 2. 4. Blood volume was the same in both groups 10 days before and 10 days after nephrectomy. 5. Sodium does not seem to be ‘necessary’ in the two-kidney, one-clip hypertension although it may play an enhancing role in the one-kidney model.


2008 ◽  
Vol 114 (3) ◽  
pp. 221-230 ◽  
Author(s):  
Salvatore Paterna ◽  
Parrinello Gaspare ◽  
Sergio Fasullo ◽  
Filippo M. Sarullo ◽  
Pietro Di Pasquale

The aim of the present study was to evaluate the effects of a normal-sodium (120 mmol sodium) diet compared with a low-sodium diet (80 mmol sodium) on readmissions for CHF (congestive heart failure) during 180 days of follow-up in compensated patients with CHF. A total of 232 compensated CHF patients (88 female and 144 male; New York Heart Association class II–IV; 55–83 years of age, ejection fraction <35% and serum creatinine <2 mg/dl) were randomized into two groups: group 1 contained 118 patients (45 females and 73 males) receiving a normal-sodium diet plus oral furosemide [250–500 mg, b.i.d. (twice a day)]; and group 2 contained 114 patients (43 females and 71 males) receiving a low-sodium diet plus oral furosemide (250–500 mg, b.i.d.). The treatment was given at 30 days after discharge and for 180 days, in association with a fluid intake of 1000 ml per day. Signs of CHF, body weight, blood pressure, heart rate, laboratory parameters, ECG, echocardiogram, levels of BNP (brain natriuretic peptide) and aldosterone levels, and PRA (plasma renin activity) were examined at baseline (30 days after discharge) and after 180 days. The normal-sodium group had a significant reduction (P<0.05) in readmissions. BNP values were lower in the normal-sodium group compared with the low sodium group (685±255 compared with 425±125 pg/ml respectively; P<0.0001). Significant (P<0.0001) increases in aldosterone and PRA were observed in the low-sodium group during follow-up, whereas the normal-sodium group had a small significant reduction (P=0.039) in aldosterone levels and no significant difference in PRA. After 180 days of follow-up, aldosterone levels and PRA were significantly (P<0.0001) higher in the low-sodium group. The normal-sodium group had a lower incidence of rehospitalization during follow-up and a significant decrease in plasma BNP and aldosterone levels, and PRA. The results of the present study show that a normal-sodium diet improves outcome, and sodium depletion has detrimental renal and neurohormonal effects with worse clinical outcome in compensated CHF patients. Further studies are required to determine if this is due to a high dose of diuretic or the low-sodium diet.


1984 ◽  
Vol 66 (3) ◽  
pp. 269-276 ◽  
Author(s):  
M. H. De Keijzer ◽  
A. P. Provoost ◽  
E. D. Wolff ◽  
W. J. Kort ◽  
I. M. Weijma ◽  
...  

1. In an experimental model of post-renal transplantation hypertension in rats, we studied the effect of a reduction of sodium intake on the development of this type of hypertension. 2. Systolic blood pressure, plasma- renin concentration and renal function were measured regularly in recipients of an allogeneic kidney transplant that had previously undergone active immunological enhancement. 3. Transplant recipients on a normal diet showed a rise in systolic blood pressure during the second week after transplantation. The systolic blood pressure of recipients on a low sodium diet remained normotensive throughout the 15 weeks follow-up period. 4. The plasma renin concentration was low in the hypertensive recipients on a normal diet, as compared with unilaterally nephrectomized controls. Although the plasma renin concentration of recipients on a low sodium diet fell below that of unilaterally nephrectomized controls on a low sodium diet, it was higher than that of recipients on a normal diet. 5. The renal function of transplant recipients was greatly reduced compared with that of control rats. The glomerular filtration rate was reduced to a greater extent than the effective renal plasma flow. 6. In a separate experiment it was revealed that a similar reduction in the glomerular filtration rate of kidneys permanently damaged by temporary ischaemia did not result in an increase in the systolic blood pressure. 7. Survival up to 6 weeks after transplantation was the same for both groups of recipients. Recipients on a low sodium diet, however, showed a better 15 weeks survival, probably owing to the absence of hypertension in this group. 8. The prevention of the development of hypertension by means of a reduction of sodium intake, points to an involvement of sodium retention in this post-transplantation hypertension model.


1968 ◽  
Vol 127 (3) ◽  
pp. 704-707 ◽  
Author(s):  
K. Otsuka ◽  
T. A. Assaykeen ◽  
W. F. Ganong ◽  
W. H. Tu

1981 ◽  
Vol 96 (3) ◽  
pp. 361-369 ◽  
Author(s):  
Cornelia Seifert ◽  
Wolfgang Oelkers

Abstract. Unknown pituitary factor(s) apart from ACTH may participate in the regulation of aldosterone (aldo) secretion in man. We investigated whether the 'sensitization' of the zona glomerulosa against angiotensin II (A II) by sodium deficiency was mediated by the pituitary gland. A II was infused in stepwise increasing doses (2, 4, 8 ng/kg/min) into 5 normal subjects (N) and into 8 patients with hypopituitarism (H) before and after 4 days on a low sodium diet. Mean cumulative sodium balance after the low sodium diet was − 145 mm in N and − 165mm in H. Plasma-aldo and aldo-exretion rate on the normal sodium diet were slightly lower in H than in N but rose less than normal during sodium depletion in H. Plasma A II and renin activity on normal sodium were slightly higher in H than in N, but the increase on the low sodium diet was blunted in H. The stimulation of plasmaaldo by A II infusion was similar in both groups on the normal sodium diet. In both groups, the response of P-aldo to A II infusion was greater in the sodium deplete than in the replete state, although 'sensitization' was slightly less marked in H than in N. This may be due to the blunted rise of plasma-A II after sodium loss in H, which may also account for abnormalities in the blood pressure response in the H group. Altogether, the results speak against a direct involvement of the pituitary gland in 'sensitization', but an indirect influence through unexplained abnormalities in renin secretion is possible.


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