Alteration of renal baroreceptor by salt intake in control of plasma renin activity in conscious dogs

1983 ◽  
Vol 245 (1) ◽  
pp. F119-F122 ◽  
Author(s):  
E. R. Farhi ◽  
J. R. Cant ◽  
A. C. Barger
Keyword(s):  
Plasma Renin Activity ◽  
Salt Intake ◽  
Plasma Renin ◽  
Renin Activity ◽  
Conscious Dogs ◽  
Salt Diet ◽  
Absolute Value ◽  
Inflatable Cuff ◽  
Low Salt ◽  
The Relationship

We investigated the relationship between renal arterial pressure (RAP) and systemic plasma renin activity (PRA) in five uninephrectomized conscious dogs on normal salt (80 meq Na+/day) and low salt (10 meq Na+/day) diets. The RAP was controlled by an inflatable cuff placed around the origin of the renal artery. In both salt states the PRA was an exponential function of the RAP: log (PRA) = (-0.026 X RAP) + 2 on the normal salt diet (r = 0.96) and log (PRA) = (-0.026 X RAP) + 2.5 on the low salt diet (r = 0.99). At any RAP, the value of the low salt PRA was 3 times that of the normal salt PRA. Accordingly, a reduction in salt intake increases the sensitivity of the renal baroreceptor so that the absolute value of PRA increases at any RAP, but the percentage change in PRA caused by any change in RAP is the same in both normal and low salt states.

scholarly journals Role of prostanoids in regulation of the renin-angiotensin-aldosterone system by salt intake

2002 ◽  
Vol 283 (2) ◽  
pp. F294-F301 ◽  
Author(s):  
Klaus Höcherl ◽  
Martin C. Kammerl ◽  
Karl Schumacher ◽  
Dirk Endemann ◽  
Horst F. Grobecker ◽  
...  
Keyword(s):  
Plasma Renin Activity ◽  
Salt Intake ◽  
Plasma Renin ◽  
Plasma Aldosterone ◽  
Renin Activity ◽  
Plasma Aldosterone Concentration ◽  
Low Salt ◽  
Renin Mrna ◽  
Cox 2 ◽  
Cox 1

We investigated the effect of cyclooxygenase (COX) activity on the regulation of the renin-angiotensin-aldosterone system by salt intake. Therefore, Sprague-Dawley rats were subjected to different salt diets [0.02, 0.6, and 8% NaCl (wt/wt)] and treated with the selective COX-2 inhibitor rofecoxib (10 mg · kg body wt−1 · day−1) or with ketorolac at a dose selective for COX-1 inhibition (2 mg · kg body wt−1 · day−1) for 3, 7, 14, and 21 days. Rofecoxib and ketorolac caused a similar reduction of renocortical PGE2 formation with a low-salt diet. Rofecoxib did not change plasma renin activity or renocortical renin mRNA abundance with any of the diets but clearly lowered plasma aldosterone concentration. In contrast, ketorolac delayed the increase in plasma renin activity and of renin mRNA in response to low salt intake but did not change plasma aldosterone concentration. Prolonged treatment with rofecoxib but not with ketorolac caused an upregulation of COX-2 expression while COX-1 mRNA abundance remained unchanged. These findings suggest that COX-1-derived, but not COX-2-derived, prostanoids are of relevance for the regulation of the renin system by salt intake.

Vasoactive intestinal peptide in the regulation of renin secretion

1985 ◽  
Vol 249 (1) ◽  
pp. F84-F89
Author(s):  
J. P. Porter ◽  
T. N. Thrasher ◽  
S. I. Said ◽  
W. F. Ganong
Keyword(s):  
Plasma Renin Activity ◽  
Vasoactive Intestinal Peptide ◽  
Plasma Levels ◽  
Plasma Renin ◽  
Renin Secretion ◽  
Renin Activity ◽  
Renal Nerves ◽  
Elevated Plasma ◽  
Salt Diet ◽  
Low Salt

We have previously shown that vasoactive intestinal peptide (VIP) is a renin-stimulating factor both in vivo and in vitro. In the present investigation we sought to determine whether VIP exerted this effect by a neural or humoral mechanism. To test for a neural effect, the renal nerves were stimulated on one side for 30 min in anesthetized dogs, and plasma VIP and renin levels were determined in the renal venous effluent. The stimulation significantly increased plasma renin activity in arterial and renal venous plasma but had no effect on VIP concentrations. A humoral action was tested in two ways. First, plasma renin activity was measured before and after elevating circulating levels of endogenously produced VIP using intravenous neostigmine (0.07 mg/kg) in control, renal-denervated, and propranolol-pretreated animals. In all three groups, the elevated plasma level of VIP was associated with a significant increase in plasma renin activity. Second, plasma levels of VIP were determined in conscious dogs with elevated plasma renin activity produced by either a low-salt diet or hemorrhage. In both cases, plasma renin activity was significantly elevated as expected, but plasma levels of VIP were unchanged. These data suggest that the effects of VIP on renin secretion are not mediated by release of the peptide from the renal nerves, the circulating level of endogenously produced VIP can be elevated sufficiently to stimulate renin secretion, but a humoral role of VIP in the elevated plasma renin activity produced by low-salt diet or hemorrhage seems unlikely.+

Control of plasma renin activity in heat-stressed baboons on varied salt intake

1987 ◽  
Vol 62 (4) ◽  
pp. 1531-1537 ◽  
Author(s):  
D. W. Proppe
Keyword(s):  
Heat Stress ◽  
Plasma Renin Activity ◽  
Salt Intake ◽  
Plasma Renin ◽  
Renin Activity ◽  
Beta Blockade ◽  
Angiotensin I ◽  
High Salt Intake ◽  
Low Salt ◽  
And Control

The characteristics and control of the increase in plasma renin activity (PRA) during environmental heating (EH) were determined in 12 unanesthetized, chronically catheterized baboons. Each EH experiment consisted of a 1.5- to 4-h exposure to an ambient temperature of 39–44 degrees C until core temperature (Tc) reached 39.5–40.0 degrees C. These EH experiments were done on the baboon in an unblocked state and during beta-adrenergic receptor blockade produced by propranolol when on normal-to-high salt intake (NHSI) and on low-salt intake (LSI). PRA rose linearly with Tc during EH, but the increase in PRA was considerably larger when the baboon was on LSI. The PRA-Tc linear regression coefficients were 2.32 and 5.98 ng angiotensin I X ml-1 X h-1 X degrees C-1 in NHSI and LSI states, respectively. This rise in PRA during EH was completely eliminated during beta-blockade in both NHSI and LSI states. It is concluded that heat stress activates the sympathetic nervous system to stimulate beta-receptor-mediated renin secretion by the kidney, this activation is controlled primarily by internal thermoreceptors, and variations in salt intake alters only the magnitude of the increase in PRA during heat stress, not the mechanisms that produce it.

VARIATIONS IN PLASMA RENIN ACTIVITY AND URINARY ALDOSTERONE EXCRETION IN NORMAL SUBJECTS AFTER SALT RESTRICTION AND ACUTE PITUITARY INHIBITION WITH 6-DEHYDRO-16-METHYLENE HYDROCORTISONE

1971 ◽  
Vol 67 (1) ◽  
pp. 159-173
Author(s):  
A. Peytremann ◽  
R. Veyrat ◽  
A. F. Muller
Keyword(s):  
Plasma Renin Activity ◽  
Salt Intake ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Inhibitory Effect ◽  
Renin Activity ◽  
Sodium Balance ◽  
Experimental Conditions ◽  
Salt Restriction ◽  
Aldosterone Production

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.

Plasma renin activity responses to graded decreases in renal perfusion pressure in fetal and newborn lambs

1992 ◽  
Vol 262 (3) ◽  
pp. R524-R529 ◽  
Author(s):  
N. D. Binder ◽  
D. F. Anderson
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Perfusion Pressure ◽  
Plasma Renin ◽  
Renal Perfusion ◽  
Renin Activity ◽  
Renal Perfusion Pressure ◽  
Arterial Blood ◽  
The Right ◽  
The Relationship

We examined the relationship between acute reductions in renal perfusion pressure, as approximated by femoral arterial blood pressure, and plasma renin activity in the uninephrectomized fetal lamb. Renal perfusion pressure was reduced and maintained at a constant value by controlled partial occlusion of the aorta above the renal artery. After 15 min of reduced blood pressure, blood samples were taken for determination of plasma renin activity. This protocol was performed 22 times in 11 fetal lambs. Additionally, three of the fetuses were delivered by cesarean section and studied as newborns for the first week of life. In the fetus, there was a linear relationship between log plasma renin activity and femoral arterial blood pressure (P less than 0.01). After birth, the relationship still existed, although it was shifted to the right (P less than 0.0001). We conclude that there is a significant relationship between plasma renin activity and renal perfusion pressure in the fetal lamb, and as early as 1 day after birth, this relationship shifts to the right in the newborn lamb.

Hypertension in Dahl salt-sensitive rats: biochemical and immunohistochemical studies

1992 ◽  
Vol 83 (1) ◽  
pp. 13-22 ◽  
Author(s):  
J. Bouhnik ◽  
J. P. Richoux ◽  
H. Huang ◽  
F. Savoie ◽  
T. Baussant ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
High Salt ◽  
Renin Activity ◽  
Deficient Diet ◽  
High Salt Diet ◽  
Salt Diet ◽  
Plasma Angiotensin

1. The renin-angiotensin and kinin-kallikrein systems of Dahl salt-sensitive and salt-resistant rats fed diets with different salt contents were analysed using biochemical and immunocytochemical techniques. 2. Blood pressure increased by 45% in salt-sensitive rats only, after 4 weeks on a high-salt diet. The plasma renin activity and plasma angiotensin II concentration remained at the same levels in salt-sensitive rats on the high-salt diet as on the normal salt diet, whereas the plasma renin activity and plasma angiotensin II concentration of salt-resistant rats fed the high-salt diet were lower. The plasma renin activity and the plasma angiotensin II concentration were elevated in both salt-resistant and salt-sensitive rats fed the salt-deficient diet but were much more elevated in salt-resistant than in salt-sensitive rats. 3. The kidney immunocytochemical data paralleled the data on plasma parameters. Salt-sensitive rats had fewer renin positive juxtaglomerular apparatuses than salt-resistant rats on the normal diet, and the increase on the sodium-deficient diet was also smaller in salt-sensitive rats. Salt-sensitive rats fed the high-salt diet and the standard diet had almost no angiotensin II immunoreactivity compared with the salt-resistant rats on the same diets. 4. The total renal kallikrein content of salt-sensitive rats was lower than that of salt-resistant rats on all three diets, as was the amount of kallikrein excreted in the urine on the standard and the high-salt diets. The differences resulted from a reduction in active kallikrein. The increase in kallikrein in salt-sensitive and salt-resistant rats on the salt-deficient diet was not significantly different. 5. There were similar changes in immunopositive kallikrein in the kidneys of salt-sensitive and salt-resistant rats with diet, with a large increase in kallikrein biosynthesis on the low-salt diet. The plasma concentration of high-molecular-mass kininogen was not significantly different in salt-sensitive and salt-resistant rats, but there was a significant increase in T-kininogen in salt-sensitive rats fed the high-salt diet. 6. In conclusion, the absence of decreases in the plasma renin activity and the plasma angiotensin II concentration in salt-sensitive rats fed the high-salt diet might partially explain the increase in blood pressure.

Plasma Renin Activity: A Method for Rapid Screening by Radioimmunoassay and a Comparison of Two Commercially Available Kits

1973 ◽  
Vol 19 (12) ◽  
pp. 1396-1399 ◽  
Author(s):  
Samuel D Goldberg ◽  
F W Spierto
Keyword(s):  
Myocardial Infarction ◽  
Essential Hypertension ◽  
Plasma Renin Activity ◽  
Salt Intake ◽  
Plasma Renin ◽  
Urinary Sodium Excretion ◽  
Renin Activity ◽  
Rapid Screening ◽  
Creatinine Ratio ◽  
Urine Specimens

Abstract Twenty to thirty percent of patients with essential hypertension have subnormal plasma renin activity (PRA) and lower incidences of stroke and myocardial infarction. NaCl intake influences PRA, which should thus be compared with 24-h urinary sodium excretion. Because such specimens are difficult to collect accurately, we investigated the relation between PRA and sodium in casual (i.e., untimed) urine specimens and found none. However, PRA and urinary Na/creatinine ratio are inversely correlated for casual specimens. This method is useful for screening individuals whose salt intake is low. Mean PRA, measured by the Schwarz-Mann procedure, was 0.62 ± 0.12 (SD) ng/ml per hour for 59 normotensive volunteers, 35% lower by the Squibb procedure.

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