Suppression of renin release by antagonism of endogenous opiates in the dog

1986 ◽  
Vol 250 (4) ◽  
pp. R633-R637
Author(s):  
J. E. Szilagyi ◽  
J. Chelly ◽  
M. F. Doursout
Keyword(s):  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Endogenous Opioids ◽  
Renin Activity ◽  
Renin Release ◽  
Endogenous Opioid ◽  
Endogenous Opiates ◽  
Arterial Blood ◽  
Before And After ◽  
Arterial Constriction

The influence of blockade of endogenous opioids on the release of renin due to partial renal arterial constriction was determined acutely and chronically in unilaterally nephrectomized dogs. In acute preparations changes in plasma renin activity, arterial blood pressure, and heart rate were determined after 15 min of 60% renal arterial constriction before and after administration of either a saline vehicle, the opiate antagonist naloxone (0.05 mg/kg), or morphine (2 mg/kg). Acute antagonism of endogenous opiates abolished the increase in plasma renin activity and mean arterial pressure associated with renal arterial constriction. Repeated renal arterial constrictions in saline- or morphine-treated animals did not alter the humoral or hemodynamic responses. In chronic preparations long-term naloxone infusion attenuated the development of renovascular hypertension and diminished the increase in plasma renin activity. These data suggest that endogenous opioid peptides are modulators in the control of renin release and may be important participants in the pathogenesis of hypertension.

α1-Adrenoceptor Blockade: Dissociation of Its Effects on Renin Release and Arterial Blood Pressure in Man

1981 ◽  
Vol 61 (s7) ◽  
pp. 307s-309s ◽  
Author(s):  
A. Morganti ◽  
Carla Sala ◽  
Anna Palermo ◽  
Lucia Turolo ◽  
A. Zanchetti
Keyword(s):  
Arterial Pressure ◽  
Plasma Renin Activity ◽  
Pressor Response ◽  
Plasma Renin ◽  
Test Dose ◽  
Blocking Agent ◽  
Renin Activity ◽  
Renin Release ◽  
Arterial Blood ◽  
Before And After

1. The possibility that the juxtaglomerular α1-adrenoceptors mediate an inhibitory action on renin release in man was examined in seven patients with essential hypertension, by measuring (i) the acute effects of prazosin (0.25 mg intravenously), a selective α1-adrenoceptor-blocking agent, on arterial pressure and plasma renin activity, the degree of α-blockade induced by the drug being assessed by comparing the pressor response with that to a test dose of phenylephrine before and after prazosin administration, and (ii) the increases in plasma renin activity in response to isoprenaline before and during the prazosin-induced α-blockade. 2. Twenty minutes after the infusion of prazosin, when the pressor response to phenylephrine was reduced by 80% with respect to control, (i) mean arterial pressure was practically unchanged, (ii) plasma renin activity was almost doubled and (iii) the increases in plasma renin activity in response to isoprenaline were significantly greater, both in absolute and percentage values, than those observed before prazosin. 3. The increments in baseline plasma renin activity induced by prazosin in the absence of decrease in arterial pressure and the enhancement in renin responsiveness to the β-adrenoceptor stimulus suggest that, in man, the juxtaglomerular α1-adrenoceptors exert a direct, suppressive action on renin release.

Enhancement of the Antihypertensive Effect of Hydrochlorothiazide in Dogs after Suppression of Renin Release by Beta-Adrenergic Blockade

1975 ◽  
Vol 48 (2) ◽  
pp. 147-151
Author(s):  
C. S. Sweet ◽  
M. Mandradjieff
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Arterial Blood Pressure ◽  
Antihypertensive Effect ◽  
Plasma Renin ◽  
Renin Activity ◽  
Renin Release ◽  
Antihypertensive Activity ◽  
Adrenergic Blockade ◽  
Arterial Blood

1. Renal hypertensive dogs were treated with hydrochlorothiazide (8−2 μmol/kg or 33 μmol/kg daily for 7 days), or timolol (4.6 μmol/kg daily for 4 days), a potent β-adrenergic blocking agent, or combinations of these drugs). Changes in mean arterial blood pressure and plasma renin activity were measured over the treatment period. 2. Neither drug significantly lowered arterial blood pressure when administered alone. Plasma renin activity, which did not change during treatment with timolol, was substantially elevated during treatment with hydrochlorothiazide. 3. When timolol was administered concomitantly with hydrochlorothiazide, plasma renin activity was suppressed and blood pressure was significantly lowered. 4. These observations suggest that compensatory activation of the renin-angiotensin system limits the antihypertensive activity of hydrochlorothiazide in renal hypertensive dogs and suppression of diuretic-induced renin release by timolol unmasks the antihypertensive effect of the diuretic.

The Role of Opioid Peptides in the Hormonal Responses to Acute Exercise in Man

1984 ◽  
Vol 67 (5) ◽  
pp. 483-491 ◽  
Author(s):  
A. Grossman ◽  
P. Bouloux ◽  
P. Price ◽  
P. L. Drury ◽  
K. S. L. Lam ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Plasma Renin Activity ◽  
Acute Exercise ◽  
Plasma Renin ◽  
Endogenous Opioids ◽  
Renin Activity ◽  
High Dose ◽  
Hormonal Responses ◽  
Physiological Variables ◽  
Severe Exercise

1. Opioid involvement in the physiological and hormonal responses to acute exercise was investigated in six normal male subjects. Each was exercised to 40% (mild exercise) and 80% (severe exercise) of his previously determined maximal oxygen consumption on two occasions, with and without an infusion of high-dose naloxone. The exercise task was a bicycle ergometer; mild and severe exercise were performed for 20 min each, followed by a recovery period. 2. Exercise produced the expected increases in heart rate, blood pressure, ventilation, tidal volume, respiratory rate, oxygen consumption and carbon dioxide production. After severe exercise, naloxone infusion increased ventilation from 94.8 ± 4.9 litres/min to 105.7 ± 5.0 litres/min (P<0.05), but had no effect on any of the other physiological variables. 3. Exercise-induced changes in several hormones and metabolites were noted, including elevations in circulating lactate, growth hormone (GH), prolactin, cortisol, luteinizing hormone (LH), follicle stimulating hormone (FSH), adrenaline, noradrenaline, plasma renin activity (PRA) and aldosterone. There was no change in plasma met-enkephalin. Naloxone infusion produced the expected increases in LH and cortisol, but also significantly enhanced the elevations in prolactin, adrenaline, noradrenaline, plasma renin activity and aldosterone (P<0.05). 4. Psychological questionnaires revealed minor mood changes after exercise, but no evidence was found for the suggested ‘high’ or euphoria of exercise. Effort was perceived as greater during the naloxone infusion than the saline infusion in every subject. 5. We conclude that endogenous opioids may be important in the control of ventilation and the perception of effort at high levels of power output, and may modulate the responses of circulating catecholamines and the renin-aldosterone system to acute physical stress.

Pharmacological and genetic evidence that cathepsin B is not the physiological activator of rodent prorenin

2010 ◽  
Vol 391 (12) ◽  
Author(s):  
M. David Percival ◽  
Sylvie Toulmond ◽  
Nathalie Coulombe ◽  
Wanda Cromlish ◽  
Sylvie Desmarais ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Cathepsin B ◽  
Plasma Renin ◽  
Renin Activity ◽  
Spontaneously Hypertensive ◽  
Protein Levels ◽  
Arterial Blood ◽  
Gene Compensation

Abstract Renin is the first enzyme in the renin-angiotensin-aldosterone system which is the principal regulator of blood pressure and hydroelectrolyte balance. Previous studies suggest that cathepsin B is the activator of the prorenin zymogen. Here, we show no difference in plasma renin activity, or mean arterial blood pressure between wild-type and cathepsin B knockout mice. To account for potential gene compensation, a potent, selective, reversible cathepsin B inhibitor was developed to determine the role of cathepsin B on prorenin processing in rats. Pharmacological inhibition of cathepsin B in spontaneously hypertensive and double transgenic rats did not result in a reduction in renal mature renin protein levels or plasma renin activity. We conclude that cathepsin B does not play a significant role in this process in rodents.

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.

Effects of blood viscosity on plasma renin activity and renal hemodynamics

1986 ◽  
Vol 250 (1) ◽  
pp. F40-F46 ◽  
Author(s):  
S. Simchon ◽  
R. Y. Chen ◽  
R. D. Carlin ◽  
F. C. Fan ◽  
K. M. Jan ◽  
...  
Keyword(s):  
Plasma Renin Activity ◽  
Blood Viscosity ◽  
Plasma Renin ◽  
Plasma Viscosity ◽  
Renal Hemodynamics ◽  
Renin Activity ◽  
Sodium Pentobarbital ◽  
Coefficient Of Correlation ◽  
Arterial Blood ◽  
Renal Vascular

The effects of alterations in apparent blood viscosity on renal hemodynamics and plasma renin activity (PRA) were studied in dogs anesthetized with sodium pentobarbital. Blood viscosity was altered isovolemically either by changes in hematocrit (Hct) or by an increase in plasma viscosity (dextran administration). Arterial blood pressure and renal blood flow (RBF) remained relatively constant when apparent blood viscosity was elevated by changes in Hct or plasma viscosity. Thus the hyperviscosity of blood was associated with a decrease of renal vascular hindrance, resulting in an essentially unchanged renal flow resistance. The decrease in renal vascular hindrance may result from renal vasodilation. In hyperviscosity induced with dextran, the increase in PRA correlates linearly with the decrease in renal vascular hindrance, with a coefficient of correlation of 0.968 (P less than 0.005). The increase in PRA that resulted when Hct was raised from 25 to 55% also can be correlated linearly with the decrease in renal vascular hindrance, with a coefficient of correlation of 0.953 (P less than 0.005). These results suggest that the decrease in renal vascular hindrance in response to a rise in apparent blood viscosity leads to an increase in PRA.

Hormonal responses to synthetic atrial natriuretic peptide in patients on regular hemodialysis

1988 ◽  
Vol 119 (2) ◽  
pp. 257-262 ◽  
Author(s):  
Sadao Nakajima ◽  
Hiromichi Suzuki ◽  
Yo Kageyama ◽  
Takashi Takita ◽  
Takao Saruta
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Arterial Blood Pressure ◽  
Mean Arterial Blood Pressure ◽  
Plasma Renin ◽  
Plasma Aldosterone ◽  
Renin Activity ◽  
Arterial Blood ◽  
Sympathetic Nervous ◽  
Regular Hemodialysis

Abstract. The effects of atrial natriuretic peptide (ANP) on mean arterial blood pressure, heart rate, plasma renin activity, aldosterone, cortisol, norepinephrine, epinephrine and arginine vasopressin were studied in 6 anuric subjects receiving regular hemodialysis. An iv bolus injection of 8 nmol of ANP followed by infusion at 32 pmol·kg−1·min−1 for 1 h in the pre- and posthemodialysis period was performed. Basal plasma ANP was higher before than after hemodialysis. ANP administration produced a reduction in mean arterial blood pressure accompanied by an elevation of norepinephrine and of plasma renin activity (from 2.49 ± 0.52 to 3.39 ± 0.85 nmol·l−1·h−1 predialysis and from 2.78 ± 0.71 to 3.15 ± 0.86 nmol·l−1·h−1 postdialysis, respectively, mean ± sem; P < 0.05). Plasma aldosterone and cortisol were significantly decreased. Plasma epinephrine and AVP remained unchanged. These hemodynamic and hormonal changes were similar in the pre- and the postdialysis period. These results suggest that 1) ANP causes a fall in mean arterial blood pressure, which in turn induces reflex tachycardia and activation of the sympathetic nervous system without diuresis; 2) the activated sympathetic nervous system as reflected in elevation of plasma norepinephrine may increase plasma renin activity; 3) reduced plasma aldosterone is not influenced by enhancement of the reninangiotensin system; therefore, 4) reduction of plasma aldosterone as well as cortisol is probably due to direct action of ANP, and finally 5) AVP had no direct relation with ANP administration.

Effects of indomethacin in dogs with acute and chronic renovascular hypertension

1981 ◽  
Vol 240 (4) ◽  
pp. H533-H538
Author(s):  
J. R. Dietz ◽  
J. O. Davis ◽  
J. M. DeForrest ◽  
R. H. Freeman ◽  
S. F. Echtenkamp ◽  
...  
Keyword(s):  
Plasma Renin Activity ◽  
Renovascular Hypertension ◽  
Acute Phase ◽  
Renal Plasma Flow ◽  
Plasma Renin ◽  
Renin Activity ◽  
Arterial Blood ◽  
Renal Prostaglandins ◽  
High Level ◽  
Vascular Receptor

This study examines the role that prostaglandins play in both the developmental and chronic phases of renovascular hypertension. Two 5-mg/kg doses of indomethacin were given to conscious dogs with renal denervation and receiving propranolol during the acute and chronic phases of one-kidney (1-KHT) and the acute phase of two-kidney (2-KHT) renovascular hypertension. Indomethacin produced striking reductions in plasma renin activity from the high level observed during the acute phase of both 1-KHT and 2-KHT. However, plasma renin activity failed to return to normal, and the hypertensive level of pressure decreased only slightly. In the chronic 1-KHT dogs, indomethacin did not lower plasma renin activity or mean arterial blood pressure unless plasma renin activity was elevated above the normal level. Also, indomethacin failed to alter renal function during the acute phase of 1-KHT but effective renal plasma flow fell during chronic 1-KHT. These results suggest that, in the dog, renal prostaglandins are involved in the pathogenesis of both acute 1-KHT and 2-KHT, whereas the role of renal prostaglandins in the regulation of arterial pressure appears to be negligible in chronic 1-KHT except during superimposed sodium depletion or severe hypertension. The data indicate that prostaglandins are involved in renovascular hypertension in the dog only under conditions where plasma renin activity is elevated. It is suggested that the release of renin after renal artery constriction is mediated by the vascular receptor that is at least partially independent of renal prostaglandin synthesis.

Human cardiovascular and humoral responses to moderate muscle activation during dynamic exercise

2000 ◽  
Vol 88 (1) ◽  
pp. 300-307 ◽  
Author(s):  
Takeshi Nishiyasu ◽  
Kei Nagashima ◽  
Ethan R. Nadel ◽  
Gary W. Mack
Keyword(s):  
Plasma Renin Activity ◽  
Arginine Vasopressin ◽  
Muscle Activation ◽  
Plasma Renin ◽  
Dynamic Exercise ◽  
Renin Activity ◽  
Positive Pressure ◽  
Muscle Metaboreflex ◽  
Arterial Blood ◽  
Ergometer Exercise

We examined the hypothesis that activation of the muscle metaboreflex during dynamic exercise would augment influences tending to cause a rise in arginine vasopressin, plasma renin activity, and catecholamines during dynamic exercise in humans. Ten healthy adults performed 30 min of supine cycle ergometer exercise at ∼50% of peak oxygen consumption with or without moderate muscle metaboreflex activation by application of 35 mmHg lower body positive pressure (LBPP). Application of LBPP during the first 15 or last 15 min of exercise increased mean arterial blood pressure, plasma lactate concentration, and minute ventilation, indicating an activation of the muscle metaboreflex. These changes were rapidly reversed when LBPP was removed. During exercise at this intensity, LBPP augmented the release of arginine vasopressin and catecholamines but not of plasma renin activity. These results suggest that, although in humans hormonal responses are induced by moderate activation of the muscle metaboreflex during dynamic exercise, the thresholds for these responses may not be uniform among the various glands and hormones.

The Effect of Mental Stress on Catecholamines, their Metabolites and Plasma Renin Activity in Patients with Essential Hypertension and in Healthy Subjects

1979 ◽  
Vol 57 (s5) ◽  
pp. 229s-231s ◽  
Author(s):  
W. Januszewicz ◽  
M. Sznajderman ◽  
B. Wocial ◽  
T. Feltynowski ◽  
T. Klonowicz
Keyword(s):  
Essential Hypertension ◽  
Plasma Renin Activity ◽  
Urinary Excretion ◽  
Mental Stress ◽  
Healthy Subjects ◽  
Plasma Renin ◽  
Renin Activity ◽  
Vanillylmandelic Acid ◽  
Before And After ◽  
Noradrenaline And Adrenaline

1. Ten patients with essential hypertension and ten healthy men were submitted to mental stress consisting of Kraepelin's arithmetic test combined with noise. Concentrations of plasma and urine catecholamines and of their metabolites as well as plasma renin activity before and after the test were studied. 2. In both groups a significant increase of noradrenaline and adrenaline in blood and noradrenaline in urine was observed. The urinary excretion of dopamine fell significantly in both groups after stress. 3. After mental stress a significant increase in urinary excretion of 3-methoxy-4-hydroxyphenylglycol was observed in both groups. The excretion of vanillylmandelic acid decreased significantly only in healthy subjects. 4. The plasma renin activity rose significantly in both groups but the increase was more pronounced in healthy subjects.

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