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Results 701 - 750 of 1266
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Resnick L M - - 1985
A role for calcium in human hypertensive disease has been suggested. However, the various, apparently contradictory, abnormalities of calcium metabolism observed in experimental and clinical hypertension do not allow for unambiguous description of the specific manner in which calcium contributes to the hypertensive process. We studied calcium metabolism in essential ...
London G M - - 1985
Cardiopulmonary blood volume (CPBV) and plasma renin activity (PRA) were measured simultaneously in five normal subjects and six patients with essential hypertension studied in the following different conditions: supine position, head-down tilt, thigh-cuffs inflation. In each individual, a significant negative correlation (r > or = 0.95) was observed between CPBV ...
Laragh J H - - 1985
The renin-angiotensin-aldosterone axis exerts major control over sodium and potassium balance and arterial blood pressure. These three functions are continuously regulated by changes in angiotensin II and aldosterone levels in response to wide variations in dietary intake of sodium and potassium. In addition, changes in intrarenal physical factors cause changes ...
Takahashi H - - 1985
As both hormonal and hemodynamic alterations similar to those occurring during exercise can also be produced in humans by hypoglycemia, the present study explored changes in hemodynamic parameters during hypoglycemia and the effects of the alpha 1-adrenergic blocker, prazosin, on those responses in hypertensive patients. In the control group, which ...
Sosa R E - - 1985
The renin-angiotensin system has been shown to play a significant role in maintaining blood pressure and sodium balance in health and disease states. The development of various pharmacologic probes that inhibit the RAS at different and specific points in the renin-angiotensin cascade has facilitated the elucidation of the role of ...
London G M - - 1985
Plasma renin activity (PRA) and systemic and forearm hemodynamics were studied during acute changes in cardiopulmonary blood volume and central venous pressure in 20 subjects, including 9 normotensive controls and 11 essential hypertensive patients of the same age. Changes in cardiopulmonary blood volume and central venous pressure were induced by ...
Mashchak C A - - 1985
The common assumption that estrogen replacement therapy (ERT) will frequently induce or aggravate hypertension cannot be supported by current evidence. While hypertension may occur as a rare idiosyncratic reaction to ERT, studies strongly suggest that blood pressure, systolic and diastolic, is consistently lowered by estrogen administration, although the decrement is ...
Goldsmith S R - - 1985
The effects of loading cardiopulmonary baroreceptors on basal norepinephrine and renin activity were studied in six normal subjects. Loading of cardiopulmonary baroreceptors was accomplished by a 60-min 30 degrees head-down tilt with small supplemental saline infusions. Central venous pressure was measured continuously by intrathoracic catheter; arterial pressure was measured indirectly ...
McGill H C HC - - 1985
We examined the relationship of hypertension and plasma renin activity to atherogenesis in 48 moderately hyperlipidemic (total serum cholesterol was about 200 mg/dl) baboons (Papio sp.). We used renal artery stenosis (two-kidney, one clip model) to produce hypertension associated with elevated plasma renin activity, and used cellophane wrapping of both ...
Packer M - - 1985
The relation between plasma renin activity before treatment and the haemodynamic and clinical responses to converting enzyme inhibition was determined in 100 consecutive patients with severe chronic heart failure who were treated with captopril or enalapril. Initial doses of captopril produced significant increases in cardiac index and decreases in left ...
Gruskin A B - - 1985
Clinical features in a comparably studied group of hypertensive and normotensive adolescents are described. Hypertensive hyperreninemia occurred in four of 28 hypertensive adolescents; suppressed plasma renin activity was found in five of 27 hypertensive adolescents. Only one of five adolescents identified as having suppressed plasma renin activity after ingesting a ...
Bulkley G B - - 1985
That local splanchnic ischemia is associated with the acute gastric "stress" erosions seen in shock is well established. The hemodynamic mechanism mediating that ischemia is unknown. Pericardial tamponade was produced in anesthetized pigs while hemodynamic parameters were monitored in the systemic circulation as a whole and in the vascular beds ...
Payen D M - - 1985
Preliminary studies indicate that nicergoline, a new alpha-antagonist, can lower HR at doses which decrease arterial BP. The present animal study was designed to quantitate the systemic and carotid (pulsed Doppler) hemodynamic and renin release consequences of nicergoline ventricular unloading, and to investigate the hemodynamic mechanisms of hypotension. In 11 ...
Reid I A - - 1985
Angiotensin II, the biologically active component of the renin-angiotensin system, acts throughout the body to produce an impressive number of cardiovascular, endocrine, metabolic, and behavioral effects. Major actions include elevation of arterial pressure, stimulation of aldosterone secretion, and a variety of effects on the kidneys, brain, and pituitary. Investigation of ...
Degli Esposti E - - 1985
Bromocriptine (2.5 mg/day orally) produced a significant fall in supine mean arterial pressure in nine hypertensive haemodialysis patients with high serum prolactin levels, without causing significant changes in heart rate. On bromocriptine, there was a significant decrease in the mean value of both serum prolactin and plasma noradrenaline, without significant ...
Takada T - - 1985
The effects of an orally active inhibitor of angiotensin-converting enzyme (SA-446) on systemic arterial pressure, renal function and renin release were examined in anesthetized dogs. Intrarenal infusion of the larger dose of SA-446 (0.1 mg/min) caused an increase in RBF, urine flow and renin release and caused a fall in ...
Godfrey N - - 1985
Blood pressure changes produced by removal of the renal artery clip in two forms of experimental renovascular hypertension in the rat (two-kidney one-clip and one-kidney one-clip hypertension) have been studied in relation to sodium balance and the renin angiotensin system. Continuous records of arterial blood pressure in conscious, freely moving ...
Goldsmith S R - - 1985
Plasma arginine vasopressin (AVP) levels are frequently increased in patients with congestive heart failure (CHF). Further, AVP does not respond normally to certain osmotic and nonosmotic manipulations in this condition. As a test of the central suppressibility of AVP in CHF, an oral ethanol challenge was given (0.7 ml/kg body ...
Lee M E - - 1985
Experiments were designed to elucidate the mechanism of the failure of systemic hypotension to stimulate renin release in the presence of elevated left heart pressure. We conducted a series of graded ascending aortic and suprarenal cuff inflations in dogs with bilateral renal denervation (n = 5). The renal perfusion pressure ...
Nabel E G - - 1985
The genesis of renovascular hypertension follows a continuum from an acute to a chronic phase. Reduction in renal perfusion initiates renin release and angiotensin-mediated systemic vasoconstriction. Aldosterone secretion, sodium and water retention, and expansion of the extracellular volume ensue. Sustained hypertension is further maintained by interacting physiologic mechanisms including increased ...
Sellars L - - 1985
Measurement of the renal vein renin ratio (RVRR) is commonly used to predict the response of blood pressure to surgery in hypertensive patients with unilateral renovascular disease. We have reviewed our experience in 37 such patients in whom renal vein renin levels were measured basally and after stimulation of renin ...
Soler A - - 1985
The effects of changes in arterial pressure and in circulating volume on Plasma Renin Activity (PRA) in the intact rat were compared by two experimental procedures. Gradual volume depletion was induced by intraperitoneal injection of a hyperoncotic polyethyleneglycol solution (PEG) in absence of acute changes in Systolic Arterial Pressure (SAP). ...
Ecoffey C - - 1985
Mean arterial pressure, heart rate, plasma catecholamines, renin activity, and vasopressin changes induced by a 30-degree head-up tilt were studied before and during epidural anesthesia with bupivacaine in eight elderly patients (ages 58-82 yr). The tilt performed before epidural anesthesia did not modify mean arterial pressure, heart rate, plasma catecholamines, ...
Guazzi M D - - 1985
We have examined the mechanisms mediating the release of renin elicited in man by reduction of renal perfusion pressure. Fifteen patients with essential hypertension and six normotensive subjects were investigated during diagnostic renal arteriography. Renal neural receptors were inhibited by propranolol (10 mg i.v.) and activated by a standard cold ...
Urata H - - 1985
A patient with unilateral ureteral obstruction by urolithiasis at the ureteropelvic junction was accompanied by hypertension. Plasma renin activity (PRA) was high in peripheral veins and was significantly higher in the renal vein drained from the affected kidney than the contralateral. Infusion of angiotensin II antagonist or an oral administration ...
Nicholson J P - - 1985
It has been reported that the first-dose response to prazosin is more common in patients who are salt-depleted or already receiving beta blockers. The relationship between the first-dose blood pressure and plasma renin responses to oral administration of 1 mg prazosin in 13 (seven male, six female) patients with essential ...
Morganti A - - 1985
To assess whether and how the activation of the renin-angiotensin system that occurs in response to changes in posture contributes to the maintenance of blood pressure, we measured blood pressure, heart rate, plasma noradrenaline and plasma active and inactive renin in patients with essential hypertension in the supine, sitting and ...
Bacher S - - 1985
Vasodilators were characterized on the basis of their first-dose effect on systolic and diastolic blood pressure, heart rate, on the product of heart rate and systolic blood pressure and on plasma renin activity (PRA) in conscious normotensive dogs. The compounds were given orally to the animals and the effects were ...
de Leeuw P W - - 1985
This review deals with the effects of chronic antihypertensive treatment with ketanserin on a series of physiological and biochemical variables, both at rest and during stimulation (exercise or stress). In four centers, different aspects were covered, with blood pressure as the common denominator in 45 hypertensive patients. Treatment periods ran ...
Vikse A - - 1985
To examine the PGE2 and renin release during autoregulatory dilation of preglomerular vessels, experiments were performed in three groups of anesthetized dogs. By reducing the arterial perfusion pressure from 113 +/- 3 to 78 +/- 3 mm Hg, renin release rose to 20 +/- 50% and PGE2 release to 74 ...
Navis G J - - 1985
Enalaprilic acid (MK 422), the active metabolite of enalapril, has recently become available for intravenous administration. In order to establish the proper dose for rapid blood pressure reduction, 9 patients with moderate to severe essential hypertension on a constant sodium intake of 100 mmol/24h were studied. They received four single ...
Resnick L M - - 1985
Despite recent appreciation of a role for calcium in clinical hypertension, evidence at present is conflicting. Thus, certain studies suggest increased calcium availability may be associated with increased levels of blood pressure, while others suggest that a calcium deficiency may contribute to the pathogenesis of hypertensive disease. Our own group ...
Simchon S - - 1985
The effects of hypotension on systemic and renal hemodynamics, plasma renin activity (PRA), and renin secretion rate (RSR) were determined in dogs anesthetized with sodium pentobarbital plus chloralose. Renal blood flow (RBF) was determined with microspheres (15 micron) and with an electromagnetic flowmeter connected to an extra-corporeal circuit from the ...
de Leeuw P W - - 1985
The aim of the present study was to investigate changes in blood pressure, heart rate, renal plasma flow, catecholamines, renin and angiotensin in fifteen patients with uncomplicated essential hypertension. During sleep a progressive fall in blood pressure and heart rate was found. Renal plasma flow and calculated renal vascular resistance ...
Levenson J A - - 1985
In patients with essential hypertension, vasodilating antihypertensive drugs act differently on small and large arteries. For similar blood pressure reductions, the diameter of the brachial artery may be unchanged (alpha- and beta-blocking drugs), decreased (dihydralazine), or increased (nitrates, renin-angiotensin and calcium-entry inhibitors). Increase in blood flow is due preferentially to ...
Skeggs L T LT - - 1985
The renin-angiotensin system does not appear to be involved in the maintenance of elevated blood pressure in experimental one-kidney, one clip hypertension. Paradoxically, direct immunization with purified hog kidney renin lowers the blood pressure of rabbits with this form of hypertension. Antirenin antibodies were removed and the IgG fraction prepared ...
Imagawa J - - 1985
The response of plasma renin activity (PRA) to stepwise reductions in renal arterial pressure (RAP) induced by suprarenal aortic constriction (SAC) or hydralazine (0.1-30 mg/kg i.v.), and the effect of indomethacin (5 mg/kg i.v.) or propranolol (1.5 mg/kg) s.c.) on the PRA response were examined in anesthetized rats whose right ...
Pals D T - - 1985
Orthostatic cardiovascular reflexes were evaluated in conscious cynomolgus monkeys during interruption of the renin-angiotensin system with the renin inhibitor: RIP (Pro-His-Pro-Phe-His-Phe-Phe-Val-Tyr-Lys-OH). RIP was synthesized via solid phase techniques and purified to homogeneity. In vitro studies indicated that it exhibited classical competitive inhibition of renin with a KI of 2.3 microM. ...
Pagny J Y - - 1985
The acute blockade of the renin-angiotensin system has been made it possible to investigate its role in the maintenance of blood pressure and aldosterone secretion in normotensive and hypertensive subjects. The administration of saralasin or captopril and, in the near future, of renin inhibitors induces a fall in blood pressure ...
Collart F - - 1985
The evolution of blood pressure, heart rate, epinephrine, norepinephrine, angiotensin II and plasma renin activity has been studied in 10 patients with essential arterial hypertension before and during a two months period of treatment with guanfacine, a new centrally acting hypotensive drug. Guanfacine was proven effective in lowering both systolic ...
Richards A M - - 1985
A 36 year old man presented with headache, polyuria, thirst and weakness of the lower limbs. Hypertension and a high haematocrit were striking features on initial assessment. Subsequently the full picture of Guillain-Barré syndrome developed. Hormone measurement revealed marked sympathetic nervous system and renin-angiotensin system activation with a return to ...
Laragh J H - - 1985
The acute, 60 min blood pressure and plasma renin responses to an oral test dose of captopril given to a quietly seated patient can be used to gain information quickly on renin dependency or lack of it in a hypertensive situation. This information is verified by a baseline renin sodium ...
Knox S S - - 1985
The object of the present study was to examine the interaction of working environment factors and the individual social support network with medical variables related to blood pressure elevations in young (mean age = 28 years) hypertensives. The results of path analyses reveal that the medical variables which explained a ...
Kiyonaga A - - 1985
Twelve patients with essential hypertension (WHO stages I-II) were subjected to mild aerobic exercise for 10 to 20 weeks. The time course of changes in the resting blood pressure and multiple hormonal responses (plasma catecholamines, prostaglandin E, renin-angiotensin system, kallikrein-bradykinin system) were monitored. Depressor response of both systolic and diastolic ...
Wynne R D - - 1985
The pharmacokinetic and haemodynamic effects of a 200 mg oral dose of BTS 49 465 (7-fluoro-1-methyl-3-methylsulphinyl-4-quinolone) were investigated in a double-blind placebo controlled study. BTS 49 465 was rapidly absorbed and cleared from the systemic circulation with a half-life of 1.6 h by oxidation to the sulphone metabolite. The metabolite ...
Michel J B - - 1985
The inhibition of the renin-angiotensin system (RAS) has important effects on different parameters of left ventricular function. Chronic inhibition of the RAS avoids hypokalemia and potassium losses by increasing aldosterone release. This potassium-sparing effect is likely to prevent cardiac arrhythmia. Inhibition of the RAS reverses cardiac hypertrophy in renovascular and ...
Takabatake T - - 1985
A patient with hypertension is shown to have both a renal artery stenosis due to fibromuscular dysplasia and a hypoplastic contralateral kidney, a condition comparable to that of the one-kidney Goldblatt hypertension. Both blood volume and plasma renin activity were increased. Blood pressure was lowered either by an angiotensin II ...
Hägg A - - 1985
Twelve hypertensive patients (mean age 46.6 years, range 37-55 years) with fibromuscular dysplasia of the renal artery were treated with percutaneous transluminal renal angioplasty (PTRA) and the effects on the renin-angiotensin-aldosterone system and blood pressure were studied in the acute phase. The technical result of PTRA measured by angiography and ...
Ogawa K - - 1985
Changes in plasma levels of active and inactive renin after the treatment with enalapril maleate (MK-421), a new angiotensin converting enzyme inhibitor, were studied in five patients with renovascular hypertension (RVH) due to unilateral renal artery stenosis. The dosage was increased when the blood pressure (BP) was not normalized for ...
Fitzpatrick M A - - 1985
Angiotensin-converting enzyme inhibitors are vasodilators that exert their beneficial hemodynamic effects in hypertension primarily by withdrawal of the vasoconstricting action of endogenous angiotension II. Although the magnitude of the initial decrease in vascular resistance depends on renin activity, the long-term arterial blood pressure response does not appear to be influenced ...
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