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Results 601 - 650 of 1262
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Ueno Y - - 1988
We characterized the hemodynamic and endocrine changes associated with the evolution of steroid-induced hypertension in conscious, trained, instrumented dogs given intramuscular injections of deoxycorticosterone (DOC) pivalate on Days 1 (20 mg/kg) and 14 (10 mg/kg) of the study. Because hypertension could be produced in these dogs without salt loading and ...
Sasaki S - - 1988
The hypotensive mechanism of percutaneous transluminal dilatation (PTD) in renovascular hypertension due to bilateral renal artery was investigated in two patients. Blood pressure was monitored continuously before, during and after PTD by use of a new automated blood pressure monitoring device based on finger volume-oscillometry. Plasma renin activity was measured ...
Persson P - - 1988
The isolated and combined influence of cardiopulmonary and sinoaortic denervation on long-term blood pressure (MAP), heart rate (HR), plasma renin activity (PRA) and plasma volume (PV) was studied in 11 conscious, chronically instrumented foxhounds receiving a normal sodium diet. MAP, HR, PV and PRA remained unchanged in the 5 dogs ...
Leenen F H - - 1988
Fifteen patients with mild-to-moderate hypertension (10 with normal and five with decreased renal function) were studied after treatment with placebo and low (1 mg), intermediate (2.5 mg), and high (5.0 mg per day) doses of indapamide, each for four weeks. Six patients--five with normal renal function--were classified as nonresponders (decrease ...
Bühler F R - - 1988
Ageing is associated with pathophysiological adaptive changes in cardiovascular regulation including reduced baroreflex sensitivity and beta-adrenoceptor-mediated cardiac and renal responses. Accordingly, owing to such blunted counterregulation, older patients gain a greater fall in blood pressure for a given peripheral vasodilation, e.g., with a calcium antagonist. Such age-related efficacy may be ...
Persson P - - 1988
The intention of the present studies was to analyze the effects of arterial baroreceptors and cardiopulmonary receptors on cardiovascular control (I,IV,VI) and renin release (I,II,IV,V). The investigations of the role of the renin-angiotensin system on arterial pressure (III,VII) were applied to interpret a possible contribution to "neurogenic hypertension". Following conclusions ...
Thornton R M - - 1988
This study, carried out in two parts, sought to determine the importance of vasopressin (VP), the renin-angiotensin system (RAS), and the sympathetic nervous system in the dehydration-produced attenuation of hindlimb (cutaneous) vasodilation during environmental heating (EH). Baboons, chronically instrumented for blood sampling and for measurement of mean iliac blood flow ...
Leonetti G - - 1988
In this paper the different aspects of the role played by alpha-adrenoceptors in the control of renin secretion from the juxtaglomerular apparatus and renal sodium and water reabsorption, and the effects of alpha-adrenoceptor antagonists on systemic haemodynamics, will be investigated. Animal experiments suggest that the renal alpha-adrenoceptors exert a restraining ...
Jansen P A - - 1988
Blood pressure, both venous and urinary catecholamines and plasma renin activity (PRA) were studied in 10 patients (6 men and 4 women, mean age 70 +/- 10 years) on the first three days after cerebral infarction. Blood pressure fell significantly (p less than 0.02) on the second and third day ...
Churchill P C - - 1988
The renin-angiotensin system plays a central role in salt and water balance and in the regulation of arterial blood pressure. The level of activity of this system is determined primarily by the rate at which the granulated juxtaglomerular cells (JG cells) secrete renin into the blood. Physiologically, renin secretory rate ...
Grassi G - - 1988
Cardiopulmonary receptors modulate renin release in several animals species. However, their involvement in reflex control of this humoral substance in humans is controversial. Furthermore, no information is available on the alteration of this control in hypertension. We studied the modulation of plasma renin activity (radioimmunoassay) in 12 normotensive subjects and ...
Brachtel D - - 1988
Arterial blood pressure, renal function and plasma concentrations of renin and renin substrate (angiotensinogen) were investigated in guinea pigs subjected to galactosamine-induced (1 g/kg i.v.) liver cell necrosis. Blood pressure declined continuously by 50% during a follow-up period of 72 h which was associated with a decrease in diuresis and ...
Rose C E CE - - 1988
The role of endogenous opioids in systemic and renal circulatory changes during combined acute hypoxemia and hypercapnic acidosis was evaluated in seven conscious female mongrel dogs in rigid sodium balance. Animals were studied 2 wk apart in separate protocols of combined acute hypoxemia (arterial O2 tension = 33 +/- 1 ...
Trimarco B - - 1987
The effects of graded lower body negative pressure (-10 and -40 mm Hg) on vascular resistance and plasma vasopressin, norepinephrine, and renin activity were assessed in seven hypertensive subjects with left ventricular hypertrophy and seven sex-matched and age-matched normotensive subjects. In both groups increasing levels of lower body negative pressure ...
Neisius D - - 1987
Hypertension was induced in marmosets by ligating the minor branch of one renal artery. The blood pressure (BP), measured by a tail-cuff method, increased to hypertensive levels within 4-5 weeks and the maximum increases occurred after 4-15 weeks (BP, mean +/- s.e.m. was 120 +/- 3 and 152 +/- 6 ...
Ehmke H - - 1987
The relationship between pressure-dependent renin release and long-term blood pressure was studied in 14 conscious dogs on a normal salt diet. Stimulus-response curves were obtained by a controlled reduction of renal artery pressure in 5 or 10 mm Hg steps down to 70 mm Hg. Pressure-dependent renin release was characterized ...
Pamnani M B - - 1987
This review summarizes our bioassay methods for determining the level of humoral sodium pump inhibiting factor after acute volume expansion in experimental animals and humans, and in low renin experimental and human essential hypertension. In brief, ouabain-sensitive 86Rb uptake and membrane potential in blood vessels from normal animals are measured ...
Katzman P L - - 1987
Studies were performed in nine patients with essential hypertension to explore the effect of the calcium antagonist felodipine on the exercise-induced responses of the sympathetic and renin-angiotensin-aldosterone systems as well as of blood pressure and heart rate. The patients were subjected to an individually graded submaximal work test (bicycling) after ...
Kageyama Y - - 1987
The effects of calcium supplementation on blood pressure and its mechanisms were investigated in two-kidney, one clip renovascular hypertensive rats. Two series of experiments were performed: one was begun just after renal artery constriction, the other after the onset of hypertension. Calcium supplementation significantly attenuated the development of hypertension (systolic ...
Valvo E - - 1987
The systemic haemodynamic pattern and its changes after at least 6 months of successful percutaneous transluminal angioplasty (PTRA) was evaluated in a group of patients with renovascular hypertension (RVH). Fourteen patients, nine males and five females, aged 21 to 58 years, were studied; 12 had fibrodysplastic and two had atherosclerotic ...
Anderson D F - - 1987
Experiments were performed on 13 fetal lambs of 126 days gestational age. Seven days after surgery, suprarenal aortic blood flow was reduced to 70% of control with an inflatable occluder for a period of at least 4 days. This produced an almost constant aortic pressure difference of 35 mmHg across ...
Harris P - - 1987
A review of the history of our knowledge and understanding of the peripheral oedema of congestive cardiac failure points to the conclusion that an inability of the heart to maintain the arterial pressure is of central importance in this condition. Although the function of the circulation is to perfuse the ...
Kawazoe N - - 1987
Pathophysiology of malignant hypertension, of which underlying disease was essential hypertension (EHT) in 33 cases and chronic glomerulonephritis (CGN) in 26 cases, was studied with reference to the renin-angiotensin system. Plasma renin activity (PRA) was significantly higher in the EHT than in the CGN group, and angiotensin II antagonist [Sar1, ...
Fischer G - - 1987
B 844-39 is a new dihydropyridine calcium antagonist with a long-lasting antihypertensive action. Preliminary tests in chronically instrumented normotensive dogs revealed that B 844-39 (0.3 mg/kg p.o.) caused a marked decrease in blood pressure which was accompanied by a counterregulatory increase in heart rate. Both effects outlasted the 6-h observation ...
Swales J D - - 1987
The fall in blood pressure, which occurs when renovascular hypertension is corrected surgically, offers a means of elucidating the factors responsible for blood pressure control. When Goldblatt two-kidney, one-clip hypertension in the rat is reversed by unclipping the renal artery, or by removal of the ischaemic kidney, restoration of normal ...
Neer C A - - 1987
A prospective study of 66 geriatric residents in 2 facilities was conducted to quantitate people-dog interactions. Residents were assigned randomly to sessions with dog activity and to sessions with other activity in a crossover design. This study involved a 12-week prestudy activity period and two 12-week activity periods, one before ...
Spence C D - - 1987
The roles of the autonomic nervous system, renin-angiotensin system, and arginine vasopressin (AVP) during the onset of ACTH-induced hypertension were investigated in conscious sheep. Autonomic ganglion blockade or combined adrenergic and cholinergic receptor blockade demonstrated that an intact sympathetic nervous system was not essential for the development or maintenance of ...
Savage J M - - 1987
Eight of 100 normotensive children who had pyelonephritic scarring secondary to urinary infection and vesicoureteric reflux were found in an earlier study to have increased plasma renin activity (PRA). Because the risk of these patients becoming hypertensive is between 10% and 20% and because renin activity may play a part ...
Michel J B - - 1987
Primate renins (human and monkey) are very similar. We used pure human renin to immunize marmosets (Callithrix jacchus) and thereby produce a chronic blockade of the renin-angiotensinogen reaction. After a control period of 2 months, five male marmosets, on their usual sodium-poor diet, were immunized against pure human renin by ...
Wyndham R N - - 1987
Initial plasma renin activity (PRA) was measured in 213 patients with untreated hypertension before beginning thiazide (chlorothiazide and hydrochlorothiazide) therapy alone to test whether patients with low-renin hypertension exhibited a greater response to diuretic therapy. Diastolic blood pressure response to treatment in the low, mid-range, and high PRA groups did ...
Takabatake T - - 1987
The response to angiotensin II analog infusion during sodium deletion and the effects of a one-month captopril treatment were compared between 15 renovascular hypertensive patients with unilateral and 6 with bilateral renal artery stenosis. Plasma renin activity, its response to sodium depletion, and the renal vein renin ratio during sodium ...
Lever E G - - 1987
The effect of TRH (200 micrograms) on blood pressure, pulse rate, TSH and GH release was investigated in 10 acromegalics, four patients with non-GH secreting pituitary tumours, and seven normal controls. TRH produced a rapid-onset, short-lived pressor response in the acromegalic group (delta mean blood pressure 33 mmHg) compared to ...
Unger T - - 1987
Local tissue renin-angiotensin systems have recently been discovered in various organs, and evidence is accumulating that inhibition of these local renin-angiotensin systems may contribute to the actions of converting enzyme (CE) inhibitors. Measurements of CE activity and angiotensin II concentrations revealed that after oral administration of CE inhibitors, CE was ...
Hof R P - - 1987
Calcium entry blockers but not nitroprusside sodium (NPS) or dihydralazine are known to enhance renin release in vitro. Isradipine (PN200-110), NPS or dihydralazine were infused at 15 min intervals into groups of 6 conscious, chronically instrumented rabbits each, at 3 doses carefully matched to elicit comparable falls in blood pressure. ...
Sanchez R A - - 1987
To change the stretch on cardiopulmonary mechanoreceptors, large shifts of blood in the capacity space were elicited by tilting and by exerting positive lower body pressure in the tilted position. Twelve volunteers underwent invasive hemodynamic studies and in 10 other subjects cardiac size was determined by radionuclide cardiography. In all ...
Wysocki M - - 1987
The haemorheological disturbances observed in primary hypertension arise mainly from haemoconcentration, which leads to an elevation of blood and plasma viscosity and increased aggregation of red blood cells (RBCs). We evaluated the rheological properties of blood and central haemodynamic indices in 13 men with untreated primary hypertension (WHO stage I ...
Devereux R B - - 1987
This article examines available data concerning the hypothesis that the renin-angiotensin system directly stimulates cardiac hypertrophy and dysfunction in hypertension. Several experiments support a direct effect of angiotensin on myocardial protein synthesis and suggest that this may be independent of adrenergic influences. However, the role played by the renin system ...
Rose J C - - 1987
We compared the cardiovascular and hormonal responses to angiotensin converting enzyme inhibition and hemorrhage of 20% of blood volume in chronically instrumented unanesthetized newborn lambs and adult sheep. Administration of the nonsulfhydryl-containing converting-enzyme inhibitor enalapril reduced mean arterial pressure in the newborn but not in the adult animals. Blood pressure ...
Atkinson J - - 1987
We have investigated the relationship between the acute blood pressure lowering effect of captopril and renin status. Differences in renin status were induced by unilateral artery clipping combined with unilateral or bilateral nephrectomy in rats. The blood pressure lowering effect of captopril correlated very closely with plasma or aortic renin ...
Ehmke H - - 1987
In 12 conscious dogs on a normal sodium diet the renal venous-arterial plasma renin activity-difference as a function of mean renal artery pressure (renin stimulus-response curve; RSRC) as well as long-term mean arterial blood pressure (MAP; pressure-histograms) were measured repeatedly. The RSRC has 1) a threshold pressure (Pth), 2) a ...
Wang H - - 1987
Enalapril (MK-421), a new angiotensin converting enzyme inhibitor, reduces the blood pressure in one-kidney, one-clip hypertensive rats at 30 mg/kg p.o. (n = 12). On the fifth day and during the fifth week after renal artery constriction, systolic blood pressure decreased from 196 +/- 4 and 240 +/- 5 mm ...
Oparil S - - 1987
The effects of exposing rats to hyperoxia (100 percent O2) at normal atmospheric pressure for periods of 24-48 hours on components of the renin-angiotensin system and on blood pressure control were examined. Intrapulmonary conversion of angiotensin I (AI) to angiotensin (AII) was assessed using an isolated lung preparation perfused at ...
Dzau V J - - 1987
The renin-angiotensin system affects blood pressure and regional blood flow through endocrine, paracrine, and autocrine influences. The circulating endocrine renin-angiotensin system (RAS) is activated for acute cardiovascular homeostasis. The recent demonstration of a local renin-angiotensin system in the blood vessel wall has led us to speculate that the local production ...
Fagard R - - 1987
Oral administration of felodipine to 10 patients with mild essential hypertension acutely reduced systemic vascular resistance (SVR) by 40% after 30 min. The change in SVR was significantly related to age (r = -0.74). The reduction in the intraarterially measured brachial artery pressure was limited to 15/13 mmHg, due to ...
Richer C - - 1987
The effects of three doses (4, 8, and 16 mg) of perindopril, a new angiotensin I converting enzyme inhibitor, on systemic blood pressure, heart rate, brachial and carotid artery flow and diameter (assessed by the pulsed Doppler technique), forearm vascular resistance, plasma converting enzyme and renin activities, and plasma aldosterone ...
Weinstein G S - - 1987
Systemic hypertension following coronary artery bypass graft (CABG) procedures has been reported to occur in 15% to 80% of cases. Previous reports have implicated the renin-angiotensin system as being responsible, at least in part, for this phenomenon. In this prospective study, 18 previously normotensive subjects were studied before, during, and ...
Morild I - - 1987
Nine white leghorn chickens were injected i.m. with furosemide (10 to 60 mg/kg body weight) twice daily for 18 days. The birds were then anesthetized with a combination of equithesin and diazepam and the kidneys perfused via the heart. Kidney tissue was sectioned serially and the granular epithelioid cells were ...
de Mey C - - 1987
The haemodynamic effects of a standard meal were assessed in a balanced cross-over study in eight normal fasting subjects, investigated under conditions applicable to many drug tests. Both the supine and erect diastolic blood pressure were reduced on average by 10 mmHg over the 4 h following the meal. The ...
MacGregor G A - - 1987
There is controversy about the efficacy of sodium restriction in the treatment of hypertension. Short-term restriction of sodium intake in normotensive subjects causes little or no fall in blood pressure. This lack of response of blood pressure to sodium restriction appears to be due, at least in part, to a ...
Stanek B - - 1987
In hepatic cirrhosis neurohumoral vasoconstrictor systems are activated to compensate for circulatory disturbances. To study the renin-angiotensin-aldosterone system in more detail, angiotensin converting enzyme in 15 patients with advanced liver disease was inhibited with captopril after moderate sodium restriction. Captopril caused an increase in plasma renin activity (p less than ...
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