bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma Noradrenaline Concentrations at Different Vascular Sites during Rest and Isometric and Dynamic Exercise
Authors: Watson R. D. S. , Page A. J. F. , Littler W. A. , Jones D. H. , Reid J. L. 
Published: August 2015

1. Blood samples were obtained simultaneously from femoral artery and vein, pulmonary artery and antecubital vein at rest and during isometric and dynamic exercise in six patients during cardiac catheterization and plasma noradrenaline was measured radioenzymatically.
2. Analysis of variance indicated that differences between vascular sites were not significant, whereas differences between patients (P &lt; 0·001) and differences between activities (P &lt; 0·001) were significant.
3. Mean systemic arterial concentrations tended to be lower than pulmonary arterial concentrations during each activity, although the difference was not significant.
4. We conclude that forearm venous plasma noradrenaline concentrations are representative of those from other sites.
Anatomical Accuracy of Echocardiographically Assessed Left Ventricular Wall Thickness
Authors: Larkin H. , Johnson D. C. , Hunyor S. N. , Caspari P. , Kaplan R. 
Published: August 2015

1. A comparison of direct measurement and M-mode echocardiography in the determination of posterior left ventricular wall thickness was performed in 26 subjects, of whom 21 underwent cardiac bypass surgery; the remainder came to necropsy.
2. In the surgical group a close correlation was demonstrated between direct measurement of posterior wall thickness and the echocardiographic end-diastolic dimension (r = 0·76, P &lt; 0·001).
3. The necropsy measurement of posterior wall thickness correlated with the echocardiographic end-systolic dimension (r = 0·99, P &lt; 0·001).
4. These findings confirm that the echocardiographic measurement of posterior wall thickness accurately reflects the anatomical dimension.
Renin Precursor Synthesis and Renin-Binding Proteins in the Mouse
Authors: Poulsen K. 
Published: August 2015

1. The precursor synthesis of renin, the storage form in the kidney and the submaxillary gland, and the molecular nature of the forms in plasma were studied in the mouse.
2. Renin is synthesized as a precursor (pre-prorenin) with a molecular weight of 50 000.
3. Renin is stored in the submaxillary gland and the kidneys as fully active renin with a molecular weight of 40 000.
4. The predominant form of renin in plasma is the active mol. wt. 40 000 form. High-molecular-weight forms of renin (800 000 and 70 000) are also present in plasma.
5. Pure 125I-labelled mol. wt. 40 000 renin binds, after a change in the tertiary structure, to the plasma protease inhibitors α2-macroglobulin, inter-α-trypsin inhibitor and α2-antithrombin. It binds also to lipoprotein and an unidentified plasma protein. No binding was seen to more than 50 other studied plasma proteins.
6. The high-molecular-weight forms of renin in plasma may be complexes of renin with plasma protease inhibitors and lipoprotein.
Haemodynamic Effects of Captopril in Hypertensive Patients: Comparison with Saralasin
Authors: Fagard R. , Amery A. , Lijnen P. , Reybrouck T. 
Published: August 2015

1. Captopril (25 mg) reduced plasma angiotensin II (ANG II) by 53% (P &lt; 0·001) and mean brachial artery pressure (MBAP) by 18·7 mmHg (P &lt; 0·001) within 75 min in 26 hypertensive patients. After 2 months (on 150–600 mg/day) MBAP had decreased by 27·1 mmHg (n = 18) with no further change of plasma ANG II. δMBAP was significantly related to control log plasma renin (PRA) and log ANG II in both conditions.
2. The acute depressor response to captopril was 11·2 mmHg greater (P &lt; 0·001) than δMBAP during saralasin infusion (n = 12).
3. Heart rate slightly increased after acute administration of captopril (+ 3·3 beats/min; P &lt; 0·005), but cardiac output was not significantly affected; systemic vascular resistance decreased by 10% (P &lt; 0·01) with unchanged pulmonary vascular resistance.
4. During chronic administration, oxygen consumption, cardiac output and stroke volume increased by 15% (P &lt; 0·01), with unchanged heart rate; systemic vascular resistance had dropped by 30% (P &lt; 0·001).
5. Plasma ANG II and plasma aldosterone decreased, and PRA and ANG I increased acutely, with no further changes during chronic treatment.
Humoral Effects of the Oral Converting-Enzyme Inhibitor Sq 14 225 in Hypertensive Patients in Supine and Tilted Position
Authors: Morganti A. , Pickering T. G. , Lopez-Ovejero J. , Laragh J. H. 
Published: August 2015

1. To evaluate the effects of converting-enzyme inhibition on the sympathetic nervous system, on renin and on the other known regulators of aldosterone secretion, we measured blood pressure, heart rate, plasma noradrenaline, adrenaline, renin activity, aldosterone, cortisol and serum potassium in 15 sodium-repleted hypertensive patients in supine position and during 30 min of 65° head-up tilt before and during treatment with SQ 14 225.
2. SQ 14 225 produced significant decreases in supine blood pressure and plasma aldosterone and significant increments in plasma renin activity and potassium; in contrast, heart rate, noradrenaline, adrenaline and cortisol were unchanged.
3. While in control tilt studies blood pressure was always maintained, during treatment three of 15 patients had vasovagal syncopes. In the remaining 12 blood pressure was maintained during tilt on SQ 14 225; however, while the tilt-induced responses in heart rate and adrenaline were as in control studies, the 30 min increments in noradrenaline were significantly higher.
4. Both before and during treatment the responses of plasma renin activity and aldosterone to tilt were parallel, and correlated with each other, and cortisol and potassium changed only slightly.
5. It is concluded that the SQ 14 225-induced fall in blood pressure occurs without a concomitant rise in sympathetic nervous activity; thus the increase in supine plasma renin activity, being a reflection of the interruption of the angiotensin feedback mechanism on renin release, indicates an effective suppression of angiotensin II formation.
6. During SQ 14 225 the persistence of aldosterone response to tilt and its relationship with renin activity suggest that the enzymatic blockade is over-ridden; however, in the presence of a reduced formation of angiotensin II a more pronounced response of the sympathetic nervous system is required to defend blood pressure against postural changes.
Catecholamines and Haemodynamics in Fixed Essential Hypertension
Authors: Agabiti-Rosei E. , Alicandri C. , Fariello R. , Muiesan G. 
Published: August 2015

1. Arterial plasma catecholamines and haemodynamic status were simultaneously studied in 27 patients with fixed essential hypertension (WHO I—II).
2. Total arterial plasma catecholamines were found to be directly related to mean arterial pressure and to calculated total peripheral resistance, and they were inversely related to stroke index.
3. The degree of total peripheral resistance reduction after α-receptor blockade (phentolamine 10 mg intravenously) and the degree of mean arterial pressure reduction after combined α- and β-receptor blockade (labetalol 100 mg intravenously) were directly related to pretreatment plasma catecholamine concentrations.
4. These findings support the view that the sympathetic nervous system, as evaluated by plasma catecholamine concentration, may have an important role in maintaining hypertension in a subgroup of patients, contributing mainly to the degree of peripheral vasoconstriction.
Autoantibodies in Untreated and Treated Essential Hypertension: Relationship to Histocompatability Leucocyte Antigen-B15 and Vascular Complications
Authors: Kristensen B. Ø. 
Published: August 2015

1. The presence of autoantibodies and the histocompatibility leucocyte antigen (HLA) antigen B15 was studied in relation to vascular complications (WHO III) in 148 patients with essential hypertension.
2. Nine of 36 patients with WHO stage III hypertension had autoantibodies, compared with seven out of 78 normotensive controls.
3. The frequency of B15 was 36·1% in hypertensive patients with stage III hypertension and 14·8% in controls. Nine of 18 patients with cerebral complications had B15 and four out of 18 with cardiac complications had B15.
4. The relative risk of vascular complications was 3·4 times higher in B15-positive patients with essential hypertension compared with B15-negative patients.
5. This study suggests that B15-positive patients with essential hypertension represent a subgroup with a higher risk of vascular complications. Long-term studies are needed to determine whether B15 might serve as predictor for vascular complications.
6. The study adds further support to suggestions of a genetic and possibly HLA-linked connection between essential hypertension, diabetes and autoimmunity.
Abnormal Whole-Body and Cellular (Erythrocytes) Turnover of 22Na+ in Normotensive Relatives of Probands with Established Essential Hypertension
Authors: Henningsen N. C. , Mattsson S. , Nosslin B. , Nelson D. , Ohlsson O. 
Published: August 2015

1. Whole-body elimination rate of 22Na+ was decreased in normotensive or borderline first-degree relatives of hypertensive probands.
2. Whole-body potassium; exchangeable sodium and urine excretion of sodium, potassium and creatinine were similar in relatives and controls.
3. Erythrocyte net influx of 22Na+ was significantly increased in normotensive relatives.
4. Abnormal whole-body and cellular handling of sodium (22Na+) demonstrated in relatives indicates that this abnormality may have an important role in the development of essential hypertension in man.
Intralymphocytic Sodium in Hypertensive Patients: A Significant Correlation
Authors: Ambrosioni E. , Tartagni F. , Montebugnoli L. , Magnani B. 
Published: August 2015

1. Intralymphocytic sodium concentration was measured in 50 patients with essential stable hypertension, 44 patients with labile hypertension and 40 subjects with normal blood pressure.
2. Intralymphocytic sodium concentration in normotensive subjects was significantly lower than in the other two groups.
3. The concentration was significantly correlated with mean blood pressure in the group as a whole and in the groups with stable and with labile hypertension. No correlation was found in normal subjects.
Clinical and Pathological Relevance of Erythrocyte Cation Fluxes Measurement in Hypertension
Authors: Garay R. P. , De Mendonca M. , Elghozi J. L. , Devynck M. A. , Dagher G. , Pernollet M. G. , Grichois M. L. , Ben-Ishay D. , Meyer P. 
Published: August 2015

1. The clinical applications of a simple laboratory test for the diagnosis of essential hypertension were further investigated on a large number of patients (124 individuals).
2. The reduced erythrocyte ratio of Na+/K+ net fluxes observed in essential hypertensives might be secondary to a functional defect in a Na+—K+ co-transport system.
3. A similar reduction in the ratio of Na+/K+ net fluxes was also observed in erythrocytes of some normotensive subjects born of hypertensive parents and of genetically hypertensive rats. This suggests that the erythrocyte membrane defect follows the genetic transmission of hypertension.
Haemodynamics of Acth-Induced Hypertension in Sheep
Authors: Scoggins B. A. , Allen K. J. F. , Coghlan J. P. , Denton D. A. , Graham W. F. , Humphery T. J. , Whitworth Judith A. 
Published: August 2015

1. Administration of adrenocorticotropic hormone (ACTH) to sheep produced increases in mean arterial pressure within 24 h associated with an increase in cardiac output and cardiac rate. Both cardiac output and blood pressure remained elevated over the 5 days of ACTH treatment.
2. Administration of ACTH during β-adrenoreceptor blockade resulted in an increase in blood pressure without changes in cardiac output at 24 h.
3. Administration of a combined steroid infusion over 5 days produced increases in cardiac output identical with the effects of ACTH but with a substantially smaller effect on blood pressure.
4. These data suggest that the observed changes in cardiac output produced by ACTH treatment may be associated with high blood concentrations of adrenocortical steroids rather than being necessary for the development of the hypertension.
Circulatory Changes during Pregnancy in Spontaneously and Renal Hypertensive Rats
Authors: Lundgren Y. , Karlsson K. , Ljungblad U. 
Published: August 2015

1. Mean arterial pressure, heart rate, cardiac output (dye-dilution technique), stroke volume, total peripheral resistance (TPR), utero—placental blood supply (microsphere technique) and foetal weights were determined 2 days before expected birth in normotensive control (NC) rats, spontaneously hypertensive (SH) rats, rats with short-standing renal hypertension induced early in pregnancy and rats with established renal hypertension induced 4 weeks before pregnancy. Non-pregnant rats in comparable states served as controls.
2. In normal pregnancy cardiac output increased by 33% and blood pressure and TPR decreased by 17 and 38% respectively. The same principal changes were noted in SH rats and those with short-standing renal hypertension, but no changes were found in rats with established renal hypertension during pregnancy.
3. Myometrial and placental blood supply was lower in all hypertensive groups compared with NC rats, the reduction being 46 and 36% in SH rats and in rats with established renal hypertension as much as 74 and 68% respectively.
4. In SH rats foetal weights were reduced compared with NC rats, but despite the 68% reduction of placental blood flow in rats with established renal hypertension foetal weights were here unchanged.
A Circulating Humoral Pressor Agent in Dahl S Rats with Salt Hypertension
Authors: Tobian L. , Pumper Mary , Johnson Susan , Iwai J. 
Published: August 2015

1. In Dahl S rats becoming hypertensive while on a diet of high NaCl content there appears to be a blood-borne humoral agent which produces vasoconstriction in a bioassay using the isolated hindquarters of rats.
2. This vasoconstrictor effect strongly suggests the presence of a humoral pressor agent or the lack of a vasodilator agent in the blood of hypertensive S rats.
3. The vasoconstrictor effect is not due to high renin concentrations.
4. This humoral vasoconstrictor action could partly account for the high vascular resistance in the hypertensive S rat.
Treatment of Mild Hypertension in Elderly Males
Authors: Morgan T. , Adam W. , Carney S. , Gibbard R. , Brown S. , Wheeler D. 
Published: August 2015

1. Males, born between 1900 and 1925, with mild hypertension have been treated for periods varying from 300 to 2000 days.
2. The life and death status of all patients (except two) was known on 1st November 1978.
3. A group of patients with mild hypertension receiving treatment based on a thiazide diuretic had a greater mortality than the other drug-treated group.
4. The increased mortality was caused by an increased number of myocardial infarcts.
5. Elderly male patients with mild hypertension probably have preexisting vascular disease and therapy should not automatically be started. If therapy is started, β-adrenoreceptor-blocking drugs may be a preferred therapy.
Haemodynamics during Long-Term Thiazide Treatment in Essential Hypertension: Differences between Responders and Non-Responders
Authors: Van Brummelen P. , Veld A. Man In 't , Schalekamp M. A. D. H. 
Published: August 2015

1. Blood pressure, systemic haemodynamics, plasma volume, renin and aldosterone were measured during placebo treatment and after 1, 4 and 12 weeks of hydrochlorothiazide in 13 patients with uncomplicated essential hypertension. Nine of these patients were also studied after 24 and 36 weeks of treatment.
2. Mean arterial pressure was lowered significantly during hydrochlorothiazide treatment. In seven patients the fall in mean arterial pressure was greater than 10% (responders); four of these were studied for 36 weeks. The remainder were considered non-responders.
3. Hydrochlorothiazide lowered cardiac output. The maximal decrease was observed after 12 weeks of treatment (P &lt; 0·01). In responders this was followed by a return to pretreatment values and a significant decrease in total peripheral resistance, whereas in non-responders cardiac output remained reduced and total peripheral resistance was permanently elevated.
4. Changes in plasma volume, renin and aldosterone were not significantly different in responders and non-responders although non-responders tended to show a greater degree of plasma volume depletion and a more pronounced increase in plasma aldosterone.
5. Thus it is unlikely that the initial decrease in cardiac output is an important determinant of the long-term haemodynamic effect of thiazide diuretics.
Effect of Exercise in Hypertension Controlled with Metoprolol or Methyldopa
Authors: Stoker J. B. , Sreeharan N. , Linden R. J. , Barbour M. P. , Lorimer A. R. , Hillis W. S. , Lawrie T. D. V. 
Published: August 2015

1. The adequacy of the control of essential hypertension during exercise was studied in patients whose resting blood pressure had been controlled for 1 year with either metoprolol or methyldopa.
2. Systolic blood pressure increased with exercise in both groups, the increase being significantly less in the metoprolol group than in the methyldopa group.
Objective Measurement of Performance during Acute Stress in Patients with Essential Hypertension: Assessment of the Effects of Propranolol and Metoprolol
Authors: Dunn F. G. , Lorimer A. R. , Lawrie T. D. V. 
Published: August 2015

1. A standardized method of objectively measuring performance during simulated car driving is described.
2. The effect of a single dose of propranolol and metoprolol were compared with placebo in two groups of patients with untreated essential hypertension.
3. Performance was similar after β-adrenoreceptor-blocking agents or placebo.
4. Blood pressure response to stress persisted after administration of the blocking agents.
SK&F 92657, a Novel Antihypertensive Acting by Precapillary Vasodilatation and β-Adrenoreceptor Blockade
Authors: Taylor E. M. , Roe A. M. , Slater R. A. 
Published: August 2015

1. The properties of a new antihypertensive agent, SK&F 92657, dl-3-[2-(3-t-butylamino-2-hydroxypropoxy)phenyl]-6-hydrazinopyridazine, have been studied.
2. The compound caused a sustained fall in blood pressure in several species as a result of precapillary vasodilatation, particularly in the renal and coronary vasculatures.
3. The β-adrenoreceptor-blocking actions of SK&F 92657 prevent reflex cardiac stimulation.
Systemic Haemodynamic Effects of Biofeedback in Borderline Hypertension
Authors: Messerli F. H. , Decarvalho J. G. R. , Christie Barbara , Frohlich E. D. 
Published: August 2015

1. Six patients with borderline hypertension underwent training in exteroceptive biofeedback (BFB) in order to increase or decrease arterial pressure.
2. Systemic haemodynamics, intravascular volume and peripheral renin activity were determined before, during and after training sessions.
3. BFB training resulted in a significant reduction in mean arterial pressure (from 116 ± 4·6 to 101 ± 2·5 mmHg) mediated through a fall in total peripheral resistance; cardiac output, heart rate, intravascular volume and plasma renin activity remained unchanged.
4. In contrast, the increase or decrease of arterial pressure that occurred during BFB training was produced predominantly through changes in cardiac output and heart rate respectively, whereas total peripheral resistance under these circumstances remained unaffected.
5. The haemodynamic effects of BFB seem remarkably similar to the immediate or chronic effects of β-adrenoreceptor blockade, initially producing a fall in cardiac output followed by a reduced arterial pressure associated with a decreased total peripheral resistance.
Sequential Changes in Plasma Noradrenaline during Bicycle Exercise
Authors: Watson R. D. S. , Hamilton C. A. , Jones D. H. , Reid J. L. , Stallard T. J. , Littler W. A. 
Published: August 2015

1. Forearm venous plasma noradrenaline, heart rate and intra-arterial blood pressure were measured sequentially during and after upright bicycle exercise in five normotensive and six hypertensive patients.
2. Plasma noradrenaline increased significantly between 4 and 8 min during exercise.
3. On stopping exercise blood pressure and heart rate decreased rapidly whilst plasma noradrenaline increased in each subject to reach a maximum at a median time of 108 s after exercise.
4. Plasma noradrenaline decreased in five of six normotensive patients between the end of exercise and 2 min after exercise performed in the supine position.
5. Evidence in favour of a reflex increase in sympathetic activity after upright exercise is discussed.
Metabolism of Vasoactive Hormones in Human Isolated Lung
Authors: Al-Ubaidi F. , Bakhle Y. S. 
Published: August 2015

1. The metabolism of some vasoactive hormones perfused through pulmonary vessels was studied in samples of human lung obtained at operations.
2. 5-Hydroxytryptamine was inactivated and this inactivation was inhibited by desmethylimipramine and mebanazine.
3. β[14C]Phenylethylamine was also metabolized in human lung.
4. Prostaglandin E2 was inactivated and this inactivation inhibited by bromocresol green and frusemide.
5. About 10% of the radioactivity from infused [14C]arachidonic acid emerged from the lung and a small amount of biological activation occurred.
6. Of [14C]arachidonic acid retained by the lung, most was present in phospholipid with lesser amounts in neutral lipid and free acid fractions.
7. The fate of the hormones studied was qualitatively similar to their fate in animal lungs.
Creatine Kinase-1 is Principally Inactivated in Serum by Complexing with Immunoglobulin-G
Authors: Nealon D. A. , Henderson A. R. 
Published: August 2015

1. The stability of enzyme activity of the creatine kinase-l-immunoglobulin-G complex has been determined at 37°C, 4°C and −20°C in heat-inactivated serum and buffer.
2. The complex was formed by incubating creatine kinase-1 and immunoglobulin G at 37°C for 30 min. It was isolated by Sephadex G-100 column chromatography.
3. At all temperatures the complex suspended in buffer was about twice as stable as it was in heat-inactivated serum. Stability decreased in the sequence of 4°C, 37°C and −20°C. Therefore all isolations of the complex were carried out at 4°C.
4. At 37°C the decay of enzyme activity of the complex was found to be biphasic first order. In serum the Kd values were −0·045 min−1 and −0·0028 min−1, and in buffer −0·023 min−1 and −0·0016 min−1.
5. From column-chromatography experiments it was found that between 10 and 20% of the total creatine kinase-1 was involved in the complexing reaction after a 30-min incubation.
6. With this 10·20% proportion it can be calculated that the overall t0·5 for the decay of total creatine kinase-1 activity must be in the range 95–201 min. This finding suggests, by comparison with other published data, that the enzyme—immunoglobulin complex is the main route of creatine kinase-1 catabolism in serum.
7. The difference between serum and buffer decay values for the complex is possibly due to the presence of cystine, urate and other substances in serum, which are additional potent creatine kinase inhibitors.