bluuebunny/crossref_metadata_2025_split huggingface dataset:
Indomethacin Increases Leucocyte β-Adrenoreceptors in Man
Authors: Güllner H.-G. , Kafka M. S. , Bartter F. C. 
Published: August 2015

1. The effect of indomethacin, an inhibitor of prostaglandin synthesis, on number and sensitivity of α- and β-adrenoreceptors was studied in normal healthy volunteer subjects.
2. The subjects were studied under metabolic conditions. To achieve inhibition of prostaglandin synthesis indomethacin (2 mg day−1 kg−1) was given orally for 7 days. This dose decreased urinary excretion of prostaglandin E-like immunoreactivity by 70%.
3. The number of α-adrenoreceptors was measured by the specific binding of [3H]dihydroergocryptine to platelet membranes and that of β-adrenoreceptors by the binding of [3H]dihydroalprenolol to leucocyte membranes.
4. The number of α-adrenoreceptors did not change with indomethacin, nor did basal, prostaglandin E1- or noradrenaline-stimulated cyclic AMP production by platelet membranes. In contrast, the number of β-adrenoreceptors increased by 92%. Indomethacin did not affect, however, basal, 1-isoprenaline- or prostaglandin E1-stimulated cyclic AMP production in leucocyte membranes.
5. These results suggest that a reflex-mediated decrease in sympathetic discharge in response to an indomethacin-induced decrease in release of vasodilator prostaglandins may lead to an ‘up-regulation’ of β-adrenoreceptor sites.
The Intrarenal Regulation of Sodium Excretion in the Dog
Authors: Nizet A. , Deheneffe J. , Robin M. 
Published: August 2015

1. The effect of sodium chloride-containing solution (saline) infusion on sodium excretion has been investigated in kidneys transplanted from donors into the neck vessels of other dogs (perfusors). The dogs (perfusors and donors) had been given sodium-enriched or sodium-poor diets (‘loaded’ and ‘deprived’ dogs).
2. Three series of experiments were performed: (A) loaded perfusor, loaded donor; (B) deprived perfusor, deprived donor; (C) deprived perfusor, loaded donor.
3. Kidneys from deprived dogs, transplanted into deprived perfusors, excreted less sodium after intravenous saline than kidneys from loaded dogs transplanted into loaded perfusors. However, the sodium excretion from the kidneys of loaded dogs transplanted into deprived perfusors was the same as that from the kidneys of loaded dogs transplanted into loaded perfusors. These differences suggest that intrarenal mechanisms are involved in the changes in sodium excretion which follow changes in dietary sodium balance.
4. The intrarenal mechanisms included changes in glomerular filtration rate and fractional sodium reabsorption, but not changes in filtration fraction or renin release.
Haemodynamic and Hormone Responses to Acute and Chronic Frusemide Therapy in Congestive Heart Failure
Authors: Ikram H. , Chan W. , Espiner E. A. , Nicholls M. G. 
Published: August 2015

1. Since important interrelationships between haemodynamic and hormone indices are possible in cardiac failure, measurements of cardiac output, mean pulmonary artery pressure, plasma renin activity, angiotensin II and aldosterone were carried out before and during acute and chronic frusemide therapy in patients with oedematous heart failure who had been given digoxin.
2. Cardiac output fell significantly 90 min after acute frusemide injection, then returned to baseline. Mean pulmonary artery pressure declined steadily throughout the 4 h of observation.
3. These haemodynamic changes occurred in the absence of major hormonal fluctuations and related presumably to direct vascular and diuretic actions of frusemide.
4. With more chronic (8–10 days) oral frusemide therapy, reciprocal changes between haemodynamic and hormone indices were observed. As the diuretic response to frusemide diminished, cardiac output and pulmonary artery pressure declined whereas the renin-angiotensin system was activated. Statistically significant inverse correlations were observed between these haemodynamic and hormone indices.
5. In both acute and chronic phases of the study, fluctuations in aldosterone levels were regulated by the renin-angiotensin system whereas ACTH, plasma potassium and plasma sodium played, at best, supportive roles.
Long-term Regulation of Arterial Pressure, Glomerular Filtration and Renal Sodium Reabsorption by Angiotensin II in Dogs
Authors: Hall J. E. , Guyton A. C. , Smith M. J. , Coleman T. G. 
Published: August 2015

1. This study was designed to quantify the role of angiotensin II in determining the chronic relationships between arterial pressure, renal haemodynamics and sodium excretion.
2. In six control dogs sodium balance was achieved during chronic increases in sodium intake from 5 to 495 mmol/day with small increases in arterial pressure (7mmHg), moderate increases in glomerular filtration rate (19%) and decreases in filtration fraction. Similar increases in sodium intake in dogs whose circulating levels of angiotensin II were fixed, due to a constant intravenous infusion of 4.85 pmol of angiotensin II min−1 kg−1, caused large increases in arterial pressure (42%), glomerular filtration rate (31%), filtration fraction and calculated renal sodium reabsorption above control. In six dogs whose angiotensin II formation was blocked by SQ 14 225, sodium balance at intakes of 5–80 mmol/day occurred at reduced arterial pressure, glomerular filtration rate, filtration fraction and sodium reabsorption although plasma aldosterone concentration was not substantially different from that in control dogs. At sodium intakes above 240 mmol/day arterial pressure was not altered by SQ 14 225.
3. These data indicate that during chronic variations in sodium intake angiotensin II plays a major role, independently of changes in plasma aldosterone concentration, in allowing sodium balance without large fluctuations in glomerular filtration rate or arterial pressure. The mechanism whereby angiotensin II conserves sodium chronically is through increased sodium reabsorption, since steady-state sodium reabsorption was increased by angiotensin II and decreased by SQ 14 225.
Evidence for the Participation of Sodium-Sensitive Pontine Catecholaminergic Neurons in the Maintenance of DOCA-Sodium Hypertension in Rats
Authors: De Champlain J. , Van Ameringen Marie-Reine 
Published: August 2015

1. A reduced noradrenaline turnover rate has been previously demonstrated in the brain stem of deoxycorticosterone acetate (DOCA)-sodium hypertensive rats. In the present study, the turnover rate was measured in smaller brain regions and the effect of sodium depletion was studied on the turnover rate of these regions.
2. Catecholamine turnover rate was significantly reduced only in the pons, was slightly but not significantly reduced in the thoracic spinal cord and was normal in the upper and lower medulla oblongata, in the mesencephalon, in the hypothalamus and in the telencephalon.
3. The administration of a sodium-free diet for 3 weeks lowered significantly the blood pressure and concomitantly accelerated the turnover rate in the pons area of DOC A hypertensive rats.
4. It is concluded that pontine catecholaminergic fibres, sensitive to sodium balance, might be involved in the maintenance of DOCA-sodium hypertension in the rat.
Influence of the Sympathetic Nervous System on Aortic Compliance
Authors: Alicandri C. L. , Fariello R. , Agabiti-Rosei E. , Romanelli G. , Muiesan G. 
Published: August 2015

1. Aortic compliance and plasma catecholamine levels were determined in 26 essential hypertensive patients: 14&lt;45 years (group 1) and 12&gt;45 years (group 2).
2. Aortic rigidity, the reciprocal of aortic compliance, was calculated by the ratio of pulse pressure to stroke volume. Pulse pressure was derived by arterial pressure measured in the ascending aorta. Stroke volume was obtained by dye dilution.
3. A significant correlation (r = 0.60) was found between aortic rigidity and plasma noradrenaline in group 2. In this group both aortic rigidity and plasma noradrenaline levels were consistently higher than in group 1.
4. In 15 patients (seven of group 1 and eight of group 2) aortic rigidity was again measured after acute phentolamine (five patients) and labetalol (ten patients) administration.
5. Aortic rigidity was reduced significantly after both α-adrenoreceptor blockade alone and combined α- and β-adrenoreceptor blockade. A highly significant correlation was found between aortic rigidity reduction and pretreatment noradrenaline levels (r = 0.77).
6. Aortic compliance is influenced, at least in part, by sympathetic nervous system activity. Drugs which block the peripheral effects of catecholamines may improve aortic compliance and consequently the control of systolic hypertension in selected cases.
Cardiac and Haemodynamic Measurements in Hypertensive Pregnancy
Authors: Larkin H. , Gallery Eileen D. M. , Hunyor S. N. , Gyory A. Z. , Boyce E. S. 
Published: August 2015

1. Haemodynamic and left ventricular variables were determined by M-mode echocardiography in 21 normotensive and 36 hypertensive patients during the last trimester of pregnancy.
2. Blood pressure of hypertensive patients was lowered by bed rest only, or by oxprenolol or methyldopa, but remained elevated.
3. Cardiac output was raised in the last trimester of pregnancy in both normotensive and hypertensive patients.
4. Left ventricular mass was increased in normal pregnancy, but displayed an exaggerated increase in hypertensive patients.
5. Total peripheral resistance was inappropriately elevated in hypertensive pregnancy, except in the oxprenolol-treated group.
6. There was no reduction in heart rate or cardiac output in the group treated with β-adrenoreceptor blocking agents. These factors, in combination with normal peripheral resistance, may contribute to the improvement in foetal outcome described in maternal hypertension of pregnancy treated with oxprenolol.
Distensibility of the Left Atrial Wall in Spontaneously Hypertensive Rats Compared with That in Normotensive Wistar-Kyoto Rats
Authors: Ricksten S.-E. , Yao T. , Ljung B. , Thorean P. 
Published: August 2015

1. The cardiac mechanoreceptors, which in rats are mainly located in the left atrial wall, are reset in spontaneously hypertensive rats. The atrial pressure has to be almost twice as high in spontaneously hypertensive rats as in normotensive controls to produce similar receptor activations, as is apparent from previous studies.
2. The present study was performed to investigate whether this resetting is due to decreased distensibility of left atrial walls in the spontaneously hypertensive rats.
3. Static load-length relationships were investigated in vitro on left atrial strips, and pressure-volume relationships were studied on isolated left atria from spontaneously hypertensive and normotensive Wistar-Kyoto rats.
4. The force per cross-sectional area exerted during a relative length increase of 80% was significantly greater in spontaneously hypertensive rats. The dynamic but not the static distensibility was significantly lower in these animals.
5. The decreased dynamic distensibility of left atrial walls in spontaneously hypertensive rats can at least partly explain the resetting of atrial receptor function.
Role of Haemodynamics, Catecholamines and Renin in Acute Hypercalcaemic Hypertension in Man
Authors: Marone C. , Beretta-Piccoli C. , Weidmann P. 
Published: August 2015

1. The effect of acute hypercalcaemia on blood pressure, blood volume, haemodynamic indices, plasma catecholamines, renin and aldosterone levels was investigated in 10 patients.
2. Calcium infusion (15 mg/kg over 3 h) increased (P&lt;0.05) plasma calcium and adrenaline levels, blood pressure, total peripheral resistance and packed cell volume. Plasma volume was decreased, and heart rate, cardiac output and plasma renin, aldosterone or dopamine levels were not significantly changed. Plasma noradrenaline was increased only minimally after 3 h of calcium infusion.
3. Mean blood pressure before and during calcium infusion correlated with concomitant serum calcium (r = 0.39; P&lt;0.02) or adrenaline levels (r = 0.57; P&lt;0.01); changes in blood pressure correlated with variations in plasma adrenaline (r = 0.68; P&lt;0.001).
4. Acute hypercalcaemic hypertension is mediated by an increase in peripheral vascular resistance and may be induced by a direct effect of calcium on blood vessels. The calcium-mediated increase in adrenaline release may play a contributory, and plasma volume contraction an inhibitory, role.
Effect of Atenolol on Left Ventricular Function in Hypertensive Patients
Authors: Ibrahim M. Mohsen , Madkour M. Aziz , Mossallam Ragaa 
Published: August 2015

1. Atenolol (100 mg/day) was given to 12 hypertensive patients for 8 weeks, and its effects on mean arterial pressure, cardiac index and ejection phase indices of myocardial performance were examined by echocardiography.
2. Echocardiographic studies were made before treatment after 4 weeks on placebo and repeated after 4 and 8 weeks of atenolol therapy. Mean arterial pressure fell by 14 and 21% after 4 and 8 weeks respectively. Cardiac index fell by 22 and 20%, and stroke index fell by 11 and 7%. Calculated peripheral resistance did not change significantly.
3. Ejection phase indices, namely fractional shortening, ejection fraction and normalized mean rate of circumferential fibre shortening, did not change. End-diastolic volume index did not change and there was no relationship between changes in heart rate and end-diastolic volume index.
4. The study shows that atenolol in the resting state has no effect on certain echocardiographic indices of left ventricular function when given orally to hypertensive patients with normal left ventricular size and function. The reduction in cardiac and stroke indices were presumably secondary to a decrease in cardiac venous filling.
Simple Method of Assessing Splenic Function in Coeliac Disease
Authors: Corazza G. R. , Bullen A. W. , Hall R. , Robinson P. J. , Losowsky M. S. 
Published: August 2015

1. Erythrocytes with membrane abnormalities seen on interference contrast microscopy (‘pitted erythrocytes’) were counted in venous blood samples from patients with treated coeliac disease and dermatitis herpetiformis, and from control subjects and patients who had had an elective splenectomy.
2. The percentage of ‘pitted erythrocytes’ was compared with the 99mTc-labelled heat-damaged erythrocyte clearance, and with the splenic size computed from scintiscans.
3. There was a significant correlation between percentage ‘pitted erythrocytes’ and the above methods of measuring splenic function and size. Increase in the percentage of ‘pitted erythrocytes’ above the control range indicated splenic hypofunction.
4. The number of coeliac patients with percentage ‘pitted erythrocytes’ above the control range increased with increasing age at which they started a gluten-free diet.
5. Counting of ‘pitted erythrocytes’ is a simple and sensitive method of assessing splenic hypofunction in treated coeliac disease. It avoids radiation exposure, and is applicable to all ages and repeatable without risk.
6. The incidence of splenic hypofunction in coeliac patients may be related to the duration of untreated disease.
No Functional Difference of the Two Iron-Binding Sites of Human Transferrin in Vitro
Authors: Van Der Heul C. , Kroos M. J. , Van Noort W. L. , Van Eijk H. G. 
Published: August 2015

1. According to the Fletcher-Huehns hypothesis there exists a functional difference between the two iron-binding sites of transferrin.
2. The aim of the study presented was to evaluate this hypothesis in a homogeneous system, with human bone marrow cells and pure human monoferric transferrins A and B.
3. For this reason normal human bone marrow cells were incubated with human monoferric transferrin. The monoferric transferrins A and B were obtained by selective labelling at different pH of apotransferrin followed by preparative isoelectric focusing in granulated gels. The uptake of iron by the cell suspensions from monoferric transferrins A and B was equal.
4. In a heterogeneous but more active system for the removal of iron from human transferrin in vitro the two human monoferric transferrins did not show any significant functional differences.
5. No support for the Fletcher-Huehns hypothesis could be obtained.
Cytosine Arabinoside Deamination in Human Leukaemic Myeloblasts and Resistance to Cytosine Arabinoside Therapy
Authors: Harris A. L. , Grahame-Smith D. G. , Potter C. G. , Bunch C. 
Published: August 2015

1. The conversion of cytosine arabinoside into its active metabolite cytosine arabinoside triphosphate, and catabolism by deamination to uracil arabinoside, was measured in intact marrow myeloblasts from patients with acute myeloid leukaemia. The ratio of uracil arabinoside/cytosine arabinoside triphosphate ranged from 0.32 to 19.11.
2. The effect of tetrahydrouridine, an inhibitor of cytosine arabinoside deamination, on cytosine arabinoside triphosphate production was studied. The greatest increase of cytosine arabinoside triphosphate production caused by addition of tetrahydrouridine was 27%.
3. The increase in cytosine arabinoside triphosphate production was not related to the ratio of uracil arabinoside/cytosine arabinoside triphosphate or to the deaminase activity per 106 cells. It was proportional to the percentage change of cytosine arabinoside in the incubation medium.
4. The sensitivity of DNA synthesis to inhibition by cytosine arabinoside was measured in myeloblasts from 11 patients. Addition of tetrahydrouridine did not increase the sensitivity of the marrow to cytosine arabinoside.
5. Cytosine arabinoside deamination is unlikely to be an important mechanism of resistance in myeloblasts in vivo, although it may produce apparent resistance in vitro.
Hepatic Organelle Pathology in Primary Biliary Cirrhosis and the Response to Low-Dose D-Penicillamine Therapy
Authors: Scott J. , Jenkins W. , Smith G. P. , Peters T. J. 
Published: August 2015

1. Analytical subcellular fractionation in combination with enzymic microanalysis has been used to investigate the hepatic organelle pathology of primary biliary cirrhosis. Activities of plasma membrane and lysosomal enzymes in hepatic needle biopsies were increased, but marker enzymes for other organelles were normal.
2. Seven patients were treated with a low dose of penicillamine, 250 mg daily, over a 3–6 month period. The initially raised serum alkaline phosphatase and IgM levels were significantly reduced. In four patients with markedly elevated hepatic copper there was a small decrease, but urinary copper excretion was unaltered. Hepatic organelle pathology was significantly improved.
3. No serious side-effects were noted and it is suggested that a controlled trial of low-dose D-penicillamine therapy is indicated in patients with primary biliary cirrhosis.
Intra-Erythrocyte Sodium and (Na+,K+-Activated)-ATPase Concentration and Urinary Aldosterone Excretion in Spontaneously Hypertensive Rats
Authors: Berglund G. , Sigström L. , Lundin S. , Karlberg B. E. , Herlitz H. 
Published: August 2015

1. Intra-erythrocyte sodium, potassium, ATP and (Na+,K+-activated)-ATPase concentrations and urinary aldosterone excretion were compared in 3-month-old spontaneously hypertensive rats (n = 11) and normotensive Wistar-Kyoto control rats (n = 11).
2. Spontaneously hypertensive rats exhibited significantly higher intra-erythrocyte sodium concentration (5.5 ± 1.3 vs 4.0 ± 1.1 mmol/l of erythrocytes, P &lt; 0.01). No significant difference was found in intra-erythrocyte potassium, ATP or (Na+,K+-activated)-ATPase concentration.
3. Mean urinary aldosterone excretion was significantly lower in spontaneously hypertensive rats (66.3 ± 6.5 pmol/24 h) than in Wistar-Kyoto rats (90.5 ± 10.6 pmol/24 h, P &lt; 0.01). No significant relationship between urinary aldosterone and intra-erythrocyte sodium concentration was found in spontaneously hypertensive or Wistar-Kyoto rats or in the pooled group.
4. These results are thus consistent with previous findings of an increased intracellular sodium concentration in spontaneously hypertensive rats, but do not support the hypothesis that aldosterone is a dominant regulator of intracellular sodium concentration.
The Relationship between Leucocyte and Muscle Zinc in Health and Disease
Authors: Jones R. B. , Keeling P. W. N. , Hilton P. J. , Thompson R. P. H. 
Published: August 2015

1. A significant correlation between leucocyte and muscle zinc contents was observed in control patients and in patients with generalized diseases.
2. As muscle contains a large proportion of the whole-body zinc, it is suggested that leucocyte zinc content may be a useful indicator of tissue zinc status.
Different Distributions of Kinetically Apparent Molecular Varieties of α2-Macroglobulin in Health and in Patients with Cryptogenic Fibrosing Alveolitis
Authors: Topping R. M. , Craven A. H. , Whiting Susan , Rigden B. G. , Turner-Warwick M. , Turton C. W. G. 
Published: August 2015

1. Proteinase inhibitors have been studied in whole serum by using a kinetic method that avoids potentially damaging protein separation procedures.
2. The α2-macroglobulin of an individual can be allocated unambiguously into one of seven categories according to the binding of trypsin to inhibitor in two kinetically apparent binding modes (β- and α-modes).
3. The distribution of α2-macroglobulin β:α ratios in a healthy adult population is defined, and shown to be independent of sex and age.
4. The distribution of β: α ratios in a group of patients with cryptogenic fibrosing alveolitis was found to be significantly different (P &lt; 0.005) from the normal distribution.
5. Changes in the β: α ratio were noted in five of six patients with cryptogenic fibrosing alveolitis after treatment, but on no occasion when two healthy subjects were assessed a total of nine times.
6. The molecular interpretation and the possible importance of altered proteinase inhibition in inflammation and fibrosis are discussed.
Blood-Volume Expansion in the Rat: Natriuresis Accompanied by a Fall in Filtration Fraction
Authors: Querido D. , Isaacson L. C. 
Published: August 2015

1. We have attempted to confirm the existence of a natriuretic hormone released in response to acute expansion of blood volume.
2. Isolated kidneys, perfused with whole blood at constant pressure, were incorporated within an extracorporeal circulation in recipient rats. In six control experiments urine flow rate, renal blood flow, glomerular filtration rate, filtration fraction, and the fractional excretion of filtered sodium and water were measured for periods of up to 120–140 min thereafter. The same variables were measured in a further 12 experiments in which, after 63 ± 11 min, the rats were volume expanded with equilibrated whole blood (15, 18 or 28 ml/kg body wt.).
3. On average the controls revealed no change in any of the variables measured; volume expansion was followed by increased renal blood flow and fractional excretion of filtered sodium and water, while the filtration fraction fell.
4. In both the control and volume-expansion experiments, there were 12 instances in which the fractional excretion of filtered sodium increased; in 10 of these, including those experiments in which the natriuresis was most marked, there was a closely correlated fall in filtration fraction.
5. In all the experiments changes in the fractional excretion of filtered sodium and water varied in parallel.
6. We conclude that volume expansion (a) changes the concentration of some circulating vasoactive substance(s) and (b) results in natriuresis and diuresis consequent upon a fall in filtration fraction.