bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is the urinary excretion of prostaglandin E in man dependent on urine pH?
Authors: Haylor J. , Toner J. M. , Jackson P. R. , Ramsay L. E. , Lote C. J. 
Published: August 2015

1. The relationship between urine pH, modified by the oral administration of either ammonium chloride or sodium bicarbonate, and the urinary excretion of prostaglandin E (PGE) was studied in healthy female subjects.
2. The urinary concentration of PGE, normally constant in man, was significantly higher (P&lt;0.02) in alkaline than in acid urine. pH-dependent metabolism and flow-dependent excretion were identified as two factors liable to obscure the demonstration of the pH-dependency of the urinary excretion rate of PGE in man.
The effect of acutely reduced plasma osmolality on acute renal failure in rats
Authors: Popovtzer Mordecai M. , Wald Hanna , Shilo Ruth 
Published: August 2015

1. The present study was designed to evaluate the effect of acute fall in plasma osmolality in three models of acute tubular necrosis in rats: (a) glycerol, (b) arterial clamping and (c) mercuric chloride.
2. Plasma osmolality was reduced by a water loading during a mild anaesthesia from 305 ± 7 to 270 ± 12 mosmol/kg of water (P&lt;0.01).
3. In the ischaemic models of acute tubular necrosis (glycerol and arterial clamping), during the first 24 h in rats with reduced plasma osmolality, the respective creatinine clearance rates (CCR), 0.04 ± 0.02 and 0.06 ± 0.04 ml/min, were strikingly lower than those in rats with normal osmolality, 0.21 ± 0.03 and 0.26 ± 0.06 ml/min (P&lt;0.001) respectively. The control CCR were 0.65 ± 0.07 and 0.62 ± 0.07 ml/min respectively.
4. During the second day after induction of ischaemic (glycerol and arterial clamping) acute tubular necrosis, rats with reduced plasma osmolality exhibited a similar worsening in CCR as on the first day, when compared with that in rats with normal osmolality.
5. In rats with acute tubular necrosis induced with mercuric chloride reduction in plasma osmolality did not aggravate the severity of renal failure.
6. These results show that acute fall in plasma osmolality worsens the renal failure in the ischaemic but not in the nephrotoxic models of acute tubular necrosis.
Fibrinogen derivatives and platelet activation products in acute and chronic liver disease
Authors: Hughes R. D. , Lane D. A. , Ireland H. , Langley P. G. , Gimson A. E. S. , Williams Roger 
Published: August 2015

1. The concentration in plasma of fibrinogen derivatives fibrinopeptide A (FPA) and Bβ1-42 and the platelet release products β-thromboglobulin (βTG) and platelet factor 4 (PF4) have been determined in patients with acute and chronic liver disease.
2. In 21 patients with fulminant hepatic failure on admission in grade III or IV coma the plasma FPA, Bβ1-42, βTG and PF4 levels were significantly increased compared with those in normal control subjects. On heparinization before haemoperfusion the FPA levels returned to the normal range and during resin and charcoal haemoperfusion there were no significant changes in the coagulation or platelet factors, except for a small increase in FPA with charcoal haemoperfusion.
3. In ten patients with compensated chronic liver disease there was a significant increase in Bβ1-42 and βTG levels but not FPA and PF4 as compared with normal controls.
4. Interpretation of the results is complicated by the possible reduced clearance of these proteins as a result of renal failure in some of the patients with fulminant hepatic failure and also by the damaged liver itself. However, these results have confirmed that disseminated intravascular coagulation can occur in both acute and chronic liver disease.
α2-Adrenoceptors in dog kidney: autoradiographic localization and putative functions
Authors: Summers R. J. , Stephenson J. A. , Lipe S. , Neylon C. B. 
Published: August 2015

1. The location of α2-adrenoceptors has been examined in slide-mounted sections of dog kidney by using labelling in vitro with [3H]rauwolscine and autoradiography.
2. [3H]Rauwolscine binding in dog kidney was of high affinity, saturable, and to a single population of sites. Stereoselectivity was observed for (−)-noradrenaline and the relative affinity of a series of competing antagonists indicated binding to α2-adrenoceptors.
3. Autoradiography of [3H]rauwolscine binding revealed localization to three areas: glomeruli, the intimal and adventitial surfaces of arcuate blood vessels and the medullary vascular bundles.
Prolonged Survival of Rat Renal Allografts after Multiple Allogeneic Pregnancies: Strain Specificity and role of Erythrocyte Antibody Rosette Inhibiting Antibodies
Authors: Asfar S. K. , Power D. A. , Mason R. J. , MacLeod A. M. , Simpson J. G. , Whiting P. H. , Engeset J. , Catto G. R. D. 
Published: August 2015

1. The influence of allogeneic pregnancies on the survival of subsequent rat renal allografts was investigated in three rat strain combinations.
2. Multiple but not single pregnancies produced significantly more long-term surviving kidney grafts than were found in virgin animals; the effect was specific for paternal antigens, as multiple pregnancies by an unrelated strain did not prolong kidney graft survival.
3. In the multiparous groups, those animals with long-surviving grafts had significantly higher levels of non-cytotoxic antibodies against paternal strain B-lymphocytes (detected by the erythrocyte antibody rosette inhibition assay) than did animals which rejected their grafts.
4. The results show that multiple pregnancies may produce a state of specific unresponsiveness to paternal antigens, similar to enhancement, which is marked by the presence of non-cytotoxic antibodies against paternal B-lymphocytes. It is suggested, therefore, that enhancement may be one of the protective mechanisms which prevent rejection of the fetus during pregnancy.
Glomerular Sialic acid in Heymann Nephritis and Diacetylbenzidine induced Nephropathy in Rats
Authors: Laitinen Liisa , Miettinen Aaro , Tikkanen Ilkka , TÖrnroth Tom , Nordling Stig 
Published: August 2015

1. Glomerular sialic acid was chemically measured in rats with experimental proteinuria induced by N,N'-diacetylbenzidine (DAB) or with autoimmune Heymann nephritis.
2. In DAB nephrosis and in Heymann nephritis the relative amount of glomerular protein was increased. In DAB nephrosis the quantity of sialic acid expressed per amount of protein was decreased, but expressed per amount of DNA, which reflects the number of cells, there was no significant change. In Heymann nephritis the amount of sialic acid was not significantly altered when expressed per amount of protein or per amount of DNA.
3. In individual animals, the amount of glomerular sialic acid expressed per amount of protein or per amount of DNA did not correlate with the severity of proteinuria. An increase in the total number of glomerular cells was found only in Heymann nephritis.
4. The results suggest that proteinuria in the reported models is not the result of changes in glomerular sialic acid.
Effect of Naloxone on the Defective Autonomic Control of Heart Rate in Uraemic Patients
Authors: Zoccali C. , Ciccarelli M. , Mallamaci F. , Maggiore Q. 
Published: August 2015

1. The role of endogenous opioids on the reflex cardiovascular control of chronic uraemic patients was investigated.
2. The opiate antagonist naloxone administered intravenously caused a significant increase in the abnormal Valsalva manoeuvre ratio in nine chronic uraemic patients, but it had no effect in six diabetic patients with normal renal function, whose response to the Valsalva manoeuvre was similar to that of chronic uraemic patients. Naloxone had no effect in eight normal subjects.
3. The increase in the Valsalva ratio observed in uraemic patients was due to restoration of the parasympathetically mediated reflex bradycardia of the release phase of the manoeuvre.
4. Naloxone did not modify supine and standing blood pressure and heart rate in any group.
5. Endogenous opioids may be involved in the defective autonomic control of heart rate in uraemic patients.
Early effects of ethinyloestradiol and norethisterone treatment in post-menopausal women on bone resorption and calcium regulating hormones
Authors: Selby Peter L. , Peacock Munro , Barkworth Stuart A. , Brown Wendy B. , Taylor Geoffrey A. 
Published: August 2015

1. The early effects of sex steroid therapy were assessed in 28 normal post-menopausal women, 18 treated with ethinyloestradiol and 10 with norethisterone.
2. There was a reduction in the fasting urinary excretion of both calcium and hydroxyproline with both treatments, indicating reduced bone resorption. This was apparent after 1 week of therapy but became more marked after 3 weeks.
3. These changes were not accompanied by any changes in plasma levels of calcitonin or parathyroid hormone.
4. Patients receiving ethinyloestradiol showed a marked increase in plasma 1,25-dihydroxyvitamin D (1,25-(OH)2D) concentration but this was explicable entirely in terms of increased plasma levels of vitamin D binding protein. There was no change in the free plasma level of 1,25(OH)2D. Patients treated with norethisterone showed no increase in plasma concentrations of 1,25(OH)2D.
5. We conclude that both ethinyloestradiol and norethisterone have a rapid and similar effect in reducing bone resorption. This is not mediated via the plasma levels of the calcium regulating hormones.
Changes in plasma volume, in transcapillary escape rate of albumin and in subcutaneous blood flow during hypoglycaemia in man
Authors: Hilsted J. , Bonde-Petersen F. , Madsbad S. , Parving H.-H. , Christensen N. J. , Adelhøj B. , Bigler D. , Sjøntoft E. 
Published: August 2015

1. Hypoglycaemia was induced by insulin injected intravenously (0.15 i.u./kg body weight) in seven healthy young males.
2. Plasma volume was measured before and during hypoglycaemia by intravenous injection of 125I before hypoglycaemia and of 131I during hypoglycaemia. Plasma volume decreased and transcapillary escape rate increased significantly during hypoglycaemia.
3. Skin temperature and local subcutaneous adipose tissue blood flow were measured in four different regions. Both tended to decrease during hypoglycaemia and decreased significantly 2 h after hypoglycaemia. There was no correlation between changes in the two measurements, suggesting that there is no simple relationship between subcutaneous blood flow and skin temperature during hypoglycaemia.
Effects of atelectasis and vascular occlusion on the simultaneous measurement of serotonin and propranolol pulmonary extraction in dogs
Authors: Dargent Françloise , Gardaz Jean-Patrice , Morel Philippe , Suter Peter M. , Junod Alain F. 
Published: August 2015

1. To test the relative sensitivity of serotonin and propranolol pulmonary extraction measurements to changes in pulmonary vascular surface, we sequentially subjected anaesthetized dogs to left upper lobe atelectasis, left lung atelectasis and left pulmonary artery occlusion.
2. We used a triple-indicator dilution technique to simultaneously measure the pulmonary extraction of serotonin and propranolol. After an initial series of measurements, dogs received dopamine and dextran to slightly increase pulmonary artery pressure and prevent further recruitment of capillaries.
3. Left upper lobe atelectasis did not modify the pulmonary extraction of serotonin and propranolol. Left lung atelectasis provoked a reduction in the serotonin extraction ratio by only 4%, whereas the propranolol extraction ratio decreased by 13%. After left pulmonary artery occlusion, propranolol and serotonin extraction ratios decreased by 16% and 5% respectively.
4. We conclude that the pulmonary extraction of propranolol is more sensitive to a decrease in pulmonary vascular surface than that of serotonin.
The effect of verapamil and inspired CO2 on the bronchoconstriction provoked by hyperventilation in normal humans
Authors: Twort C. H. C. , Neild J. E. , Cameron I. R. 
Published: August 2015

1. Two groups of eight normal subjects were investigated in separate studies to demonstrate the effects of changes in end-tidal Pco2, and of pretreatment with the calcium antagonist drug verapamil, on bronchoconstriction provoked by voluntary hyperventilation.
2. Total respiratory resistance (Ros) was measured by the forced oscillation technique before and after 90s voluntary hyperventilation. End-tidal Pco2 during hyperventilation was varied by altering inspired CO2 concentration. When end-tidal Pco2 fell during hyperventilation, there was a rise in Ros. This did not occur if end-tidal Pco2 was controlled at a normal resting level during hyperventilation.
3. Specific conductance (sGaw) was measured before and after 90 s voluntary hyperventilation of air. Subjects were treated with oral verapamil or placebo for 2 1/2 days and the effect of hyperventilation on sGaw was reassessed. Verapamil reduced significantly the fall in sGaw caused by hyperventilation. Placebo had no effect.
4. In normal humans, bronchoconstriction provoked by hyperventilating air at ambient temperature and humidity is mediated by the fall in Pco2, and is also reduced by verapamil.
Enhancement of the sympathoadrenal response to the cold-pressor test by naloxone in man
Authors: Bouloux Pierre-Marc , Grossman Ashley , Al-Damluji Saad , Bailey Timothy , Besser Michael 
Published: August 2015

1. The effects of naloxone (8 mg) on the pressor and plasma catecholamine response to a standard cold-pressor test have been evaluated in six normal male subjects. Plasma catecholamines were estimated by high performance liquid chromatography coupled to electrochemical detection.
2. Cold stimulation induced significant elevations in plasma noradrenaline and adrenaline to reach mean peak levels 61% and 108% above their respective basal levels (P &lt; 0.05). Systolic blood pressure increased by 23 ± 6.5 mmHg (P &lt; 0.001), and heart rate increased by 7.5 ± 2.5 beats/min (P &lt; 0.001).
3. Naloxone pretreatment significantly enhanced the plasma adrenaline response to the cold stimulus by 98% (P &lt; 0.01) with concomitant changes in peak systolic blood pressure (peak increment 31 ± 6 mmHg) and pulse rate (12.5 ± 3.5 beats/min) responses (both P &lt; 0.05). The mean plasma noradrenaline response to cold also increased after naloxone, but this failed to achieve significance.
4. Endogenous opioids are likely to be involved in the sympathoadrenal response to a mild acute stress in man.
A technique for the measurement of orthophosphate in human erythrocytes, and some studies of its determinants
Authors: Challa A. , Bevington A. , Angier C. M. , Asbury A. J. , Preston C. J. , Russell R. G. G. 
Published: August 2015

1. A technique is described for the determination of orthophosphate (Pi) in human erythrocytes. The advantages of the technique are that it uses whole blood rather than separated erythrocytes, that it avoids major hydrolysis of organic phosphates, that it takes account of incomplete recovery of Pi and that it minimizes the effects of chilling the cells.
2. In chilled samples from 46 patients in an intensive care unit, the cellular concentration of Pi was proportional to that in plasma.
3. Blood samples from nine normal subjects were incubated at 37°C. The cellular Pi was 0.79 mmol/litre of cells using an external standardization and 0.67 using an internal standardization. When the same cell samples were chilled on ice for 30 min, the internally standardized value decreased further to 0.57 mmol/litre of cells. These results suggest that differences in recovery, and the extent of chilling, contribute to the variability in the previously reported values for erythrocyte Pi.
4. If Pi, like chloride, had distributed passively between cells and plasma in these samples, the cell to plasma molar concentration ratio for Pi should have been 0.29, compared with the measured value of 0.64. This difference suggests that some factor, in addition to passive diffusion, determined the distribution of Pi.
Effect of chlorothiazide on serial measurements of exchangeable sodium and blood pressure in spontaneously hypertensive rats
Authors: Manhem P. J. O. , Clark S. A. , Brown W. B. , Murray G. D. , Robertson J. I. S. 
Published: August 2015

1. Chlorothiazide (100 mg/kg body weight) was given by gavage daily to spontaneously hypertensive rats for 4 weeks. Another group of spontaneously hypertensive rats was given only tap water and served as control.
2. Measurements of total exchangeable sodium, blood pressure and weight were performed for 2 weeks before and for 4 weeks during treatment.
3. Before treatment, exchangeable sodium, blood pressure and weight were similar in the two groups of rats.
4. Chlorothiazide significantly attenuated the blood pressure increase in spontaneously hypertensive rats, the effect being most marked during the first 2 1/2 weeks of treatment and less thereafter.
5. Rats in the chlorothiazide-treated group gained weight more slowly than did those of the control group.
6. Exchangeable sodium, expressed as mmol/kg body weight, did not differ significantly between the two groups at any stage.
7. When exchangeable sodium was expressed as mmol/rat, there was a more gradual rise in the chlorothiazide-treated animals, in accordance with their slower gain in weight.
8. There was no temporal association between the antihypertensive effect of chlorothiazide and changes in exchangeable sodium.
9. Thus whereas chlorothiazide treatment of spontaneously hypertensive rats slows the increase of both weight and exchangeable sodium, other mechanisms are apparently responsible for the antihypertensive action of the drug.
Effect of 1,25-dihydroxyvitamin D deficiency on the metabolic clearance rate of 1,25-dihydroxyvitamin D3: studies using pigs with vitamin D-dependent rickets type 1
Authors: Fox John , Care Anthony D. 
Published: August 2015

1. We have used pigs with inherited vitamin D-dependent rickets type 1 to study the effect of 1,25-dihydroxyvitamin D deficiency on the metabolic clearance rate of 3H-1,25-dihydroxyvitamin D3 infused to steady-state levels in plasma.
2. Plasma levels of 1,25-dihydroxyvitamin D were 24 ± 1 (sem) pmol/l in the hypocalcaemic, homozygous piglets and 196 ± 27 pmol/l in their normocalcaemic, heterozygous siblings.
3. The metabolic clearance rate of 1,25-dihydroxyvitamin D3 was the same in both normal heterozygous (0.90 ± 0.02) and hypocalcaemic, homozygous piglets (0.90±0.01 ml−1 min−1 kg−1 metabolic bodysize).
4. We conclude that a deficiency of circulating 1,25-dihydroxyvitamin D does not influence the clearance of 1,25-dihydroxyvitamin D3 from the circulation of pigs.
Left ventricular diastolic function of spontaneously hypertensive rats and its relationship to structural components of the left ventricle
Authors: Nishimura Hikaru , Kubo Shinichiro , Nishioka Akinori , Imamura Kikuko , Kawamura Keishiro , Hasegawa Motoharu 
Published: August 2015

1. Left ventricular (LV) diastolic function was investigated in three different age groups (15, 28 and 50 weeks) of paired spontaneously hypertensive (SHR) and normotensive (WKY) rats under pentobarbital anaesthesia. A time constant of LV pressure decay, represented by T, was used as an index of LV relaxation. We assessed the relationship between haemodynamic parameters and LV structural components as quantified by microspectrophotometry (MSP), using multivariate analysis.
2. T was significantly prolonged in the 28 and 50 week old SHR compared with their normotensive counterparts (P &lt; 0.05 and P &lt; 0.01, respectively). T was prolonged by volume loading but was not affected with afterload elevation by angiotensin infusion in all age groups of the SHR and WKY.
3. LV wall thickness was greater in the SHR at all ages and was positively correlated with T (r = 0.42, P &lt; 0.05).
4. A significant correlation was found between the increase in cardiac muscle fibre and collagen, the decrease in elastin and glycoprotein, and T on multivariate analysis (r = 0.53, P &lt; 0.05).
5. We conclude that LV relaxation of SHR is disturbed from a relatively young age (28 weeks), for which we consider myocardial hypertrophy and LV structural changes found by MSP as being responsible.
A vasopressin-mediated diminution of potassium excretion in water-loaded man
Authors: Buckley J. , Gebruers E. M. , Hall W. J. , Harrington N. M. B. 
Published: August 2015

1. Intravenous vasopressin (1–3 μ-units min−1 kg−1) had an antidiuretic effect on water-loaded man and also diminished potassium excretion. As noted by others, aspirin (2.4 g) enhanced the antidiuretic effect of vasopressin, but the fall in potassium excretion was not modified by prior administration of aspirin, which makes it unlikely that the fall was due to the release of endogenous prostaglandins.
2. After terminating the infusion of vasopressin, the fall in potassium output persisted longer than the antidiuresis, which makes it unlikely that the antikaliuretic effect of vasopressin is secondary to its effect on urine flow.
3. The unchanged antikaliuretic effect of vasopressin after aspirin treatment, together with its persistence after terminating the infusion, suggest the possible existence of vasopressin-mediated potassium absorption in the distal nephron in certain circumstances.
4. Aspirin administration had specific effects of its own in water-loaded man. It decreased both the water diuresis and sodium excretion but did not alter potassium excretion or urine osmolality.
Dietary fish oil prevents dexamethasone induced hypertension in the rat
Authors: Codde James P. , Beilin Lawrence J. 
Published: August 2015

1. This study was designed to examine the effect of dexamethasone treatment on tissue and urinary prostanoids, and to determine whether inhibition of prostaglandin biosynthesis by manipulation of dietary fatty acids accelerates the development of glucocorticoid hypertension.
2. Forty-eight rats were placed on either a 2-series prostaglandin ‘inhibitory’ diet (cod liver oil/linseed oil) or a control diet of saturated fat for an initial period of 4 weeks. The groups were then divided into two so that half of each received dexamethasone in their drinking water (2.5 mg/1) for 1 week whilst continuing their respective dietary regimens.
3. Rats on the cod liver oil diet incorporated eicosapentaenoic acid into tissue stores with a corresponding decrease in arachidonic acid, and significantly impaired ability to generate serum thromboxane B2 (33%), aortic 6-oxo-prostaglandin F1α (44%), renal homogenate prostaglandin E2 (45%) and 6-oxo-prostaglandin F1α (74%) and urinary prostaglandin E2 (84%) and 6-oxo-prostaglandin F1α (79%).
4. Despite the diminished levels of vasodilator 2-series prostaglandins, the cod liver oil diet prevented the development of glucocorticoid induced hypertension.
5. Relative to their respective dietary controls, dexamethasone treatment resulted in decreased serum thromboxane B2 (20%) but increased aortic 6-oxo-prostaglandin F1α (186%), renal homogenate prostaglandins (127–230%) and urinary excretion of prostaglandin E2 (640–860%) and 6-oxo-prostaglandin F1α(230–365%) in both dietary groups.
6. It therefore seems unlikely that glucocorticoid induced hypertension is a consequence of inhibition of vasodilator prostaglandin synthesis.
Glutamine synthesis in the perfused rat kidney and in isolated rat cortical tubules: regulation by pH
Authors: Lanctin Henri , Brosnan John T. , Ross Brian D. 
Published: August 2015

1. The possible involvement of renal glutamine synthesis in the regulation of ammoniagenesis during metabolic acidosis has been investigated.
2. Using an isotope dilution technique glutamine synthesis has been demonstrated in the intact perfused rat kidney, despite zero net balance for glutamine in this preparation.
3. Inhibition of glutamine synthesis resulted in increased ammonia production in isolated cortical tubules. The rates of these processes were comparable.
4. We conclude that recycling of nitrogen through glutamine synthesis and glutamine hydrolysis could play a quantitatively significant role in the control of ammonia excretion by the kidney, particularly in acute acidosis where the fall in pH seems to inhibit glutamine synthesis.