bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancement of specific [3H]ouabain binding and ouabain sensitive 86rubidium influx in intact human lymphocytes by a dialysable factor in human and fetal calf serum
Authors: Oh V. M. S. , Taylor E. A. , Ding J. L. , Boon N. A. , Aronson J. K. , Grahame-Smith D. G. 
Published: August 2015

1. We have measured specific [3H]ouabain binding and ouabain sensitive 86rubidium influx in intact human lymphocytes incubated for up to 7 days in media containing different concentrations of fetal calf serum and human serum.
2. Incubation for periods of up to 7 days with fetal calf serum and human serum produced increases in both specific [3H]ouabain binding and ouabain sensitive 86rubidium influx that were dependent on concentration and time.
3. Neither specific [3H]ouabain binding nor ouabain sensitive 86rubidium influx was altered when dialysed serum was used, suggesting that both fetal calf serum and human serum contain a dialysable factor or factors which stimulate specific [3H]ouabain binding and ouabain sensitive 86rubidium influx in intact human lymphocytes.
4. To further elucidate the mechanisms underlying these changes we also measured the activity of two other enzymes of the lymphocyte plasma membrane, 5′-nucleotidase and γ-glutamyltransferase, the uptake of [3H]thymidine by the intact cells, and the effects of cycloheximide, puromycin, and anisomycin, inhibitors of protein synthesis.
5. The activity of 5′-nucleotidase was increased after incubation of the lymphocytes in fetal calf serum for 72 h, but the activity of γ-glutamyltransferase was not changed, suggesting some selectivity of the stimulatory effect.
6. Measurements of [3H]thymidine uptake by the lymphocytes showed that the major part of the observed changes in specific [3H]ouabain binding and ouabain sensitive 86rubidium influx was not attributable to transformation of the lymphocytes to lymphoblasts.
7. All three inhibitors of protein synthesis prevented the increase in specific [3H]ouabain binding due to fetal calf serum.
Adrenergic control of plasma magnesium in man
Authors: Whyte Kenneth F. , Addis George J. , Whitesmith Robert , Reid John L. 
Published: August 2015

1. Regulation of magnesium balance is poorly understood. However, hypomagnesaemia has been reported in patients in clinical situations where circulating catecholamines are raised including myocardial infarction, cardiac surgery and insulin-induced hypoglycaemia stress tests.
2. The effects of l-adrenaline infusions, sufficient to achieve pathophysiological levels of adrenaline, and of therapeutic intravenous infusions of salbutamol, a β2-agonist, on plasma magnesium, plasma potassium, plasma glucose and plasma insulin levels were studied in a placebo-controlled design in eight normal subjects.
3. Plasma magnesium levels fell significantly during the adrenaline infusion and also during the salbutamol infusion, though more slowly. In a 1 h period of observation after cessation of the infusions no recovery of plasma magnesium levels was seen. Significant falls in plasma potassium levels were also observed during both infusions with spontaneous recovery within 30 min after the infusions.
4. No significant changes in plasma insulin levels occurred with either salbutamol or l-adrenaline compared with control. Plasma glucose levels rose significantly during the adrenaline infusion.
5. The study suggests that both l-adrenaline and salbutamol cause shifts in plasma magnesium which are not mediated by insulin. We propose that intracellular shifts of magnesium occur as a result of β-adrenergic stimulation.
Plasma atrial natriuretic peptide concentrations during exercise in sodium replete and deplete normal man
Authors: Richards A. M. , Tonolo G. , Cleland J. G. F. , McIntyre G. D. , Leckie B. J. , Dargie H. J. , Ball S. G. , Robertson J. I. S. 
Published: August 2015

1. To explore the effects of exercise on plasma atrial natriuretic peptide (ANP) concentrations, eight normotensive volunteers performed maximal treadmill exercise in sodium replete and deplete states.
2. Baseline immunoreactive plasma ANP concentrations were significantly lower during sodium depletion. During exercise plasma ANP rose in all subjects on both occasions. Plasma peptide responses were attenuated by sodium depletion with peak exercise levels only double baseline values, in contrast to the threefold increase in ANP concentrations observed when subjects were sodium replete.
3. Plasma renin and aldosterone concentrations also rose with exercise. In contrast to changes in plasma ANP, the responses of both were enhanced by sodium depletion.
Intrathyroidal autonomic nerves can directly influence hormone release from rat thyroid follicles: A study in vitro employing electrical field stimulation and intracellular microelectrodes
Authors: Green Stephen T. 
Published: August 2015

1. The role of the autonomic nervous system in the control of thyroxine release from the rat thyroid gland in vitro, has been investigated using electrical field stimulation as a device to induce intrathyroidal nerves to release their neurotransmitters.
2. The effects of field stimulation on follicular cell membrane potential and input resistance have been investigated using continuous intracellular recordings from individual cells.
3. Electrical field stimulation promotes up to an eightfold increase in throxine release from the thyroid gland in vitro. This effect is blocked by the neurotoxin, tetrodotoxin.
4. Electrical field stimulation has no effect on follicular cell membrane potential or input resistance. This is consistent with the results of previous pharmacological experiments using this preparation.
5. It is concluded that electrical field stimulation induces intrathyroidal nerves to release their neurotransmitters, and that the net effect of this is to cause thyroxine release from the thyroid follicles. The existence of a directly acting secretomotor innervation to the thyroid follicle is suggested.
Effects of ethanol ingestion on blood pressure reactivity
Authors: Eisenhofer G. , Lambie D. G. , Johnson R. H. 
Published: August 2015

1. We examined the acute effects of ethanol consumption on circulatory responses to the cold pressor test, to handgrip exercise and to intravenous infusion of methoxamine in eight normal male subjects.
2. Ethanol consumption reduced systolic blood pressure responses to the cold pressor test and to handgrip exercise and depressed both systolic and diastolic blood pressure responses to infusion of methoxamine. The depressant effects of ethanol on blood pressure responses to methoxamine were considerably greater than the effects on the cold pressor test and handgrip exercise. Catecholamine concentrations during the cold pressor test and handgrip exercise were not significantly different with or without prior ethanol consumption.
3. Alcohol has been shown to have an acute hypotensive action with all the stimuli.
Oral absorption of the somatostatin analogue SMS 201–995: Theoretical and practical implications
Authors: Fuessl Hermann S. , Domin Jan , Bloom Stephen R. 
Published: August 2015

1. Oral administration of SMS 201–995 (SMS), a subcutaneously injectable somatostatin analogue, was investigated in five healthy volunteers, who drank 2 mg of SMS with 75 g of glucose.
2. Mean maximal plasma SMS concentrations after the 2 mg oral dose were comparable with those after subcutaneous injection of 50 μg, although the peak was delayed (90 vs 15 min).
3. Biological activity of absorbed SMS was shown by significant and lasting suppression of plasma insulin concentrations, resulting in significant hyperglycaemia at 90 and 120 min compared with the control study.
4. The feasibility of oral administration of SMS may extend its use in the treatment of acromegaly and gut endocrine tumours. Other peptide hormone analogues, structurally ‘protected’ against enzymatic degradation, may also be active orally and thus be useful therapeutically.
Cardiac and renal hyperplasia in newborn spontaneously hypertensive rats
Authors: Kunes Jaroslav , Pang Stephen C. , Cantin Marc , Genest Jacques , Hamet P. 
Published: August 2015

1. Cardiac hyperplasia in newborn spontaneously hypertensive rats (SHR) has been noted by our group as well as by other investigators. The present study was designed to establish whether early (neonatal) hyperplasia is confined to the heart or is a generalized phenomenon in this hypertensive model.
2. The ventricles, kidney and liver of newborn SHR, Wistar and Wistar-Kyoto (WKY) rats were analysed for their protein and DNA content.
3. Total organ weight and the organ/body weight ratio of the heart and kidney but not of the liver were significantly greater in the SHR than in the control rats, irrespective of total body weight.
4. The higher relative DNA content (per 100 mg of tissue or 100 g body weight) indicated that hyperplasia rather than hypertrophy was responsible for the enlarged heart as well as the kidney of newborn SHR.
5. The cause of this selective cardiac and renal hyperplasia is not yet known: it may be due to putative ‘haemodynamic growth stimuli’, an intrinsic genetic abnormality of cells in the heart and kidney, circulating growth-promoting factors, or innervation.
Atrial natriuretic peptide: Evidence of action as a natriuretic hormone at physiological plasma concentrations in man
Authors: Anderson J. V. , Donckier J. , Payne N. N. , Beacham J. , Slater J. D. H. , Bloom Pr S. R. 
Published: August 2015

1. The administration of exogenous atrial natriuretic peptide (ANP) causes a natriuresis and diuresis in man, but this has, to date, only been demonstrated at plasma ANP concentrations within the high pathological or pharmacological ranges. Evidence that ANP acts physiologically requires the demonstration of a natriuretic effect when it is infused to recreate plasma concentrations similar to those observed after physiological stimuli.
2. We infused human α-ANP (1–28) at a calculated rate of 1.2 pmol min−1 kg−1 for 3 h into seven water-loaded normal subjects, achieving plasma ANP concentrations within the upper part of the physiological range. The subjects' resting plasma ANP concentration increased from 3.8 ± 1.5 to 20.9 ± 1.9 pmol/l.
3. The infusion of ANP caused a 60% increase of mean urinary sodium excretion from 111 ± 18 to 182 ± 30 μmol/min (P &lt; 0.001) and a 28% increase of mean water excretion from 10.8 ± 0.8 to 13.8 ± 1.6 ml/min (P &lt; 0.01).
4. The infusion suppressed mean plasma renin activity from 1.55 ± 0.10 to 1.17 ± 0.06 pmol of ANG I h−1 ml−1 (P &lt; 0.001). Mean plasma aldosterone concentration (242 ± 16 basally and 215 ± 15 pmol/l at the end of ANP infusion) did not change significantly. Pulse rate and blood pressure were unchanged throughout the study.
5. No significant change in any of the variables mentioned above occurred during the infusion of the vehicle alone on a separate study day.
6. The demonstration that recreation of plasma concentrations of ANP within the physiological range by intravenous infusion induces a natriuresis provides new evidence supporting the role of ANP as a natriuretic hormone.
Reduced brain Na+,K+-ATPase activity in rats with galactosamine-induced hepatic failure: relationship to encephalopathy and cerebral oedema
Authors: Ede Roland J. , Gove Christopher D. , Hughes Robin D. , Marshall William , Williams Roger 
Published: August 2015

1. Previously we have shown that sera from patients with fulminant hepatic failure (FHF) will inhibit partially purified rat brain Na+,K+-ATPase and sodium efflux from human leucocytes in vitro. Similar inhibition may be involved in the pathogenesis of encephalopathy and cerebral oedema in these patients.
2. In the present study we have attempted to establish whether the activity of brain Na+,K+-ATPase is decreased in vivo in rats with d-galactosamine induced hepatic failure using homogenates of snap-frozen brains.
3. Na+,K+-ATPase activity was significantly reduced in the forebrain region at the stage of mild encephalopathy (43 h after injection), while at the deeper stage of coma (43–53 h after injection) enzyme activity was further reduced in the forebrain region and was also significantly reduced in the hindbrain region. Ouabain insensitive ATPase activity was not significantly altered at any time.
4. While a significant increase in the water content (0.5%) of the hindbrain region was found 43 h after galactosamine, there was no clear correlation between the development of cerebral oedema and the reduction of Na+,K+-ATPase activity.
5. The activity of partially purified normal rat brain Na+,K+-ATPase was 15% lower when incubated with sera from rats in the deep stage of coma compared with control sera.
6. These data support other evidence that the reduction in brain Na+,K+-ATPase is likely to be due to toxic substance circulating in serum which have been shown to inhibit this enzyme in vitro and to cause coma when administered to normal animals.
Effect of dietary linoleate content on the metabolic response of rats to Escherichia coli endotoxin
Authors: Wan Jennifer M. , Grimble R. F. 
Published: August 2015

1. Dietary fat influences many aspects of immune function. Escherichia coli endotoxin is a potent stimulator of interleukin 1 production from macrophages.
2. The present study examines the effect of feeding with fat diets rich (corn oil) and poor (coconut oil) in linoleate at high and low concentrations on responses to endotoxin.
3. Spleen phosphatidylcholine linoleate contents were higher in the corn oil than in the coconut oil group and arachidonate concentrations were highest in the group fed a high concentration of corn oil.
4. Coconut oil completely abolished the responses to endotoxin.
5. The inhibitory effects of coconut oil could largely be due to reduced prostaglandin and leukotriene synthesis.
The ulcerogenic and protective action of rice and rice fractions in experimental peptic ulceration
Authors: Jayaraj A. P. , Tovey F. I. , Clark C. G. , Rees K. R. , White J. S. , Lewin M. R. 
Published: August 2015

1. The ulcerogenic and protective effects of various rice fractions in the diet were studied in the pylorus ligated ulcer model in the rat.
2. Oil present in rice and particularly rice bran becomes ulcerogenic on storage and in this model results in a significant increase in the median (range) numbers of ulcers from six (one to ten) to nine (six to 15) (P &gt; 0.05). The ulcerogenic effect of stored rice bran oil was reversed by cysteine which significantly reduced the ulcer incidence from 100% to 60% (P &gt; 0.005) and the numbers of ulcers from 26 (six to 70) to one (zero to four) (P &gt; 0.001).
3. Fresh rice bran significantly reduced the numbers of ulcers from six (one to ten) to one (one to four) (P &gt; 0.05). Similarly, unmilled rice and freshly milled newly harvested rice was also shown to be protective in this model by significantly reducing the ulcer incidence from 87.5% to 50% and 0% respectively (P values &gt; 0.025) and the numbers of ulcers from three (zero to 17) to one (zero to one) and zero (zero to zero) respectively (P values &gt; 0.001).
4. These results could in part explain the geographical distribution of duodenal ulceration, where the incidence is high in all the rice eating areas of the world, and provide a plausible hypothesis to explain the mechanism of dietary ulcerogenesis.
Changes in the plasma levels of atrial natriuretic peptides during mineralocorticoid escape in man
Authors: Cappuccio Francesco P. , Markandu Nirmala D. , Buckley Martin G. , Sagnella Giuseppe A. , Shore Angela C. , MacGregor Graham A. 
Published: August 2015

1. Plasma levels of atrial natriuretic peptide (ANP) were measured by radioimmunoassay in eight normal healthy volunteers before and during mineralocorticoid escape.
2. Mean plasma ANP on a fixed sodium intake before fludrocortisone was 6.5± sem 1.1 pg/ml. Within 24 h of fludrocortisone administration there was a significant increase in plasma ANP which continued to increase daily reaching a plateau by day 4 (14.9 ± 2.4 pg/ml) to day 7 (15.1 ± 2.6 pg/ml).
3. The rise in plasma ANP was closely related to the amount of sodium retained during the fludrocortisone treatment and the sodium ‘escape’ occurred by days 4 to 7.
4. These results support the concept that ANP could play an important hormonal role in overcoming the sodium-retaining effects of mineralocorticoids in man.
β-Adrenoceptor blockade and plasma lipoproteins. Comparison of the effects of propranolol and pindolol on plasma lipoproteins including high-density lipoprotein subfractions
Authors: Northcote Robin J. , Ballantyne David 
Published: August 2015

1. β-Adrenoceptor blocker therapy is known to cause disturbances of the lipoprotein profile. The long-term effects of β-adrenoceptor blockers and the influence of intrinsic sympathomimetic activity (ISA) has not been clearly defined. We measured serum lipoproteins during chronic β-adrenoceptor blockade in patients with stable angina pectoris treated with propranolol (without ISA) (n = 21) or pindolol (with ISA) (n = 19).
2. No significant changes occurred in the lipoprotein profile of the patients taking pindolol. In those taking propranolol, very low density lipoprotein (VLDL) increased at 52 weeks (P &lt; 0.05) and total high density lipoprotein (HDL) decreased at 26 weeks (P &lt; 0.01) and at 52 weeks (P &lt; 0.05). However, HDL2 rose significantly at 52 weeks (P &lt; 0.05). There was a corresponding increase in HDL2/HDL3 ratio.
3. We conclude that pindolol is less likely to exert a harmful effect on plasma lipoproteins than β-adrenoceptor blockers without ISA.
The relationship between the plasma potassium concentration and renal potassium excretion in the adrenalectomized rat
Authors: West M. L. , Sonnenberg H. , Veress A. , Halperin M. L. 
Published: August 2015

1. The purpose of this study was to evaluate the renal mechanisms which lead to a high urine [K+] in adrenalectomized (ADX) rats devoid of aldosterone.
2. By dividing the urine [K+] by the urine to plasma osmolality ratio, the [K+] in the cortical collecting duct luminal fluid can be estimated; dividing this value by the plasma [K+] yields an index of the transtubular [K+] gradient (TTKG) in vivo.
3. The TTKG was close to 7 in aldosterone deficient ADX rats while on a normal K+ diet and fell towards unity when amiloride or a low K+ diet was administered to these rats.
4. With a longer time on a low K+ diet, the TTKG was less than 1 in ADX rats. This suggests that K+ was reabsorbed in the medullary collecting duct under these conditions.
5. Hyperkalemia appears to have an ‘aldosterone-like’ action in the cortical collecting duct in vivo in the absence of aldosterone in ADX rats. This action of hyperkalemia permits normal K+ excretion rates despite the absence of mineralocorticoids.
Bronchial effects of leukotriene D4 inhalation in normal human lung
Authors: Bisgaard Hans , Groth Steffen 
Published: August 2015

1. The aim of the study was to investigate whether inhaled leukotriene (LT) D4 could mimic the characteristics of asthmatic patients after allergen-induced attack, i.e. a prolonged subclinical bronchial obstruction, an increased reactivity of the airways and a late reaction. The effects of LTD4 were compared with those of histamine and the mechanism of action sought.
2. Thirty-three non-atopic individuals participated in the study. The two drugs were inhaled as an aerosol of small particles causing a relative peripheral deposition pattern in order to mimic the preferential involvement of peripheral airways in asthmatic patients out of attack.
3. LTD4 caused a dose-dependent obstruction of the airways as measured by partial flow-volume curves and volume of trapped gas, yet only minor changes in forced expiratory volume in 1 s (FEV1) and peak expiratory flow rate. LTD4 was 1900–7000 times more potent than histamine. LTD4 inhalations were almost symptomless as opposed to the irritative and dyspnoeic symptoms seen after inhalation of histamine.
4. The time duration for the induced change in partial flow-volume curves was the same for the two drugs. Approximately 30 min elapsed until the bronchial obstruction had decreased by 50% of the maximum effect, and no delayed reaction was observed within 10 h.
5. The reactivity of the airways did not change during 10 h after inhalation of LTD4 as tested by repeated exercise challenges.
6. Pretreatment with ipratropium bromide prevented the effect of LTD4 on FEV1, yet not on partial flow-volume curves. Pretreatment with either cimetidine and mepyramine or with indomethacin, did not affect the bronchial obstruction after LTD4.
7. In conclusion, peripheral deposition of LTD4 in non-atopic subjects causes symptomless reduction in airflow with changes in lung function imitating that found in asthmatic patients out of attack. Unlike an allergen-induced asthmatic attack, inhalation of LTD4 does not seem to induce bronchial hyper-reactivity to exercise nor a late reaction. These findings are compatible with LTD4 as a mediator involved in bronchial asthma.
Gliadin binding to rat and human enterocytes
Authors: Colyer J. , Kumar P. J. , Waldron N. M. , Clark M. L. , Farthing M. J. G. 
Published: August 2015

1. Binding of 125I-crude gluten digest (Frazer's fraction III, FF-III) and 125I-concanavalin A (Con A) to isolated rat enterocytes and of 125I-FF-III to human enterocytes was investigated.
2. Specific binding of 125I-FF-III to rat enterocytes was observed but binding was not inhibited by any of a range of simple and complex saccharides, although casein and bovine serum albumin displaced FF-III at high concentrations.
3. Con A also bound to enterocytes in a specific manner and was inhibited by α-methyl-D-mannoside, confirming a lectin-mediated interaction.
4. 125I-FF-III exhibited quantitatively similar specific binding to both normal human and coeliac enterocytes.
5. The primary interaction of gliadin peptides with the enterocyte surface membrane is not lectin-mediated and unlikely to be of fundamental importance in the pathogenesis of coeliac disease.
Haemodynamic consequences of experimental papillary necrosis in the rat
Authors: Russell Gavin I. , Bing Robert F. , Thurston Herbert , Swales John D. 
Published: August 2015

1. Experimental renal papillary necrosis induced by 2-bromoethylamine hydrobromide (BEA) results in hypertension in the rat. The haemodynamics of this increase in blood pressure were investigated with radiolabeled microspheres, thus enabling individual organ blood flows to be evaluated.
2. Total peripheral resistance was raised in BEA-treated rats (3.6 ± 0.3 mmHg ml−1 minm 100 g) compared with control rats (2.87 ± sem 0.2, P &lt; 0.05) whilst cardiac index remained similar (39.9 ± 3.6 vs 39.2 ± 3.1 ml min−1 100g−1).
3. Heart and brain from BEA rats demonstrated a significant rise in vascular resistance with a normal blood flow. In the kidneys vascular resistance increased still further and here there was a reduction in renal blood flow despite an increase in kidney size.
4. These findings are compatible with a loss of renomedullary vasodepressor mechanisms acting directly or indirectly on the resistance vessels.