bluuebunny/crossref_metadata_2025_split huggingface dataset:
Whole-body and tissue protein synthesis during brief and prolonged fasting in the rat
Authors: Cherel Yves , Attaix Didier , Rosolowska-Huszcz Danuta , Belkhou Rajae , Robin Jean-Patrice , Arnal Maurice , Maho Yvon Le 
Published: August 2015

1. Little information is currently available on protein turnover during chronic protein loss situations. We have thus measured the whole-body and tissue protein fractional synthesis rates (ks), the whole-body fractional protein degradation rate (kd), the capacity for protein synthesis (Cs) and the efficiency of protein synthesis (kRNA) in vivo in fed and fasted (1, 5 and about 9 days) 400 g rats.
2. One day of starvation resulted in a reduced ks and an increased kd in the whole body. ks was selectively depressed in skeletal muscles, mainly owing to a reduced kRNA, and was not modified in heart, liver and skin. The contribution of skin to whole-body protein synthesis increased by 39%.
3. During the phase of protein sparing (5 days of fasting), kd in the whole body decreased below the control fed level. ks in skeletal muscles was sustained because kRNA was restored to 82–98% of the control value.
4. Rats were in a protein-wasting phase after 9 days of starvation. kd in the whole body did not increase and was actually 78% of the value observed in fed animals. By contrast, ks in the whole body and tissues decreased to 14–34% of the control values, owing to reductions in both Cs and kRNA. Whatever the duration of the fast, the contribution of the skin to whole-body protein synthesis largely exceeded that of skeletal muscle.
5. The present findings suggest that the main goal in the treatment of chronic protein loss should be to sustain protein synthesis. Our data also emphasize the importance of skin in whole-body protein synthesis in fasting and possibly in other protein loss situations.
ATP production in isolated muscle mitochondria from haemodialysis patients: effects of correction of anaemia with erythropoietin
Authors: Bárány Peter , Wibom Rolf , Hultman Eric , Bergström Jonas 
Published: August 2015

1. The ATP production rate in isolated skeletal muscle mitochondria was measured with a bioluminescence method, before and during erythropoietin treatment, in 21 anaemic haemodialysis patients. In addition, the concentrations of ATP, phosphocreatine and total creatine and the ratio of alkali-soluble protein to DNA were determined in skeletal muscle. Maximal oxygen uptake and maximal exercise capacity were determined on a bicycle ergometer.
2. The results unexpectedly showed a 35% higher mitochondrial ATP production rate in the patients before erythropoietin treatment than in sedentary control subjects. On the other hand, mitochondrial density, as measured by the activity of the matrix enzyme glutamate dehydrogenase, was the same in the patients as in the sedentary control group. After 1 year on maintenance erythropoietin treatment, the ATP production rate per kg of muscle decreased in five out of seven patients and reached the same level as in the sedentary control subjects. The ratio between ATP production rate and glutamate dehydrogenase activity was on average 40% higher in the patients at the start and decreased towards the control level in six out of seven patients after 1 year on maintenance erythropoietin treatment. When related to the mitochondrial protein content, a significant reduction in the ATP production rate was observed.
3. The ratio of alkali-soluble protein to DNA in skeletal muscle and the concentrations of ATP, phosphocreatine and total creatine in skeletal muscle at rest were normal in the patients and did not change during the study. The maximal aerobic power improved by 25% after the correction of anaemia.
4. These results suggest that the enhanced mitochondrial ATP production rate in renal anaemia is a metabolic adaptation to decreased oxygen transport and is reversed by long-term correction of anaemia.
Feedback inhibition of insulin secretion in type 2 diabetes
Authors: Baynes C. , Anyaoku V. , Johnston D. G. , Elkeles R. S. 
Published: August 2015

1. The purpose of the present study was to examine the ability of insulin to inhibit its own secretion in type 2 diabetes independently of the prevailing plasma glucose concentration.
2. The responses of the plasma C-peptide concentration to sustained hyperinsulinaemia were assessed during a 200 min isoglycaemic clamp study in 14 patients with type 2 diabetes and seven age-and weight-matched control subjects. The arterialized venous plasma glucose concentration was clamped at ∼ 0.3 mmol/l below each subject's own basal level and was not permitted to rise above the basal level.
3. In the fasting state, the plasma C-peptide concentration was slightly, but not significantly, higher in the diabetic patients than in the control subjects (667 versus 413 pmol/l, respectively, P = 0.07), but it remained significantly higher in the diabetic patients during the clamp studies in absolute terms (minimum plasma C-peptide concentration 400 pmol/l in diabetic patients versus 151 pmol/l in control subjects, P &lt;0.05) and was suppressed to a lesser extent when expressed as a percentage change from basal (35.8% in diabetic patients versus 59.4% in control subjects, P &lt;0.01).
4. In order to investigate whether a high plasma glucose concentration was maintaining the plasma C-peptide concentration in the diabetic patients, six of these patients underwent a second clamp study at euglycaemia (plasma glucose concentration 5.2 mmol/l). Under these conditions, the plasma C-peptide concentration was suppressed to the same extent as in the control subjects (from 623 to 195 pmol/l, a change of 62.7%).
5. The results suggest that the insulin-β feedback loop is intact in type 2 diabetes when euglycaemia is acutely restored, but that basal hyperglycaemia maintains elevated insulin secretion rates and may, therefore, blunt the ability of insulin to regulate its own secretion in this condition.
Dilator actions of arginine in human peripheral vasculature
Authors: Calver Alison , Collier Joe , Vallance Patrick 
Published: August 2015

1. l-Arginine is the physiological precursor for the formation of endothelium-derived nitric oxide. The synthesis of nitric oxide is stereospecific: d-arginine is not a substrate for nitric oxide synthase. It is possible that the provision of excess l-arginine substrate might increase the vascular synthesis of nitric oxide. We have examined this possibility by studying the effects of local infusion of l-and d-arginine in the forearm resistance bed and the superficial dorsal hand veins of healthy subjects.
2. Drugs were either infused locally into a vein on the back of the hand and then the vein diameter was measured using a linear displacement technique, or into the brachial artery and then the forearm blood flow was measured by venous occlusion plethysmography.
3. In the superficial hand veins, l- and d-arginine free base and l- and d-arginine hydrochloride (all four preparations at a dose of 5 μmol/min) all caused a significant increase in venous diameter. The responses of the l-and d-enantiomers did not differ significantly from one another.
4. In the forearm resistance bed, l- and d-arginine free base and l-arginine hydrochloride were without effect at doses of 10 and 40 μmol/min. However, at doses of 160 μmol/min all three preparations of arginine caused a significant increase in forearm blood flow compared with control values. The responses to the three preparations of arginine did not differ significantly from one another.
5. These results show that arginine in high dose is a vasodilator in both human resistance vessels and superficial veins in vivo. The response to arginine was not stereospecific: both the l- and d-enantiomers had the same effect. The dilator effect of high-dose arginine showed neither arterio-nor veno-selectivity.
6. This suggests that the hypotensive effect of systemic infusions of l-arginine in man is mediated by peripheral vasodilatation. It is not possible to ascribe the actions of arginine supplementation in this study to activation of the l-arginine/nitric oxide pathway through the provision of excess substrate.
Effects of l-arginine on systemic and renal haemodynamics in conscious dogs
Authors: Murakami Marohito , Suzuki Hiromichi , Ichihara Atsuhiro , Naitoh Mareo , Nakamoto Hidetomo , Saruta Takao 
Published: August 2015

1. The effects of l-arginine on systemic and renal haemodynamics were investigated in conscious dogs. l-Arginine was administered intravenously at doses of 15 and 75 μmol min−1 kg−1 for 20 min.
2. Mean arterial blood pressure, heart rate and cardiac output were not changed significantly by l-arginine infusion. However, l-arginine infusion induced a significant elevation of renal blood flow from 50 ± 3 to 94 ± 12 ml/min (means ± sem, P &lt; 0.01).
3. Simultaneous infusion of NG-monomethyl-l-arginine (0.5 μmol min−1 kg−1) significantly inhibited the increase in renal blood flow produced by l-arginine (15 μmol min−1 kg−1) without significant changes in mean arterial blood pressure or heart rate.
4. Pretreatment with atropine completely inhibited the l-arginine-induced increase in renal blood flow, whereas pretreatment with indomethacin attenuated it (63 ± 4 versus 82 ± 10 ml/min, P &lt; 0.05).
5. A continuous infusion of l-arginine increased renal blood flow in the intact kidney (55 ± 3 versus 85 ± 9 ml/min, P &lt; 0.05), but not in the contralateral denervated kidney (58 ± 3 versus 56 ± 4 ml/min, P &gt; 0.05).
6. These results suggest that intravenously administered l-arginine produces an elevation of renal blood flow, which may be mediated by facilitation of endogenous acetylcholine-induced release of endothelium-derived relaxing factor and vasodilatory prostaglandins.
Fat-cell heat production, adipose tissue fatty acids, lipoprotein lipase activity and plasma lipoproteins in adiposis dolorosa
Authors: Fagher Birger , Monti Mario , Nilsson-Ehle Peter , Åukesson Björn 
Published: August 2015

1. Gluteal adipose tissue was examined in 13 patients with generalized adiposis dolorosa, a clinical condition characterized by painful adiposity with a chronic intractable course. The total metabolic activity of fat cells, isolated by collagenase and suspended in Krebs-Ringer bicarbonate buffer with glucose and insulin, was assessed by the measurement of heat production at 37°C using microcalorimetry.
2. Fat cells were markedly enlarged; their metabolic activity expressed in terms of μW/g, but not in pW/cell, was significantly decreased when compared with both lean and weight-matched non-painful subjects. Both mean values were, however, significantly higher than in grossly obese subjects with similar mean cell size. Heat production as expressed per g of tissue, but not per cell, was inversely correlated with body mass index. One additional patient had unilateral disease, and fat cells from the painful side had a lower heat production than cells from the unaffected side.
3. The fatty acid composition of adipose tissue, as determined by g.c., revealed a significantly increased proportion of monounsaturated (18:1 and 16:1) at the expense of saturated (14:0 and 18:0) fatty acids compared with healthy control subjects. The activity of adipose tissue lipoprotein lipase was slightly, but not significantly, decreased.
4. It is concluded that a metabolic pathogenetic factor cannot be ruled out in adiposis dolorosa. As the results do not explain the nature of the diffuse pain, further studies need to be performed.
Amiloride-sensitive lithium reabsorption during doxazosin-induced blood pressure reduction in rats
Authors: Petersen Jørgen Søberg , Shalmi Michael , Bak Martin , Lomholt Niels , Christensen Sten 
Published: August 2015

1. The effects of acute systemic α1-anoceptor blockade by doxazosin on glomerular filtration rate, urine flow, sodium clearance and lithium clearance were investigated in acutely prepared conscious rats.
2. Clearance experiments were performed during water diuresis (20 mmol/l NaCl and 110 mmol/l glucose, 3 ml/h). After a control period, animals were randomized to one of the following treatments: time-control (n = 9), doxazosin (50 μg primer; 30 μg h−1 kg−1) (n = 10), amiloride (1 mg primer; 2.4 mg h−1 kg−1) (n = 10) and doxazosin plus amiloride (n = 9).
3. Doxazosin reduced the mean arterial blood pressure from 125 to 108 mmHg; this was associated with transient reductions in glomerular filtration rate, urine flow and lithium clearance. After the transient anti-diuresis, the sodium excretion rate remained reduced in doxazosin-infused animals. Amiloride increased the sodium excretion rate without having effects on other variables. When doxazosin was given together with amiloride, the reduction in lithium clearance observed during the transient reduction in glomerular filtration rate and urine flow, was partly abolished. Thus the fractional lithium excretion was transiently increased in rats given doxazosin plus amiloride (from 29 to 40%), whereas in rats given doxazosin alone a non-significant reduction was observed (from 28 to 25%). The dissociation between lithium clearance and fractional lithium excretion in the two doxazosin-infused groups was only significant during the transient reduction in glomerular filtration rate and urine flow.
4. The results provide evidence for an amiloride-sensitive lithium reabsorption during acute systemic α1-adrenoceptor blockade. It is suggested that activation of baroreflexes during the acute reduction in mean arterial blood pressure is responsible for stimulation of distal lithium reabsorption by an unknown mechanism.
Electrocardiographic changes during steady mild hypothermia and normothermia in patients with poikilothermia
Authors: MacKenzie Marius A. , Aengevaeren Wim R. M. , Hermus Ad R. M. M. , van der Werf Tjeerd , Pieters Gerlach F. F. M. , Smals Anthony G. H. , Kloppenborg Peter W. C. 
Published: August 2015

1. ECG changes observed in short-term induced and accidental hypothermia are well known. To assess the influence of steady-state spontaneous hypothermia on the ECG, we subjected four patients with acquired poikilothermia (severe thermolability) to 24 h ECG recording, exercise testing and thermal stress.
2. Twenty-four hour Holter monitoring showed a significant reduction in heart rate and a prolongation of the QT interval during steady-state mild hypothermia (rectal temperature 33.9 ± 0.7°C, mean ± sd) compared with during normothermia; no significant changes occurred in the PR interval, QRS complex and QTc interval (QT interval corrected for heart rate).
3. Unlike during normothermia, during steady hypothermia atrioventricular Wenckebach blocks were observed in two patients, whereas another patient showed markedly more atrioventricular Wenckebach blocks during hypothermia.
4. During steady hypothermia the heart rate variability was significantly enhanced in comparison with normothermia.
5. Exercise tolerance was similar during mild hypothermia and normothermia.
6. Heat exposure (ambient temperature 40°C) induced significantly greater changes in rectal temperature, heart rate and PR interval, QRS complex and QT interval in the patients than in the control subjects (n = 8).
7. The present study reveals that even mild steady spontaneous hypothermia can elicit ECG changes, presumably mediated by relatively enhanced cardiac vagal tone. Hence, spontaneous abnormalities in core temperature should be taken into account in interpreting the ECG in clinical practice.
Effect of haemodialysis on plasma levels of brain natriuretic peptide in patients with chronic renal failure
Authors: Lang Chim C. , Maria Anna , Choy J. , Henderson Iain S. , Coutie Wendy J. , Struthers Allan D. 
Published: August 2015

1. Plasma human brain natriuretic peptide-like immunoreactivity (hBNP-li) was measured in ten patients with chronic renal failure before and after 4 h of haemodialysis.
2. Plasma hBNP-li was elevated in all patients before dialysis (mean ± sem 21.0 ± 3.8 pmol/l) compared with healthy control subjects (1.3 ± 0.2 pmol/l, n = 11), but showed considerable inter-patient variability. Before dialysis plasma hBNP-li bore no relationship to the serum creatinine level or to the mean blood pressure.
3. Plasma hBNP-li fell significantly (P = 0.04) during 4 h of haemodialysis. The fall in plasma hBNP-li correlated significantly with the degree of postural blood pressure drop (r2 = 0.44, P = 0.05) and with the fall in body weight (r2 = 0.64, P&lt;0.01) after haemodialysis. In all patients, plasma hBNP-li at the end of treatment remained above that in healthy subjects.
4. There was no significant correlation between the fall in plasma hBNP-li and the fall in serum creatinine level, and between the fall in plasma hBNP-li and the fall in supine systolic or diastolic blood pressure, during haemodialysis.
5. We have shown that plasma hBNP-li is elevated in patients with chronic renal failure and is decreased during haemodialysis. The fact that the plasma hBNP-li was not reduced to normal by haemodialysis despite restoration to normovolaemia gives tentative support to the view that, in addition to hypervolaemia, another factor may also be responsible for the elevated plasma hBNP-li seen in these patients.
Differences in ouabain-induced natriuresis between isolated kidneys of Milan hypertensive and normotensive rats
Authors: Foulkes Roland , Ferrario Romana G. , Salvati Patricia , Bianchi Giuseppe 
Published: August 2015

1. Several observations support the hypothesis that in rats of the Milan hypertensive strain elevated levels of a circulating ouabain-like factor might normalize the elevated Na+ reabsorption, but, on the other hand, might contribute to the development of hypertension.
2. As the receptor occupancy of this endogenous factor seems to be reversible, the aim of our study was to test, in vitro, the hypothesis of its presence in isolated kidneys from Milan hypertensive rats by studying the response to exogenous ouabain before and after prolonged washing.
3. The kidneys were isolated from adult Milan hypertensive rats and from age-matched normotensive controls and ouabain was given at two different experimental time intervals: shortly (15 min) after washout or after a further 60 min of washout (75 min in total). Comparative experiments with the diuretic hydrochlorothiazide were performed using the same protocol.
4. Ouabain given after 15 min of perfusion caused an increase in renal vascular resistance, diuresis and natriuresis; these haemodynamic and tubular responses were similar in kidneys from both Milan hypertensive and Milan normotensive rats. If given after the washout period, ouabain caused a comparable increase in renal vascular resistance, but a significantly greater natriuresis in kidneys from Milan hypertensive rats as compared with kidneys from Milan normotensive rats. On the other hand, hydrochlorothiazide caused similar natriuresis in kidneys from both strains after washout.
5. These results support the hypothesis that a factor, capable of interacting with the ouabain receptor on the Na+/K+−ATPase of tubular cells, is present in the kidney of adult Milan hypertensive rats and that it can be removed by prolonged washout.
Kinetics of sodium-lithium countertransport activity in patients with uncomplicated type I diabetes
Authors: Rutherford Peter A. , Thomas Trevor H. , Carr Susan J. , Taylor Roy , Wllklnson Robert 
Published: August 2015

1. Increased erythrocyte sodium-lithium countertransport activity has been reported to be associated with nephropathy in type 1 diabetes and linked to a family history of essential hypertension.
2. This study aimed to determine the mechanism of increased sodium-lithium countertransport activity. Sodium-lithium countertransport kinetics were measured in uncomplicated and hyperlipidaemic type 1 diabetic patients.
3. In the nine out of 31 uncomplicated type 1 diabetic patients who had high sodium-lithium countertransport activity, the sodium affinity (Km) was normal but the maximum velocity (Vmax.) was increased.
4. Hyperlipidaemia, when present in diabetic patients, was associated with increased sodium-lithium countertransport activity, but could not explain the high activity in uncomplicated type 1 diabetic patients in whom plasma lipid concentrations were normal.
5. Sodium-lithium countertransport activity is increased in type 1 diabetes by a mechanism different to that in essential hypertension, where the mechanism is a low Km (increased sodium affinity). Hence familial hypertension cannot explain the raised sodium-lithium countertransport activity in type 1 diabetes.
Extent of ischaemia caused by hepatic vascular exclusion as evaluated in a canine model
Authors: Egawa Hiroto , Morimoto Taisuke , Takeuchi Toshihiko , Yamaoka Yoshio , Ozawa Kazue , Yamaguchi Tetsuya , Yamamoto Naritaka 
Published: August 2015

1. The difference in the extent of liver ischaemia between a hepatic vascular exclusion model and an inflow occlusion model were investigated by determining Indocyanine Green retention and hepatic mitochondrial redox state during 2 h of ischaemia in 10 mongrel dogs. The splanchnic venous bed and/or the infra-hepatic inferior vena cava were decompressed by pump-driven veno-venous bypass.
2. The Indocyanine Green retention test revealed that there was no hepatic blood flow in the hepatic vascular exclusion model during ischaemia (96.8 ± 0.73% retention of the dye after 20 min), whereas hepatic blood perfusion was still present significantly in the inflow occlusion model (78.1 ± 1.19% retention of the dye after 20 min) (P &lt;0.01).
3. The mitochondrial redox potential of the liver in the dogs with hepatic vascular exclusion decreased immediately after the induction of ischaemia and remained fixed at extremely low levels. By contrast, in the dogs with inflow occlusion the redox potential decreased gradually after induction and was maintained significantly higher than that in dogs with hepatic vascular exclusion during 2 h of ischaemia (P&lt;0.01).
4. It is concluded that the extent of liver ischaemia in the hepatic vascular exclusion model with pump-driven shunt is significantly different from that in the inflow occlusion model with shunt.