bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lack of angiotensin I accumulation after converting enzyme blockade by enalapril or lisinopril in man
Authors: Nussberger J. , Brunner D. B. , Waeber B. , Biollaz J. , Brunner Hans R. 
Published: August 2015

1. In nine normal volunteers, a series of five venous blood samples was obtained before and up to 24 h after converting enzyme inhibition by a single oral dose of enalapril or lisinopril. Plasma renin activity and blood angiotensin I were measured.
2. A close linear relationship was found between the increase in plasma renin activity and the increase in blood angiotensin I.
3. The linear correlation between plasma renin activity and blood angiotensin I remained after converting enzyme inhibition.
4. Thus, the rise in angiotensin I after inhibition of the conversion of angiotensin I to angiotensin II is due to an enhanced release of renin rather than to accumulation of angiotensin I.
AMP deaminase deficiency: Study of the human skeletal muscle purine metabolism during ischaemic isometric exercise
Authors: Sinkeler S. P. T. , Binkhorst R. A. , Joosten E. M. G. , Wevers R. A. , Coerwinkel M. M. , Oei T. L. 
Published: August 2015

1. Muscle biopsies were taken from 10 control subjects and five AMP deaminase (AMPD) deficient individuals before and after an ischaemic isometric exercise test and analysed for purine nucleotide, NAD+, creatine phosphate (CP) and lactate content.
2. The decrease of ATP induced by the exercise test was significantly lower in the AMPD deficient patients than in the controls, but the decrease of creatine phosphate and the increase of lactate did not differ. There were no significant differences in the exertional performance level between patients and controls and no evidence was obtained of an increased energy expenditure per unit of performance in AMPD deficiency.
3. The AMPD deficient individuals were equally capable of maintaining a high adenylate energy charge (EC) as the control subjects, which indicates a normal regulation of the balance between ATP consumption and ATP regeneration.
4. ATP, ADP and total adenine nucleotide (TAN) but not AMP, were significantly elevated in the AMPD deficient patients as compared with the controls before as well as after the exercise test. This underlines the role of AMPD activity in the adenine nucleotide catabolism of skeletal muscle.
Effects of variation of the tri-iodothyronine/reverse triiodothyronine ratio in vivo on the metabolic characteristics of subsequently isolated hepatocytes
Authors: Al-Saadi A. , Sprague D. , Sugden M. , Goode A. , Orr S. 
Published: August 2015

1. Reverse tri-iodothyronine (3,3′,5′-tri-iodothyronine, rT3), a major product of the peripheral monodeiodination of thyroxine, was administered subcutaneously to fed rats at a dose of 100 μg/100 g body weight for 2 consecutive days.
2. This dose induced a 17-fold increase in plasma rT3 (from 0.05±sem 0.01 to 0.85±0.11 ng/ml, P &gt; 0.001) whilst the plasma T3 concentration was decreased to half of the control value (0.40 ± 0.03 to 0.20 ± 0.02 ng/ml, P &gt; 0.01).
3. As a result of these changes the T3/rT3 ratio was therefore decreased from 8.0 ±1.6 to 0.23 ± 0.03 (P &gt; 0.001).
4. Hepatocytes prepared from control or rT3treated rats were incubated with [l-14C]oleate and the rates of 14CO2 release and glucose production were estimated. Despite the changes in ratio of T3 to rT3 observed in vivo, rates of 14CO2 release and glucose production rate from hepatocytes subsequently isolated were unchanged.
Influence of age on deterioration of the remnant kidney in uninephrectomized rats
Authors: Okuda Seiya , Motomura Kenichi , Sanai Tohru , Tsuruda Hiroshi , Oh Yukinori , Onoyama Kaoru , Fujishima Masatoshi 
Published: August 2015

1. To investigate the influence of age on the remnant kidney, unilateral nephrectomy was performed in rats at 1 day (group N-0), 2 weeks (group N-2), 4 weeks (group N-4) or 8 weeks (group N-8) of age. Serial changes in urinary protein during 48 weeks after the uninephrectomy and blood chemistries and renal histology at week 48 were compared between the groups.
2. The increase in proteinuria was significantly greater in groups N-0, N-2 and N-4 than in group N-8 from week 32 to week 48 after the uninephrectomy. There was no significant difference in urinary protein between groups N-0, N-2 and N-4. Hypoproteinaemia and hypoalbuminaemia were also more severe in groups N-0, N-2 and N-4 than in group N-8 at week 48.
3. A compensatory renal growth in groups N-0 and N-4 was significantly greater than that in group N-8 at week 48 after the uninephrectomy.
4. Focal and segmental glomerular sclerosis, a characteristic finding in the uninephrectomy groups, was significantly more marked in groups N-0, N-2 and N-4 than in group N-8 at week 48.
5. We conclude that uninephrectomy at young ages leads to increased incidence of glomerular sclerosis in rats compared with uninephrectomy in the adult.
Exercise-induced changes in renal function and their relation to plasma noradrenaline in insulin-dependent diabetic children and adolescents
Authors: Johansson B.-L. , Berg U. , Bohlin A.-B. , Lefvert A.-K. , Freyschuss U. 
Published: August 2015

1. Exercise-induced changes in renal haemodynamics, water homoeostasis, urinary albumin excretion and their possible relation to plasma noradrenaline were studied in seven insulin-dependent diabetic children and adolescents without signs of autonomic or somatic neuropathy. Six age-matched clinically healthy patients in remission from the minimal change nephrotic syndrome served as controls.
2. The diabetic patients had a higher glomerular filtration rate and effective renal plasma flow and a lower venous plasma noradrenaline level in the basal state. They also had a higher systolic blood pressure compared with the controls. During exercise the diabetic patients showed a less marked reduction in glomerular filtration rate and urinary flow and a greater increase in filtration fraction. Their heart rate increase during exercise was lower. An inverse correlation between the percentage changes in noradrenaline and glomerular filtration rate during exercise was noted solely in the diabetic patients. They also showed a less marked increase in the ratio between potassium and sodium clearances during and 20 min after exercise. Albumin excretion did not differ between the two groups.
3. We suggest that the sympatho-adrenergic effects of exercise on heart rate, renal haemodynamics and water homoeostasis are blunted in our diabetic patients. Hence, signs of impaired sympathetic activity might be disclosed in young diabetic patients with a disease of fairly short duration.
Cigarette smoke-induced ‘chronic bronchitis’: A study in situ of laryngo–tracheal hypersecretion in the rat
Authors: Rogers D. F. , Turner N. C. , Marriott C. , Jeffery P. K. 
Published: August 2015

1. Mucous secretion and mucosal permeability by the larynx and trachea, isolated in situ, was investigated in normal rats and in those in which ‘chronic bronchitis' was induced by daily exposure to cigarette smoke for 2 weeks. Fucose was used as a specific marker for the secretion of mucus glycoprotein, and hexose and protein were markers both for mucus and plasma-type glycoproteins present in tissue fluid transudate. Albumin was used as an indicator of the contribution of serum to the secretions.
2. After equilibration, the mean basal secretion of fucose (μg/30 min collection) was significantly higher in ‘bronchitic’ rats than in the controls (P &lt; 0.01). Mean values for controls were: fucose 3 (sem 1; n = 9), hexose 41 (sem 9; n = 8), protein 1082 (sem 385; n = 8), albumin &lt;2 (n = 8); for ‘bronchitic’ rats the values were: 24 (sem 6; n = 7), 101 (sem 26; n = 8), 2000 (sem 520; n = 8) and &lt;2 μg (n = 7) respectively.
3. In control and bronchitic animals acute administrations of cigarette smoke, blown directly through the laryngo-tracheal segment after equilibration, caused significant (P &lt; 0.05) transient increases in the secretion of fucose, hexose and protein, but not of albumin.
Time course of changes in hepatic metabolism in response to sepsis in the rat: Impairment of gluconeogenesis and ketogenesis in vitro
Authors: De Vasconcelos Paulo R.L. , Kettlewell Michael G. W. , Williamson Dermot H. 
Published: August 2015

1. The time course (12, 24 and 48 h) of changes in blood metabolites, and in gluconeogenesis and ketogenesis, in isolated hepatocytes from rats made septic by caecal ligation and puncture was measured.
2. Blood glucose was not significantly different in septic rats, but lactate was increased at 12, 24 and 48 h; pyruvate and alanine were increased at 48 h. The blood ketone body concentrations were decreased at all times studied after induction of sepsis. These changes were accompanied by increased plasma insulin in the septic rats.
3. The rate of hepatic lipogenesis in vivo was increased at 24 and 48 h.
4. There were appreciable increases in the hepatic concentrations of alanine (200%), lactate (200%) and pyruvate (100%) as well as other intermediates in the gluconeogenic pathway. The hepatic concentrations of acetyl-CoA and ketone bodies were decreased.
5. The rate of gluconeogenesis from added lactate, pyruvate, alanine and glutamine was depressed in isolated hepatocytes from septic rats at 24 and 48 h.
6. The basal rate of ketogenesis or the rate from butyrate in isolated hepatocytes was not significantly altered by sepsis, whereas the rate from oleate was decreased at all time points.
7. It is concluded that there is an impairment of the capacity for gluconeogenesis and ketogenesis in livers of septic rats. The latter may be due to decreased entry of long-chain acyl-CoA into the mitochondria for oxidation. The possibility that these changes are in part brought about by the hyperinsulinaemia associated with the sepsis is discussed.
Absorption of 5-fluorouracil and related pyrimidines in rat small intestine
Authors: Bronk J. R. , Lister Norma , Lynch Susan 
Published: August 2015

1. The transport of 5-fluorouracil, uracil and thymine has been studied with isolated jejunal loops of rat small intestine. High performance liquid chromatography was used to identify the pyrimidines and measure their concentrations.
2. When the lumen of the intestine was perfused with 5-fluorouracil or uracil at 0.1 mmol/l or 0.2 mmol/l, the concentration in the serosal secretions was significantly higher than that in the lumen. For thymine the serosal concentration exceeded that in the lumen only at 0.1 mmol/l.
3. Analysis of the mucosal tissue water at the end of the perfusion demonstrated that when the intestinal lumen was perfused with any one of the three pyrimidines at 0.1 mmol/l or 0.2 mmol/l the concentration within the tissue was significantly above that in the lumen.
4. After an initial lag period linear rates of transport from the lumen to the serosal secretions were obtained for all three pyrimidines over a 10-fold concentration range from 0.1 mmol/l to 1 mmol/l.
5. Uracil and thymine inhibited the transmural transport of 5-fluorouracil.
6. The transport of 5-fluorouracil was also studied with a vascularly perfused preparation of rat small intestine. At 0.1 mmol/l the rate of transmural transport of the drug in this preparation was substantially higher than in the jejunal loops. This difference was eliminated by adding 5-fluorouracil to the vascular perfusate, suggesting that the higher transport rate in the vascularly perfused preparation was due to the lower serosal drug concentrations in the mesenteric circulation of the perfused intestine.
7. At a concentration of 5 mmol/l 5-fluorouracil inhibited water transport in the isolated loops and transmural D-galactose transport in the vascular perfusions.
Blood fuel metabolites in asthma during and after progressive submaximal exercise
Authors: Packe G. E. , Wiggins J. , Singh B. M. , Nattrass M. , Wright A. D. , Cayton Ruth M. 
Published: August 2015

1. Ten male stable asthmatic subjects and 10 matched control subjects performed a progressive exercise test on a treadmill to 85% of their predicted maximum heart rate.
2. Blood lactate, pyruvate, hydrogen ion, glucose, alanine, glycerol and total ketone body concentrations were measured at frequent intervals during and up to 60 min after exercise. Carbon dioxide production, oxygen consumption, ventilation, respiratory exchange ratio and oxygen saturation were also measured during and up to 10 min after exercise.
3. There were no significant differences between the asthmatic and control subjects in levels of carbon dioxide production, oxygen consumption and ventilation. The respiratory exchange ratio was greater in the asthmatic subjects during recovery from exercise (P &lt; 0.05). No changes in oxygen saturation were observed during exercise in either group.
4. In both asthmatic and control subjects, lactate, pyruvate, hydrogen ion, alanine and glycerol concentrations showed an increase from baseline levels, reaching maximum levels up to 10 min after exercise and returning to baseline within 1 h after exercise. Total ketone body concentrations decreased during exercise.
5. There were no significant differences between the asthmatic and control subjects in the concentration of any metabolite over the study period.
6. These data indicate that fuel metabolism during and after short-term progressive exercise is similar in stable asthmatic and normal subjects.
Relationship between hepatic levels of glutathione and sulphobromophthalein retention in hyperthyroidism
Authors: Sir Teresa , Wolff Carlos , Soto Juan Ramon , Perez Gilberto , Merino Rodolfo Armas 
Published: August 2015

1. Sulphobromophthalein (BSP) retention and liver glutathione levels were studied in uncomplicated hyperthyroid patients.
2. BSP retention was increased in 52.5% of the subjects at admission (n = 40) and in 28% of the cases after 3 months of propylthiouracil treatment (300–400 mg/day) (n = 25).
3. Hepatic levels of glutathione were measured in six patients and significant inversed power correlation with BSP retention was observed (r = 0.968, P &lt; 0.001).
4. These data support the contention that the alteration of the BSP retention observed in hyperthyroidism could be due to a decreased availability of hepatic glutathione for conjugation.
Bronchial hyper-responsiveness after human cardiopulmonary transplantation
Authors: Glanville Allan R. , Burke Conor M. , Theodore James , Baldwin John C. , Harvey James , Vankessel Antonius , Robin Eugene D. 
Published: August 2015

1. Bronchial responsiveness to inhaled methacholine was studied in ten heart-lung transplant (HLT) recipients a mean 10.6 months (range 1.5–28 months) post-HLT and in ten normal subjects.
2. The mean provocation dose of methacholine producing a 20% fall in FEV1 (PD20 FEV1) was significantly lower in the HLT recipients (1.70 ± 3.96 mg vs 11.55 ± 3.79 mg; P &lt; 0.001), as was the mean provocation dose of methacholine producing a 50% fall in specific airway conductance (PD50 sGAW) (0.08 ± 0.08 mg vs 5.13 ± 5.47 mg; P &lt; 0.005).
3. These results establish the presence of significant bronchial hyper-responsiveness to inhaled cholinergic agonists in the transplanted lung.
Measurement of lung tissue mass, thoracic blood and interstitial volumes by transmission/emission scanning using [99mTc]pertechnetate
Authors: Briggs B. A. , Bradley T. M. , Vernon P. , Cooke N. T. , Drinkwater C. , Gillett M. K. , Snashall P. D. 
Published: August 2015

1. We have developed a method for non-invasive measurement of lung tissue mass, thoracic blood and interstitial volumes by a combination of transmission and emission scanning with technetium isotope (99mTc).
2. In a lung model we demonstrated that emission counts could be successfully corrected for attenuation with data obtained by transmission scanning, despite an uneven distribution of radioactivity and attenuation in the model.
3. In dogs we compared regional transthoracic tissue thickness, measured by transmission scanning, and regional ‘thickness’ of blood measured by transmission/emission scanning with direct gravimetric measurements made post mortem. Scanning and direct measurements correlated significantly.
4. In man we used a [99mTc]pertechnetate (99mTcO4) flood source to obtain antero–posterior transmission scans with a gamma-camera. The thickness of attenuating tissue was estimated in each pixel. Scans were obtained of thoracic blood (by labelling erythrocytes with 99mTcO4) and of interstitium (with 99mTc-labelled diethylene-triaminepenta-acetic acid and subtraction of the blood image). We used a computer program to correct the emission scans for attenuation using the transmission scan derived tissue thickness, pixel by pixel. Finally we took a lateral chest radiograph to estimate chest wall thickness.
5. In normal man lung tissue thickness at hilar level was 3.1 ± 0.5 cm (n = 8). Thoracic blood thickness increased from the apex downwards in the upright lung, being 1.2 ± 0.1 cm at the hilar level and 2.0 ± 0.3 cm at the lung base. Interstitial thickness was 0.8 ± 0.3 cm at the hilum and 0.85 ± 0.2 at the base. These values compare well with data in the literature.
6. In emphysema (n = 5) lung tissue and blood thickness were decreased; interstitial thickness was normal. In patients with interstitial pneumonitis (n = 7) lung tissue thickness was approximately doubled, and interstitial thickness similarly increased. In two patients with acute pulmonary sarcoidosis interstitial thickness was not increased despite a marked increase in lung tissue thickness.
7. In conclusion, this technique gives information not readily obtainable by other methods, which may be of clinical utility. Further evaluation and development is warranted.
The effects of atrial fibrillation on coronary blood flow and performance of ischaemic myocardium in dogs with coronary artery stenosis
Authors: Ertl Georg , Meesmann Malte , Krumpiegel Klaus , Kochsiek Kurt 
Published: August 2015

1. Atrial fibrillation may impair coronary blood flow by tachycardia and reflex vasoconstriction. It has not been documented, however, whether in the presence of coronary stenosis atrial fibrillation exceeds the effects of rhythmic atrial tachycardia.
2. The effects of experimentally induced atrial fibrillation compared with atrial tachycardia, therefore, were tested in 22 anaesthetized dogs. Stenosis of the left anterior descending coronary artery was induced to reduce coronary blood flow by about 40%.
3. In the presence of coronary stenosis, atrial fibrillation (ventricular rate: 234 ± 21 beats/min) reduced coronary blood flow from 58 ± 7 to 44 ± 8 ml min−1 100 g−1 (P &lt; 0.001, mean ± sem) and subendocardial segment shortening (ultrasonic crystals) from 12 ± 2 to 4 ± 2% (P &lt; 0.0025), and resulted in a lactate production of 30 ± 11% (P &lt; 0.005 vs sinus rhythm).
4. Atrial tachycardia (heart rate: 216 ± 21 beats/min, NS vs atrial fibrillation) did not significantly change coronary blood flow and reduced segment shortening to 7 ± 3% (P &lt; 0.05 vs atrial fibrillation). Significant lactate production did not occur.
5. Since mean arterial pressure fell from 100 ± 4 mmHg at sinus rhythm to 89 ± 3 mmHg (P &lt; 0.01) during atrial fibrillation but not during atrial tachycardia, it was held constant in 13 dogs by a pressurized blood reservoir. Coronary blood flow, however, fell from 43 ± 6 to 36 ± 5 ml min−1 100 gv1 (P &lt; 0.0025).
6. Thus atrial fibrillation may reduce coronary blood flow and induce myocardial ischaemia in the presence of coronary stenosis in excess of atrial tachycardia.
Influence of exercise on ascorbic acid status in man
Authors: Gleeson M. , Robertson J. D. , Maughan R. J. 
Published: August 2015

1. The response of circulating leucocytes with regard to changes in number, proportion of granulocytes and lymphocytes, as well as changes in the ascorbic acid (AA) concentration of plasma and isolated lymphocytes, were studied in nine men who ran a 21 km race. A marked leucocytosis was noted 5 min after the race, the predominant increase being in granulocytes (P &lt; 0.001) with smaller relative increases in circulating lymphocytes (P &lt; 0.01) and platelets (P &lt; 0.001). Numbers of leucocytes and platelets returned to pre-exercise levels within 24 h after the race.
2. The concentration of AA in plasma increased from 52.7 ± 4.1 μmol/l before the race to 67.0 ± 5.3 μmol/l within 5 min after the race (P &lt; 0.001). This increase in plasma AA concentration was positively correlated with the rise in plasma Cortisol concentration during the race (r = 0.89; P &lt; 0.01). However, within 24 h after the race the plasma concentration of AA fell 20 ± 4% below pre-exercise values (P &lt; 0.01) and remained low for at least the next 2 days (P &lt; 0.05).
3. Lymphocyte AA concentration increased from 15.6 ± 0.6 to 19.7 ± 0.9 μmol/g of lymphocyte protein during the race (P &lt; 0.01) but returned to normal levels within 2 days after the race.
4. It is suggested that the adrenal gland may be the major source of AA efflux into the circulation during exercise.
Ageing and the α2-adrenergic system of the platelet
Authors: Davis Pamela B. , Silski Catherine 
Published: August 2015

1. Platelets taken from healthy unmedicated subjects over 65 years of age display less inhibition of prostaglandin E1 (PGE1)-stimulated adenosine 3′:5′-cyclic monophosphate (cyclic AMP) synthesis by noradrenaline than do platelets taken from young adults aged 18–25 years (P &lt; 0.03). The inhibition of cyclic AMP production by noradrenaline (10−5 mol/l) correlates negatively with age over the range 18–92 years (r = −0.338, n = 108, P &lt; 0.005). The reduced cyclic AMP inhibition by noradrenaline in the elderly is not explained by basal cyclic AMP levels or degree of stimulation of platelets by PGE1, which do not differ between young and elderly subjects. The reduction itself is small, though, and cannot be demonstrated for a more potent agonist, adrenaline.
2. Despite the reduced noradrenaline response in the cyclic AMP system in the aged, platelet aggregation in response to α2-adrenergic agents is normal or even slightly increased. Aggregation responses to adrenergic agents correlate well with aggregation responses to adenosine 5′-diphosphate, suggesting that the effector system is a major determinant of the aggregation response.
3. α2-Adrenoceptor number measured by Scatchard analysis of equilibrium binding of [3H]yohimbine to platelet membranes is comparable in young and old subjects, and does not correlate with age. The KD for [3H]yohimbine does not correlate with age. The IC50 for noradrenaline displacing [3H]yohimbine is comparable in young and elderly subjects. Therefore the reduced inhibition of cyclic AMP production by noradrenaline in platelets from elderly subjects is not explained by changes in α2-adrenoceptor number, or agonist- or antagonist-binding properties, but may reside in the coupling of receptor to cyclase.