bluuebunny/crossref_metadata_2025_split huggingface dataset:
Localization of Central Noradrenergic Mechanisms in Cardiovascular Regulation in Rats
Authors: Boudier H. Struyker , Smeets G. , Brouwer G. , Van Rossum J. 
Published: August 2015

1. Various drugs were injected stereotactically into the brain of anaesthetized rats.
2. Noradrenaline injected into the area of the nucleus of the tractus solitarius in the lower brain stem or into the far anterior hypothalamus/pre-optic region induced a fall in blood pressure and in heart rate related to the administered dose.
3. When injected into the anterior hypothalamus/pre-optic region, clonidine and alpha-methyl-noradrenaline induced a long-lasting decrease in blood pressure and heart rate.
Dopa, Catecholamines and Their Metabolites in Essential Hypertension
Authors: Januszewicz W. , Wocial B. 
Published: August 2015

1. Urinary excretion of dopa, catecholamines and their metabolites (vanillylmandelic acid, methoxycatecholamines, 3-methoxy-4-hydroxyphenylglycol and homovanillic acid) were studied in eighty patients with essential hypertension and in twenty-five healthy control subjects.
2. Increased urinary excretion of catecholamines, dopa and catecholamine metabolites was found in a proportion of cases.
3. The relationship between urinary excretion of catecholamine metabolites and the excretion of dopa and noradrenaline was studied.
4. In view of the suggested significance of 3-methoxy-4-hydroxyphenylglycol as an index of brain catecholamine metabolism, particular attention was paid to urinary excretion of this metabolite in the subjects under study.
Adrenergic Responses to Sustained Handgrip in Patients with Juvenile-Onset-Type Diabetes Mellitus
Authors: Nazar K. , Tatoń J. , Chwalbińska-Moneta J. , Brzezińska Z. 
Published: August 2015

1. The response of plasma noradrenaline, arterial blood pressure and heart rate to sustained handgrip at 30% of maximal voluntary contraction was studied in patients with long-term juvenile-onset-type diabetes mellitus and healthy subjects of comparable age.
2. There was no significant difference between the intensity and duration of handgrip in diabetic patients and healthy subjects.
3. Sustained handgrip produced an increase in plasma concentration of noradrenaline both in diabetic and healthy subjects but the response in the diabetic subjects was significantly less.
4. The increase in systolic blood pressure during handgrip was significantly greater in diabetic subjects than in normal subjects. The increases in diastolic and mean blood pressure did not differ significantly.
5. The increase in heart rate during handgrip was greater in healthy subjects than in diabetic subjects. The response was smaller in diabetic patients with retinopathy than in the patients without retinopathy.
6. The sustained handgrip test may be useful for the diagnosis of abnormal sympathetic nervous system and haemodynamic responsiveness in diabetic patients.
Changes in the Renal and Extrarenal Handling of Phosphate Induced by Disodium Etidronate (EHDP) in Man
Authors: Walton R. J. , Russell R. G. G. , Smith R. 
Published: August 2015

1. The diphosphonate, disodium etidronate (disodium ethane-1-hydroxy-1,1-diphosphonate; EHDP), is known to increase plasma inorganic phosphate in man. The present study examines the mechanism of this effect.
2. When EHDP was given by mouth at a dose of 80 μmol (20 mg) kg−1 day−1, plasma phosphate was significantly increased 24 h after the first dose but did not reach its maximum value for 2–3 weeks. When the drug was stopped, plasma phosphate returned to pretreatment values within 3 weeks.
3. Urinary excretion rate of phosphate was not greatly changed during treatment with EHDP despite the large increase in plasma phosphate, suggesting an alteration in renal handling. This was examined directly by infusing phosphate and inulin in six patients off and on EHDP.
4. EHDP had no effect on glomerular filtration rate (GFR) but produced a large increase in the maximum rate of renal tubular reabsorption of phosphate (Tm,P). The ratio Tm,P/GFR increased from a mean value of 1.15 mmol/l to 2.10 mmol/l on EHDP. This increase accounted for the hyperphosphataemia.
5. The same amount of phosphate infused at the same rate produced a greater rise in plasma phosphate when patients were on EHDP than when they were not, indicating a reduced net rate of entry of phosphate into tissues other than kidney.
6. Fasting total plasma calcium concentration and urine calcium excretion rate were not significantly altered by EHDP but the ability of infused phosphate to decrease plasma calcium was diminished.
7. It is suggested that EHDP alters phosphate transport in kidney and other tissues by a mechanism which is probably independent of the known hormonal influences on phosphate metabolism.
Effect of Liver Failure on the Response of Ventilation and Cerebral Circulation to Carbon Dioxide in Man and in the Goat
Authors: Stanley N. N. , Salisbury B. G. , McHenry L. C. , Cherniack N. S. 
Published: August 2015

1. The acid-base state of arterial blood and cerebrospinal fluid, and the ventilatory response to CO2, were measured in twelve patients with liver disease. The CO2 response was also measured in eight goats before and after the experimental production of liver failure. Arterial Pco2 and pH, cerebral blood flow and the cerebral metabolic rate for oxygen were also measured in four of the goats while they breathed air and various CO2-enriched gas mixtures.
2. Liver failure was accompanied by a respiratory alkalosis in both the patients and in the goats. Decreased Pco2 and increased pH occurred in the cerebrospinal fluid and in the arterial blood of the patients.
3. The slope of the ventilatory response to CO2 was reduced when liver failure was severe, in patients and goats alike. In addition there was a reduction in the extrapolated Pco2 at zero ventilation, even when liver failure was mild.
4. Cerebral blood flow and metabolic rate were consistently reduced in the goats during liver failure. There was also less cerebral vasodilatation and a greater reduction in cerebral metabolism during experimental hypercapnia when these animals were in liver failure.
5. The decreases in the ventilatory and cerebral circulatory responsiveness to CO2 indicate that the brain is less well defended against hypercapnia in liver failure, and these changes are especially unfavourable as cerebral function deteriorates when the Pco2 is increased.
Effect of Proportional Reduction of Sodium Intake on the Adaptive Increase in Glomerular Filtration Rate/Nephron and Potassium and Phosphate Excretion in Chronic Renal Failure in the Rat
Authors: Espinel C. H. 
Published: August 2015

1. The influence of dietary sodium intake on the glomerular filtration rate (GFR/nephron) and potassium and phosphate excretion was examined at three stages of progressive chronic renal failure produced in rats by sequential partial nephrectomies.
2. The adaptive increased sodium excretion per nephron in the control group receiving a constant sodium intake did not occur in the experimental group that had a gradual reduction of dietary sodium in direct proportion to the fall in GFR.
3. Despite the difference in sodium excretion, the increase in GFR/nephron, the daily variation in the amount of potassium and phosphate excreted, the increase in potassium and phosphate excretion per unit nephron, and the plasma potassium and phosphate concentrations were the same in the two groups.
4. The concept of ‘autonomous adaptation’ in chronic renal failure is presented.
Increased Plasma Calcitonin in Early Acute Renal Failure
Authors: Ardaillou R. , Beaufils M. , Nivez Marie-Paule , Isaac R. , Mayaud C. , Sraer J.-D. 
Published: August 2015

1. High plasma immunoreactive calcitonin concentrations were observed in ten of eleven patients with acute renal failure, particularly in the oliguric phase.
2. Immunoreactive calcitonin decreased progressively with time, independently of recovery of renal function.
3. Radioimmunoassay curves obtained with serial dilutions of plasma from these patients were parallel to or superimposed upon those obtained with calcitonin standards.
A Common Mechanism for Transport of Di- and Tri-Peptides by Hamster Jejunum in Vitro
Authors: Addison Jill M. , Burston D. , Dalrymple Judith A. , Matthews D. M. , Payne J. W. , Sleisenger M. H. , Wilkinson S. 
Published: August 2015

1. This paper describes the results of a survey of the effects of peptides and amino acids on uptake by rings of everted hamster jejunum in vitro of glycylsarcosylsarcosine, a tripeptide which is taken up by an active mechanism but is very resistant to hydrolysis, appearing intact in the rings. The results of a small number of similar experiments with β-alanylglycylglycine, another tripeptide which is taken up with very little hydrolysis, are also described.
2. Uptake of the two tripeptides was inhibited by other di- and tri-peptides, but not by free amino acids. The results suggest that dipeptides and tri-peptides share a common uptake mechanism. The tetrapeptide glycylsarcosylsarcosylsarcosine did not inhibit uptake of glycylsarcosylsarcosine, and appears to be unable to utilize the uptake mechanism.
3. The results add to information about the influence of molecular structure on intestinal uptake of peptides by the system used by glycylsarcosylsarcosine, which is shared by a wide range of other di- and tri-peptides. In conjunction with previous results, they suggest that substitution of the N-terminal amino or C-terminal carboxyl groups reduces affinity for transport, that the presence of a β-amino acid residue in a peptide is tolerated by the transport system, and that the presence of a d-amino acid residue reduces affinity for transport. Some peptides containing or made up of basic or acidic amino acid residues appear to have a low affinity for the transport system used by glycylsarcosylsarcosine.
4. Of two biologically active peptides, one, cephalexin, a peptide antibiotic, inhibited uptake of glycylsarcosylsarcosine and is probably transported by the same system. The other, prolylleucylglycineamide, which has the action of a hypothalamic regulatory factor, did not, and its structural features may make it unsuitable for carrier-mediated transport by the small intestine.
The Direct Effect of Calcium on the Hyperparathyroidism of Chronic Renal Failure
Authors: Kaye M. 
Published: August 2015

1. The direct effect of calcium on the hyperparathyroidism of chronic renal failure was studied in rats with induced chronic renal failure, who were fed on a diet low in phosphate and who received supplemental phosphate by injection. They were given a normal (0·8%), or low (0·1%) or high (1·7%) calcium diet.
2. The animals on the low calcium diet had larger parathyroids and more severe bone disease at the end of 4 weeks, indicating the importance of calcium intake in directly influencing the degree of hyperparathyroidism.
3. Increasing the calcium content of the diet from 0·8% to 1·7% produced no additional benefits.
Hepatic Glutathione Depletion and Impaired Bromosulphthalein Clearance Early after Paracetamol Overdose in Man and the Rat
Authors: Davis M. , Ideo G. , Harrison N. G. , Williams R. 
Published: August 2015

1. Plasma clearance of bromosulphthalein was impaired in patients within 8 h, and in rats within 2 h, of paracetamol overdose, before biochemical signs of liver damage had appeared.
2. Paracetamol and bromosulphthalein competed for uptake into the liver and excretion into the bile. Impaired hepatic uptake of bromosulphthalein could also be demonstrated in man at doses of the drug within the therapeutic range.
3. In patients studied a smaller proportion of bromosulphthalein was retained in the plasma as the glutathione conjugate after an overdose than after therapeutic doses. This effect could be reproduced in the rat and shown to be due to depletion of hepatic glutathione and to impairment in the activity of the enzyme glutathione-S-aryl transferase.
4. These studies provide further evidence that depletion of hepatic glutathione occurs after paracetamol overdose in man, as in the experimental animal, allowing the subsequent accumulation and binding of a toxic metabolite of the drug within liver cells. Impaired enzymic conjugation of the toxic metabolite with hepatic reduced glutathione may also be important in this situation.
Systolic Blood Pressure Variation during the First 6 Days of Life
Authors: De Swiet M. , Fancourt R. , Peto J. 
Published: August 2015

1. Systolic blood pressure was measured by a Doppler ultrasound technique in twenty normal babies on 6 successive days after the day of delivery. In three babies blood pressure was recorded every 15 min for 24 h.
2. Systolic blood pressure during the first 6 days of life was 95 (sem = 2) mmHg.
3. Systolic blood pressure increased on average by 2 mmHg/day, but increased most between the second and third days of life.
4. Systolic blood pressure was 11 mmHg higher when awake than when the babies were asleep.
5. There was marked within-baby variation in the systolic blood pressure of neonates, which could not be accounted for by age or recognizable changes in level of consciousness.
Plasma Uric Acid Concentration Related to the Urinary Excretion of Aldosterone and of Electrolytes in Normal Subjects
Authors: Ramsay L. E. , Auty R. M. , Horth C. E. , Levine D. , Shelton J. R. , Branch R. A. 
Published: August 2015

1. The relations between the concentration of plasma uric acid and urinary excretion of aldosterone, sodium and potassium, were studied in ten healthy males on a diet containing 160 mmol of sodium and 90 mmol of potassium per day.
2. Plasma uric acid correlated positively with aldosterone excretion and this correlation was statistically independent of sodium and potassium excretion.
3. Plasma uric acid correlated positively with potassium excretion and negatively with the urinary sodium/potassium ratio. There was no significant simple correlation with sodium excretion but the partial correlation of plasma uric acid and sodium excretion was negative and significant when excretion of aldosterone and potassium were held constant.
The Acute Effects of Respiratory and Metabolic Acidosis on Renal Function in the Dog
Authors: Farber M. O. , Szwed J. J. , Dowell A. R. , Strawbridge R. A. 
Published: August 2015

1. Effective renal plasma flow, glomerular filtration rate and cardiac output were measured in osmotically loaded dogs before and during comparable acute respiratory and metabolic acidosis.
2. Urine output increased in control dogs and in animals with metabolic acidosis, but declined with respiratory acidosis. Effective renal plasma flow and glomerular filtration rate declined with respiratory and metabolic acidosis.
3. When respiratory acidosis was buffered with sodium bicarbonate, urine volume increased and glomerular filtration rate and effective renal plasma flow were unchanged; with trihydroxymethylaminomethane, urine volume increased but glomerular filtration rate and effective renal plasma flow fell.
4. When metabolic acidosis was buffered with sodium bicarbonate, urine volume increased; with trihydroxymethylaminomethane, urine volume increased but glomerular filtration rate fell. Cardiac output declined only during metabolic acidosis, both buffered and unbuffered.
5. These studies demonstrate that, even with osmotic loading: (1) respiratory acidosis causes a decrease in glomerular filtration rate, effective renal plasma flow and urine volume; (2) metabolic acidosis depresses glomerular filtration rate and effective renal plasma flow but does not change urine volume even though cardiac output falls; (3) sodium bicarbonate is more effective than trihydroxymethylaminomethane in preserving renal function during respiratory and metabolic acidosis.
Cell Size and Glucose Oxidation Rate in Adipose Tissue from Non-Diabetic and Diabetic Obese Human Subjects
Authors: Harrison L. C. , King-Roach A. P. 
Published: August 2015

1. The rate of oxidation of [1-14C]glucose to 14CO2 was examined in subcutaneous adipose tissue from fifteen obese non-diabetic subjects and from eleven obese maturity-onset diabetic patients. Production of 14CO2, measured in the basal state and in the presence of insulin, was significantly correlated with mean cell size in both the non-diabetic and the diabetic subjects, independent of age, relative weight and fasting plasma insulin concentration.
2. Comparison of the regressions of glucose oxidation rates on mean cell size indicated: (i) that insulin produced a significant increase in activity over the basal value in both groups, and (ii) that basal and insulin-stimulated activity were both significantly lower in diabetic than in non-diabetic adipose tissue.
Changes in the Carotid Body and the Ventilatory Response to Hypoxia in Chronically Hypoxic Rats
Authors: Barer Gwenda R. , Edwards C. W. , Jolly Angela I. 
Published: August 2015

1. Young rats were kept in a hypoxic chamber for 2–11 weeks and compared with littermate control animals.
2. The carotid bodies of the hypoxic rats enlarged, resembling those of men and animals living at high altitude.
3. Permanent blunting of the ventilatory response to hypoxia did not occur. Immediately on removal from the chamber, the rats, lightly anaesthetized, showed a smaller increase in ventilation during hypoxia than did control animals but this difference disappeared after 3 days' recovery in normoxia.
Branched-Chain Amino Acids, Nitrogen Excretion and Injury in Man
Authors: Wedge J. H. , De Campos R. , Kerr A. , Smith R. , Farrell Rose , Ilic Vera , Williamson D. H. 
Published: August 2015

1. Venous blood concentrations of the branched-chain amino acids, valine, leucine and isoleucine, and urinary nitrogen excretion have been measured in sixteen adult males, from 2 h to 7 days after injury, and in four adults after elective skin grafts.
2. In the injured group the concentrations of these amino acids rose significantly 24 h after injury and had doubled at 4 days and remained high; in contrast the skin-graft patients showed no significant change.
3. In those injured patients with initial hyperketonaemia, defined as more than 0·2 mmol/l, the increase in concentrations of branched-chain amino acids at the fourth and seventh days after injury was significantly less than in those with normoketonaemia, and was accompanied by lower urinary nitrogen excretion throughout the whole period.
4. It is suggested that the changes in the concentration of branched-chain amino acids after injury indicate decreased uptake by muscle or excessive release due to an imbalance between protein synthesis and protein catabolism in this tissue.
The Effect of Anaesthesia of the Airway in Dog and Man: A Study of Respiratory Reflexes, Sensations and Lung Mechanics
Authors: Cross Brenda A. , Guz A. , Jain S. K. , Archer Sietske , Stevens J. , Reynolds Felicity 
Published: August 2015

1. The effect of breathing an anaesthetic aerosol of 5% bupivacaine hydrochloride has been assessed in dog and man.
2. In the dog, the cough reflex was abolished and the Hering—Breuer inflation reflex severely impaired or abolished; breathing became slower and deeper; no pathological changes were found in the lungs of these dogs.
3. In man, no untoward effects resulted from a 10 min period of aerosol inhalation; there were no systematic effects on airway resistance or lung volumes and the cough reflex in response to either tactile or chemical (citric acid aerosol) stimulation was invariably abolished. The Hering—Breuer inflation reflex was impaired, but this was not associated with any change in resting ventilation. The V̇E/CO2 response was enhanced after aerosol anaesthesia; subjects felt an exaggerated dyspnoea. The aerosol anaesthesia abolished the afferent pathway of a reflexly elicited bronchoconstriction in one subject. There was no effect on the ability to hold the breath, or on the quality of the associated sensation.
4. Control aerosols of sodium chloride solution or phosphate buffer produced no effects. Control experiments with intravenous infusions of bupivacaine proved that none of the effects could have been produced by systemic effects of the absorbed anaesthetic.
5. Plasma concentrations of bupivacaine in man did not exceed a recognized toxic level. The experiments demonstrate a safe reversible anaesthesia of the airways in man lasting for a period of 10–20 min.
Studies of Amino Acid and Protein Metabolism in Normal Man with l-[U-14C]Tyrosine
Authors: James W. P. T. , Garlick P. J. , Sender P. M. , Waterlow J. C. 
Published: August 2015

1. Six men were infused intravenously for 10 h with a tracer amount of l-[U-14C]tyrosine while on a standardized food intake.
2. Measurements of plasma l-[14C]-tyrosine specific radioactivity and the excretion rate of 14CO2 were made at frequent intervals and showed plateau labelling of plasma and expired carbon dioxide within 6–8 h. The tyrosine flux was calculated from the specific radioactivity in plasma at plateau value.
3. The excretion rate of 14CO2, corrected for retention of label within the bicarbonate pool, showed that oxidation accounted for 20% of the tyrosine flux. Urinary excretion of label was negligible.
4. Rates of protein synthesis were calculated from the flux of tyrosine after subtracting the proportion oxidized. Although the mean rate of synthesis was consistent with other measurements of protein turnover, the individual values ranged from 284 to 387 g/day. The variation was not reduced by relating turnover to body weight, lean body mass or energy expenditure.
5. Estimating the rates of protein breakdown from the tyrosine flux involved some assumptions about pathways of phenylalanine metabolism. The use of a labelled essential amino acid would therefore give more accurate values for short-term measurements of whole body protein turnover.
The Transport of Endogenous Vitamin B12 in Normal Human Serum
Authors: England J. M. , Down Margaret C. , Wise Irene J. , Linnell J. C. 
Published: August 2015

1. Serum from normal subjects has been chromatographed on Sephadex G-200 columns and the fractions containing transcobalamins 0, I and II have been identified.
2. The fractions corresponding to transcobalamin I contained, on average, 90% of the endogenous vitamin B12. Only 3% was attached to transcobalamin 0, and 7% was bound to transcobalamin II.
The Sodium-Retaining Effect of Renal Nerve Activity in the Cat: Role of Angiotensin Formation
Authors: Johns E. J. , Lewis Barbara A. , Singer Bertha 
Published: August 2015

1. The effect of low-frequency stimulation of the renal nerves on renal function and renin release has been investigated. The experiments were performed in unilaterally nephrectomized, anaesthetized cats in which the nerves to the remaining kidney were sectioned.
2. When stimulation frequency was adjusted to reduce renal blood flow by approximately 15% for 15 min, glomerular filtration rate was hardly affected. The ratio sodium clearance/glomerular filtration rate was significantly reduced and plasma renin activity was significantly increased.
3. When the renal nerves were similarly stimulated in the presence of the β-adrenergic receptor blocking agent, propranolol, the glomerular filtration rate was significantly reduced and the rise in plasma renin activity was significantly inhibited. The reduction of sodium clearance/glomerular filtration rate was as great as in the control animals.
4. The results are consistent with the view that the maintenance of glomerular filtration rate, during renal nerve stimulation which reduced renal blood flow, may be mediated by the local generation of angiotensin. The results also suggest that angiotensin does not play an important role in the sodium retention associated with increased renal nerve activity.