bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison of the Bronchodilator and Vasopressor Effects of Exercise Levels of Adrenaline in Man
Authors: Warren J. B. , Dalton N. 
Published: August 2015

1. Plasma adrenaline was measured at rest and on exercise in six normal, non-atopic subjects. The exercise test produced a minimum tachycardia of 158 beats/min and a mean plasma adrenaline level of 1.89 nmol/l.
2. On a separate occasion, two doses of l-adrenaline (0.025 μg min−1 kg−1 and 0.05 μg min−1 kg−1) were infused in the same subjects at rest to produce two mean plasma levels similar to those found on exercise.
3. Significant bronchodilation and elevation of plasma glucose occurred with both infusion doses when compared with placebo.
4. Neither infusion caused a significant change in heart rate and only the higher dose caused a small but significant rise in systolic and fall in diastolic blood pressure.
5. Our results suggest that adrenaline as a hormone, at the levels found on exercise, is capable of causing bronchodilation and glycogenolysis in normal subjects. Its contribution to the cardiovascular response to exercise appears to be slight and suggests that its role in cardiovascular physiology may also be marginal.
Physical Exercise as Prophylaxis against Involutional Vertebral Bone Loss: A Controlled Trial
Authors: Krølner Bjørn , Toft Birte , Nielsen Stig Pors , Tøndevold Erik 
Published: August 2015

1. The skeletal effects of physical training were studied in a controlled trial involving 31 healthy women (aged 50–73 years) with previous Colles' fracture of the forearm. The bone mineral content of the lumbar spine and both distal forearms was measured by dual-photon (153Gd) absorptiometry.
2. The participants were allocated to either a physical exercise group or a control group. The former group followed a standardized exercise programme, exercising for 1 h twice weekly during 8 months.
3. Twenty-seven women completed the study. Lumbar spine bone mineral content of the exercise group increased by 3.5%, whereas that of the control group decreased by 2.7%. The rate of bone loss in the control group equalled that of age-matched normal women.
4. The changes in forearm bone mineral content appeared to be independent of the exercise. The bone mineral content of the previously fractured forearm remained nearly unchanged. The bone mineral content of the uninjured forearm decreased on average by 3.5%.
5. The data suggest that physical exercise can inhibit or reverse the involutional bone loss from the lumbar vertebrae in normal women. Physical exercise may prevent spinal osteoporosis.
Intravenous Ethanol Can Provide Bronchodilatation in Asthma
Authors: Ayres Jon G. , Clark T. J. H. 
Published: August 2015

1. The effect of intravenous infusions of saline, and 2, 4 and 8% (v/v in saline) ethanol on airflow were assessed in five normal male subjects and five male patients with asthma.
2. Normal subjects showed no response to intravenous ethanol at any dose.
3. in patients with asthma, specific airways conductance (sGaw) showed a sustained rise of approx. 32.8% from baseline with 8% ethanol which was not seen at lower doses. By contrast, salbutamol (400 μg by aerosol) caused a mean rise in sGaw of 84.4% from baseline.
4. Blood ethanol concentrations showed a sustained rise over the full duration of the study with 8% ethanol but not with lower doses.
5. Ethanol causes a sustained improvement in sGaw in patients with asthma (38.9% of the response to salbutamol) if blood ethanol levels are sufficiently elevated.
Haemodynamic Responses to Static and Dynamic Handgrip before and after Autonomic Blockade
Authors: Lewis Steven F. , Taylor W. Fred , Bastian Bruce C. , Graham Robert M. , Pettinger William A. , Blomqvist C. Gunnar 
Published: August 2015

1. Six healthy men performed static and dynamic handgrip to local muscular fatigue in approximately 6 min under control conditions, i.e. without drugs and after combined para-sympathetic and β-adrenergic blockade with atropine and metoprolol.
2. From rest to exercise at fatigue, systolic, diastolic and mean arterial pressures increased by 32 ± 4 and 39 ± 3 mmHg, 24 ± 3 and 26 ± 4 mmHg, and 26 ± 3 and 30 ± 3 mmHg respectively for static and dynamic handgrip. There were no significant differences between the pressor responses for the two modes of contraction. Cardiac output increased significantly only during dynamic exercise. Total peripheral resistance increased by 2.3 ± 1.0 units for static handgrip (P &lt; 0.05) and by 0.7 ± 0.8 unit (P &gt; 0.05) for dynamic handgrip. Autonomic blockade abolished the heart rate response to both static and dynamic handgrip. For both modes of contraction the systolic arterial pressure responses were 9–12 mmHg lower (P &lt; 0.05) after autonomic blockade, but the diastolic and mean pressure responses were not significantly affected. A significant increase in cardiac output persisted during dynamic exercise. The increase in peripheral resistance during static exercise tended to be greater after blockade. Plasma noradrenaline and adrenaline levels showed only minor elevations in response to static and dynamic handgrip and were not changed by autonomic blockade.
3. These data indicate that when performed to a common end-point with identical small muscle groups static and dynamic exercise produce an equally large pressor response, which is only slightly attenuated by autonomic blockade.
Effects of Acute Blood Volume Expansion on Vascular Resistance and Reactivity in Anaesthetized Dogs
Authors: Jandhyala Bhagavan S. , Hom Gary J. 
Published: August 2015

1. The effects of acute volume expansion on vascular resistance and reactivity to noradrenaline and angiotensin II are reported in this study. The estimated circulating blood volume of pentobartibal-anaesthetized dogs was expanded by about 35% with equilibrated donor blood. The animals were bilaterally nephrectomized to sustain expanded volume.
2. Functional changes in vascular smooth muscle were determined in the flow controlled, vascularly isolated, denervated, perfused hind limb preparation in the same animal.
3. Systemic volume expansion per se had no immediate influence on vascular resistance. However, resistance in the hind limb, as determined by the shift of the pressure-flow curves, progressively increased 60 and 120 min after volume expansion. The changes noted after 120 min were significantly greater than those observed after 60 min.
4. The changes in vascular resistance were accompanied by potentiation of the vascular responses to noradrenaline but not to angiotensin II. Significant shifts which occurred in the noradrenaline dose-response curves were similar to those of the resistance curves.
5. in closely simulated control experiments in dogs whose kidneys were intact or had been removed, and whose blood had or had not been equilibrated with donor blood, the above-mentioned vascular changes were not observed in the absence of volume expansion.
6. It is suggested that the functional changes observed in the hind limb vasculature after volume expansion are related to the presence of a circulating substance. From the data obtained from the experimental model used in this study, it can be concluded that such a substance is not released from the kidney.
Hypokalaemia Stimulates Prostacyclin Synthesis in the Rat
Authors: GÜLlner Hans-Georg , Graf Andrew K. , Gill John R. , Mitchell Murray D. 
Published: August 2015

1. To examine the hypothesis that the normalcy of blood pressure, despite an increase in circulating angiotensin II, and the blood pressor hyporesponsiveness to infusion of pressor agents which are associated with hypokalaemia, are due to overproduction of prostacyclin, the principal prostaglandin (PG) synthesized by the vascular endothelium, we studied the effect of experimental hypokalaemia on the urinary excretion of immunoreactive 6-keto-prostaglandin F1α, a stable metabolite of prostacyclin, in the rat.
2. The animals were fed on a potassium-deficient diet for 9 days. Twenty-four hour urine samples were collected daily for measurement of urinary excretion of immunoreactive 6-keto-PGF1α, PGE2 and 13,14-dihydro-15-keto-PGF2α (PGFM).
3. Hypokalaemia caused significant increases of the three prostaglandins measured.
4. We conclude that hypokalaemia is a potent stimulus of both renal and vascular prostaglandins. The results suggest that an increase in prostacyclin synthesis in peripheral blood vessel walls may be responsible for the resistance of blood pressure to infusion of pressor substances as well as for the normalcy of blood pressure, despite the presence of high circulating angiotensin II concentrations, in conditions associated with hypokalaemia.
The Ventilatory Effects of Doxapram in Normal Man
Authors: Calverley P. M. A. , Robson R. H. , Wraith P. K. , Prescott L. F. , Flenley D. C. 
Published: August 2015

1. To determine the mode of action of doxapram in man we have measured ventilation, oxygen uptake, CO2 production, hypoxic and hypercapnic ventilatory responses in six healthy men before and during intravenous infusion to maintain a constant plasma level.
2. Doxapram changed neither resting oxygen uptake nor CO2 production but produced a substantial increase in resting ventilation at both levels of end-tidal CO2 studied.
3. Doxapram increased the ventilatory response to isocapnic hypoxia from − 0.8 ± 0.4 litre min−1 (%Sao2)−1 to −1.63 ± 0.9 litres min−1 (%Sao2)−1. This was similar to the increase in hypoxic sensitivity which resulted from raising the end-tidal CO2 by 0.5 kPa without adding doxapram.
4. The slope of the ventilatory response to rebreathing CO2 rose from 11.6 ± 5.3 litres min−1 kPa−1 to 20,4 ± 9.8 litres min−1 kPa−1 during doxapram infusion.
5. The marked increase in the ventilatory response to CO2 implies that doxapram has a central action, but the potentiation of the hypoxic drive also suggests that the drug acts on peripheral chemoreceptors, or upon their central connections, at therapeutic concentrations in normal unanaesthetized subjects.
Normal Adrenocortical Response to Adrenocorticotrophic Hormone in Patients with Homozygous Familial Hypercholesterolaemia
Authors: Allen J. M. , Thompson G. R. , Myant N. B. 
Published: August 2015

1. Plasma cortisol concentration was measured in three subjects with homozygous familial hypercholesterolaemia immediately before, and 30 and 60 min after, an intramuscular injection of adrenocorticotrophic hormone. The baseline values and the values at 30 and 60 min were within the normal range.
2. We conclude that in the presence of a genetic deficiency of low-density lipoprotein receptors, the human adrenal cortex can respond to a single injection of adrenocorticotrophic hormone with a normal increase in corticosteroid production.
Plasma Catecholamines do Not Invariably Reflect Sympathetically Induced Changes in Blood Pressure in Man
Authors: Mancia G. , Ferrari A. , Gregorini Luisa , Leonetti G. , Parati G. , Picotti G. B. , Ravazzani Carla , Zanchetti A. 
Published: August 2015

1. Plasma concentrations of noradrenaline and adrenaline were measured radioenzymatically in nine subjects during 4 min pressor and depressor responses (intra-arterial measurements) induced by increasing and reducing sympathetic vasoconstrictor tone via carotid baroreceptor deactivation and stimulation (neck chamber technique).
2. During the pressor response (15 ± 3 mmHg, mean ± se) plasma noradrenaline and adrenaline showed various changes in the different subjects and on average were not significantly increased above control. During the depressor response (−9 ± 2 mmHg) plasma noradrenaline and adrenaline also showed various changes in the subjects and were on average not significantly reduced below control.
3. In contrast the same subjects all showed an increase in noradrenaline and adrenaline (average 76 and 117%) at the fourth minute of a tilting manoeuvre with- a return to pretilting values no more than 4 min after resumption of the supine position.
4. These results suggest that the moderate and/or restricted alterations in sympathetic tone produced by manipulating a single baroreflex, though capable of affecting blood pressure, are not reflected by alterations in plasma catecholamines. To modify these humoral indices significantly, the more drastic or more diffuse alterations in sympathetic activity that may be produced by manipulating low as well as high pressure reflexogenic areas are needed.
Blood Pressure and Casual Urine Electrolytes in 93 London Factory Workers
Authors: Khaw Kay Tee 
Published: August 2015

1. A survey of blood pressure in 93 male London factory workers found a significant correlation between individual systolic blood pressure and sodium/creatinine and sodium/potassium ratios estimated from casual urine samples.
2. Casual urine samples may have value in assessing the dynamic relationship between blood pressure and electrolytes.
Haemodynamic and Metabolic Effects of α-Adrenoceptor Blockade with Phentolamine at Rest and during Forearm Exercise
Authors: Hartling O. J. , Trap-Jensen J. 
Published: August 2015

1. The pre- and post-junctional α-adrenoceptor blocking agent, phentolamine, was given by intravenous infusion to eight healthy volunteers during rest, forearm exercise and post-exercise.
2. Phentolamine produced a sustained increase in heart rate. The diastolic blood pressure decreased slightly whereas systolic and mean blood pressures remained unchanged. Phentolamine caused a marked increase in the forearm blood flow and a decrease in vascular resistance at rest and post-exercise, but did not influence the blood flow or vascular resistance in the exercising forearm.
3. There was a small increase in arterial blood glucose concentration, and a decrease in blood alanine concentration during drug infusion. Blood lactate was not affected by phentolamine. The arterial concentrations of free fatty acids and glycerol increased, and the concentration of triglycerides decreased during phentolamine infusion.
4. Forearm exchange of glucose, lactate, alanine, glycerol, free fatty acids, triglycerides and forearm oxygen consumption were not changed significantly.
5. These findings corroborate the concept that α-adrenoceptor induced vasoconstriction plays a subordinate role in exercising skeletal muscle. All of the metabolic findings might be explained as secondary to an increased noradrenaline release during phentolamine infusion.
The Dependence of Maximal Flow in Man on the Airway Gas Physical Properties
Authors: MacNee W. , Power J. , Innes A. , Douglas N. J. , Sudlow M. F. 
Published: August 2015

1. The changes in maximum expiratory flow rates after washing out lung air with a helium/oxygen mixture (He/O2, 80: 20) were measured in 24 patients with chronic irreversible airflow obstruction (FEV1 1.77 ± sd 0.39 litres; FVC 3.62 ± 0.59 litres), and in six normal subjects. The percentage increase in flow breathing He/O2 was variable; however, it was similar in normal subjects and in patients with airflow obstruction, and in both groups decreased at low lung volumes. Contrary to previous studies, only three patients with chronic airflow obstruction failed consistently to increase flow rates by 20% when breathing He/O2 at all lung volumes measured.
2. In six normal subjects and 12 patients with chronic airflow obstruction airway gas viscosity was increased by breathing a neon/oxygen mixture (Ne/O2, 80:20). The response to Ne/O2 was again variable (normal subjects δVmax.40 4 ± sd 14%; patients δVmax.40 18 ±8%). Only two normal subjects and one patient with airflow obstruction consistently reduced their flow rates when breathing Ne/O2.
3. These results indicate either that there is no difference in the distribution of airflow resistance in normal subjects and in patients with chronic airflow obstruction, or that density as well as viscosity is an important determinant of flow in very small airways. In either case, He/O2 breathing is not a good discriminator of the site of airflow obstruction.
Mechanisms of Airway Narrowing in Acute Pulmonary Oedema in Dogs: Influence of the Vagus and Lung Volume
Authors: Chung K. F. , Keyes S. J. , Morgan B. M. , Jones P. W. , Snashall P. D. 
Published: August 2015

1. In spontaneously breathing dogs (n = 8), maintained in the upright position, bronchial luminal diameter was measured from tantalum bronchograms. Changes in total intrathoracic lung volume were measured from radiographs taken at functional residual capacity (FRCR).
2. With cooling of the cervical vagi to 0–4°C mean bronchial diameter increased to 117 ±15 (sd)% of baseline diameter and FRCR increased to 113 ± 16 of baseline volumes respectively. There was a significant correlation between changes in FRCR and bronchial diameter.
3. After the vagi were rewarmed, pulmonary oedema was induced by rapid intravenous infusion of Hartmann's solution. Bronchi narrowed to a mean of 86 ± 9% of baseline calibre and FRCR decreased (mean = 95 ± 15%).
4. With vagotomy bronchial diameter increased (mean = 102 ± 12% of baseline diameter) but FRCR did not change significantly.
5. Excluding one dog with gross oedema, changes in bronchial diameter due to oedema correlated positively with changes in FRCR; after vagotomy the relationship between diameter and FRCR was similar to that seen after vagal cooling in the baseline state, though individual values were lower.
6. The shift in the diameter-FRCR relationship with vagotomy demonstrates that the direct bronchoconstrictor effect of the vagus is approximately doubled in the presence of pulmonary oedema.
7. Bronchial and peribronchial oedema does not appear to directly narrow the bronchial lumen.
A 45 000 Molecular Weight Human Renin Precursor is Synthesized in a Cell-Free Translation System
Authors: Parmentier Marc , Inagami Tadashi , Pochet Roland 
Published: August 2015

1. Human kidney mRNA species were isolated and fractionated through a continuous sucrose gradient ultracentrifugation.
2. mRNA fractions were translated by using a rabbit reticulocyte lysate and [35S]metbionine as tracer. Double immunoprecipitation was carried out with highly specific anti-human renin and anti-rabbit γ-globulin antisera.
3. A 15S mRNA has been found to direct synthesis of a 45 000 molecular weight protein immunoprecipitable with anti-human renin. This protein is considered to be the ultimate precursor of renin (preprorenin).
Increased Excretion of Kallikrein during Dexamethasone Administrationl in Normal Man on Low and Normal Salt Intake
Authors: López José M. , Arteaga Eugenio , Rodriguez José A. , Croxatto Héctor 
Published: August 2015

1. The effect of dexamethasone administration for 3 days on urinary kallikrein excretion was studied in 12 normal men with normal sodium intake (n=6) or low sodium intake (n=6). Urinary excretion of sodium, potassium, 17-hydroxycorticosteroids, aldosterone and water was also measured in all subjects.
2. Dexamethasone administration was associated with a significant increase in urinary kallikrein excretion (F3, 30 = 6.9; P &lt; 0.001) regardless of sodium intake. No significant correlation could be established between the increase in urinary kallikrein excretion and changes in urinary sodium, potassium, 17-hydroxycorticosteroids, aldosterone or water.
3. These results suggest that dexamethasone can exert a direct action on the renal kallikrein-kinin system.
Leucine Uptake by Splanchnic and Leg Tissues in Man: Relative Independence of Insulin Levels
Authors: Eriksson Ljusk Siw , Hagenfeldt Lars , Felig Philip , Wahren John 
Published: August 2015

1. The influence on leucine disposal of physiological alterations in plasma insulin concentrations was examined in three groups of healthy male subjects, six in each group. After an overnight fast the subjects received an intravenous infusion of either leucine (300 μmol/min for 150 min, series A), or leucine plus glucose (2.2 mmol/min, series B), or leucine, somatostatin (7 μg/min) and glucagon (1 ng/min, series C). Arterial concentrations of substrates and their net exchange across the splanchnic and leg tissues were determined with a catheter technique.
2. Insulin concentrations rose from 12 ± 2 to 20–22 μ-units/ml in series A, from 11 ± 3 to 60–65 μ-units/ml in series B and decreased from 8 ± 1 to approximately 5 μ-units/ml in series C.
3. The basal leucine concentration for all subjects was 109 ± 8 μmol/l and it rose progressively during the infusions. In series A, the level was 598 ±20 μmol/l after 150 min. The corresponding value was 542 ±38 μmol/l in series B and 651 ±25 μmol/l in series C. Significant differences were observed between series A and B (P &lt; 0.05) and series A and C (P &lt; 0.01) when data for 90–150 min of infusion were combined (analysis of variance).
4. In all groups the leucine infusion resulted in an augmented net uptake of leucine across the leg (77-85 μmol/min) and across the splanchnic bed (61-72 μmol/min) but no significant inter-group differences were observed.
5. From these findings we conclude that insulin accelerates and hypoinsulinaemia slows the disposal of an exogenous load of leucine. These effects of insulin result in only modest differences in arterial leucine concentrations and in no demonstrable changes in peripheral or splanchnic leucine exchange, suggesting that insulin plays only a minor role in the disposal of leucine.
Urinary Coproporphyrin in Lead Intoxication: A Study in the Rabbit
Authors: Henderson M. J. , Toothill C. 
Published: August 2015

1. Lead acetate was administered to adult New Zealand White rabbits in their drinking water. Their mean blood lead level rose to 4.5 μmol/l within a week and then remained relatively constant.
2. The rabbits developed a marked coproporphyrinuria. Plasma levels of coproporphyrin increased but not in proportion to the urine excretion. Thus the renal clearance of coproporphyrin rose from a mean of 1.8 ml/min to 32.2 ml/min whilst creatinine clearance remained constant.
3. The concentration of coproporphyrin in renal venous blood from control rabbits was found to be slightly lower than that in arterial blood. In the lead intoxicated rabbits the concentration of coproporphyrin in renal venous blood was approximately three times higher than the arterial concentration.
4. Significantly higher levels of lead, porphobilinogen, uroporphyrin, coproporphyrin and protoporphyrin were found in renal tissue than in brain, heart or liver.
5. Renal tissue homogenates from control rabbits were able to synthesize porphobilinogen, uroporphyrin, coproporphyrin and protoporphyrin when incubated with 5-aminolaevulinic acid. Renal tissue from lead intoxicated rabbits was also able to synthesize these haem precursors although at a reduced rate.
6. Three enzymes from the haem biosynthetic pathway were assayed in renal mitochondria. Compared with those from controls, mitochondria from lead intoxicated rabbits showed no significant difference in ferrochelatase activities, but the activities of coproporphyrinogen oxidase were decreased, and those of 5-aminolaevulinate synthase were increased.
7. It was concluded that a large portion of the excess coproporphyrin excreted by the lead intoxicated rabbits was of renal origin.