bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma Adrenaline and Noradrenaline in Essential Hypertension and after Long-Term Treatment with β-Adrenoreceptor-Blocking Agents
Authors: Franco-Morselli R. , Baudouin-Legros M. , Meyer P.
Published: August 2015

1. Plasma adrenaline and noradrenaline were measured in supine and upright positions in 27 essential hypertensive patients and in 12 age-matched control subjects.

2. Plasma adrenaline was markedly increased in a large proportion of patients, compared with control subjects, either in supine or in upright positions, whereas no significant differences were found in plasma noradrenaline.

3. Six hypertensive patients were chronically treated with β-adrenoreceptor-blocking agents (five with propranolol and one with pindolol). Plasma noradrenaline was not significantly changed in the supine position but was markedly increased on standing in four out of six patients. Plasma adrenaline was decreased in five out of six patients either in supine or upright positions.

4. These findings support the view that the adrenergic system participates in the mechanism of essential hypertension.
Redistribution of Regional Blood Flow after Administration of Saralasin in Salt-Depleted Dogs
Authors: Liang Chang-Seng , Gavras Haralambos , Brunner H. R.
Published: August 2015

1. Salt depletion was produced in five dogs by a low salt diet and daily administration of frusemide for 5 days; a control group of five dogs was placed on the same diet, to which 2·5 g of sodium chloride was added.

2. Saralasin infusion (0·5 μg min−1 kg−1) reduced mean aortic blood pressure and total peripheral vascular resistance and increased cardiac output in salt-depleted dogs, but did not affect the heart rate and left ventricular dP/dt.

3. Saralasin infusion increased mean aortic blood pressure slightly in normal dogs; other systemic haemodynamic parameters did not change significantly.

4. Saralasin decreased hepatic arterial flow in both normal and salt-depleted dogs, but increased blood flow to left ventricle and kidneys only in salt-depleted dogs.

5. These results suggest that saralasin exerts a partial agonist effect in normal dogs to increase arterial blood pressure, but causes a depressor response during salt depletion because it reverses the vasoconstrictor effect of angiotensin II, particularly on the renal and coronary circulations.
Haemodynamic Effects of a Calcium Antagonistic Agent (Nifedipine) in Hypertension: Therapeutic Implications
Authors: Bartorelli C. , Magrini F. , Moruzzi P. , Olivari M. T. , Polese A. , Fiorentini C. , Guazzi M.
Published: August 2015

1. In 27 severe primary hypertensive patients nifedipine (10 mg), administered orally, induced prompt (–21% of control at 30 min) and persistent (–17% at 120 min) fall of mean arterial pressure mediated through reduction of peripheral vascular resistance with rise of cardiac output.

2. The sublingual route (nine cases) showed more rapid onset of action and equal antihypertensive effectiveness.

3. In five patients with hypertensive crisis and acute left ventricular failure, the drug strikingly reduced systemic and pulmonary arterial pressures and relieved pulmonary oedema.

4. Prompt efficacy, ease of administration, absence of important side effects indicate that nifedipine may be a useful therapeutic agent in severe hypertension and in critical conditions that require rapid lowering of blood pressure.
Arousal and the Circadian Rhythm of Blood Pressure
Authors: Floras J. S. , Jones J. V. , Johnston J. A. , Brooks D. E. , Hassan M. O. , Sleight P.
Published: August 2015

1. We have recorded ambulant intra-arterial blood pressure in five normo- and 14 hyper-tensive subjects over 24 h, particular attention being paid to the timing of arousal.

2. The data were edited beat-by-beat before storing systolic, diastolic, and mean blood pressure ± sd for every 2 min period on a computer file.

3. When pooled hourly mean data are plotted there is a rise of 52·9 mmHg systolic and 22·3 mmHg diastolic pressure from 03.00 hours to 11.00 hours in the 14 hypertensive subjects.

4. When the data are plotted in 20 min periods for the hours before and after arousal it is clear that the major rise in pressure occurs abruptly at that time. The 2 h period before arousal shows only a small rise in pressure, i.e. 6·9 mmHg systolic and 2·9 mmHg diastolic.

5. It is suggested that the apparent rapid early morning rise of blood pressure is an artifact of the method of analysis.
Relaxation Rate of Constituent Muscle-Fibre Types in Human Quadriceps
Authors: Wiles C. M. , Young A. , Jones D. A. , Edwards R. H. T.
Published: August 2015

1. Muscle fibres may be subdivided into type I (with slow-twitch contractile properties) and type II (fast-twitch) depending on their myosin adenosine triphosphatase activity. In voluntary isometric contractions type I fibres are utilized at low forces (<20% of maximum) whereas type II fibres are recruited in addition at high forces. This physiological recruitment order has enabled us to measure the relaxation rate of type I and II fibres in vivo in normal human subjects.

2. Relaxation rate was measured in 16 subjects from low (10% of maximum) and maximum isometric quadriceps contractions and the muscle-fibre type composition determined from needle-biopsy specimens in 10 subjects. The relaxation rate of type II fibres was calculated to be twice as fast as that of type I.

3. It was not possible to estimate, from studies in 33 quadriceps muscles (25 normal subjects), the contribution of type II fibres to overall fibre area from the relaxation rate as determined from electrically stimulated isometric contractions.
Erythropoiesis, Iron Stores and Tissue Iron Exchange in Man
Authors: Cavill I. , Ricketts C. , Jacobs A.
Published: August 2015

1. The exchange of iron between plasma and erythroid and non-erythroid tissues was measured in 14 normal subjects, 17 iron-deficient patients, nine patients with primary idiopathic haemochromatosis and in 13 patients with haemolytic disorders.

2. The two main factors determining tissue iron turnover were shown to be the level of iron stores and the erythropoietic activity of the bone marrow.
Heart-Rate Response to Sustained Hand Grip: Comparison of the Effects of Cardiac Autonomic Blockade and Diabetic Autonomic Neuropathy
Authors: Hume L. , Ewing D. J. , Campbell I. W. , Reuben S. R. , Clarke B. F.
Published: August 2015

1. The heart-rate response during sustained hand grip was studied in four normal subjects before and after intravenous atropine, propranolol and combined cardiac autonomic blockade with both drugs. The results suggest that the increase in heart rate during the first 30 s is due to parasympathetic withdrawal, whereas the further increase between 30 s and 180 s is probably mediated by a combination of parasympathetic withdrawal and sympathetic stimulation.

2. The increases in heart rate during each minute of sustained hand grip were compared in 26 normal subjects, 37 diabetic subjects without and 24 diabetic subjects with proven autonomic neuropathy. In the diabetic subjects with autonomic neuropathy the increase in heart rate during the first minute was impaired, whereas the increases during the second and third minutes were similar in all three groups.

3. The initial increase in heart rate over the first 30 s of hand grip and the later increase between 30 s and 180 s were compared in nine normal subjects, ten diabetic subjects without and six diabetic subjects with autonomic neuropathy. The increase during the first 30 s was impaired in the diabetic subjects with autonomic neuropathy, whereas the later phase of the response was similar in all three groups.

4. It is concluded that impairment of the heart-rate response to sustained hand grip in diabetic autonomic neuropathy is mainly due to impairment of the early parasympathetic phase, but that the presence of cardiac sympathetic damage can also be detected.
Plasma Level and Renal Clearance of Oxalate in Normal Subjects and in Patients with Primary Hyperoxaluria or Chronic Renal Failure or Both
Authors: Constable A. R. , Joekes A. M. , Kasidas G. P. , O'regan P. , Rose G. A.
Published: August 2015

1. Plasma oxalate has been measured by a radioisotopic method applicable to all concentrations of plasma oxalate and renal function, and also by an enzymatic method which was only applicable to raised concentrations of plasma oxalate.

2. Where the two methods could be applied simultaneously, the agreement between them was good.

3. Plasma oxalate was 86% ultrafiltrable at concentrations of up to 44 μmol/l.

4. Oxalate clearance and the exchangeable oxalate pool were also measured. The ratio of oxalate clearance to creatinine clearance was greater than unity in most normal subjects and patients.

5. These methods were used in normal subjects and in patients with primary hyperoxaluria and/or chronic renal failure. A raised plasma oxalate concentration was found in both conditions. Chronic renal failure is probably the most common cause of a raised plasma oxalate.
Arterial Distensibility in Normal and Hypertensive Man
Authors: Gribbin B. , Pickering T. G. , Sleight P.
Published: August 2015

1. The pulse-wave velocity along the brachial radial artery was measured in 38 subjects and volume distensibility values were calculated.

2. Measurements made at each subject's resting blood pressure showed that those with high blood pressure had higher pulse-wave velocity values and hence less distensible arteries.

3. An acute rise in arterial distending pressure was accompanied by a rise in pulse-wave velocity.

4. When pulse-wave velocity was remeasured in all subjects at identical arterial distending pressures, no difference was found between hypertensive and normal subjects.

5. It appears that poor distensibility of large arteries in hypertensive subjects is a consequence of the elevated distending pressures and not due to irreversible structural changes in the arterial wall.
Effects of Aprotinin on Renal Function and Urinary Prostaglandin Excretion in Conscious Rats after Acute Salt Loading
Authors: Kramer H. J. , Moch T. , Von Sicherer L. , Düsing R.
Published: August 2015

1. Aprotinin, a potent kallikrein inhibitor, was given to conscious rats with and without expansion of the extracellular fluid volume with isotonic saline.

2. In noa-expanded rats aprotinin had no effect on arterial pressure, glomerular filtration rate (GFR), hippuran clearance, urinary flow rate, absolute sodium and potassium excretion or free-water clearance.

3. In volume-expanded rats aprotinin significantly reduced GFR, hippuran clearance, urine volume (V) UNaV, UKV and Cwater/GFR without effect on systemic arterial pressure.

4. Urinary immunoreactive prostaglandin E2 excretion significantly increased during the expansion phase but returned to below the control range during stable extracellular fluid volume expansion.

5. Aprotinin significantly suppressed urinary immunoreactive prostaglandin E2 excretion in non-expanded rats and in volume-expanded rats during the expansion phase, but not during stable expansion.

6. The results suggest that the kallikrein-kinin system may contribute to changes in renal function during extracellular volume expansion. This action may not necessarily be associated with changes in renal prostaglandin E2 activity.
The Relationships between Plasma Substrates and Hormones and the Severity of Injury in 277 Recently Injured Patients
Authors: Stoner H. B. , Frayn K. N. , Barton R. N. , Threlfall C. J. , Little R. A.
Published: August 2015

1. The plasma concentrations of glucose, lactate, amino acids, non-esterified fatty acids, glycerol, ketone bodies, ethanol, cortisol and insulin were measured in patients within a few hours of injury and before treatment. The severity of the injuries was assessed by the Injury Severity Score (ISS) method.

2. Plasma lactate and glucose concentrations both rose significantly with increasing ISS.

3. The concentrations of non-esterified fatty acids and glycerol were greater after moderate (ISS 7–12) than after minor (ISS 1–6) injuries. The glycerol concentrations were no higher and the non-esterified fatty acid concentrations were lower after severe (ISS > 12) than after moderate injuries. The concentrations of total ketone bodies tended to follow those of non-esterified fatty acids and there was a highly significant correlation between them.

4. The total concentration of amino acids was not affected by the severity of injury and there were no systematic changes in the concentrations of individual ones.

5. Plasma insulin concentrations were very variable and not related to severity. A weak correlation with the plasma glucose concentration seen after minor and moderate injuries was lost in the severely injured.

6. The plasma cortisol concentration was positively related to ISS up to ISS 12 but negatively so in the severely injured.

7. Factors such as age, sex and time after last meal were investigated. The most important factor modifying the response was intake of ethanol, which reduced the plasma concentrations of glucose, non-esterified fatty acids and alanine and raised that of lactate as well as the [β-hydroxybutyrate]/[acetoacetate] ratio.
Subcellular Fractionation Studies of the Intestinal Mucosa in Congenital Sucrase—Isomaltase Deficiency
Authors: Cooper B. T. , Candy D. C. A. , Harries J. T. , Peters T. J.
Published: August 2015

1. Jejunal biopsy specimens from three children with congenital sucrase—isomaltase deficiency were assayed for disaccharidase activity and were subjected to analytical subcellular fractionation with enzymic microanalysis.

2. By use of the highly sensitive fluorigenic modification of the disaccharidase assay, brush-border sucrase and isomaltase activities were depressed but nevertheless detectable in each child.

3. Apart from the expected decrease in brush-border α-glucosidase activity, the other enterocyte marker-enzyme activities were normal.

4. There were no abnormalities in the enterocytes of any child on analytical subcellular fractionation or on electron microscopy.
The Ratio between Thickness of Media and Internal Radius in Cerebral, Mesenteric and Renal Arterial Vessels in Spontaneously Hypertensive Rats
Authors: Nordborg C. , Johansson B. B.
Published: August 2015

1. Larger arterial vessels of 15-day-old spontaneously hypertensive (SH) rats showed significantly greater media/internal radius ratio than those of Wistar—Kyoto rats in the brain, kidney and mesentery.

2. Since larger cerebral and renal arteries of adult SH rats did not differ from controls the above results indicate the presence of a non-pressure-dependent vascular abnormality in young SH rats.

3. There were marked differences between the vascular beds of adult SH rats in the increase of media/radius ratio. Thus the changes were evident in all sizes of mesenteric arteries but only in the smallest cerebral arteries.
The Effect of High Animal Protein Intake on the Risk of Calcium Stone-Formation in the Urinary Tract
Authors: Robertson W. G. , Heyburn P. J. , Peacock M. , Hanes F. A. , Swaminathan R.
Published: August 2015

1. Studies were carried out on six normal male subjects to determine the short-term effect of increasing the dietary consumption of animal protein on the urinary risk factors for stone-formation, namely, volume, pH, calcium, oxalate, uric acid and glycosaminoglycans.

2. An increase of 34 g/day of animal protein in the diet significantly increased urinary calcium (23%) and oxalate (24%). Total urinary nitrogen increased by an average of 368 mmol/day. The accompanying increase in dietary purine (11 mmol of purine nitrogen/day) caused a 48% increase in the excretion of uric acid.

3. The overall relative probability of forming stones, calculated from a combination of the risk factors, was markedly increased (250%) throughout the period of high animal protein ingestion.
Activation of Inactive Plasma Renin by Plasma and Tissue Kallikreins
Authors: Derkx F. H. M. , Tan-Tjiong H. L. , Veld A. J. Man In 'T , Schalekamp M. P. A. , Schalekamp M. A. D. H.
Published: August 2015

1. Normal human plasma contains a pro-activator of inactive renin. The pro-activator is activated at physiological pH in plasma that has been pretreated with acid. This activation in vitro leads to the conversion of inactive renin into the active form with simultaneous generation of kallikrein activity.

2. The endogenous activator of inactive renin has the same pH profile and inhibitor spectrum as plasma kallikrein.

3. Inactive renin can also be activated by exposure of plasma to exogenous trypsin, and in normal plasma the quantities of inactive renin that are activated after acidification and with trypsin are identical. Prekallikrein (Fletcher factor)-deficient plasma, however, has much lower renin activity after acidification than with trypsin. Thus acid activation of inactive renin depends on plasma prekallikrein, whereas the action of trypsin is independent of prekallikrein.

4. Highly purified tissue (pancreatic) kallikrein, in a concentration of less than 2 × 10−8 mol/l, activates inactive renin that has been isolated from plasma by ion-exchange chromatography. In this respect it is at least 100 times more potent than trypsin.

5. It is therefore possible that plasma and/or tissue (renal) kallikreins are also involved in the activation of inactive renin in vivo.
Protein Synthesis and Composition of Cardiac and Vascular Tissue in Spontaneously Hypertensive Rats and the Effects of β-Adrenergic Antagonist Treatment
Authors: Boström S.-L. , Fryklund J.
Published: August 2015

1. Propranolol and metoprolol were given in the diet of spontaneously hypertensive (SH) rats during the development of hypertension.

2. At the early established phase of hypertension, protein synthesis and protein composition of the left ventricle, aorta, mesenteric artery and vena cava were measured.

3. The left ventricle, aorta and mesenteric artery from the SH rats were hypertrophied compared with control Wistar—Kyoto rats, and protein composition was not dramatically changed. The increased protein content could only in a few cases be assigned to an increased protein synthesis at this age.

4. Both β-adrenergic antagonists prevented the hypertrophy of aorta and mesenteric artery but not in heart.
Mathematical Analysis of the Diagnostic Relevance of Clinical Findings
Authors: Llewelyn D. E. H.
Published: August 2015

1. The process of diagnosis by elimination in terms of probabilities is analysed mathematically.

2. A piece of evidence which is only associated with a small number of differential diagnoses is of particular importance.

3. To deal with a differential diagnosis, a feature is required which occurs commonly in a postulated diagnosis but rarely in its rivals, irrespective of its frequency in those already discriminated against.

4. By using this analysis, inadequate evidence may be identified, new tests developed, and their effectiveness assessed in a logical and efficient way.

5. The approach is illustrated by considering the differential diagnosis of localized right lower quadrant abdominal pain.
Origin of Kallikrein in Rat and Human Exocrine Glands and Kidney
Authors: Ørstavik T. B. , Nustad K. , Brandtzaeg P.
Published: August 2015

1. The cellular localization of kallikrein was investigated in rat and human exocrine glands and kidney by a direct immunofluorescence technique.

2. Kallikrein was found in the duct system of the rat and human major salivary glands.

3. Kallikrein was found in the distal tubular cells of the rat kidney. Attempts to localize kallikrein in the human kidney were unsuccessful.

4. In the rat and human pancreas, kallikrein was found as a pro-enzyme in the acinar cells.
Physical Activity and the Circadian Rhythm of Blood Pressure
Authors: Mann S. , Craig M. W. Millar , Melville D. I. , Balasubramanian V. , Raftery E. B.
Published: August 2015

1. Ambulatory blood pressure monitoring was carried out in 10 subjects for a period of 48 h, the first or second 24 h part of which was selected randomly to be a period of complete bed rest.

2. Heart rate was significantly lower throughout the period of bed rest except for the period 04.00–08.00 hours, when there was little difference.

3. The circadian variation of blood pressure was reduced during the day of bed rest but this was mainly due to higher night-time pressures.
Relationship between the Basal Blood Alanine Concentration and the Removal of an Alanine Load in Various Clinical States in Man
Authors: Elia M. , Ilic Vera , Bacon Susan , Williamson D. H. , Smith R.
Published: August 2015

1. Blood alanine was measured in six patients undergoing total hip replacement and in four normal subjects starved for 4 days. Hypoalaninaemia occurred in both groups and persisted in the surgical patients despite an adequate diet. The blood alanine was also low in four insulin-dependent diabetic patients and in four patients with muscular dystrophy; it was normal in four patients with cirrhotic liver disease.

2. The removal of an intravenous l-alanine load (12 g; 133 mmol) was significantly increased after surgery and in the diabetic patients, unaltered by starvation, and decreased in the cirrhotic patients.

3. Increases in blood glucose were observed when alanine infusion was performed 6 h after surgery and after 3 days' starvation. Increases in blood lactate and pyruvate always occurred after alanine infusion but were most marked 6 h after surgery.

4. These results show that the metabolic response to an alanine load and the ability of the body to remove it alter with change in physiological state, and that the hypoalaninaemia after surgery and in diabetes is related to an increased removal of intravenous alanine, whereas that during starvation is not.
Cooling Responses in Shivering and Non-Shivering Dogs during Induced Hypothermia
Authors: Auld C. D. , Light I. M. , Norman J. N.
Published: August 2015

1. Hypothermia to a temperature of 30°C was induced in both shivering and non-shivering groups of dogs.

2. There was a sustained increase in oxygen consumption in the dogs allowed to shiver and this was up to 300% greater than the oxygen consumption in the relaxed dogs.

3. The increased tissue requirement for oxygen was met both by increased cardiac output and increased oxygen extraction from haemoglobin.

4. Oxygen utilization remained adequate in hypothermia, as shown by the absence of hypoxic acidosis.

5. Heart rate fell during cooling and stroke volume increased to meet the increased oxygen demands associated with shivering during the induction of hypothermia.
Resistive Load Detection during Passive Ventilation
Authors: Killian K. J. , Mahutte C. K. , Campbell E. J. M.
Published: August 2015

1. By using standard psychophysical techniques resistive load detection was estimated in five normal subjects during spontaneous breathing and during passive ventilation in a Drinker respirator.

2. During assisted ventilation a gross deterioration in resistive load detection occurred.

3. The findings imply that active respiratory muscle contraction plays an essential role in the detection of added resistive loads.
Effects of Prostaglandins on Renin Substrate Production by the Liver
Authors: Murakami Eiki , Hiwada Kunio , Kokubu Tatsuo
Published: August 2015

1. The effects of prostaglandin (PG) E1, PGE2 and PGF2α on plasma renin substrate concentration in rats and renin substrate production by perfused rat liver were investigated.

2. After bilateral nephrectomy, both plasma renin substrate concentration and renin substrate production were remarkably elevated.

3. The increase in plasma renin substrate level and production of renin substrate by the liver after nephrectomy was markedly suppressed by the treatment with PGE1 or PGE2.

4. In contrast PGF2α had no suppressive effect on renin substrate synthesis.

5. These findings suggest that PGE1 and PGE2 might be inhibitory factors in the regulation of renin substrate synthesis.
Presence of Postsynaptic α2-Adrenoreceptors of Predominantly Extrasynaptic Location in the Vascular Smooth Muscle of the Dog Hind Limb
Authors: Langer S. Z. , Massingham R. , Shepperson N. B.
Published: August 2015

1. In the autoperfused hind limb of the dog prazosin (10μg/kg intravenously) markedly antagonized responses to lumbar sympathetic stimulation, whereas responses to injected nor-adrenaline were largely unaffected.

2. In β-adrenoreceptor- and ganglion-blocked animals, the hind limb pressor responses to phenylephrine were antagonized to a greater degree by prazosin than responses to injected noradrenaline.

3. Rauwolscine, a selective α2-adrenoreceptor-blocking agent, antagonized responses to the α2-adrenoreceptor agonist guanabenz, but not those to phenylephrine.

4. Hind limb pressor responses to noradrenaline were significantly inhibited by rauwolscine and further reduced by prazosin.

5. These results demonstrate that in this vascular bed α1- and α2-adrenoreceptors are located postsynaptically. Furthermore the results suggest that neuronally released noradrenaline acts mainly upon α1-adrenoreceptors, whereas exogenous noradrenaline acts upon α1- and α2-adrenoreceptors.

6. It is suggested that this selectivity of prazosin in blocking the vasoconstriction to neuronally-released noradrenaline may in part explain the effectiveness of this drug as an antihypertensive agent.
Metoprolol in Diabetes Mellitus: Effect on Glucose Homeostasis
Authors: Garrett B. N. , Raskin P. , Kaplan N. M.
Published: August 2015

1. In eight hypertensive diabetic subjects receiving hydrochlorothiazide, glucose homeostasis as measured by the changes in plasma glucose, insulin and glucagon after an oral glucose load was not significantly affected by 8 weeks of therapy with metoprolol.

2. The combination of metoprolol plus hydrochlorothiazide significantly lowered blood pressure in all subjects.

3. Plasma renin activity was suppressed by therapy with metoprolol.
The Effect of Respiratory Muscle Fatigue on Respiratory Sensations
Authors: Gandevia S. C. , Killian K. J. , Campbell E. J. M.
Published: August 2015

1. Eight subjects maintained maximal inspiratory pressure as long as possible. The subjects accurately judged the pressure developed, but considered that the sense of effort or motor command increased progressively during the contraction as fatigue developed.

2. A reference inspiratory load was overestimated after maximal inspiratory contractions.

3. These findings are consistent with the hypothesis that awareness of the motor command or effort contributes to the estimation of respiratory loads.
Dependence of Transcutaneous Oxygen Tension on Local Arteriovenous Pressure Gradient in Normal Subjects
Authors: Wyss C. R. , Matsen F. A. , King Racheal V. , Simmons C. W. , Burgess E. M.
Published: August 2015

1. We studied the relationship between trans-cutaneous oxygen tension at the foot and local arteriovenous pressure difference in 15 normal men and women; arteriovenous pressure difference was varied by changing the height of the foot with respect to the heart and by applying external pressure to the foot.

2. Control transcutaneous oxygen tension was 67 ± 9 sd mmHg (8.9 ± 1.2 kPa) at a control arteriovenous pressure difference of 80 ± 6 sd mmHg (10.6 ± 0.8 kPa).

3. In every subject transcutaneous oxygen tension fell non-linearly with a decrease in arteriovenous pressure difference; transcutaneous oxygen tension was relatively insensitive to changes in arteriovenous pressure difference when arteriovenous pressure difference was high, but always fell sharply to zero at some positive arteriovenous pressure difference [range 13-34 mmHg (1.7-4.5 kPa)].

4. An analysis of the data indicated that transcutaneous oxygen tension varied with arteriovenous pressure difference approximately as the oxygen tension of cutaneous venous blood under the sensor varied (in the absence of changes in cutaneous vascular resistance and oxygen consumption).

5. This analysis was supported by studies in three subjects in whom the oxygen tension of superficial venous drainage from a warmed hand or foot was measured along with Transcutaneous oxygen tension while arteriovenous pressure difference was varied.
Regional Blood Flow in Borderline and Sustained Essential Hypertension
Authors: Temmar M. M. , Safar M. E. , Levenson J. A. , Totomoukouo J. M. , Simon A. Ch.
Published: August 2015

1. Cardiac output, lower-limb blood flow, hepatic and renal blood flows were studied in 16 patients with borderline and 16 patients with sustained essential hypertension and compared with 16 age-matched control subjects.

2. In borderline hypertension cardiac output and lower-limb blood flow were significantly elevated, while hepatic and renal blood flows were within the normal range. Cardiac output and lower-limb blood flow were positively correlated.

3. In sustained hypertension cardiac output, lower-limb blood flow and hepatic blood flow were within the normal range. Renal blood flow was significantly reduced. Lower-limb blood flow was negatively correlated with mean arterial pressure.

4. If borderline hypertension is an early stage of fixed hypertension, the present study suggests that the changes in cardiac output observed in hypertension are mainly related to lower-limb (and muscle) blood flow.
Variations in Individual Organ Release of Noradrenaline Measured by An Improved Radioenzymatic Technique; Limitations of Peripheral Venous Measurements in the Assessment of Sympathetic Nervous Activity
Authors: Brown M. J. , Jenner D. A. , Allison D. J. , Dollery C. T.
Published: August 2015

1. The validity of plasma noradrenaline as an index of sympathetic nervous activity was assessed by estimating variation in individual organ contribution to circulating concentrations.

2. Arteriovenous (A—V) differences in noradrenaline and adrenaline concentration were measured across several organs in nine patients with mild essential hypertension, in five with renal artery stenosis and 15 phaeochromocytoma patients.

3. In patients with phaeochromocytomas the percentage extraction of noradrenaline and adrenaline (estimated from the A—V differences) was similar across all organs, suggesting that adrenaline extraction could be used as a marker for noradrenaline extraction.

4. In the non-tumour patients the A—V difference for noradrenaline was less than that for adrenaline across most organs studied, reflecting the net result of noradrenaline release and extraction. The estimated contribution of various organs to the noradrenaline concentrations in their venous effluent was: heart. 21%; kidney 47%; legs 68%.

5. This pattern of A—V difference proved a positive diagnostic feature for non-tumour patients since it was not found even in the patients with small phaeochromocytomas, whose peripheral venous noradrenaline concentration alone did not distinguish them.

6. The venous-arterial difference across the adrenal glands of non-tumour patients was more than 10-fold greater for adrenaline than that for noradrenaline. Since the mean arterial concentration of noradrenaline was more than fivefold higher than that of adrenaline, the normal adrenal contribution to circulating noradrenaline is likely to be less than 2%.

7. In the patients with renal artery stenosis renal venous concentrations of noradrenaline (from the ischaemic kidney) were higher than arterial values, but mean arterial values were no higher than in the essential hypertensive patients.

8. Local variations in sympathetic activity may occur without altering the plasma noradrenaline concentration measured in peripheral plasma.
Relation of Arterial Pressure with Exchangeable and Total Body Sodium and with Plasma Exchangeable and Total Body Potassium in Essential Hypertension
Authors: Beretta-Piccoli C. , Davies D. L. , Boddy K. , Brown J. J. , Cumming A. M. M. , East W. B. , Fraser R. , Lever A. F. , Padfield P. , Robertson J. I. S. , Weidmann P. , Williams E. D.
Published: August 2015

1. Arterial pressure, plasma electrolytes and exchangeable sodium were measured in 91 patients with essential hypertension and in 121 normal control subjects. Total body sodium, exchangeable potassium and total body potassium were also measured in some of the hypertensive patients.

2. Mean plasma sodium concentration was slightly but significantly lower in the hypertensive patients as a group, but mean values for other electrolyte measurements were close to normal or predicted normal.

3. Exchangeable sodium was not related to arterial pressure in normal subjects but in hypertensive patients exchangeable sodium correlated significantly with systolic and diastolic pressures. These correlations were significant with two methods of expressing exchangeable sodium, in the whole group of patients, in men and in older patients. Exchangeable sodium was not significantly related to arterial pressure in young patients.

4. Total body sodium also correlated significantly with systolic and diastolic pressures in hypertensive patients.

5. Exchangeable sodium was significantly related to age in hypertensive patients but not in normal subjects. Mean exchangeable sodium was significantly lower than normal in young patients.

6. Plasma potassium concentration was not related to arterial pressure in normal subjects but in essential hypertensive patients plasma potassium concentration, exchangeable potassium and total body potassium correlated negatively with systolic and diastolic pressures. These correlations were also significant in young, but not in old patients.
Adrenaline Neurons and PNMT Activity in the Brain and Spinal Cord of Genetically Hypertensive Rats and Rats with DOCA—salt Hypertension
Authors: Chalmers J. P. , Howe P. R. C. , Wallmann Y. , Tumuls I.
Published: August 2015

1. We have studied the number of phenylethanolamine-N-methyltransferase (PNMT)-containing nerve cells in the medulla and the activity of PNMT in the medulla, spinal cord and hypothalamus of the rat.

2. At 4 weeks of age there was an increase in the number of PNMT cells counted in the medulla of the spontaneously hypertensive rat (SHR; 21%, P < 0.01) and the stroke-prone spontaneously hypertensive rat (SHR-SP; 22%, P < 0.01) compared with the Wistar-Kyoto (WKY) control rat.

3. At 4 months of age there were no significant differences in the number of medullary PNMT cells in two normotensive strains (WKY and Fisher rats), two genetically hypertensive strains (SHR and SHR-SP) and in DOCA-salt hypertensive rats.

4. In four week old rats the activity of PNMT was increased by about 50% in the spinal cord and medulla of the SHR and SHR-SP compared with the WKY rats, and immunotitration experiments suggest that this is due to an increased concentration of enzyme.

5. At 4 months of age there were no increases in PNMT activity of either genetically hypertensive rats or DOCA-salt hypertensive rats.
Effect of Converting Enzyme Inhibition on the Systemic and Renal Responses to Acute Isotonic Volume Expansion in Normal Man
Authors: Mimran A. , Ribstein J.
Published: August 2015

1. Systemic, humoral and renal responses to isotonic volume expansion (1800 ml in 3 h) were assessed in normal subjects before and during captopril administration.

2. Captopril, which otherwise induced a decrease in pre-saline mean arterial pressure (MAP), unmasked the volume-dependence of MAP, which increased linearly during volume expansion (+ 18.7 ± 3.8% at the end of volume expansion).

3. Captopril prevented the fall in plasma aldosterone produced by volume expansion but did not modify the natriuretic response to saline.

4. These results suggest that intrarenal rather than circulating angiotensin II may be one of the determinants of the natriuretic response to volume expansion in normal man.
Kallikrein and Renin: Molecular Biology and Biosynthesis
Authors: Morris B. J. , Catanzaro D. F. , Richards R. I. , Mason A. , Shine J.
Published: August 2015

1. A cDNA clone library was constructed from male mouse submandibular gland poly(A)+RNA.

2. A 500 base-pair sequence consisting of a 3′ untranslated region plus a 447 base-pair region coding for an amino acid sequnce having 57% homology with the C-terminal 149 amino acids in the 230 amino acid chain of porcine pancreatic kallikrein was identified.

3. The sequence was strongly but not completely homologous with known mouse submandibular gland serine proteinase sequences and represents the first report of a DNA base sequence for a serine proteinase. It may be part of the gene coding for kallikrein.

4. The biosynthetic pathway for renin was established by continuous-labelling, pulse-chase and cell-free translation studies of submandibular gland tissue from normal and testosterone-induced mice.

5. Renin was synthesized as a mol. wt. 46 000 preprorenin which is likely to be hydrolysed before completion of the nascent chain. A prorenin of mol. wt. 44 500, pI 6.4 was identified and shown to be rapidly converted into a mol. wt. 40 000, pI 6.2 renin, which was then converted more slowly into forms of mol. wt. 35 500, pI 5.6 and mol. wt. 34 000, pI 5.4.
BM 12.434, a Novel Compound with Vasodilating and β-Adrenoceptor-Blocking Activities
Authors: Von Möllendorff E. , Huschka C. , Schröter E. , Abshagen U.
Published: August 2015

1. BM 12.434 was compared with a known β-adrenoceptor-blocking agent, metipranolol, and a combination of metipranolol and isosorbide-5-mononitrate in healthy volunteers. BM 12.434 and metipranolol were given in equi-effective β-adrenoceptor-blocking doses (reduction of exercise-increased pulse-pressure product).

2. Responses of the cardiovascular system were determined by non-invasive methods.

3. BM 12.434 increased the peripheral resistance less than metipranolol.

4. After BM 12.434, in contrast to metipranolol, both arterial flow and the venous capacity showed significant increase.

5. The combination of isosorbide-5-mononitrate and metipranolol differed from metipranolol alone mainly by the effect on venous capacity, which showed a slight increase.

6. BM 12.434 is a β-adrenoceptor-blocking agent whose additional actions on the veins and arteries are potentially useful for the treatment of both coronary heart disease and of arterial hypertension.
Magnesium Reduces Calcium Oxalate Crystal Formation in Human Whole Urine
Authors: Hallson P. C. , Rose G. A. , Sulaiman S.
Published: August 2015

1. A low urinary magnesium was induced in normal volunteer subjects by giving cellulose phosphate; magnesium was added in vitro to yield urine samples of normal and high magnesium concentrations

2. After rapid evaporation of these urine samples at pH 5.3 to standard osmolality the calcium oxalate crystals were measured by microscopy and isotopic methods

3. There was a clear inverse correlation between magnesium concentration and calcium oxalate crystal formation

4. The case for treating calcium oxalate urolithiasis with magnesium is strengthened.
Factors affecting Excretion of Human Urinary Tamm—Horsfall Glycoprotein
Authors: Lynn K. L. , Shenkin A. , Marshall R. D.
Published: August 2015

1. Tamm—Horsfall glycoprotein was determined, by radioimmunoassay, in samples of urine from normal individuals under a variety of physiological conditions

2. The amount of glycoprotein excreted in 24 h by our population (39 ± 13 mg, corrected for body surface area) was found not to be influenced by sex, age (19–60 years) or amounts of Ca2+, Mg2+ and Na+ excreted

3. Urine samples collected at 2 h intervals over 24 h from individuals drinking in response to thirst, contained quantities of the glycoprotein which showed high positive correlations with urine volumes, but not with Ca2+, Mg2+ or Na+ excretion

4. The amounts of urine and of the glycoprotein were correlated for individuals in anti- diuresis, induced by restriction of water intake. Relatively small amounts of glycoprotein were excreted by individuals in states of water-induced diuresis

5. The amounts of glycoprotein excreted after exercise were positively correlated with the small volumes of urine voided, but they were uninfluenced by the degree of proteinuria or of hyaline cast formation

6. The half-life for turnover of the glycoprotein in a given individual is highly variable, from a minimum of 3–7 to a maximum of 168 h.
Effects of Meclofenamate and Captopril on Renal and other Regional Vascular Beds after Mild Haemorrhage in Conscious Rabbits
Authors: Banks R. A. , Beilin L. J. , Soltys J. , Davidson L.
Published: August 2015

1. The role of prostaglandins and angiotensin II in blood flow regulation was studied in conscious rabbits subjected to mild haemorrhage.

2. Haemorrhage caused a 13% fall in arterial pressure and a 21% fall in cardiac output, responses which were unchanged by sodium meclofenamate, an inhibitor of prostaglandin synthesis, or captopril, an inhibitor of the angiotensin converting enzyme.

3. Haemorrhage doubled plasma adrenaline and noradrenaline levels. Plasma renin activity trebled after haemorrhage and was further elevated by captopril.

4. Renal blood flow was maintained after haemorrhage alone. Meclofenamate given immediately after haemorrhage caused a 31% fall in renal blood flow. Captopril given immediately after haemorrhage caused renal vasodilation, but when given after meclofenamate augmented renal vasoconstriction.

5. Splenic vasoconstriction was seen after haemorrhage and meclofenamate, and subsequently was augmented by captopril.

6. Results suggest that prostaglandins variably modulate regional blood flow in conscious rabbits subjected to mild haemorrhage. Enhanced sympathc—adrenal activity increases reno-vascular and splenic dependence on vasodilator prostaglandins, but not that of coronary, cerebral, hepatic or adrenal circulations. Renal and splenic vasoconstriction seen with meclofenamate are not due to circulating angiotensin II.
Isolation and Characterization of a Pancreatic Elastase from Plasma of Patients with Acute Pancreatitis
Authors: Toki Naotika , Takasugi Sumiyoshi , Sumi Hiroyuki
Published: August 2015

1. An elastase-like enzyme in plasma of patients with acute pancreatitis was purified by DEAE-cellulose column chromatography and polyacrylamide-gel disc electrophoresis.

2. In this way 0.24 mg of purified enzyme with a specific activity of 3.94 succinyl-l-alanyl-l-alanyl-l-alanyl-p-nitroanilide units/mg of protein was obtained from 10 ml of plasma.

3. The purified material was homogeneous as ascertained by sodium dodecyl sulphate/polyacrylamide-gel disc electrophoresis and had an apparent molecular weight of 24 000 as measured by gel filtration on Sephadex G-100.

4. This enzyme hydrolysed denatured casein and Congo Red—elastin as well as succinyl-l-alanyl-l-alanyl-l-alanyl-p-nitroanilide. Its amidolytic activity was inhibited by soya bean trypsin inhibitor, but not by aprotinin.

6. We propose that an elastase-like enzyme, probably different from elastase 1 or elastase 2, is liberated from the pancreas into blood during acute pancreatitis and becomes combined with α2-macroglobulin.
Effect of Acute Unilateral Renal Denervation on Intrarenal Haemodynamics and Urinary Excretion in Rats before and during Hypervolaemia
Authors: Veressa A. T. , Chong C. K. , Sonnenberg H.
Published: August 2015

1. The possible involvement of renal nerves in the diuresis and natriuresis of blood volume expansion was studied in anaesthetized rats. Acute unilateral renal denervation caused increased excretion of fluid, sodium and potassium.

2. Renal blood and plasma flows were elevated without change in filtration rate. Intracortical blood flow distribution was not affected by the denervation.

3. Blood infusion caused diuresis, natriuresis and kaliuresis in both denervated and shamdenervated kidneys, associated with comparable initial increases in filtration and decreases in renal blood flow. No change in flow distribution was found, whether or not renal nerves were intact.

4. Although the magnitude of the excretory response to hypervolaemia was greater in denervated kidneys, the temporal pattern was identical with that of sham-operated kidneys. Our data thus do not show an effect of efferent renal nerve activity on volume natriuresis.
Sodium Balance, Fluid Homeostasis and the Renin–Aldosterone System during the Prolonged Exercise of Hill Walking
Authors: Milledge J. S. , Bryson E. I. , Catley D. M. , Hesp R. , Luff N. , Minty B. D. , Older M. W. J. , Payne N. N. , Ward M. P. , Withey W. R.
Published: August 2015

1. The effect of 5 consecutive days of hill walking on electrolyte balance, fluid homeostasis, plasma renin activity and plasma aldosterone concentration was studied in five male subjects.

2. The 5-day exercise period was preceded by a 4-day control period and followed by a 4-day recovery period. Throughout the 13-day study subjects ate a fixed diet.

3. After 5 days of exercise subjects had retained a mean of 264 mmol (sd 85) of sodium. Plasma sodium concentration remained constant at 142.0 mmol/l (sd 5.4). This indicates an expansion of the extracellular space by 1.84 litres.

4. By the end of the exercise period there was a positive water balance of about 0.9 litre. Thus there was a net movement of 0.94 litre of fluid from the intracellular to the extracellular space.

5. Packed cell volume decreased from a mean of 43.5% to 37.9% after 5 days of exercise, indicating that about 0.9 litre of the extracellular fluid entered the vascular compartment. The remaining fluid may be responsible for the significant increase in lower leg volume.

6. During the exercise period plasma aldosterone concentration and plasma renin activity rose, and there was a highly significant correlation between these values and the sodium retention. There was also a significant correlation between sodium retention and the increase in leg volume, which suggests that oedema may be the result of prolonged exercise of this type.
Activation by Exercise of Human Skeletal Muscle Pyruvate Dehydrogenase In Vivo
Authors: Ward G. R. , Sutton J. R. , Jones N. L. , Toews C. J.
Published: August 2015

1. The activity of pyruvate dehydrogenase in its active and inactive forms was measured in biopsy samples obtained from the vastus lateralis muscle of healthy subjects before and after exercise.

2. At rest, 40 ± 4% (mean ± sem) of the enzyme was in the active form.

3. After progressive aerobic exercise to exhaustion (n = 5), 88 ± 2·3% was in the active form.

4. After intermittent supramaximal short-term exercise (1 min exercise, 3 min rest) to exhaustion (n = 6), 60 ± 2·2% was in the active form.

5. After isometric maximal exercise of 65 ± 3·6 s duration (n = 3), only 39 ± 1% of the enzyme was in the active form.

6. Muscle glycogen depletion was greatest with intermittent exercise and least with isometric maximal exercise; in contrast, the increase in muscle lactate was least with progressive exercise (1·3 to 9·4 μmol/g), intermediate in intermittent maximal exercise (1·2 to 13·1 μmol/g) and greatest after isometric exercise (1·8 to 17·6 μmol/g). There were no significant differences between the three studies in the changes in lactate/pyruvate ratios.

7. In three subjects who exercised with one leg, activation of the enzyme was twice as great in the exercised as in the inactive leg.

8. The ratio of active to total enzyme in biopsies of resting muscle was greater in four well-trained athletes than in four untrained control subjects (70% compared with 41% respectively).

9. The activation of pyruvate dehydrogenase appears to play an important part in regulating the use of glycogen and glucose during exercise in man.