bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of Glomerular Capillary Pressure and Filtration Rate in Young Kyoto Hypertensive Rats
Authors: Azar S. , Johnson M. A. , Scheinman J. , Bruno L. , Tobian L.
Published: August 2015

1. Single nephron pressures, flows and resistances were studied in 17–18 week old genetically hypertensive and normotensive Kyoto rats resembling one another in renal weight, total filtration rate, morphology and number of glomeruli in the kidney.

2. Glomerular capillary pressures were similar in the two groups; however, the hypertensive rats had lower pressures at the end of the efferent arteriole than did the normotensive animals. Nephron filtration rates were similar in both groups. At the same time, the hypertensive rats had higher nephron filtration fractions, and their glomerular blood flow was lower than that of the normotensive rats. These changes in the hypertensive animals were due to their higher afferent and efferent arteriolar resistances. Despite their high blood pressure, the glomerular ultrafiltration forces in hypertensive rats were almost identical with those in normotensive rats.

3. We conclude that the regulation of glomerular capillary pressure and filtration rate in young Kyoto hypertensive rats is due to a balance of afferent—efferent arteriolar tonus. The normal glomerular capillary pressures and low efferent arteriolar pressures of these animals are most likely the functional basis for the lack of structural changes at these sites. These results suggest that the Kyoto animal's renal response to hypertension resembles that of most essential hypertensive patients, both in function and morphology.
Effects of ‘Elemental’ Diets on Absorptive and Enzymic Activities and on 5-Fluorouracil Toxicity in Rat Small Intestine
Authors: Gardner M. L. G. , Heading R. C.
Published: August 2015

1. Water absorption and cytoplasmic dipeptidase activities were determined in isolated rat small intestine after animals had fed on various ‘elemental’ diets or a standard rat diet and after a single injection of 5-fluorouracil.

2. Vivonex diets were associated with a decrease in dry weight of the small intestine and an increase in glucose and water absorption in vitro.

3. The nature of the dietary nitrogen profoundly affects the activities of intestinal peptidases.

4. Water absorption was severely depressed 3 days after 5-fluorouracil administration: the extent of depression was independent of the diet. Thus, any ameliorative effects of ‘elemental’ diets on 5-fluorouracil toxicity are unlikely to be mediated by direct protection of intestinal absorption.
Plasma and Urine Dopamine in Man Given Sodium Chloride in the Diet
Authors: Oates N. S. , Ball S. G. , Perkins C. M. , Lee M. R.
Published: August 2015

1. Plasma and urine free dopamine were measured daily for 5 days in six normal subjects maintained on a low sodium diet. The subjects were then given dietary supplements of sodium chloride for 5 days and the measurements repeated.

2. Throughout the experiment the 24 h free dopamine excretion rates for all the subjects were higher than could be accounted for by renal clearance. Dopamine excretion increased significantly in response to the added sodium chloride whereas plasma dopamine remained unchanged. The rise in dopamine excretion preceded that of sodium excretion.

3. It is concluded that free dopamine is formed within the kidney in response to increased dietary sodium and may have a role in the control of sodium excretion.
The Relationship between Concentrations of Glycosylated Haemoglobins and of Serum High-Density-Lipoprotein Cholesterol in Diabetic Patients
Authors: Yudkin J. S. , Boucher B. J. , France M. W. , Welch S. G. , Swindlehurst C.
Published: August 2015

1. Concentrations of high-density-lipoprotein cholesterol and of glycosylated haemoglobins [HbA1(a+b+c)] were measured in non-fasting blood samples taken from 171 diabetic patients.

2. Mean concentrations of high-density-lipoprotein cholesterol were lower in men, and in patients not requiring insulin.

3. There was no correlation between concentrations of high-density-lipoprotein cholesterol and of HbA1(a+b+c) in the patients as a whole, but a significant positive correlation was found between these values in male diabetics not requiring insulin.

4. Changes in the concentrations of HbA1(a+b+c) were not correlated with changes in concentrations of high-density-lipoprotein cholesterol.
Synthetic Detergents in Bile-Salt-Deficient Steatorrhoea
Authors: King R. F. G. J. , Howdle P. D. , Kelleher J. , Losowsky M. S.
Published: August 2015

1. Fat malabsorption caused by bile-salt deficiency is not easily corrected by standard therapy. It has been shown in rats with bile-salt deficiency that non-ionic detergents can replace bile salts and improve fat absorption. A careful assessment of the place of synthetic detergents such as Tween in human therapy has not been reported.

2. The effects of Tween were studied in 13 patients with bile-salt-deficient steatorrhoea, eight of whom received Tween 80 and five Tween 20.

3. Tween therapy reduced steatorrhoea in 10/13 patients; a mean decrease in faecal fat of 33% was achieved with best effect seen in patients with severe steatorrhoea.

4. In the five patients given Tween 20, duodenal/jejunal intubation was conducted using meals with or without added Tween. Jejunal bile salt concentrations were low in all subjects and Tween had no effect on bile-salt output.

5. With Tween addition micellar free fatty acids and phospholipids were increased in four out of the five patients (mean increases 100% and 260% respectively). The mean ratio of fatty acid to bile salt increased from 1·26 to 3·53 and of phospholipid to bile salt from 0·09 to 0·21 in the presence of Tween.

6. The results suggest that in steatorrhoea due to bile-salt deficiency Tween causes increased micellization of ingested fat and improvement in fat absorption.

7. Tween and other non-ionic detergents may, therefore, find a place in therapy of bile-salt deficiency.
Prolactin in Primary Aldosteronism
Authors: Düsing R. , Gill J. R. , Bartter F. C.
Published: August 2015

1. This study was done to examine the possibility that escape from the sodium retention produced by aldosterone may be associated with an inhibition of prolactin secretion. Plasma prolactin concentrations were determined in seven patients with adrenal adenoma and aldosteronism, before and after unilateral adrenalectomy, at a time when they were in balance on a sodium intake of 109 mmol/day.

2. After operation, plasma aldosterone was normal [before operation, 52·7 ± 12·1 (supine), 64·6 ± 9·1 ng/dl (upright); after operation, 6·8 ± 1·5 (supine), 11·1 ± 3·0 ng/dl (upright)], while plasma prolactin remained unchanged [before operation, 19·6 ± 2·8 (supine), 15·5 ± 3·3 ng/ml (upright); after operation, 23·8 ± 2·3 (supine), 11·1 ± 3·0 ng/ml (upright)].

3. Our results do not support a role for prolactin in the renal response to aldosterone in man.
Effect of Acid—Base Changes on the Intracellular Sodium, Potassium and Water Content of Human Leucocytes in Vitro
Authors: Jones R. B. , Johnson Valerie E. , Patrick J. , Hilton P. J.
Published: August 2015

1. Leucocytes were isolated from blood of healthy volunteer subjects and incubated in media of which the bicarbonate, Pco2 and pH composition were varied.

2. The intracellular sodium, potassium and water content of leucocytes were virtually unaffected by the acid—base composition of the media used.
Absorption of Inorganic Phosphate in the Human Small Intestine
Authors: Walton J. , Gray T. K.
Published: August 2015

1. Intestinal phosphate absorption in human subjects was studied by the technique of triple lumen intestinal perfusion in vivo.

2. Ileal phosphate absorption increased as the intraluminal phosphate concentration was increased.

3. Ileal rates of phosphate absorption were lower at any given intraluminal phosphate concentration than previously described jejunal rates. Acidification of the ileal lumen did not increase phosphate absorption.

4. Phosphate absorption was shown in the jejunum to be dependent on the intraluminal sodium concentration.

5. Phosphate absorption in the human small intestine consists of at least two components, one directly proportional to water movement and the second apparently independent of water movement.
The Rate of Change of Mouth Occlusion Pressure during Exercise
Authors: Siafakas N. , Morris A. J. R. , Prime F. J.
Published: August 2015

1. The initial rate of change of pressure at the mouth (dP/dt) during a brief occlusion of the airways at the beginning of inspiration has been estimated in nine healthy subjects at rest, during exercise and during the first 2 min of recovery. Exercise was carried out with progressively increasing loads to the maximum tolerated (progressive exercise) and also for a period of 6 min at a constant load of 60% of the maximum (steady-state exercise).

2. A highly significant linear relationship was found between work loads and dP/dt during progressive exercise in all our subjects.

3. A highly significant linear relationship was found between ventilation and dP/dt in both forms of exercise, but the slope of the regression line was steeper during progressive than during steady-state exercise in six out of nine subjects.

4. The pattern of breathing (VT, f, VT/Tinsp., Tinsp./Ttot.) did not account for the difference in the relationship between dP/dt and ventilation during the two forms of exercise.

5. These results are in agreement with the hypothesis that dP/dt is an index of central inspiratory drive.
Long-Term versus Short-Term Effects of Hydrochlorothiazide on Renal Haemodynamics in Essential Hypertension
Authors: Van Brummelen P. , Woerlee M. , Schalekamp M. A. D. H.
Published: August 2015

1. Renal blood flow, glomerular filtration rate, renal vascular resistance and filtration fraction were studied in ten patients with essential hypertension, during placebo, and after 1 week, 3, 6 and 9 months of hydrochlorothiazide. Plasma renin concentration and urinary excretion of vanillylmandelic acid were also measured.

2. Mean arterial pressure was lowered significantly during hydrochlorothiazide, the long-term effect being slightly more pronounced than the short-term effect.

3. The decrease in renal blood flow during the first week (P < 0·01) was followed by a progressive rise. After 9 months renal blood flow was above placebo level in eight of the ten patients. After an initial decrease, glomerular filtration rate returned gradually to its original value. Renal vascular resistance and filtration fraction increased during the first week and declined thereafter. After 3, 6 and 9 months renal vascular resistance was significantly lower compared with placebo values.

4. Plasma renin concentration and urinary excretion of vanillylmandelic acid increased significantly during the first week of hydrochlorothiazide. Subsequently, vanillylmandelic acid fell to below pretreatment amounts (P < 0·05), whereas plasma renin concentration remained elevated.

5. Long-term treatment of essential hypertension with hydrochlorothiazide has a favourable effect on abnormal renal haemodynamics. Besides the influence of blood pressure reduction per se, humoral and neural factors may be involved.
Sodium Distribution in Mesenteric Arterial Wall of Rats with Hypertension Induced by Drinking Saline
Authors: Madden Jane A. , Smith G. A. , Llaurado J. G.
Published: August 2015

1. Hypertension was induced in rats by substituting 2% (w/v) sodium chloride solution for drinking water. Sodium distribution in isolated mesenteric arterial wall was studied with the aid of 22Na, which was continuously washed out. Data were analysed by digital computer simulation without recourse to ancillary chemical measurements of extracellular space.

2. A three-compartment model consisting of (i) extracellular, (ii) intracellular and (iii) subcellular space was found to represent adequately the kinetics of 22Na. Transport rate constants were chosen as primary parameters describing intercompartmental sodium exchanges; the ratio of extra- to intra-cellular sodium compartments was calculated.

3. Results show the following significant changes in mesenteric arterial wall of salt-loaded hypertensive rats: (i) slowed sodium turnover; (ii) a decrease of the transport rate constant, which is presumed to reflect sodium movements from the intra- to the extra-cellular compartment; (iii) an increase of the transport rate constant, presumed to reflect sodium movements from the extra- to the intra-cellular compartment; (iv) a diminution of the extra- to intra-cellular compartment ratio for sodium.

4. The results suggest net movement of sodium into the cells; this change may be relevant to smooth muscle contraction and hence to the pathogenesis of blood pressure elevation in this model.
Kinetics of Uptake of An Amino Acid and a Dipeptide into Hamster Jejunum and Ileum: The Effect of Semistarvation and Starvation
Authors: Schedl H. P. , Burston D. , Taylor Elizabeth , Matthews D. M.
Published: August 2015

1. This paper reports an investigation of the effects of semistarvation and starvation on the kinetics of uptake of an amino acid, l-leucine, and a hydrolysis-resistant dipeptide, Gly-Sar, by rings of everted hamster jejunum and ileum in vitro. The concentration range used was 0·1–100 mmol/l. Total uptake, non-mediated uptake and Kt and Vmax. for mediated influx were estimated.

2. At many concentrations, both semistarvation and starvation caused a decrease in uptake of the peptide and the amino acid. Uptake of the peptide was more severely depressed than that of the amino acid. In control animals, the jejunum was the site of maximal uptake of Gly-Sar, and the ileum the site of maximal uptake of leucine. In semistarved and starved animals, the ileum became the site of maximal uptake of Gly-Sar, as it was for leucine. The effects of semistarvation and starvation on uptake were similar whether this was expressed per unit wt. or per unit length, though they were accentuated when expressed per unit length, since the intestine lost weight per unit length.

3. The main effect of semistarvation and starvation on the kinetics of mediated influx of the amino acid and the peptide was to reduce Vmax. in both jejunum and ileum. This effect was compatible with a reduction in the number of mediated transport sites for both the amino acid and the peptide. The observation that mediated influx of the peptide was more severely affected than that of the amino acid supports the hypothesis of the independence of the mechanisms for intestinal uptake of peptides and amino acids.
Catabolic Effects of Adrenaline and Angiotensin II in the Perfused Liver of Normal and Genetically Obese (ob/ob) Mice
Authors: Ma G. Y. , Gove C. D. , Cawthorne M. A. , Hems D. A.
Published: August 2015

1. Rapid effects of hormones on the metabolism of glycogen and fatty acids were studied in the perfused liver of normal and genetically obese (ob/ob) mice.

2. In livers from normal and obese mice adrenaline and angiotensin II stimulated glycogenolysis.

3. These hormones inhibited the synthesis de novo of long-chain fatty acids in livers from normal mice, but not in livers from obese mice.

4. The proportion of acetyl-CoA carboxylase in the active form was decreased by adrenaline but not by angiotensin II in livers from obese mice.

5. The potency of hormone effects on liver suggests that they could occur in the intact animal.

6. The results add to the evidence that hepatic fatty acid synthesis in genetically obese (ob/ob) mice is irreversibly resistant to inhibition by a range of hormones. Such resistance could be of primary significance in the pathogenesis of the obesity.
Histamine, Basophils and Eosinophils in Severe Asthma
Authors: Charles T. J. , Williams S. J. , Seaton A. , Bruce Christine , Taylor W. H.
Published: August 2015

1. Arterial and venous whole blood and plasma histamine concentrations and eosinophil and basophil counts were determined in five patients with acute severe asthma who had not previously received steroid therapy, in five who had been maintained on steroid therapy and in a control group of nine patients with acute non-respiratory illnesses.

2. No significant arteriovenous differences were observed for any of these measurements in any of the groups of patients. Significant net loss of arterial histamine does not therefore occur peripherally in acute asthma.

3. When compared with the values for the controls, statistically significant increases were observed, in the group not receiving steroids, for arterial and venous whole blood histamine concentrations, eosinophil counts and basophil counts, and, in those receiving steroids, for the venous basophil counts.

4. When compared with the venous plasma histamine concentration of normal subjects, that of the asthmatic subjects not receiving steroids was significantly raised.

5. The venous plasma histamine concentration of the control group was also significantly higher than that of normal subjects, but less so than in the asthmatic subjects, suggesting that acute illness per se produces an increased plasma histamine concentration.

6. Both groups of asthmatic patients were treated similarly with hydrocortisone and bronchodilators. There was a striking fall in whole blood histamine concentration and in eosinophil and basophil counts, but plasma histamine fell more slowly, especially in those who had not previously received steroids.

7. The mean histamine content of the basophil cell is 0·01 pmol and significant differences in this value did not occur within the various groups or as a result of treatment. The approximate number of molecules of histamine per basophil cell is 6·0 × 109.
Studies on Porphyrin Biosynthesis and the Enzymes Involved in Bovine Congenital Erythropoietic Porphyria
Authors: Del Batlle Alcira M. , De Xifra Eva A. Wider , Stella Ana Maria , Bustos Norma , With T. K.
Published: August 2015

1. Porphyrin biosynthesis and the enzymes succinyl-CoA synthetase (EC 6.2.1.5), δ-aminolaevulinate synthase (EC 2.3.1.37), δ-aminolaevulinate dehydratase (EC 4.2.1.24) and porphobilinogenase enzyme complex at 37°C and 45°C were studied in blood, bone marrow, spleen, liver and kidney of normal bulls and a bull with congenital erythropoietic porphyria (CEP).

2. Biosynthesis by erythrocytes and spleen was low and slightly lower in CEP than in the normal animals. In liver and kidney biosynthesis was somewhat higher and still lower in CEP than in normal animals. In bone marrow it was high and considerably higher in CEP than in normal animals. In all tissues biosynthesis was higher from porphobilinogen than from δ-aminolaevulinic acid.

3. The porphyrin biosynthesis pattern was 40% uroporphyrin, 15% heptacarboxylic porphyrin, 25% coproporphyrin and 20% suburoporphyrin in the normal animals, but in CEP it was 50% uroporphyrin I, 20–30% uroporphyrin III, 10–12% heptacarboxylic porphyrin and 10–20% suburoporphyrin.

4. In CEP gall-bladder bile contained 100 μmol of coproporphyrin/l and the fresh bladder urine 9 μmol/l, which on standing increased to 21 μmol/l, pointing to excretion of most porphyrin as porphyrinogen in the urine. The blood plasma contained only traces of porphyrin.

5. Enzyme determinations showed threefold increased succinyl-CoA synthase in CEP bone marrow as compared with normal animals, many-fold increase of aminolaevulinate synthase, normal aminolaevulinate dehydratase, sevenfold increase of porphobilinogenase activity on incubation at 45°C and threefold increase at 37°C. In blood, aminolaevulinate synthase and aminolaevulinate dehydratase were increased in CEP, whereas porphobilinogenase at 45 °C was reduced. In liver, aminolaevulinate synthase was normal and porphobilinogenase decreased.

6. Our results show that in this animal with CEP there was an increased porphobilinogen deaminase and a significant enhancement of aminolaevulinate synthase concomitant with a diminished activity of uroporphyrinogen III cosynthase.
Absence of Adrenergic Mediation of Agonist Response to [Sar1,Ala8]Angiotensin II in Conscious Normotensive and Hypertensive Dogs
Authors: Zimmerman B. G.
Published: August 2015

1. In the conscious normotensive and two-kidney Goldblatt hypertensive dog a transient agonist response to the intravenous infusion of saralasin (1 μg min−1 kg−1) was manifested by a small increase in blood pressure (6–12 mmHg) and 28–30% increase in renal vascular resistance.

2. These increases in blood pressure and renal vascular resistance were unaffected by administration of either phentolamine or guanethidine.

3. The agonist response in the conscious dog is most likely accounted for by a direct action of saralasin on vascular angiotensin receptors.
Superficial or Membrane Digestion of Peptides in Dinitrophenol-Inhibited Rat Small Intestine
Authors: Gardner M. L. G.
Published: August 2015

1. Hydrolysis of peptides has been measured in isolated rat small intestine perfused with a pancreatic digest of lactalbumin in the presence of 2,4-dinitrophenol.

2. Although transport of water and amino acids was severely inhibited by 2,4-dinitrophenol, peptide hydrolysis to free amino acids was apparently unimpaired.

3. Only a small fraction of the hydrolysis observed could be accounted for by leakage of enzymes into the lumen.

4. The results show that the brush-border enzymes proximal to the transport mechanism(s) can be an important site of hydrolysis of peptides to amino acids under conditions where the transport of unhydrolysed peptides is inhibited. The results are consistent with the concept of membrane (contact) digestion, although the significance of intracellular hydrolysis and of transmural transport of intact peptides is also discussed.
Sodium Excretion in Man, and Adaptation to a Low-Sodium Diet: Effect of Intravenous Sodium Chloride
Authors: Gordon D. , Peart W. S.
Published: August 2015

1. The aim of this study was to test whether a postulated gastrointestinal or portal monitor of sodium intake plays any part in adjusting renal sodium excretion when dietary sodium is reduced.

2. Normal male subjects were given 50 mmol of sodium chloride intravenously three times daily for 3 days to replace or to supplement a constant oral intake of sodium chloride.

3. When oral sodium chloride was replaced with intravenous sodium chloride, renal sodium excretion remained constant.

4. When oral sodium chloride was kept constant, sodium administered as intravenous sodium chloride was promptly excreted in three out of four subjects. There was a delay in the increase in sodium excretion in the fourth subject.

5. Infusions containing 50 mmol of sodium chloride in 50 ml given intravenously over 22 min produced a rise in plasma sodium concentration and a fall in concentration of total plasma solids.

6. These results provide no evidence for a gastrointestinal or portal monitor of sodium intake, but do not disprove the existence of such a monitor.
Biochemical Discrimination of Hurler and Scheie Syndromes
Authors: Hopwood J. J. , Muller Vivienne
Published: August 2015

1. Homogenates of cultured skin fibroblasts derived from patients with α-l-iduronidase-deficiency disorders (Hurler and Scheie syndromes) were capable of hydrolysing iduronosyl anhydro-[l-3H]mannitol 6-sulphate although at considerably reduced rates compared with normal controls.

2. The Vmax. values of α-l-iduronidase from patients with Hurler or Scheie syndromes and from normal controls were 11, 12 and 833 pmol min−1 mg−1 of protein respectively; the corresponding apparent Km values were 656, 50 and 53 μmol/l respectively. The α-l-iduronidases from normal and Scheie fibroblast homogenates were shown to exhibit pH optima at 3·6 and 4·1 and were competitively inhibited by both chloride and sulphate ions: Hurler α-l-iduronidase activity exhibited one pH optimum at 3·8 and was also inhibited by chloride and to a lesser extent by sulphate ions.

3. The thermal stability of Hurler, Scheie and normal α-l-iduronidase activities at 55°C gave half-lives of approximately 1·0, 2·5 and 1·0 h respectively.

4. These biochemical findings clearly demonstrate enzyme differences for these two clinically distinct phenotypes and provide biochemical evidence that the Hurler and Scheie syndromes result from different allelic mutations.
Muscle Relaxation Rate, Fibre-Type Composition and Energy Turnover in Hyper- and Hypo-Thyroid Patients
Authors: Wiles C. M. , Young A. , Jones D. A. , Edwards R. H. T.
Published: August 2015

1. Quadriceps strength, relaxation rate, fibre-type composition and energy-turnover rate during a submaximal contraction have been measured in hypo- and hyper-thyroid patients and compared with findings in normal subjects.

2. Six out of eight hypothyroid patients had normal strength whereas four out of five hyperthyroid patients were weak.

3. Relaxation rate was decreased in all the hypothyroid patients but increased in only three out of five hyperthyroid patients.

4. In hypothyroidism there was a marked reduction in the percentage contributed by type II fibres to muscle cross-section, partly due to type II atrophy but also due to a decrease in the relative frequency of type II fibres. In hyperthyroidism both fibre types tended to atrophy.

5. The rate of ATP turnover during submaximal contraction held to fatigue was reduced in hypothyroidism. This was probably due to decreased ATP utilization rather than an impaired supply of energy-supplying substrates. In hyperthyroidism the rate of ATP turnover was increased.

6. Altered relaxation rate and ATP-turnover rate may be explained on the basis of changes in myosin ATPase activity with thyroid status. Changes in muscle-fibre-type composition, as determined histochemically, could not per se account for the functional abnormalities.
A Method for Standardizing Airway Resistance for Variations in Lung Volume
Authors: Higenbottam T. , Clark T. J. H.
Published: August 2015

1. The inverse relationship between airway resistance and lung volume contributes to variation in measurement of resistance, as it is difficult to control precisely the lung volume at which resistance is determined each time. A correction for variation in lung volume was applied to measurement of airway resistance by using analysis of covariance with lung volume as a covariate. This method provides an assessment in each subject of degree of association between airway resistance and lung volume and uses the individual's unique slope, relating resistance to volume in order to correct resistance to a single lung volume. The corrected measurement of airway resistance was compared with conventional volume-standardized variables such as specific airway resistance, specific airway conductance and the logarithmic transformation of the latter.

2. Eight normal male subjects had airway resistance and lung volume measured in a body plethysmograph, a mean of seven measurements being made. They then inhaled histamine.

3. Airway resistance showed only a limited association with lung volume and the slopes relating the two measurements varied between subjects. Covariance-corrected airway resistance appeared more sensitive than other methods of volume standardization in detecting bronchoconstriction.

4. Analysis of covariance adequately corrects airway resistance for variations in lung volume but further studies are required to validate its precision and sensitivity.
Plasma 25-Hydroxy-Vitamin D in Normal Subjects and Patients with Terminal Renal Failure, on Maintenance Haemodialysis and after Transplantation
Authors: Eastwood J. B. , Daly A. , Carter G. D. , Alaghband-Zadeh J. , De Wardener H. E.
Published: August 2015

1. Plasma 25-hydroxy-vitamin D concentration was measured in 40 normal subjects, 19 patients with terminal renal failure, 137 patients who had been on dialysis up to 11 years and in 17 renal transplant patients.

2. The mean plasma concentration of 25-hydroxy-vitamin D was below normal in patients with terminal renal failure and in patients who had been on maintenance haemodialysis for less than 1 year. The mean concentration in patients who had been on dialysis for more than 1 year and in renal transplant patients was normal.

3. The seasonal variation of plasma 25-hydroxy-vitamin D concentration found in the 58 patients on maintenance haemodialysis for more than 2 years is similar to that reported in normal subjects.
Interaction of Amino Acids with Glycyl-l-leucine Hydrolysis and Transport in Monkey Small Intestine
Authors: Ganapathy V. , Radhakrishnan A. N.
Published: August 2015

1. There are two saturable transport processes in the monkey small intestine for glycyl-l-leucine, one with Kmax 1 μmol min−1 g−1 wet weight of tissue and an affinity constant (kt) of 5 mmol/l, and the other with Vmax. 3·9 μmol min−1 g−1 wet weight of tissue and kt 33 mmol/l.

2. Glycyl-l-leucine uptake is inhibited by a wide variety of amino acids, although to a variable extent. The inhibition was shown to be competitive with leucine used as the representative amino acid. Phenylalanine, methionine, alanine and leucine are the most potent in their inhibitory action.

3. The effect of various amino acids on the hydrolysis of glycyl-l-leucine by particulate and cytosol fractions of monkey small intestine was studied. All the amino acids, except glycine, proline, alanine and glutamic acid, inhibit both the particulate and cytosol glycyl-l-leucine hydrolase activities. In general, the cytosol enzyme is more susceptible to amino acid inhibition than the particulate enzyme.

4. There is no correlation between the effects of amino acids on glycyl-l-leucine uptake and hydrolysis of glycyl-l-leucine by either particulate or cytosol fraction.
Relationship between Exchangeable Sodium and Blood Pressure in Different Forms of Hypertension in Man
Authors: Davies D. L. , McElroy K. , Atkinson A. B. , Brown J. J. , Cumming A. M. M. , Fraser R. , Leckie B. J. , Lever A. F. , MacKay A. , Morton J. J. , Robertson J. I. S.
Published: August 2015

1. Arterial pressure and exchangeable sodium (NaE) were measured in patients with Conn's syndrome, essential hypertension, renal artery stenosis and chronic renal failure. Comparison was made with a control group. Urine sodium excretion was measured separately from the two kidneys in patients with renal artery stenosis.

2. Compared with control, mean NaE was significantly increased in Conn's syndrome, and was normal in essential hypertension, renal artery stenosis and chronic renal failure.

3. The correlation of arterial pressure with NaE was positive and significant in Conn's syndrome, essential hypertension and chronic renal failure.

4. In contrast the correlation was significantly negative in unilateral renal artery stenosis. Patients with lowest NaE had hyponatraemia, hypokalaemia and secondary hyperaldosteronism.

5. Urinary sodium excretion from the unaffected kidney in unilateral renal artery stenosis correlated positively with arterial pressure, possibly reflecting the phenomenon of pressure-natriuresis. Patients subsequently responding least well to surgery excreted least sodium from the untouched kidney for a given arterial pressure.

6. The findings suggest important roles for arterial pressure in the regulation of sodium balance (predominant in renal artery stenosis), and for sodium balance in the regulation of arterial pressure (predominant in Conn's syndrome). The observations in essential hypertension are compatible either with an exact balance between these mechanisms or with the existence of some other mechanism raising blood pressure.
Baroreflex Control of Blood Pressure and Plasma Noradrenaline during Exericse in Essential Hypertension
Authors: Sleight P. , Floras J. S. , Hassan M. O. , Jones J. V. , Osikowska B. A. , Sever P. , Turner K. L.
Published: August 2015

1. Twelve subjects (mean age 46·3 ± 12·5 years) with mild to moderate hypertension were studied before, during and after bicycle ergometer exercise.

2. Baroreflex sensitivity was determined by the Oxford phenylephrine method; sensitivity at rest was inversely related to intra-arterial pressure and age. Age and resting arterial pressure were not related.

3. Exercise for 5 min at 50 W and 5 min at 75 W raised the mean arterial pressure from 116·4 ± 18·0 to 150·0 ± 25·4 mmHg, the heart rate from 73·2 to 126·7 beats/min and the plasma noradrenaline from 541 ± 142·7 to 1309·8 ± 543·5 pg/ml (P < 0·001).

4. The increase in noradrenaline during exercise and the maximum mean pressure achieved were inversely related to resting baroreflex sensitivity (r = −0·68 and −0·77 respectively). Resting values of noradrenaline were not related to baroreflex sensitivity, age, or resting blood pressure.

5. It is possible that the rise in both plasma noradrenaline and arterial blood pressure produced by exercise is controlled by the baroreceptor reflexes; these are less effective in hypertensive subjects and thus the increases in noradrenaline and arterial pressure during exercise are greater in subjects with raised blood pressure.
Uptake and Efflux of Noradrenaline from Platelets; a Model System for Neurogenic Mechanisms in Essential Hypertension
Authors: Mattiasson I. , Mattiasson B. , Hood B.
Published: August 2015

1. The rate (k) of initial efflux of noradrenaline from platelets was determined in 63 individuals. A highly significant correlation was found between diastolic blood pressure and efflux rate.

2. When platelets are incubated in buffers with various Na+ concentrations in the range 110–170 mmol/l a higher Na+ concentration will give a faster efflux of noradrenaline for each concentration tested.

3. The value for k was determined in 41 normotensive first-degree relatives of hypertensive individuals and 21 persons with no family history of hypertension. Efflux rate of noradrenaline was significantly higher in the relatives and within this group was a subgroup with very high k values.
Inhibition of Urinary Kallikrein Excretion by Semi-Purified Renin in the Rat
Authors: Croxatto H. R. , Silva G. , Boric M.
Published: August 2015

1. Rat kidney extracts obtained at successive stages of a purification procedure, which allows the separation of renin and kallikrein, were used in order to investigate their effect upon urinary excretion of kallikrein, sodium, potassium and water in hyperhydrated rats.

2. Only the purified fraction containing renin reduced kallikrein excretion. The decrease of kallikrein coincided with a considerable increase in sodium, potassium and water excretion.

3. The natriuretic effect of renin extract did not depend on the presence of kallikrein. The injection of a mixture of renin and kallikrein attenuated the effect of renin alone, indicating that both enzymes exert antagonistic actions on the excretion of electrolytes and water by the kidneys.

4. A purified fraction of kidney extract containing no kallikrein and only traces of renin activity, had a stimulatory effect on kallikrein, water and elctrolyte excretion.
Effects of High Salt Intake and Meclofenamate on Arterial Pressure and Renal Function in the Spontaneously Hypertensive Rat
Authors: Chrysant S. G.
Published: August 2015

1. The effects of prolonged high sodium intake (duration 3 months) and meclofenamate were studied in two groups of male spontaneously hypertensive (SH) rats.

2. Group 1 (eight rats) received 1% NaCl in water and served as controls, and group 2 received 1% NaCl in water plus meclofenamate (3·5–4·0 mg daily).

3. Group 2 rats developed higher arterial pressure, renal vascular resistance and left ventricular weight and greater renal histological changes, with lower effective renal plasma flow, renal blood flow and glomerular filtration rate, than group 1. No differences were observed between the two groups in heart rate, body weight, fluid intake, urine volume, UNaV, UKV and right ventricular weight.

4. The results suggest that the combination of high sodium intake and meclofenamate exerts a greater damaging effect on the arterial pressure and renal function of SH rats than salt alone.
Familial Resemblance in Casual Blood Pressure—a Maternal Effect?
Authors: Bengtsson B. , Thulin T. , Scherstén B.
Published: August 2015

1. The familial resemblance in casual blood pressure was studied in material derived from an ophthalmic population survey. The population consisted of 1078 individuals forming 373 families and 1410 pairs divided into groups with different relationships. In order to adjust for age, the difference between the logarithm of the systolic blood pressure and that of the value expected from a linear regression on age was used instead of the observed pressure.

2. There was no significant correlation between spouses. Children did not resemble their fathers at all. Sons and daughters were significantly correlated with their mothers. The resemblance between siblings was even greater and highly significant. The familial resemblance was not dependent on synchronized pressure readings or on a common household and was not related to the time available for cumulation of effects.

3. Together these findings formed a pattern strongly suggesting long-lasting maternal effects on the systolic blood pressure.
Factors Determining the Variability of Arterial Pressure in Hypertension
Authors: Watson R. D. S. , Stallard T. J. , Littler W. A.
Published: August 2015

1. Intra-arterial pressure was recorded continuously in 26 patients with uncomplicated essential hypertension under standardized conditions. Pressure was analysed beat by beat by computer and variability measured as the standard deviation of the normally distributed frequency histogram.

2. Variability was strongly influenced by physical activity, being least during sleep and increasing progressively with bed rest and ambulation. Variability during daytime was not related to time.

3. Systolic variability correlated directly with systolic pressure. An independent inverse relationship with baroreflex sensitivity was observed. Systolic variability tended to increase with obesity.

4. None of the following were related independently with variability: age; race; sex; plasma renin activity; plasma angiotensin II; plasma noradrenaline; plasma adrenaline.
Treatment of Hypertension: State of the Art in 1979
Authors: Freis E. D.
Published: August 2015

1. The results of the Veterans Administration Co-operative Study have been extended by the subsequent clinical trials, which included patients of both sexes and with less vascular disease. The later studies confirm the effectiveness of treatment in preventing most complications except myocardial infarction and sudden death. Furthermore, the lower diastolic blood pressure in which treatment has been shown to have a significant beneficial effect has been lowered from 105 mmHg as indicated by the Veterans Study to 100 mmHg as shown by the much larger Australian trial. The possibility of reducing the incidence of sudden death and fatal myocardial infarction has been suggested by other recent control trials using β-adrenoreceptor-blocking drugs, an approach that needs further exploration.

2. A number of interesting and useful new drugs have appeared which include tienilic acid, minoxidil, saralasin and captopril, and in addition recent controlled trials have re-emphasized the effectiveness of the old drug, reserpine, when combined with a diuretic. The art of treatment of hypertension therefore appears to be in a healthy state and we should expect more advances in the future.
One Year Follow-Up of Hyperuricaemic Hypertensive Patients Treated with Tienilic Acid or a Diuretic with or without Uric Acid-Lowering Drugs
Authors: Waal-Manning H. J. , Simpson F. O.
Published: August 2015

1. Fifty-four hypertensive, hyperuricaemic patients were pair-matched for age, sex and current therapy (diuretic, uric acid-lowering drug).

2. One member of each pair was randomly assigned to continue on the previous therapy and the other member to treatment with tienilic acid (ticrynafen). Routine potassium chloride supplements were given only to subjects who were or had previously been on uric acid-lowering drugs.

3. Blood pressure control was equally good in the tienilic acid-treated and control groups. Serum uric acid was significantly lower in patients treated with tienilic acid.

4. In patients (32) not given supplements of potassium chloride, mean serum K+ did not fall but in four patients (three on tienilic acid, one on cyclopenthiazide) serum K+ fell to 3·5 mmol/l or less and potassium chloride was added.

5. Liver-function tests changed from pretrial results in nine patients. In eight of these (four on tienilic acid and four in the control group) minor rises in alkaline phosphatase only occurred. In the ninth patient, who was also taking metoprolol, serum aspartate transaminase rose markedly after 2 months and fluctuated for 4 months. Eventually there were also rises in alkaline phosphatase and bilirubin; these reverted to normal after stopping tienilic acid.
Assessment of the Antihypertensive Effect of Atenolol with 24 H Ambulatory Monitoring of Blood Pressure
Authors: Floras J. S. , Fox P. , Hassan M. O. , Jones J. V. , Sleight P. , Turner K. L.
Published: August 2015

1. Twenty-four hour intra-arterial blood pressure measurements and electrocardiograms were obtained from 12 subjects with untreated essential hypertension.

2. The patients kept records of their activity, paying particular attention to times of retiring to bed, and times of waking in the morning.

3. All subjects were treated with a single daily dose of atenolol (50 to 200 mg) for between 2 and 9 months, and then underwent a second 24 h blood pressure study.

4. Arterial blood pressure was lowered significantly throughout the 24 h period with a single daily dose of atenolol.
Action of Clonidine on Centrally Evoked Salivation in Anaesthetized Cats
Authors: Green G. J. , Wilson H. , Breckenridge A. M.
Published: August 2015

1. Clonidine (4 μg/kg) given intracisternally to anaesthetized cats inhibited brain stem-evoked parasympathetic submaxillary or parotid salivation by 62% at 5 Hz and 44% at 15 Hz.

2. The inhibitory action of clonidine on salivation was equally prevented by pretreatment with either intracisternal yohimbine (175 μg/kg) or phentolamine (250 μg/kg), used as preferential pre- and post-synaptic α-adrenoreceptor-blocking drugs respectively.

3. The inhibition of centrally evoked salivation by clonidine is due to an action on α-adrenoreceptors but no clear evidence was obtained to indicate whether these were located pre- or post- synaptically. This is in contrast to the preferential presynaptic action of clonidine in reducing peripheral parasympathetic nerve-evoked salivation.
Disappearance of Angiotensin II and Noradrenaline from the Renal and Femoral Circulations of the Dog
Authors: Miller M. J. S. , Scroop G. C.
Published: August 2015

1. The relative ability of the renal and femoral vascular beds to remove infused angiotensin II and noradrenaline was examined in anaesthetized greyhounds.

2. The degree of extraction of infused drug by each vascular bed was expressed as a percentage, calculated by comparing the pressor response to intra-arterial infusion with that obtained when the same dose was administered by the intravenous route.

3. When compared with the same dose given intravenously, the pressor responses after renal artery administration of angiotensin II were reduced by a mean of 77·8 ± 4·1% (mean ± sem, n = 12), whereas those after femoral artery infusions at the same dose were reduced by a mean of only 27·2 ± 4·9%(n = 12).

4. The pattern of extraction seen with noradrenaline infusions administered in a similar manner was the reverse of that with angiotensin II. There was a 28·9 ± 6·8% (n = 7) reduction in pressor responses to renal artery infusions; in contrast, femoral artery infusions of the same dose exhibited a 99·0 ± 1·0% (n = 7) reduction in the pressor responses.

5. Local arterial administration of the angiotensin II competitive antagonist, [Sar1,Ile8]angiotensin II, potentiated the systemic pressor responses to renal artery infusions of angiotensin II, but not those to femoral artery infusions.

6. It is suggested that the marked ability of the renal vascular bed to remove circulating angiotensin II may, in part, involve receptor-binding, although this seems not to be the case in the femoral vascular bed.
Ultrasound Measurements of Pulse-Wave Velocity in the Peripheral Arteries of Diabetic Subjects
Authors: Scarpello J. H. B. , Martin T. R. P. , Ward J. D.
Published: August 2015

1. Pulse-wave velocity in both upper and lower limbs has been measured in a series of diabetic and control subjects. Subjects were studied with a Doppler ultrasound system and a real-time frequency analyser.

2. The subjects comprised three groups: (a) diabetic subjects with peripheral neuropathy (43); (b) non-complicated diabetic subjects (8); (c) non-diabetic control subjects (11). Those diabetic subjects with peripheral neuropathy included 12 with non-infected foot ulcers, nine with healed foot ulcers and 22 who gave no history of foot ulceration. All of the diabetic and control subjects had clinically normal peripheral pulses.

3. In the upper limbs the pulse-wave velocity was similar for all groups. By contrast, in the lower limbs pulse-wave velocity was significantly increased (P < 0·005) in patients with healed or ulcerated feet compared with controls, non-complicated diabetic subjects or diabetic subjects with peripheral neuropathy alone.

4. It is suggested that the increased pulse-wave velocity results from an underlying, diffuse, atherosclerosis. This is not detectable clinically and was found to predominantly affect the lower limb arteries rather than the upper limb vessels. This may be an important aetiological factor in the development of foot ulcers in these patients.
Long-Term Clearance of [57Co]Cyanocobalamin in Vegans and Pernicious Anaemia
Authors: Amin S. , Spinks T. , Ranicar A. , Short M. D. , Hoffbrand A. V.
Published: August 2015

1. Whole-body counting has been used to monitor the clearance of [57Co]cyanocobalamin in normal subjects, vegans and patients with pernicious anaemia. After oral administration of 57Colabelled cyanocobalamin (1 μg/l μCi), subjects were counted for radioactivity monthly for a maximum period of 1 year.

2. The results obtained were consistent with a monoexponential clearance model and a least-squares fit showed that there was no significant difference between the mean clearance rates for the vegans and normal subjects.

3. The patients with pernicious anaemia cleared the vitamin significantly more quickly than the normal control subjects.

4. This may be due to failure to reabsorb biliary vitamin B12 in pernicious anaemia because of the absence of intrinsic factor.
Fate of Vasopressin Perfused into Nephrons of Wistar and Brattleboro (Diabetes Insipidus) Rats
Authors: Lindheimer M. D. , Reinharz A. , Grandchamp A. , Vallotton M. B.
Published: August 2015

1. Iodinated vasopressin was microinjected into early proximal or distal tubules of Wistar and Brattleboro (diabetes insipidus) rats. Sites of infusion were determined by the lissamine green transit time method.

2. Urinary recovery of 125I after proximal and distal injections was 89 ± se 1·7% and 94 ± 1·0% in Wistar rats (corrected for inulin) and 81 ± 20 and 92 ± 2·0% in Brattleboro rats (uncorrected); injection of hormone into vascular stars resulted in similar 125I recoveries from punctured and contralateral kidneys.

3. Radioactive substances excreted after perfusing proximal and distal sites in Brattleboro animals, and 125I-labelled hormone added to urine from the contralateral kidney, bound similarly to a specific arginine vasopressin antiserum and demonstrated similar radioactive elution profiles after passage through Sephadex G25 columns.

4. Incubation of labelled and unlabelled vasopressin with rat kidney homogenates resulted in similar and complete degradation of the hormone.

5. Results indicate that most of the vasopressin injected into either proximal or distal nephrons enters the urine intact, and no evidence of tubular secretion was found when perfusing vascular stars. Enzymes in rat renal tissue degrade labelled vasopressin, but the ability of the proximal tubule to hydrolyse the 125I-labelled vasopressin is limited, especially when compared with that reported for several linear peptide hormones.