bluuebunny/crossref_metadata_2025 huggingface dataset:
Renovascular Hypertension: Comparison of Medical and Surgical Therapy
Authors: Whelton P. K. , Harris A. P. , Russell R. P. , Walsh P. C. , Williams G. M. , Harrington D. P. , Walker W. G.
Published: August 2015

1. Results of medical and surgical therapy were compared in 28 patients with hypertension and unilateral renovascular ischaemia.

2. Renal function remained normal in both groups throughout the study period. After 6 months of follow-up systolic and diastolic blood pressures were significantly lower in the surgically treated patients. After 12 months of follow-up there was no significant difference between the two groups in diastolic blood pressure and after 24 months of follow-up there was no significant difference between the two groups in either systolic or diastolic blood pressure.

3. Sixty per cent of surgically treated patients were cured 6 months after operation, but only 40% remained cured after 24 months of follow-up.

4. All patients cured at 6 months who subsequently required antihypertensive medication had arteriosclerotic renovascular disease.
Transport of Lignocaine by Rabbit Choroid Plexus In Vitro
Authors: Spector R.
Published: August 2015

1. Lignocaine readily passes from blood into cerebrospinal fluid. The isolated rabbit choroid plexus, a locus of the blood—cerebrospinal fluid barrier, accumulated [14C]lignocaine by two processes: an active, saturable transport process and a non-saturable process.

2. The accumulation of [14C]lignocaine by choroid plexus was not due to non-specific binding or metabolism of lignocaine within or on the choroid plexus.

3. These results suggest that the choroid plexus may transport lignocaine between blood and cerebrospinal fluid in vivo by a specific carrier-mediated process.
The Influence of Physical Activity on Arterial Pressure during Ambulatory Recordings in Man
Authors: Rowlands D. B. , Stallard T. J. , Watson R. D. S. , Littler W. A.
Published: August 2015

1. Ambulatory blood pressure recordings were made over a 48 h period on six hypertensive patients. The conditions of study were standardized, particularly with regard to physical activity, and during one period of each day the patients were randomly allocated to be active or inactive.

2. Results show that blood pressure was highest during physical activity and lowest during sleep. There was no significant difference between the arterial pressures measured during the same physical activities carried out at the same time each day. However, during the same time on consecutive days when activity was randomized, there was a significant difference between the pressure recordings during physical activity compared with those during inactivity. Heart rate changes showed a similar trend during the randomized period.

3. Physical activity and sleep have a profound effect on continuous arterial blood pressure recordings and these are independent of time alone. These observations should be taken into account when using this ambulatory system to assess hypotensive therapy.
Serum Inorganic Fluoride: Changes Related to Previous Fluoride Intake, Renal Function and Bone Resorption
Authors: Waterhouse Christine , Taves D. , Munzer A.
Published: August 2015

1. Inorganic fluoride concentrations were determined in serum and urine specimens of 24 subjects receiving a standardized low fluoride intake. Serum fluoride was directly correlated with previous intake and appeared to reflect bone fluoride stores.

2. A positive correlation between creatinine and fluoride clearance was found. However, striking reductions in fluoride clearance, which resulted in increases in serum fluoride, were not usually seen until the creatinine clearance was below 25 ml/min.

3. Parathormone produced an increase in serum fluoride and thyrocalcitonin a decrease, probably by their action on bone.

4. Six patients with chronic increased bone resorption had elevated fluoride concentrations. In five, when treatment was successful, serum fluoride fell. Interpretation of the data from this group of patients is complicated by initially low filtration rates associated with hypercalcaemia and hypercalciuria.

5. The sensitivity of the serum fluoride concentration to previous intake, glomerular filtration and the intensity of bone resorption suggests that the human organism exerts no direct homeostatic control over this ion.
Cardiogenic Hypertension: Experimental Evidence from a Comparison between Intravenous and Intracoronary Administration of Dobutamine in Conscious Dogs
Authors: Liard J.-F.
Published: August 2015

1. We have studied whether the progressive rise in peripheral resistance observed in response to chronic intracoronary administration of dobutamine in conscious dogs could have resulted from extracardiac or non-β-adrenergic cardiac effects of the drug.

2. Six conscious dogs received dobutamine, 1.56 × 10−8 mol min−1 kg−1, intravenously for a 7 day period and seven conscious dogs were given dobutamine, 1.51 × 10−8 mol min−1 kg−1, into the left coronary artery under oral propranolol treatment for the same period while arterial pressure, cardiac output (electromagnetic flowmeter) and heart rate were measured.

3. Intravenous dobutamine produced no increase in arterial pressure, but a decrease in peripheral resistance and an increase in cardiac output which persisted until the end of the infusion.

4. With propranolol treatment intracoronary dobutamine induced no significant haemodynamic changes but a short-lasting increase in mean arterial pressure and peripheral resistance.

5. It is concluded that β-adrenergic cardiac effects of dobutamine are essential to the development of hypertension and increased peripheral resistance after prolonged intracoronary infusion of this drug.
Monocytes in Inflammatory Bowel Disease: Monocyte and Serum Lysosomal Enzyme Activity
Authors: Mee A. S. , Jewell D. P.
Published: August 2015

1. The activity of a specific lysosomal marker enzyme N'-acetyl-β-d-glucosaminidase has been determined fluorimetrically in the monocytes and in the serum of patients with Crohn's disease and ulcerative colitis and compared with results obtained from healthy and disease control subjects.

2. Enzyme activities were measured in a monocyte-enriched suspension from a Ficoll-Triosil gradient and in an adherent monocyte preparation.

3. The results indicate that enzyme activity is greater in both monocytes and sera of patients with Crohn's disease and ulcerative colitis than in those from control subjects (P0.01)

4. Enzyme activity within monocytes correlated with disease activity (P0.05)

5. Lysosomal enzymes may contribute to the pathogenesis of the mucosal inflammation in inflammatory bowel disease.
Effects of Indomethacin on the Metabolism of Glycerol by Rat-Kidney Tubules: An Alternative Explanation for the Enhancement of Glycerol-Induced Acute Renal Failure by Indomethacin
Authors: Craig Elizabeth , Cooney G. J. , Dawson A. G.
Published: August 2015

1. The metabolism of glycerol by isolated rat-kidney tubules was investigated.

2. Indomethacin, at a concentration of 0.1 mmol/l, markedly inhibited the utilization of glycerol and its conversion into glucose and CO2.

3. The glycerol 3-phosphate production rose significantly when indomethacin was present, indicating a fall in the rate at which glycerol 3-phosphate was oxidized.

4. The results are discussed in relation to the observation that indomethacin increases the severity of glycerol-induced acute renal failure.
Haemodynamics in Patients with Phaeochromocytoma
Authors: Levenson J. A. , Safar M. E. , London G. M. , Simon A. CH.
Published: August 2015

1. Cardiac haemodynamics were studied in 14 male patients with phaeochromocytoma, in comparison with 33 normal male subjects and 65 males with essential hypertension.

2. At the time of the investigation, seven patients with phaeochromocytoma were hypertensive and seven were normotensive. Cardiac output was within normal limits. Total peripheral resistance was elevated in the hypertensive patients. Heart rate was elevated both in the normotensive and in the hypertensive patients, but decreased after surgical treatment.

3. The relationships between blood volume and blood pressure and between blood volume and cardiac output were the same as those observed in the control groups.

4. During tilt, a predominant systolic orthostatic hypotension was observed and was associated with decreased stroke volume and impaired adaptation of total peripheral resistance during tilt, indicating inadequate arteriolar and venous reflexes.

5. The study suggested that, except for tachycardia, the haemodynamic pattern of patients with phaeochromocytoma and with essential hypertension was nearly the same.
The Use of Isolated Digital Arteries to Study Factors Influencing Adrenergic-Transmitter Release in Man
Authors: Rittinghausen R. E. , Moulds R. F. W.
Published: August 2015

1. In order to compare pre- and post-synaptic mechanisms influencing human vascular smooth muscle contraction, post-mortem digital arteries have been studied in vitro. After preloading transmitter stores with [3H]noradrenaline, stimulation-induced total tritium outflow and the associated pressure response were measured.

2. Tetrodotoxin either partially or completely abolished both stimulation-induced tritium outflow and constrictor response.

3. Neither the total tritium outflow nor the degree of its reduction by tetrodotoxin was related to the time after death the arteries were removed. Similarly no correlation was observed between stimulation-induced tritium outflow and age, sex, previous medications or underlying disease of the patient from whom the arteries were removed.

4. Total tritium outflow per impulse was markedly enhanced by increasing the frequency of stimulation from 1 Hz to 6 Hz.

5. Cocaine produced only a modest increase in stimulation-induced tritium outflow. Phentolamine more markedly enhanced stimulation-induced tritium outflow, whereas clonidine significantly reduced the outflow, thus demonstrating the presence of presynaptic α-adrenoreceptors.

6. It is concluded that post-mortem human digital arteries are suitable for the study of adrenergic transmitter release in man and that the two most important factors influencing transmitter release are frequency of stimulation and presynaptic receptors.
Basal Activity of the Natriuretic Factor Extracted from the Rat Kidney as a Function of the Diet and its Role in the Regulation of the Acute Sodium Balance
Authors: Louis F. , Favre H.
Published: August 2015

1. The effect of the sodium content of the diet on the natriuretic activity of an extract from the kidneys was studied in non-expanded and volume-expanded rats.

2. The kidney tissue was homogenized and the supernatant fractionated by gel filtration on Sephadex G-25. A single low-molecular-weight fraction eluted after the salt possessed the natriuretic activity and was tested on a rat bioassay.

3. The natriuretic activity of the fraction obtained from the kidneys of non-expanded rats was related to the sodium intake.

4. After an acute extracellular volume expansion, the natriuretic activity obtained from the fraction extracted from the kidneys was much greater than before expansion and was related to the dietary intake of sodium.
The Induction of Lysosomal Enzyme Release from Leucocytes of Normal and Emphysematous Subjects and the Effects of Tobacco Smoke upon Phagocytosis
Authors: Hutchison D. C. S. , Desai R. , Bellamy D. , Baum H.
Published: August 2015

1. The lysosomal enzymes of circulating polymorphonuclear leucocytes contain a potent elastase; release of this enzyme within the lung is thought to be responsible for the destruction of elastic tissue in pulmonary emphysema.

2. The release of lysosomal enzymes from blood leucocytes of normal and emphysematous subjects during phagocytosis of particulate material was studied In vitro. Acid phosphatase and acid ribonuclease were used as markers of lysosomal enzyme release, no sufficiently sensitive assay for elastase being available. Cigarette smoke was separated into ‘particulate’ and ‘soluble’ fractions. In a preliminary study, the particulate fraction stimulated enzyme release; in the experiments reported here, latex particles were used to produce this effect.

3. Approximately one-third of the total lysosomal enzyme content was released to the exterior of the cell during phagocytosis of latex particles. In this respect there was no difference between normal and emphysematous subjects.

4. The effects of the non-particulate soluble fraction of cigarette smoke on phagocytosis-induced enzyme release were studied. This fraction inhibited enzyme release from polymorphonuclear leucocytes of normal subjects but not from those of emphysematous patients. When the ‘cigarette-smoke solution’ was replaced by the respiratory inhibitor, antimycin A, a similar inhibition of enzyme release occurred. The inhibition of phagocytosis in cells of normal subjects is presumed to be due to a respiratory inhibitor such as carbon monoxide in the soluble fraction of the smoke. We postulate that the polymorphonuclear leucocytes of emphysematous patients are adapted to hypoxic conditions so that inhibition of enzyme release does not occur.
Heart-Rate Changes on Standing in Elderly Patients with Orthostatic Hypotension
Authors: White N. J.
Published: August 2015

1. The heart-rate changes on standing were studied in 16 elderly patients with idiopathic orthostatic hypotension and compared with those of 20 controls. The mean age of both groups was 78 years, and all were in sinus rhythm.

2. The patients with orthostatic hypotension differed from the control patients in having no early peak in heart rate, and a significantly smaller and slower rise in heart rate within the first 40 s after standing (P<0.05).

3. It is concluded that there is a failure of the autonomic reflex in elderly patients with orthostatic hypotension, which may contribute towards their symptoms.
Impaired Intestinal Absorption of Dipeptide in Tropical Sprue Patients in India
Authors: Hellier M. D. , Ganapathy V. , Gammon A. , Mathan V. I. , Radhakrishnan A. N.
Published: August 2015

1. Intestinal absorption of glycylglycine was studied in four control subjects and six patients with tropical sprue by using a direct technique of intestinal perfusion.

2. The patients with tropical sprue showed significant impairment in the absorption of the dipeptide.
The Effect of an Energy-Restricted Diet on the Protein Metabolism of Obese Adolescents: Nitrogen-Balance and Whole-Body Nitrogen Turnover
Authors: Pencharz P. B. , Motil K. J. , Parsons H. G. , Duffy B. J.
Published: August 2015

1. The effect of an energy-restricted (46 kJ day−1 kg−1), adequate protein diet (1.47 g day−1 kg−1) on the nitrogen metabolism of five obese rapidly growing adolescents (two males and three females) was assessed by means of nitrogen-balance measurements and determination of whole-body nitrogen turnover.

2. The energy-restricted diet had no significant effect on nitrogen balance (P > 0.1) for the entire group when compared with the control dietary intake; however, significant (P < 0.01) differences in nitrogen balance were noted among individuals at each dietary interval.

3. Mean values for whole-body nitrogen turnover, protein synthesis and breakdown for the control period were: 45.5 ± 13.2 mg of nitrogen day−1 kg−1, and 5.72 ± 1.96 and 5.74 ± 1.92 g of protein day−1 kg−1 respectively. These values are 82% of those measured in infants.

4. Reducing the mean non-protein energy intake to 20 kJ day−1 kg−1 had no significant effect on whole-body nitrogen turnover, protein synthesis or protein breakdown.

5. The results are discussed in relation to the regulation of whole-body nitrogen metabolism, by dietary protein and energy intakes.
Dissociation of Renin-Aldosterone and Renal Prostaglandin E during Volume Expansion Induced by Immersion in Normal Man
Authors: Epstein M. , Lifschitz M. D. , Re R. , Haber E.
Published: August 2015

1. The relationship of the renin-angiotensin-aldosterone axis with renal prostaglandin E is complex. Although studies have suggested that these two hormonal systems respond to experimental manipulations in a parallel manner, their interdependence has not been assessed fully during volume expansion. Since studies have demonstrated that in normal man the central hypervolaemia induced by water immersion to the neck produces a prompt and profound suppression of plasma renin activity and plasma aldosterone concentration without concomitant alteration of plasma composition, immersion afforded a unique opportunity to assess simultaneously the effects of central hypervolaemia on plasma renin activity, plasma aldosterone concentration and prostaglandin E excretion.

2. Seven normal subjects were studied twice while in balance on a diet containing 10 mmol of sodium/day, 100 mmol of potassium/day: with indomethacin administration (50 mg given every 6 h for five doses) and without indomethacin. Urinary prostaglandin E excretion was measured hourly and plasma renin activity and plasma aldosterone concentration at 30 min intervals.

3. Immersion was associated with a marked suppression of plasma renin activity (59 ± 7%) and plasma aldosterone concentration (55 ± 3%) with a return to pre-study values during the recovery hour. Concomitantly, urinary prostaglandin E excretion increased from 4.7 to a peak of 10.9 ng/min. Although administration of indomethacin lowered the basal rate of urinary prostaglandin E excretion and plasma renin activity, it did not prevent the subsequent augmentation of urinary prostaglandin E or the suppression of plasma renin activity and plasma aldosterone during the subsequent 4 h of immersion.

4. These results demonstrate a dissociation of renin-aldosterone and prostaglandin E during hypervolaemia and suggest that whereas prostaglandin E may constitute one of the major determinants of renin release clinically and experimentally, these two hormonal systems can be dissociated from each other in response to central volume expansion in man.
Effect of Neonatal Sympathectomy with 6-Hydroxydopamine on Reactivity of the Renin-Angiotensin System in Spontaneously Hypertensive Rats
Authors: Sinaiko A. R. , Cooper M. J. , Mirkin B. L.
Published: August 2015

1. Chemical sympathectomy was produced in spontaneously hypertensive rats by intraperitoneal injection of 6-hydroxydopamine hydrobromide (6-OHD) (100 μg/g body weight) on days 1, 4 and 7 of neonatal life and weekly thereafter until 6 weeks of age. The dose was then reduced to 50 μg/g body weight and injected every 2 weeks.

2. Studies were performed at 6 and 12 weeks of age in pentobarbital-anaesthetized rats. Plasma renin activity was measured before and 5 and 15 min after the administration of intravenous hydrallazine (5 mg/kg). Tissue noradrenaline concentration was determined in brains, hearts and kidneys from rats killed immediately upon completion of blood sampling.

3. The blood pressure of 6-OHD-treated rats was significantly lower than in untreated rats at 6 weeks (117 ± 3 and 146 ± 2 mmHg respectively) and 12 weeks (151 ± 5 and 196 ± 4 mmHg respectively).

4. Kidneys and hearts from 6-OHD-treated rats demonstrated a highly significant reduction in noradrenaline concentration at both 6 and 12 weeks; brain noradrenaline in treated rats was normal at 6 weeks and reduced only to 80% of normal at 12 weeks.

5. Control (pre-hydrallazine) plasma renin activity was significantly lower in 6-OHD-treated rats at 6 and 12 weeks. Nevertheless, renin release in response to intravenous hydrallazine, expressed in terms of absolute values of plasma renin activity, was not significantly different in the treated and untreated rats. When the percentage increase in plasma renin activity from control to 15 min post-hydrallazine samples was calculated, the response of the 6-OHD-treated rats was found to be significantly greater than the response in the untreated rats at each age.

6. These data show that treatment of neonatal rats with 6-OHD results in a significant reduction in basal activity of the renin-angiotensin system but does not interfere with the release of renin in response to hypotensive stress. In cases of severe compromise of adrenergic nervous system function, alternative mechanisms exist which allow the renin-angiotensin system to manifest a maximal response in order to maintain cardiovascular homeostasis.
Influence of Leucine on Arterial Concentrations and Regional Exchange of Amino Acids in Healthy Subjects
Authors: Hagenfeldt L. , Eriksson S. , Wahren J.
Published: August 2015

1. l-Leucine was given to healthy, post-absorptive subjects as a continuous intravenous infusion (300 μmol/min) during 2 1/2 h. Arterial blood concentrations and regional exchange of amino acids were measured across the splanchnic region, the brain and a leg, by the catheter technique. Renal clearance of amino acids was also determined.

2. During the infusion of leucine its concentration rose four- to six-fold, while the concentrations of several other amino acids declined continually, the effect being most pronounced for isoleucine (−55% of initial value), methionine (−55%), valine (−40%), tyrosine (−35%) and phenylalanine (−35%).

3. The infused leucine was taken up by muscle tissue (55%), by the splanchnic region (25%) and by the brain (10%). Neither leg-muscle release nor splanchnic uptake of aromatic amino acids was affected. Renal clearance and tubular reabsorption of amino acids were uninfluenced by leucine infusion. The uptake of isoleucine and methionine by the brain, seen in the basal state, was inhibited during leucine infusion.

4. The marked reduction in the concentrations of the aromatic amino acids, the uptake of leucine by the brain and the inhibition of brain methionine uptake, which accompany leucine infusion in healthy subjects,-5-be of relevance for the treatment of patients with portal-systemic encephalopathy.
Determination of Circulating 25,26-Dihydroxycholecalciferol in Man by Radioimmunoassay
Authors: Fraher L. J. , Clemens T. L. , Papapoulos S. E. , Redel J. , O'Riordan J. L. H.
Published: August 2015

1. A radioimmunoassay for 25,26-dihydroxycholecalciferol has been developed with an anti-serum raised in a sheep, tritiated 1,25-dihydroxycholecalciferol as tracer and synthetic 25,26-dihydroxycholecalciferol as standard. The metabolite was purified from serum extracts by Sephadex LH 20 and high-pressure liquid chromatography; recovery was monitored with biologically generated, tritiated 25,26-dihydroxycholecalciferol.

2. The mean ± sem concentration of 25,26-dihydroxycholecalciferol in serum from 18 healthy subjects was 587 ± 65 pmol/l. Seven Asian patients with osteomalacia due to vitamin D deficiency had very low or undetectable (< 96–231 pmol/l) circulating 25,26-dihydroxycholecalciferol concentrations.

3. The metabolite was detectable in the sera from seven anephric patients (mean 262 ± 43 pmol/l), indicating that extrarenal sites for the 26-hydroxylation of 25-hydroxycholecalciferol exist in man.

4. A strong positive correlation between the concentrations of 25-hydroxycholecalciferol and those of 25,26-dihydroxycholecalciferol in serum was obtained. Thus it appears that in man the production of this dihydroxy metabolite of vitamin D depends on the concentration of its precursor, 25-hydroxycholecalciferol.
Interconversion between High- and Low-Molecular-Weight Forms of Renin in Dog Kidney
Authors: Yamamoto K. , Ikemoto F. , Kawamura M. , Takaori K.
Published: August 2015

1. The low-molecular-weight (40 000) form of renin was converted into the high-molecular-weight (60 000) form of renin with sulphydryl oxidation, and the high-molecular-weight form of renin was re-converted into the low-molecular-weight form with a reduction of disulphide bonds in the renal cortical homogenate of the dog. Therefore, the low- and high-molecular-weight forms of renin were interconvertible.

2. The formation of high-molecular-weight form of renin required a renin binding substance which was found to be included in the cytosol fraction of kidney cortex of the dog.

3. The renin binding substance of the dog was unstable to heat and low pH, but vitally resistant to Triton X-100 and chloroform. It did not bind to concanavalin A Sepharose 4B.

4. The renin binding substance was eluted in the molecular-weight region between 156 000 and 60 000 on Sephadex G-200, and such apparent molecular weight was not altered by urea at 4 mol/l; thus molecular weight greater than the theoretically expected value of 20 000 was indicated.
Demonstration by a Rosette-Forming Technique of Surface Receptors for Low-Density Lipoproteins on Lymphoblastoid Cells
Authors: Valente A. J. , Morris C. J. , Walton K. W.
Published: August 2015

1. A simple technique of ‘rosette’ formation by low-density-lipoprotein-coated erythrocytes around human lymphoblastoid cells, stimulated to generate specific high affinity low-density lipoprotein receptors, is described.

2. Rosette formation is specific for high-affinity surface binding alone and the properties of the low-density lipoprotein receptors defined by it are identical with those found by using 125I-labelled low-density lipoprotein binding at 4°C.

3. Preliminary observations suggest that specific surface binding of low-density lipoprotein is shown by some, but not all, lymphoid cell lines, is independent of certain other surface receptors and is unrelated to whether the cells originate from B or T cells.

4. Loss of low-density lipoprotein surface receptors on lymphoid cell lines (as with other surface receptors) may occur simply from prolonged culture rather than as a result of genetically mediated familial abnormality.
Speed of Change in Pancreatic Mass and in Intestinal Bacteriology of Parenterally Fed Rats
Authors: Hughes C. A. , Prince A. , Dowling R. H.
Published: August 2015

1. Indices of pancreatic mass and bacterial counts for jejunal and ileal mucosa were studied in rats after 3, 6, 10 and 15 days of total parenteral nutrition and compared with the results from orally fed and sham intravenously fed control rats.

2. Pancreatic wet weight corrected for body weight decreased significantly by 31–42% after 3, 6, 10 and 15 days of total parenteral nutrition. The most striking decrease occurred within 3 days. Other indices of pancreatic mass (protein and DNA) showed a similar pattern suggesting pancreatic hypoplasia. There was more DNA per g of pancreas, indicating that unless there were changes in tissue water cellular hypotrophy must have accompanied the hypoplasia.

3. Pancreatic RNA also decreased significantly after 3–10 days of total parenteral nutrition, suggesting reduced protein synthesis.

4. Bacterial counts (log number) whether expressed as number/unit length of intestine or number/g wet weight of mucosa were decreased for anaerobic bacteria in the jejunum after 3–15 days of total parenteral nutrition. In the ileum both aerobic and anaerobic bacteria increased after 6 days of parenteral nutrition and then decreased significantly.

5. The changes in bacterial flora are unlikely to account for the adaptive hypoplasia seen in the intestine of intravenously fed rats.
Subcellular Distribution of Low- and High Molecular-Weight Renin and its Relation to a Renin Inhibitor in Pig Renal Cortex
Authors: Sagnella G. A. , Caldwell P. R. B. , Peart W. S.
Published: August 2015

1. The subcellular distribution of low-molecular-weight and high-molecular weight forms of pig renin has been investigated.

2. Renin, in aqueous extracts of a ‘renin granular fraction’ prepared by differential centrifugation, after gel filtration on Sephadex G-100 displayed an apparent molecular weight of 40 000 and was not activated by acidification to pH 2.8.

3. Renin in the soluble fraction separated on Sephadex G-100 at neutral pH displayed a main peak of activity with an apparent molecular weight of 40000. When eluates were acidified to pH 2.8 (2°C, 60 min) a marked increase in renin activity was observed in the region corresponding to an apparent molecular weight of 50 000.

4. A renin inhibitory material was isolated from the soluble fraction by DEAE chromatography. This material displayed an apparent molecular weight of 50000 and it was destroyed by acidification to pH 2.8.

5. The presence of the proteolytic inhibitor N-ethylmaleimide yielded an apparently high-molecular-weight form of renin (60000–70000) from the soluble fraction, but this was not found in the granular fraction.

6. We conclude that pig renal renin is stored within membrane-bounded subcellular organelles as the low-molecular-weight form. High-molecular-weight renin and renin inhibitory activity are localized to the cortical soluble fraction. In addition, the soluble fraction contains a material which in the presence of N-ethylmaleimide results in the formation of an apparently high-molecular-weight renin.
The Demonstration of Sialic Acid in Kidney Stone Matrix
Authors: Melick R. A. , Quelch K. J. , Rhodes M.
Published: August 2015

1. The organic matrices of 12 kidney stones containing calcium and two composed of uric acid were solubilized, with ethylenediaminetetra-acetate for the former and sodium hydroxide for the latter.

2. The solubilized matrices and residual fine particulate material were examined for sialic acid by the thiobarbituric acid method.

3. Sialic acid was found in every stone in either the soluble and/or insoluble material.

4. The identity of sialic acid was confirmed by the absorption spectrum of the colour produced and by its release from the protein by neuraminidase.

5. The presence of sialic acid in all stones despite widely varying composition suggests that it may be passively deposited.
Ambulant Blood Pressure: Reproducibility and the Assessment of Interventions
Authors: Mann S. , Craig M. W. Millar , Balasubramanian V. , Cashman P. M. M. , Raftery E. B.
Published: August 2015

1. We have assessed the day-to-day reproducibility of intra-arterial blood pressure by monitoring 17 freely ambulant hypertensive patients for a period of 48 h. Eight had no change of therapeutic regimen throughout and nine took a single dose of a hypotensive agent before retiring on the second night.

2. Records were analysed to provide hourly mean values of heart rate, systolic and diastolic blood pressure. No significant differences between first and second day recordings were found except after the intervention in the second group.

3. Allowing subjects to follow their normal daily routine produces inevitable variation in their pattern of physical and other activity. However, by the use of these methods of recording and analysis, with pooled measurements from a small group of subjects, reproducibility is sufficiently good to permit the reliable assessment of therapeutic interventions.
The Effect of the Methionine Enkephalin Analogue DAMME on the Vasopressin Response to Tilt in Man
Authors: Lightman S. L. , Forsling Mary L.
Published: August 2015

1. Infusion of the methionine enkephalin analogue DAMME (Sandoz) inhibits the rise in plasma arginine vasopressin after a 65° head-up tilt.

2. DAMME does not significantly affect the blood pressure, pulse rate or plasma volume changes produced by tilt.
Brain Angiotensin II Stimulates Release of Pituitary Hormones, Plasma Catecholamines and Increases Blood Pressure in Dogs
Authors: Schölkens B. A. , Jung W. , Rascher W. , Schömig A. , Ganten D.
Published: August 2015

1. The mechanisms of central angiotensin II blood pressure effects in conscious dogs on normal or sodium-deficient diets were examined.

2. The biosynthesis of brain angiotensin II in cerebrospinal fluid from its local precursor angiotensinogen was induced in vivo by injection of 0.5 unit of hog kidney renin through a chronically implanted cannula into the third brain ventricle in conscious dogs.

3. Intracerebroventricular administration of renin induced an increase of arterial blood pressure and a marked drinking response under both dietary regimens. Sodium restriction had no effect on the magnitude of the central angiotensin pressor response.

4. Plasma concentrations of renin and angiotensin II decreased, and plasma antidiuretic hormone, noradrenaline, adrenaline and corticosterone increased, in both groups of dogs.

5. Simultaneous intraventricular administrations of captopril with renin inhibited the central renin effects. Intracerebroventricular injections of [Sar1, Val5, Ala8] angiotensin II alone increased plasma renin and angiotensin II concentrations.

6. It is concluded that endogenous brain angiotensin II participates in central mechanisms of blood pressure regulation by the stimulation of the release of antidiuretic hormone, adrenocorticotrophic hormone, adrenaline and noradrenaline.
Angiotensin II in Human Cerebrospinal Fluid May Be An Immunoassay Artifact
Authors: Semple P. F. , MacRae W. A. , Morton J. J.
Published: August 2015

1. Concentrations of angiotensin II (ANG II) were measured by radioimmunoassay in cerebrospinal fluid and plasma from neurosurgical patients and patients having spinal anaesthesia. Cerebrospinal fluid concentrations of renin, renin substrate and ANG I were also measured.

2. Cerebrospinal fluid concentrations of ANG II measured with antiserum 30/VI were low in neurosurgical patients (mean 6 pmol/l, range < 2-12 pmol/l, n = 7) and lower in spinal anaesthesia patients (mean 1 pmol/l, range < 2–4 pmol/l, n = 14) and unrelated to concurrent plasma concentrations of ANG II.

3. A second more sensitive immunoassay with ANG II antiserum 9/P gave higher cerebrospinal fluid concentrations of ANG II in spinal anaesthesia patients (mean 15 ± 1 pmol/l, n = 7, P < 0.01).

4. Paper chromatography showed that the ANG II immunoreactive material measured with antiserum 9/P was not ANG I, ANG II, ANG II-(2-8), ANG II-(3-8) or ANG II-(4-8).

5. The concentration of ANG I in cerebrospinal fluid was low (4 ± 0.04 pmol/l, n = 7). No renin was detected (n = 32) and the concentration of renin substrate was 45 ± 2.6 nmol/l (n = 24).

6. Much of the immunoreactive ANG II in human cerebrospinal fluid is an immunoassay artifact
Adrenal Angiotensin II Receptors and Vascular Reactivity to Angiotensin II in the Rat during Continuous Inhibition of Angiotensin Converting Enzyme
Authors: Millar J. A. , Casey D. J. , Johnston C. I.
Published: August 2015

1. The effect of continuous infusion of captopril (80 μg/h) for up to 5 days on blood pressure, adrenal angiotensin II receptors and vascular reactivity to exogenous angiotensin II, arginine vasopressin and noradrenaline was studied in the rat.

2. In treated rats, blood pressure decreased transiently to a minimum after 2 days (−18 mmHg). Vascular reactivity to angiotensin II, but not to arginine vasopressin, was also increased significantly after 2 days, but vascular reactivity to noradrenaline decreased. After 5 days, vascular reactivity to angiotensin II had returned to normal and was similar to that of sham-treated controls. Adrenal angiotensin II receptor concentrations decreased significantly after 1 and 2 days, but at 5 days were again similar to controls. There was no change in receptor affinity.

3. Converting enzyme inhibition with captopril causes transient specific changes in adrenal angiotensin II receptors and vascular reactivity. The receptor and vascular effects may facilitate and oppose, respectively, the early changes in blood pressure with captopril, but a long-term contribution from either is unlikely.
Captopril Affects Blood Pressure Equally in Renovascular and Essential Hypertension and in the Fluid-Depleted Anephric State
Authors: De Bruyn J. H. B. , Wenting G. J. , Man in 'T Veld A. J. , Derkx F. H. M. , Schalekamp M. A. D. H.
Published: August 2015

1. The haemodynamic effects of 100 mg of captopril in renovascular hypertension (n = 11), essential hypertension (n = 12) and the anephric state (n = 7) were compared. Brachial artery pressure was measured in all patients, and changes in right atrial pressure, pulmonary artery pressure, pulmonary capillary wedge pressure and cardiac output were followed in renovascular and essential hypertension. Nephrectomized patients were studied before and after fluid withdrawal by ultrafiltration.

2. The pretreatment concentration of active renin in plasma was 100 ± 24 μ-units/ml (mean ± sem) in renovascular hypertension, and 24 ± 4 μ-units/ml in essential hypertension. In nephrectomized patients pretreatment renin was 1.7 ± 0.3 μ-units/ml, and renin was unresponsive to withdrawal of 1.8 ± 0.2 1 of body fluid.

3. The effects of captopril were maximal after 60–90 min. Mean arterial pressure after 90 min was lowered by 19 ± 4% in renovascular hypertension, by 17 ± 4% in essential hypertension and by 16 ± 3% in fluid-depleted nephrectomized patients. These changes were not significantly different despite the marked differences in renin. Captopril had no effect on arterial pressure in the fluid-replete anephric state.

4. The effects of captopril on cardiac filling pressures and cardiac output in renovascular and essential hypertension were also not different.

5. It is concluded that the antihypertensive action of captopril may be largely independent of circulating renin.
Effects of β-Lipotropin on Aldosterone Production in Rats
Authors: Matsuoka Hiroaki , Mulrow Patrick J. , Franco-Saenz Roberto , Li Choh Hao
Published: August 2015

1. β-Lipotropin has a potent aldosterone stimulating effect in vitro and in vivo in rats.

2. The maximum aldosterone response to β-lipotropin was the same as to ACTH and greater than to angiotensin II.

3. Although doses of ACTH which maximally stimulated aldosterone significantly increased cyclic AMP production, maximally stimulating doses of sheep β-lipotropin did not increase cyclic AMP production significantly.

4. These data suggest that β-lipotropin may play a role in aldosterone regulation through a mechanism different from that of ACTH.
Interactions of Prostaglandins with the Kallikrein-Kinin and Renin-Angiotensin Systems
Authors: McGiff J. C.
Published: August 2015

1. Prostaglandins together with the kallikrein-kinin system comprise a major vasodepressor system.

2. Prostaglandins can antagonize the actions of pressor hormones and the adrenergic nervous system. They also contribute to the blood pressure-lowering effects of kinins by enhancing the vasodilator and diuretic-natriuretic actions of the peptide.

3. Deficiency of the vasodepressor system may lead to hypertension without any increase in the basal activity of the blood pressure-elevating system.

4. Increased activity of the renin-angiotensin and adrenergic nervous systems evoked by stressful stimuli enhances prostaglandin synthesis, which protects organ function from excessive effects of angiotensins and catecholamines.

5. Several findings preclude unqualified acceptance of prostacyclin as the only important vascular prostaglandin: first, in some blood vessels prostacyclin is not the principal product of enzymic transformation of the cyclic endoperoxides. Secondly, prostaglandin E2, which is also synthesized in the vascular wall, may be the principal modulator prostaglandin. Lastly, prostacyclin may be transformed by some tissues to 6-keto-prostaglandin E1, a more stable product having similar biological potency.

6. Synthesis of prostaglandins by the kidney is important to mechanisms which control renin release and renal vascular resistance.
Circulating Prostacyclin Concentrations May Be Increased by Bendrofluazide in Patients with Essential Hypertension
Authors: Webster J. , Dollery C. T. , Hensby C. N.
Published: August 2015

1. A within-patient randomized double-blind crossover study was performed on mechanisms of action of bendrofluazide in mild essential hypertension. Significant reductions in lying, standing and post-exercise blood pressure were seen after both 3 days and 10 weeks treatment with bendrofluazide (10 mg daily).

2. Plasma levels of 6-oxo-prostaglandin F1α, the chemical hydrolysis product of prostacyclin, were significantly increased by both 3 days and 10 weeks therapy with bendrofluazide. This raises the possibility that thiazides may reduce peripheral resistance by increasing prostacyclin biosynthesis.
Inhibition by Bradykinin of the Vascular Effects of Pressor Hormones in the Canine Kidney: Relationship to Prostaglandins
Authors: Sušić H. , Nasjletti A. , Malik K. U.
Published: August 2015

1. Renal arterial injection of bolus doses of angiotensin II or noradrenaline, (0.06, 0.12 and 0.25 μg) caused renal vasoconstriction and decreased blood flow to the kidney in a dose-related manner in dogs anaesthetized by sodium pentobarbital.

2. The effect of angiotensin II and noradrenaline in lowering renal blood flow was reduced during renal arterial infusion of either bradykinin (10 ng min−1 kg−1) or prostaglandin E2 (4 ng min−1 kg−1).

3. Pretreatment of the dogs with an inhibitor of prostaglandin synthesis, sodium meclofenamate (5 mg/kg), blunted the inhibitory action of bradykinin, but not that of prostaglandin E2, on renal vascular reactivity to angiotensin II and noradrenaline.

4. These results indicate that bradykinin reduces the renal vasoconstriction induced by angiotensin II and noradrenaline in the dog by a mechanism dependent upon synthesis of prostaglandins.
Blood Volume and Interstitial Fluid Pressure in the Development and Reversal of Renal Hypertension in Rats
Authors: Trippodo N. C. , Ziegler L. P.
Published: August 2015

1. During the development and maintenance of one-kidney, one-clip hypertension in rats, there were no significant differences in blood volume or interstitial fluid pressure compared with one-kidney control rats.

2. Rats with one-kidney, one-clip hypertension of 25 days' duration were either unclipped, sham-operated or nephrectomized. Over 24 h the changes in arterial pressure, blood volume and interstitial pressure in the sham and nephrectomized groups were insignificant. In the unclipped group arterial pressure decreased 50 mmHg to normal by 24 h and was associated with increased diuresis and a small decrease in blood volume (9.8%). Unclipped rats with the greatest urine outputs showed the largest decreases in interstitial pressure (r = 0.70, P<0.02).

3. Thus, in the reversal of this hypertension, changes in blood volume played only a partial role; decreased interstitial pressure was secondary to tissue fluid depletion from increased diuresis and normalization of arterial pressure required the presence of the unclipped kidney.
Effect of Inheritance and Stress on the Diurnal Excretion of Sodium and Potassium in Young People with and without a Family History of Hypertension
Authors: Parfrey P. S. , Wright P. , Ledingham J. M.
Published: August 2015

1. The diurnal excretion of sodium and potassium was observed in young people, with and without a genetic predisposition to hypertension, both in the presence and absence of psychological stress.

2. In the absence of stress, the normal day/night sodium excretion ratio was reversed in the children of hypertensive parents. This was significantly less than day/night sodium excretion in children of normotensive parents. A similar finding was observed for day/night potassium excretion.

3. There was a significant negative correlation between systolic blood pressure and day/night sodium excretion in children of hypertensive parents but not in children of normotensive parents.

4. After the mental stress of a University examination day/night sodium reverted to normal in children of hypertensive parents.
Sodium—Potassium-Dependent ATPase Activity in Erythrocyte Ghosts of Patients with Primary and Secondary Hypertension
Authors: Wambach G. , Helber A. , Bounner G. , Hummerich W. , Konrads A. , Kaufmann W.
Published: August 2015

1. We have investigated the function of the Na+-K+ pump in the erythrocytes of patients with various types of hypertension by measuring the activity of ouabain-sensitive Na+-K+-dependent ATPase and ouabain-insensitive ATPase in the erythrocyte ghosts of these patients.

2. Mean Na+-K+-ATPase activity was increased threefold in six patients with Cushing's syndrome and hypertension (0.985 ± sd 0.288 μmol of phosphate h−1 mg−1) compared with that in 49 control subjects (0.334 ± 0.147 μmol of phosphate h−1 mg−1) (P<0.0025), but not in four patients with primary aldosteronism (0.278 ± 0.108 μmol of phosphate h−1 mg−1).

3. Na+-K+-ATPase activity slightly exceeded the control range in 57 patients with primary hypertension (0.410 ± 0.245 μmol of phosphate h−1 mg−1; P<0.025) and in 12 patients with renal hypertension (0.475 ± 0.250 μmol of phosphate h−1 mg−1) (P<0.025).

4. There was no difference in ouabain-insensitive ATPase between the controls and the different types of hypertension.

5. The data support the hypothesis of an activation of the Na+ pump in patients with glucocorticoid excess. This helps to explain previous observations of a redistribution of sodium and water to the extracellular compartment in experimental glucocorticoid-induced hypertension.
Studies on the Role of Sodium-Potassium-Activated ATPase as Determinant of Vascular Reactivity in Wistar-Kyoto and Spontaneously Hypertensive Rats
Authors: Gouthberg G. , Jandhyala B. , Folkow B.
Published: August 2015

1. The role of Na+-K+-activated ATPase in the regulation of resistance vessel reactivity to barium chloride and noradrenaline was investigated with a pair-perfused hindquarter technique in spontaneously hypertensive rats and Wistar-Kyoto rats (6 and 12 week old). Ouabain (10−4 mol/l) was used to inhibit the sodium pump.

2. In all groups studied, dose-response curves to agonists were shifted to the left when ouabain was added to the perfusion medium. This potentiation in vascular reactivity produced by ouabain was expressed as ‘index for sodium-pump inhibition’ (ISPI = ED50 of an agonist/ED50 + ouabain).

3. In mature rats index for sodium-pump inhibition calculated for both agonists was significantly greater in spontaneously hypertensive rats in comparison with Wistar-Kyoto rats, but not so in young spontaneously hypertensive rats. There was, however, a trend towards increased noradrenaline sensitivity in spontaneously hypertensive rats although the difference from Wistar-Kyoto rats was not statistically significant.

4. The data may suggest that there is some increase in the activity of the sodium pump in the resistance vessels of mature spontaneously hypertensive rats, perhaps to compensate for an increased passive sodium permeability.
Erythrocyte 22Na Efflux and Urinary Sodium Excretion in Essential Hypertension
Authors: Fitzgibbon W. R. , Morgan T. O. , Myers J. B.
Published: August 2015

1. The rate constant for total 22Na efflux from erythrocytes was examined in patients with mild to moderate hypertension and in normotensive controls. No difference in 22Na efflux rate constant was found when the cells from both groups were incubated in artificial medium. When the cells from both groups were incubated in their own plasma, the rate constant for Na efflux was significantly elevated for hypertensive patients compared with controls (0.40 ± 0.02, 0.36 ± 0.01 respectively; P<0.05).

2. In hypertensive patients sodium efflux rate constant varied inversely with 24 h urinary sodium excretion when erythrocytes were incubated in artificial medium (r = − 0.34, P<0.05) or in plasma (r = −0.42, P<0.05). No association between sodium efflux rate constant and urinary sodium excretion occurred in normotensive subjects.

3. These findings provide further evidence that sodium is an important aetiological factor in hypertension. In ‘salt-sensitive’ individuals dietary sodium may interact with the regulation of cellular sodium transport via both humoral and cellular mechanisms to elevate blood pressure.