bluuebunny/crossref_metadata_2025 huggingface dataset:
Solitary Kidney and Ageing as Causes of Low Renin and Aldosterone Concentrations: Relevance to ‘Low-Renin’ Essential Hypertension
Authors: Gordon R. , Doran Freda , Thomas M. , Thomas Frances , Cheras P.
Published: August 2015

1. As experimental models of reduced nephron population in man, (a) twelve men aged 15–32 years who had one kidney removed 1–13 years previously and (b) fourteen normotensive men aged 70–90 years were studied. Results were compared with those in eighteen normotensive men aged 18–28 years and eleven men aged 19–33 years with essential hypertension.

2. While the subjects followed a routine of normal diet and daily activity, measurements were made, after overnight recumbency and in the fasting state, of plasma volume and renin activity on one occasion in hospital and of blood pressure on five to fourteen occasions in the home. Blood pressure was also measured after standing for 2 min and plasma renin activity after 1 h standing, sitting or walking. Twenty-four hour urinary aldosterone excretion was also measured.

3. The measurements were repeated in the normotensive subjects and subjects in (a) and (b) above after 10 days of sodium-restricted diet (40 mmol of sodium/day).

4. The mean plasma renin activity (recumbent) in essential hypertensive subjects was higher than in normotensive subjects. In subjects of (a) and (b) above, it was lower than normotensive subjects, and was not increased by dietary sodium restriction in subjects of (a).

5. The mean aldosterone excretion level was lower in old normotensive subjects than in the other groups, and increased in each group after dietary sodium restriction.

6. Mean plasma volume/surface area was not different between the four groups and in normotensive, essential hypertensive and nephrectomized subjects but not subjects aged 70–90 years was negatively correlated with standing diastolic blood pressure.
Determination of Renin-Dependency and Sodium-Dependency in the Three Renin Sub-Groups of Essential Hypertension
Authors: Gavras H. , Ribeiro A. , Brunner H. R. , Gavras I.
Published: August 2015

1. In all three renin sub-groups of essential hypertension, the state of sodium balance determines the degree of participation of the renin-angiotensin system in sustaining high blood pressure.

2. Even the low-renin type can become renin-dependent when sufficient sodium depletion has been achieved.

3. The main difference between patients of these sub-groups appears to be their variable capacity to become depleted of sodium under standard dietary regimens.
Increased Central Blood Volume: A Possible Pathophysiological Factor in Mild Low-Renin Essential Hypertension
Authors: Julius S. , Esler M.
Published: August 2015

1. Patients with mild low-renin hypertension characteristically have increased central blood volume. The total blood volume is normal; the larger central blood volume reflects a shift of the blood from peripheral to central (cardiopulmonary) segments of the capacity system.

2. A relationship between central blood volume and plasma renin activity is demonstrable during tilting in normal and hypertensive subjects. In thirteen individuals there was a strong correlation between the decrease of the central blood volume and the increase in plasma renin activity in response to 12 min of 35° head-up tilt.

3. We propose that the elevated central blood volume causes greater stretch of cardiopulmonary mechanoreceptors and this in turn depresses renin release in mild low-renin hypertension.
The Haemodynamic Response to Salt and Water Loading in Patients with End-Stage Renal Disease and Anephric Man
Authors: Kim K. E. , Onesti G. , Delguercio E. T. , Greco J. , Fernandes M. , Swartz C.
Published: August 2015

1. Patients with end-stage renal disease and anephric patients underwent expansion and depletion of body fluids with salt and water. This resulted in four different sequential haemodynamic patterns: (i) no significant increase in blood pressure; (ii) increase in blood pressure associated with a rise in cardiac output and no effect on total peripheral resistance; (iii) increase in cardiac output followed by a rise in blood pressure and total peripheral resistance; (iv) increase in total peripheral resistance and blood pressure without significant changes in cardiac output.

2. It is concluded that an initial rise in cardiac output is not necessary to increase blood pressure in either anephric man or patients with end-stage renal disease.
Renal Urinary Kallikrein in Normotensive and Hypertensive Rats during Enhanced Excretion of Water and Electrolytes
Authors: Croxatto H. R. , Albertini R. , Arriagada R. , Roblero J. , Rojas M. , Rosas R.
Published: August 2015

1. Urinary kallikrein excreted by normal rats is significantly increased (P < 0·001) 2 h after: (a) water loading, (b) water loading plus frusemide, 0·27 mmol (10 mg) per rat, (c) salt loading. In water-loaded rats, 5 i.u. of renin strikingly reduced kallikrein excretion (P < 0·01) but considerably increased sodium excretion (P < 0·001).

2. Renal kallikrein, measured by its kininogenase activity within 2 h of water loading, was significantly increased (P < 0·05); after water loading and frusemide it was 40% decreased (P < 0·001) and after salt loading it was reduced by approximately 50% (P < 0·02). Renin did not change renal kallikrein.

3. Severely hypertensive (one-kidney) rats (blood pressure >150 mmHg) showed no increase of urinary kallikrein after water loading, although there was a marked natriuresis; in moderately hypertensive rats (blood pressure <150 mmHg) urinary kallikrein was only one-third of that observed in control normotensive rats, after an equal degree of water loading.
Urinary Kallikrein and Plasma Renin during the Reversal of Renovascular Hypertension in Rats
Authors: Gulati O. P. , Carretero O. A. , Morino T. , Oza N. B.
Published: August 2015

1. Urinary kallikrein, sodium, potassium and water excretion, and plasma renin activity were measured before and during the reversal of experimental hypertension produced by unclamping the renal artery in rats.

2. Kallikrein excretion decreased significantly after unclamping, suggesting that it does not play a significant role in the reversal of hypertension.

3. A decrease in plasma renin activity coupled with a slight increase of sodium excretion was observed, indicating that these might participate in the reversal of hypertension.
Contribution of Prostaglandins to the Renal Vascular Supersensitivity to Vasoconstrictor Agents Exhibited by New Zealand Genetic Hypertensive Rats
Authors: Armstrong J. M. , Bell Caroline , Lattimer N. , McGiff J. C. , Mullane K. M.
Published: August 2015

1. Studies were made of the effects on responses to vasoconstrictor agents of prostaglandins released from Krebs perfused isolated kidneys of genetic hypertensive and normotensive rats.

2. Prostaglandin E-like activity, detected by bio-assay, was released from kidneys of both groups of rats during the vasoconstriction produced by noradrenaline, angiotensin or prostaglandin F2α.

3. In preparations obtained from hypertensive rats, responses to higher doses of noradrenaline or angiotensin were initially greater than those from normotensive rats and these were then reduced to a greater extent by infusion of indomethacin, which abolished release of prostaglandin E-like activity. Thereafter, in kidneys of either group, vasoconstriction to noradrenaline was potentiated by infusion of prostaglandin E2.

4. We conclude that, in rats, renal prostaglandins released in response to vasoconstrictor agents could augment the effect of such agents and in genetic hypertensive rats release of renal prostaglandins could contribute to the disease.
Functional-morphological Correlates of Renomedullary Interstitial Cells
Authors: Pitcock J. A. , Rightsel W. A. , Brown P. , Brooks B. , Muirhead E. E.
Published: August 2015

1. Indomethacin treatment of renomedullary interstitial cells (RIC) causes a marked increase in number and size of their lipid droplets. The anti-hypertensive function is retained.

2. After multiple passages in tissue culture, RIC lose their ability to produce an anti-hypertensive effect in hypertensive animals. Along with this functional loss, lipid droplets and a prominent cisternal system become attenuated or disappear.

3. We conclude that preservation of the lipid granule—cisternal organelle relationship is important in preservation of the anti-hypertensive endocrine function of RIC.
Deoxycorticosterone Measured by a Radioimmunoassay in vivo in Rats Undergoing Adrenal Regeneration
Authors: Hauger-Klevene Julia H. , Vecsei P.
Published: August 2015

1. The free deoxycorticosterone pool in the rat was measured by means of a radioimmunoassay in vivo.

2. The free deoxycorticosterone pool in rats with adrenal regeneration with normal or high blood pressure was similar.

3. In rats with adrenal regeneration, the free deoxycorticosterone pool 21 days post-operatively was significantly lower than that in sham-operated control rats and returned to control values at 60 days.
Aldosterone Regulation in Primary Aldosteronism: Differences between Adenoma and Bilateral Hyperplasia
Authors: Mantero F. , Gion M. , Armanini D. , Opocher G.
Published: August 2015

1. The diurnal patterns of plasma aldosterone, plasma renin activity (PRA), Cortisol and adreno-corticotrophic hormone (ACTH) in the supine and in the upright position have been studied in fourteen patients with primary aldosteronism, five with adenoma and nine with bilateral hyperplasia. Blood samples were drawn at intervals from 6 h to 30 min.

2. Supine patients with an adenoma showed marked diurnal variations of aldosterone, with maximal values at 08.00 hours and minimal values at 18.00 hours and secretory spurts beginning after 02.00 hours. Plasma Cortisol paralleled aldosterone, and ACTH seemed to anticipate aldosterone and Cortisol variations; PRA remained unchanged. In patients with hyperplasia, aldosterone was signicantly lower than in the adenoma group at 08.00 hours, and its decline during the day was less marked; fluctuations rather than secretory episodes were seen.

3. After patients assumed the upright posture, aldosterone remained unchanged or decreased in patients with adenoma, whereas it significantly increased in hyperplasia; PRA remained low, although a slight increment was seen in the latter group. The different response of aldosterone in the two groups was not modified by the administration of propranolol, apparently excluding a renin-dependent mechanism. On the other hand, dexamethasone seemed to affect the response of aldosterone to the upright posture in both groups; in adenoma there was a slight but significant increase, and in hyperplasia the usual rise was partially suppressed.

4. It is concluded that ACTH has a predominant role in regulating aldosterone secretion in primary aldosteronism due to adenoma, whereas its action in bilateral hyperplasia is only permissive.
Carotid Baroreceptor Reflex in Normotensive and Hypertensive Subjects
Authors: Mancia G. , Ludbrook J. , Ferrari A. , Gregorini L. , Valentini R. , Zanchetti A.
Published: August 2015

1. A graded decrease and increase in carotid baroreceptor activity (induced by a varying pressure in a neck chamber) caused a linearly related increase and decrease in arterial blood pressure. This occurred in both normotensive and hypertensive subjects.

2. Decrease of carotid baroreceptor activity caused a greater increase of blood pressure in normotensive than in hypertensive subjects. Increasing the activity caused changes of similar magnitude in the two groups.

3. Decrease of baroreceptor activity also caused an increase in heart rate although increasing the activity of the reflex had little effect on heart rate, particularly in normotensive subjects. Thus the carotid baroreceptor effect on blood pressure does not always reflect that on heart rate and inference of one reflex response from measurement of the other may be in error.
Resetting of the Baroreceptor in Hypotension in Rats
Authors: Salgado H. C. , Krieger E. M.
Published: August 2015

1. A progressive but incomplete adaptation of the aortic baroreceptor was observed after 1 and 6 h of hypotension in rats subjected to controlled bleeding. Administration of phenoxybenzamine produced a greater downward displacement of baroreceptor activation range

2. Complete adaptation was observed after 48 h of maintained hypotension in rats treated with reserpine.

3. The range of the aortic baroreceptor activation shifted upward as pressure returned to normotension, indicating the reversibility of baroreceptor adaptation in hypotension.
Relationship of Age and Blood Pressure to Baroreflex Sensitivity and Arterial Compliance in Man
Authors: Randall O. S. , Esler M. D. , Bulloch G. F. , Maisel A. S. , Ellis C. N. , Zweifler A. J. , Julius S.
Published: August 2015

1. The relationship between baroreflex sensitivity (BRS) and arterial compliance index (ACI) has been investigated (a) in paired subjects matched in one instance for systolic blood pressure with differing ages, and (b) in another instance matched for age with differing systolic blood pressures.

2. There was a significant negative correlation between BRS and age and between ACI and age in the twelve systolic blood pressure-matched subjects.

3. A significant negative correlation of systolic blood pressure with both BRS and ACI was observed in the fourteen age-matched subjects.

4. Both BRS and ACI appear to decrease with increasing age and systolic blood pressure. This decrease in BRS is probably due at least in part to the observed reduction in arterial distensibility.
Interplay of Sino-Aortic Reflexes and Haemodynamic Changes during Natural Sleep in the Cat
Authors: Baccelli G. , Albertini R. , Mancia G. , Zanchetti A.
Published: August 2015

1. When the sino-aortic afferents are intact, desynchronized sleep causes a small decrease in the blood pressure, a vasodilatation in the mesenteric and renal beds, and a vasoconstriction in the external iliac bed.

2. After sino-aortic deafferentation desynchronized sleep causes a larger fall in the blood pressure, a greater vasodilatation in the mesenteric and renal beds, and a vasodilatation replaces the vasoconstriction in the external iliac bed.

3. The sino-aortic reflexes play an active role in controlling circulation during desynchronized sleep by opposing the centrally induced reduction in adrenergic sympathetic tone. This effect of sinoaortic reflexes is similar on both visceral and muscular vessels. In addition, the muscular bed, but not the visceral one, is regulated by a spinal reflex vasoconstriction mechanism which is apparent only when the sino-aortic reflexes are intact.
Lack of Hypotensive Effect on Central Injection of Angiotensin Inhibitors in Spontaneously Hypertensive (SH) and Normotensive Rats
Authors: Elghozi J. L. , Altman J. , Devynck M. A. , Liard J. F. , Grunfeld J. P. , Meyer P.
Published: August 2015

1. Injections of antagonists of angiotensin II into the cerebral ventricles of normotensive and spontaneously hypertensive rats were performed in order to assess the role of the isorenin—angiotensin system in the brain.

2. No hypotensive effect was obtained in either normotensive or hypertensive rats, suggesting that intracranial isoangiotensin has little role in the pathogenesis of spontaneous hypertension in the rat.
Anti-Hypertensive Effect of Acebutolol: Its Relation to Sympathetic Nervous System Responsiveness and to Plasma Renin and Dopamine-β-Hydroxylase Activities
Authors: Fournier A. , Hardin J. M. , Alexandre J. M. , Lombaert M. , Ronco G. , Bezoc J. F. , Desmet G. , Quichaud J.
Published: August 2015

1. Acebutolol, a β1-receptor blocker, has, at a daily dose of 800 mg, a mild but significant anti-hypertensive effect in moderate sustained essential hypertension with normal or low plasma renin activity.

2. Prediction of its anti-hypertensive effect is better based on the evaluation of the sympathetic nervous system responsiveness to head-up tilt than on the evaluation of plasma renin activity or dopamine-β-hydroxylase.

3. The anti-hypertensive effect of acebutolol is better explained on the basis of inhibition of the sympathetic nervous system activity than on the basis of suppression of plasma renin activity.

4. A positive correlation between plasma renin activity and dopamine-β-hydroxylase in patients on diuretics suggests the common dependence of these two variables on sympathetic overactivity.
Increased Plasma Noradrenaline Concentrations in Essential Hypertension and Their Decrease after Long-Term Treatment with a β-Receptor-Blocking Agent (Prindolol)
Authors: Brecht H. M. , Banthien F. , Ernst W. , Schoeppe W.
Published: August 2015

1. Plasma noradrenaline was measured in fiftynine patients with mild to severe essential hypertension and in fifteen normotensive control subjects under basal and orthostatic conditions.

2. In patients with essential hypertension mean plasma noradrenaline concentrations were significantly higher than in control subjects under basal and orthostatic conditions.

3. In patients with essential hypertension basal diastolic blood pressure correlated closely with the corresponding plasma noradrenaline concentrations.

4. Long-term treatment with prindolol of patients with essential hypertension led to a significant fall in diastolic and systolic blood pressure and heart rate and to a significant decrease in plasma noradrenaline concentrations under basal and orthostatic conditions.

5. The adrenergic response to upright posture, reflected by an increase in plasma noradrenaline, was not abolished by prindolol.

6. It is concluded that the anti-hypertensive effect of prindolol in patients with essential hypertension is at least partially mediated by a decrease of sympathetic nervous activity.
Compared Incidence of First Myocardial Infarction in Hypertensive Patients under Treatment Containing Propranolol or excluding β-Receptor Blockade
Authors: Stewart I. McD. G.
Published: August 2015

1. After some exclusions, 169 severe uncomplicated essential hypertensive patients presenting consecutively were divided into two groups according to their treatment. Of these, 121 had been given long-term treatment containing propranolol (PC group) and forty-eight had been treated with hypotensive agents excluding any β-receptor-blocker group, the non-β-receptor-blocker (NBB) group.

2. There were no significant differences in myocardial infarction risk factors between the two groups.

3. After a mean follow-up of 5·25 years, nine of the 121 subjects (7·5%) in the PC group had suffered first infarctions and fifteen of the forty-eight subjects (31%) in the NBB group, a significant difference (P < 0·01).

4. It was concluded that the presence of propranolol had prevented more or caused fewer infarctions, perhaps a combination of both, than had the older hypotensive agents unsupported by β-receptor blockade.
Quantitative Effects of Timolol and Hydrochlorothiazide on Blood Pressure, Heart Rate and Plasma Renin Activity: Results of a Double-Blind Factorial Trial in Patients with Essential Hypertension
Authors: Chalmers J. P. , Horvath J. S. , Korner P. I. , Tiller D. J. , Bune A. J. , England J. D. , Fletcher P. J.
Published: August 2015

1. The anti-hypertensive actions of timolol and hydrochlorothiazide were analysed in a double-blind 2 × 2 factorial trial in twenty patients with essential hypertension. Each patient went through four phases of 8 weeks in randomized order, receiving timolol alone, hydrochlorothiazide alone, timolol plus hydrochlorothiazide, and placebo.

2. Supine mean arterial pressure fell from 119 mmHg in the placebo phase, to 110 mmHg during the thiazide phase, 106 mmHg during the timolol phase, and to 101 mmHg during the combined timolol plus hydrochlorothiazide phase.

3. Factorial analysis revealed that the hypotensive actions of the β-receptor-blocking drug and the diuretic were additive, without any synergism or antagonism.

4. Plasma renin activity measured in ng 3 h—1 ml—1 rose from 502 in the placebo phase to 9·54 in the diuretic phase, but fell to 1·79 in the β-receptor blockade. It was unchanged in the combined therapy phase, despite the greater drop in blood pressure. These results suggest that the fall in plasma renin activity during β-receptor blockade is of little importance in the hypotensive action of β-receptor-blocking drugs.
Medical Research Council's Treatment Trial for Mild Hypertension: An Interim Report
Authors: Miall W. E. , Brennan P. J. , Mann A. H.
Published: August 2015

The pilot phase of the British multicentre randomized controlled trial of treatment for mild hypertension has shown: (1) that unselected subjects, aged 35–64 years, with mild hypertension are willing to enter and remain in a long-term trial even though asymptomatic; (2) that the differences of mean systolic and mean diastolic pressure achieved between treated and control subjects is sufficient to produce the expected difference in terminating events with the 18 000 patients calculated as needed for the full-scale trial; (3) that side effects with the two selected active primary regimens (bendrofluazide and propranolol) are common but mild (no serious side effects or toxic reactions have been reported); (4) that the work load imposed by the trial, though considerable during screening and the initiation of patients into the trial, can largely be taken by specially trained nursing staff, and when screening is completed the trial does not impose a heavy burden of follow-up examinations; (5) that there are no adverse psychological effects caused by alerting asymptomatic people to their raised pressure and enrolling them into a prolonged programme of clinical attendance; (6) that the total costs of carrying out a full-scale trial-estimated at about £2m ($U.S. 4m)-are commensurate with the potential annual savings in health service expenditure whether the trial shows treatment to be effective or unwarranted.
Treatment of Severe Hypertension with Minoxidil and its Effects on Systemic and Pulmonary Haemodynamics
Authors: Hall D. , Froer K. L. , Loracher C.
Published: August 2015

1. The chronic administration of minoxidil, 0024–0·212 mmol (5–40 mg) daily, to fifty-two severely hypertensive patients resulted in an average reduction of mean arterial pressure from 170 to 111 mmHg.

2. Haemodynamic studies in twelve of these patients indicated that the rise in pulmonary arterial pressure in patients without heart failure appears to be a direct result of a disproportionately large increase in cardiac output with respect to a relatively small decrease in pulmonary vascular resistance. Anti-hypertensive treatment of patients with congestive heart failure resulted in a decrease in mean pulmonary arterial pressure.
Double-Blind Comparison of Minoxidil and Hydrallazine in Severe Hypertension
Authors: Connor G. , Wilburn R. L. , Bennett C. M.
Published: August 2015

1. Thirty moderately severely hypertensive patients were studied in a double-blind comparison of minoxidil and hydrallazine in combination with frusemide and propranolol.

2. Blood pressure control in both groups of patients was satisfactory but long-term control appeared to be better in the minoxidil group.

3. Renal function was well preserved in both groups. Evidence of cardiac hypertrophy was slow to resolve despite good control of blood pressure. Side effects were negligible, and patient acceptance and rehabilitation was excellent.
Haemodynamic and Endocrinological Changes during Anti-Hypertensive Treatment with a new Vasodilator Substance (L6150) and Propranolol
Authors: Wester A. , Zaal G. A. , De Leeuw P. W. , Birkenhäger W. H.
Published: August 2015

1. In eighteen subjects with mild to moderate hypertension the effectiveness of the new vasodilator drug L6150 (Lepetit) was studied. Its mechanism of action was identified by systemic and renal blood flow measurements and by estimating changes in plasma renin and aldosterone concentration and plasma volume. The reflexly induced hyperkinetic circulatory state could be completely corrected by adding propranolol or prevented by pretreatment with the latter drug.

2. Sodium retention was an invariable phenomenon. It was not due to a stimulation of the renin—angiotensin-aldosterone axis since plasma aldosterone was significantly decreased, presumably as a consequence of plasma volume expansion.
Comparison of the Effects of Pharmacological Therapy and a Low-Sodium Diet on Mild Hypertension
Authors: Magnani B. , Ambrosioni E. , Agosta R. , Racco F.
Published: August 2015

1. The effect of a low-sodium diet and pharmacological therapy has been compared in eighty-one patients with mild hypertension.

2. Both pharmacological therapy and a low-sodium diet reduced lying and standing systolic and diastolic blood pressure significantly.
Report on Progress in the Australian National Blood Pressure Study (NBPS)
Authors: Abernethy J. D. , Baker J. L. , Bullen M. U. , Lamb M. L. , Stewart M. R.
Published: August 2015

1. The National Blood Pressure Study (NBPS) is a single blind trial designed to test the efficacy of active drug treatment in reducing complications from mild hypertension (mean diastolic pressure = 95–109 mmHg).

2. Between 1973 and 1975, four centres screened about 104 000 subjects aged 30–69 years, yielding an estimated prevalence of hypertension (≥95 mmHg diastolic) of 16% and of moderate-to-severe hypertension (≥110 mmHg diastolic) of 1·3%.

3. Some 4000 subjects selected for untreated uncomplicated mild hypertension were randomized to either active treatment (chlorothiazide + α-methyldopa and/or a β-adrenoreceptor antagonist as required) or to matching placebos.

4. At 1 year mean pressures had fallen significantly below entry pressures in both groups but in the active group the fall was greater by a margin of 14·4±1·3 (sem) mmHg systolic and 71 ±0·7 mmHg diastolic. At 1 year 5% of subjects in the placebo group had been placed on active treatment on the ethical grounds that pressure had exceeded the mild hypertension limit.

5. Trial end-points (death, morbidity from stroke, hypertensive heart and renal disease, and ischaemic heart disease) number 106 (nine deaths) thus far, of which ischaemic heart disease accounts for 71% and stroke 19%.

6. The duration of trial may need to be extended beyond the original estimate of 5 years.
Blood Pressure Response to Physical Activity in Hypertensive Subjects at Different Times of the Day
Authors: Krönig B. , Knappen F. , Dufey K. , Wolff H. P.
Published: August 2015

1. Active orthostasis causes a fall of systolic blood pressure in the morning; this fall was more extensive in severe arterial hypertension.

2. Everyday physical activity produces a marked rise of systolic blood pressure, which is higher at noon and in the evening than in the morning; the hypertensive response is somewhat greater in WHO II and III, than in WHO I, grades of hypertension.

3. In studies on blood pressure behaviour in hypertensive subjects the circadian variability not only of the blood pressure at rest but also of the blood pressure response to various stimuli has to be considered.
Molecular Exclusion Electrophoresis of Human Serum Lipoproteins: Patterns in Control and Ischaemic Heart-Disease Populations
Authors: Green J. , Carney S.
Published: August 2015

1. Electrophoresis of pre-stained lipoproteins on acrylamide-gel gradients has been carried out on serum from populations of control subjects and patients with ischaemic heart disease. The technique resolves components intermediate in position and, by inference, in size, between very-low-density and low-density lipoproteins.

2. These central band components were found in 37% of a control population but the incidence varied with age and sex, being lowest in young males and highest in elderly males.

3. The incidence of central band components in patients with ischaemic heart disease was 64% (males) and 71% (females), and the difference between these figures and those for matched control subjects was highly significant. The intensity of central band components in the group with ischaemic heart disease was significantly greater than in the control group.

4. The presence and intensity of central bands show positive correlation with serum cholesterol and triglyceride values, but many patients showing the phenomenon have normal lipid values. Of patients with ischaemic heart disease 31% showed central band components and had normal lipid values.
Binding of Transferrin and Uptake of Iron by Rat Erythroid Cells in Vitro
Authors: Verhoef N. J. , Noordeloos P. J.
Published: August 2015

1. The binding of transferrin and the uptake of iron by rat bone-marrow-cell suspensions was investigated by the use of transferrin doubly labelled with 125I and 59Fe.

2. The pattern of transferrin binding was found to depend on the transferrin concentration in the incubation medium. At relatively low concentrations, binding of transferrin at 0–4 °C was lower than the binding at 37°C. At higher concentrations no difference could be observed between binding at 0–4°C and at 37°C. This phenomenon was explained in terms of a rapid non-specific adsorption of transferrin at 0–4°C, which takes place especially at higher transferrin concentrations, and a specific binding of transferrin at 37°C observed presumably at low concentrations.

3. The maximum number of specific transferrin-binding sites was found to be approximately 190 000 sites per rat reticulocyte and 330 000 sites per nucleated rat bone-marrow cell. The latter number corresponds to 500 000–700 000 sites per nucleated erythroid cell.

4. It was concluded that maturation of the erythroid cell is accompanied with a progressive loss of transferrin binding sites on the cell membrane.

5. When bone-marrow cells obtained after incubation with doubly-labelled transferrin were lysed with distilled water or with the detergent Nonidet P-40, differences in the subcellular distribution of the radioactivities could be observed.

6. It was concluded that the membrane fraction contains appreciable amounts of 59Fe not bound to 125I-labelled transferrin, which indicates that dissociation of the iron—transferrin complex is one of the earlier steps in the mechanism of iron uptake by erythroid cells.
Lack of Dependence of Urine Pco2 upon Reduction of Glomerular Filtration Rate in Alkalotic Dogs
Authors: Stinebaugh B. J. , Hostetter T. H. , Peraino R. A. , Schloeder F. X. , Suki W. N.
Published: August 2015

1. The Pco2 gradient between alkaline urine and arterial blood (U—B Pco2) is thought to depend primarily on distal hydrogen ion secretion. However, other variables affecting the U—B Pco2 include the urine flow rate, the urinary bicarbonate and phosphate excretion rates and the glomerular filtration rate.

2. In order to evaluate the effects of acute changes in these factors on the U—B Pco2, bicarbonate-loaded dogs with maximal U—B Pco2 values were subjected to either acute unilateral elevations of ureteral pressure or hypotension caused by nitroprusside infusion. The results demonstrate that acute reduction in the glomerular fiitration rate does not cause a decrease in the U—B Pco2 as long as the urinary concentrations of phosphate and bicarbonate do not decline.

3. Urinary concentrations of phosphate and bicarbonate appeared more important than their excretion rates in the maintenance of elevated U—B Pco2 values.
Effect of Pentobarbitone Sodium on Serum Creatine Kinase of Normal and Dystrophic Hamsters
Authors: Neerunjun J. S. , Dubowitz V.
Published: August 2015

1. The dose of pentobarbitone required for anaesthesia was significantly greater for dystrophic hamsters than for normal animals.

2. Serum creatine kinase activity was significantly higher in dystrophic than in normal hamsters.

3. Brain, heart and tibialis anterior muscle from dystrophic animals contained significantly less creatine kinase than the normal tissues.

4. Creatine kinase in normal and dystrophic sera, as in skeletal muscles, consisted of MM isoenzyme. Heart creatine kinase consisted of both MM and MB types and brain contained only the BB isoenzyme.

5. Pentobarbitone raised serum creatine kinase activity of normal and dystrophic hamsters to the same extent, elevation of enzyme activity being dependent on the amount of pentobarbitone injected.

6. The sera of pentobarbitone-treated normal and dystrophic hamsters contained only the MM isoenzyme.
Inhibition of Frusemide-Induced Natriuresis by Indomethacin in Patients with the Nephrotic Syndrome
Authors: Tiggeler R. G. W. L. , Koene R. A. P. , Wijdeveld P. G. A. B.
Published: August 2015

1. In four patients with nephrotic syndrome indomethacin not only reduced proteinuria but also inhibited the natriuretic effect of high doses of frusemide.

2. The inhibition of natriuresis by indomethacin could not be antagonized by albumin infusions.

3. Only the combined use of spironolactone and frusemide induced a natriuresis during indomethacin treatment. Spironolactone alone was ineffective.

4. It is suggested that inhibition of prostaglandin synthesis by indomethacin, in the presence of a stimulated renin-angiotensin system and hyperaldosteronism, may cause this strong tendency to sodium retention.
Comparison of the Effect of Two Groups of Diuretics on Renin Secretion in the Anaesthetized Dog
Authors: Imbs J. L. , Schmidt M. , Velly J. , Schwartz J.
Published: August 2015

1. The effects of two groups of diuretics on renin secretion have been compared in dogs anaesthetized with pentobarbital.

2. Frusemide, ethacrynic acid and bumetanide cause an immediate rise in renin secretion which is not inhibited either by dl-propranolol or by a bilateral ureterovenous anastomosis which prevents salt and water loss.

3. Clopamide, metolazone and indapamide do not cause an immediate rise in renin secretion. Renin hypersecretion is induced only 1 h after intravenous injection of these diuretics.

4. Renin secretion was studied for 6 h after frusemide injection: the immediate rise was followed by a later increase in renin secretion. This later rise was inhibited by propranolol and by ureterovenous anastomosis.

5. These results allow us to distinguish between a direct renal mechanism responsible for early renin hypersecretion, which appears to be connected with the action of the diuretic on the ascending limb of Henle's loop, and an indirect mechanism responsible for late renin hypersecretion, which appears to be connected with salt and water loss.
Concentrations of Prostaglandin A-, E- and F-Like Substances in Gastric Mucosa of Normal Subjects and of Patients with Various Gastric Diseases
Authors: Schlegel W. , Wenk K. , Dollinger H. C. , Raptis S.
Published: August 2015

1. Prostaglandin A-, prostaglandin E-and prostaglandin F-like substances were determined radioimmunologically in antral biopsy material obtained by endoscopy.

2. In patients with gastritis, the concentrations of prostaglandin (E + A)-like substances were six times as high and of prostaglandin F-like substances twice as high as in normal subjects. In chronic atrophic gastritis, the concentrations of prostaglandin (E+A)-like material was four times as high as in normal subjects whereas prostaglandin F-like material remained unchanged. In acute gastric ulcer, prostaglandin (E+A)-like material reached concentrations four times higher than in normal subjects, accompanied by a fivefold increase of prostaglandin F-like substances. After healing of the gastric ulcer, prostaglandins returned to normal values.

3. There was no correlation between gastrin and prostaglandins in all biopsy specimens.
Blood Pressure Response of Nephrectomized Hypertensive Rats to Converting Enzyme Inhibition: Evidence for Persistent Vascular Renin Activity
Authors: Thurston H. , Swales J. D.
Published: August 2015

1. Blood pressure and plasma renin activity were studied after bilateral nephrectomy in groups of rats with hypertension caused by unilateral renal ischaemia with the opposite kidney left intact.

2. Although blood pressure showed only a small fall in the first hour after bilateral nephrectomy, plasma renin activity fell rapidly with a half-life of 10 min.

3. Infusion of converting enzyme inhibitor (SQ20881) produced a 26·1% fall in blood pressure 1 h after nephrectomy, 24·0% at 2 h and 4·6% at 6 h.

4. An angiotensin antagonist (Sar1-Ala8-angiotensin II) was infused into hypertensive rats 1 h after nephrectomy; this blocked the vasodepressor action of the converting enzyme inhibitor, indicating that the fall in blood pressure produced by the inhibitor was due to its action upon the renin-angiotensin system.

5. The renin—angiotensin system maintains blood pressure in this model even after plasma renin has fallen to insignificant levels. This supports the view that vascular renin activity has a longer half-life than circulating renin and is important in the control of blood pressure.
Leucocyte Intracellular pH in Patients with the Metabolic Acidosis of Renal Failure
Authors: Levin G. E. , Baron D. N.
Published: August 2015

1. Human leucocytes were isolated from venous blood and resuspended in the subject's plasma.

2. Intracellular pH measurements were made in vitro by the dimethyloxazolidinedione technique in 13 healthy subjects and in 11 subjects with renal failure and metabolic acidosis.

3. The intracellular pH of the healthy subjects was found to be 7·07 (sd 0·04), significantly lower than that of the patients, which was 7·11 (sd 0·03). For all estimations plasma Pco2 was maintained at approximately 5·5 kPa. The methodological and possible metabolic reasons for this difference in intracellular pH are discussed.
Plasma Calcitonin in Paget's Disease of Bone
Authors: Kanis J. A. , Heynen G. , Walton R. J.
Published: August 2015

1. Plasma levels of immunoreactive calcitonin were measured in 22 patients with untreated Paget's disease of bone and in 22 control subjects matched for age and sex.

2. No significant differences in plasma calcitonin were found between patients and control subjects, and hormone levels did not correlate significantly with activity of plasma alkaline phosphatase.

3. These results suggest that Paget's disease of bone is not due to deficient secretion of endogenous calcitonin.
Comparison of the Effects of Water Immersion and Saline Infusion on Central Haemodynamics in Man
Authors: Levinson R. , Epstein M. , Sackner M. A. , Begin R.
Published: August 2015

1. The effects of acute intravenous infusion of 2 litres of saline/120 min on pulmonary capillary blood flow (Q̇c), diffusing capacity per unit of alveolar volume (DL/VA), functional residual capacity (FRC), and pulmonary tissue plus capillary blood volume (VTPC) were compared with the changes induced by water immersion to the neck for 4 h. Serial measurements were made at 30 min intervals in five normal subjects, utilizing a non-invasive rebreathing method with a gas mixture containing 0·5% acetylene, 0·3% C180, 10% He, 21% O2 and 68·2% N2.

2. Infusion of saline produced a rise in Q̇c which was similar to that induced by immersion. This increment in Q̇c persisted for the 3 h of observation after stopping the infusion, in contrast to the prompt decrease in Q̇c to pre-study values after cessation of immersion.

3. DL/VA was unaffected by saline administration in contrast to the marked and prompt increment induced by immersion.

4. Pulmonary tissue plus capillary blood volume was unchanged during both saline administration and immersion, suggesting that neither gradual saline administration nor immersion induces major extravasation of fluid into the pulmonary interstitial space.

5. The present data indicate that the ‘volume stimulus’ of immersion is similar to that of saline-induced extracellular fluid volume expansion in normal seated subjects. Immersion may be a preferred investigative approach for assessing the effects of volume expansion in subjects in whom rapid reversibility of the ‘volume stimulus’ is desirable.
Failure of Selected Endocrine Organ Ablation to Modify the Natriuresis of Blood Volume Expansion in the Dog
Authors: Kaloyanides G. J. , Cohen Loren , DiBona G. F.
Published: August 2015

1. Selected organ-ablation experiments were performed in dogs in an attempt to identify the source of the natriuretic hormone postulated to participate in the natriuresis of blood volume expansion.

2. An isolated dog kidney perfused with blood from the femoral artery of deoxycorticosterone-loaded dogs subjected to acute volume expansion with equilibrated blood served as the bioassay system for the natriuretic factor. Four groups were studied after the following procedures: group I, no ablation; group II, thyroparathyroidectomy; group III, hypophysectomy; group IV, adrenalectomy.

3. In all groups, the administration of equilibrated blood promoted a significant increase in sodium chloride excretion in the isolated kidney. The natriuresis was unrelated to changes in glomerular filtration rate, renal blood flow, renal arterial pressure, plasma protein concentration or packed cell volume. In the absence of volume expansion, sodium chloride excretion in the isolated kidney did not change or decreased.

4. These results argue against the thyroid, parathyroid, adrenal and pituitary glands as the source of natriuretic hormone.
Bronchial Provocation in the Study of Sensations Associated with Disordered Breathing
Authors: Rubinfeld A. R. , Pain M. C. F.
Published: August 2015

1. Lung volumes, airway resistance and flow/volume curves were measured in ten asthmatic subjects at times when tightness in the chest was just sensed (threshold symptom).

2. These measurements when the threshold symptom was induced by methacholine inhalation were compared with those when a similar symptom occurred spontaneously, in the same subjects.

3. Values during the methacholine-induced thresholds were very similar to those observed when threshold symptoms developed spontaneously.

4. Controlled bronchial provocation mimics spontaneous asthma sufficiently well to allow this technique to be used in the study of sensations associated with breathing. This has some advantages over the already established models utilizing external hindrances to breathing.
The Effect of 25-Hydroxy Vitamin D3 in the Osteomalacia of Chronic Renal Failure
Authors: Eastwood J. B. , Stamp T. C. B. , De Wardener H. E. , Bordier P. J. , Arnaud C. D.
Published: August 2015

1. Five patients with the osteomalacia of chronic renal failure were given 50–100 nmol of 25-hydroxy vitamin D3 intravenously per day for 24–28 days.

2. In all five patients, during administration of 25-hydroxy vitamin D3 there was a substantial rise in the plasma concentration of 25-hydroxy vitamin D from initially abnormally low values.

3. Significant improvement in bone mineralization, intestinal calcium absorption and muscle strength occurred in the three patients with the greatest rise in plasma 25-hydroxy vitamin D.
The Effect of Dietary Sodium Intake on the Blood Pressure and Cardiac Output Responses to Angiotensin II in Unanaesthetized Rats
Authors: Slack Barbara L. , Ledingham J. M.
Published: August 2015

1. Dose—response curves for the pressor activity of angiotensin II have been determined in unanaesthetized rats receiving diets containing 2·5% (w/w) or 0·007% (w/w) sodium and administered in various sequences.

2. Dose—response curves were shifted to the left in rats on a high-, compared with a low-, sodium intake. This response was maintained for 7 days on changing from high to low sodium.

3. There was no difference in the relation between the fall of cardiac output and the rise of blood pressure in any of the experimental groups.

4. Dose—response curves for peripheral resistance showed the same directional change as seen for the pressor response in rats on high- and low-sodium diets. Since depression of cardiac output was proportional to the pressure rise, the absolute change in peripheral resistance was greater than the blood pressure response. The proportional changes were similar.

5. It is concluded that alterations in the pressor response to angiotensin caused by changes in sodium loading are attributable to changes in peripheral resistance and not to changes in the cardiac output response to the acute rise in blood pressure.
Mitochondrial Functions and Content of Microsomal and Mitochondrial Cytochromes in Human Cirrhosis
Authors: Gil J. Díaz , Rossi I. , Escartín P. , Segovia J. M. , Gosálvez M.
Published: August 2015

1. Mitochondria and microsomal fractions have been isolated from liver biopsies from patients with alcoholic cirrhosis, cryptogenic cirrhosis or chronic aggressive hepatitis.

2. Cirrhotic livers yielded fewer mitochondria than normal liver.

3. The most significant change was a decrease in mitochondrial respiratory control. Cirrhotic microsomal fractions had a 50% diminution in cytochrome b5 and cytochrome P-450 content.

4. The two patients with chronic aggressive hepatitis showed similar mitochondrial and microsomal changes.
Effect of Glycylglycine on Absorption from Human Jejunum of an Amino Acid Mixture Simulating Casein and a Partial Enzymic Hydrolysate of Casein Containing Small Peptides
Authors: Fairclough P. D. , Silk D. B. A. , Clark M. L. , Matthews D. M. , Marrs T. C. , Burston D. , Clegg K. M.
Published: August 2015

1. A jejunal perfusion technique has been used in normal volunteer subjects to study jejunal absorption of amino acid residues from a partial enzymic hydrolysate of casein in which about 50% of the amino acids existed as small peptides, and also from an equivalent mixture of free amino acids.

2. The effect of a high concentration of the dipeptide glycylglycine on the absorption of amino acid residues from these preparations was studied to quantify the importance of mucosal uptake of intact peptides during absorption of the partial hydrolysate of casein.

3. The results were unexpected. Glycylglycine significantly inhibited absorption of several amino acid residues (aspartic acid + asparagine, serine, glutamic acid + glutamine, proline, alanine, phenylalanine, threonine and isoleucine) from the free amino acid mixture, whereas it significantly inhibited the absorption of only two (serine, glutamic acid + glutamine) from the peptide-containing partial casein hydrolysate.

4. The effect of glycylglycine on absorption of amino acids from the mixture of free amino acids was apparently due to inhibition of amino acid uptake by free glycine liberated from the dipeptide during perfusion. The reason for the failure of glycylglycine to cause extensive inhibition of absorption from the partial hydrolysate is not clear. It may be due to glycylglycine being only a weak inhibitor of peptide uptake, but the possibility that some peptides are taken up by a system unavailable to glycylglycine has to be considered.
Coeliac Disease: The Abolition of Gliadin Toxicity by Enzymes from Aspergillus Niger
Authors: Phelan J. J. , Stevens Fiona M. , McNicholl B. , Fottrell P. F. , McCarthy C. F.
Published: August 2015

1. Gliadin from which carbohydrate was removed by treatment with carbohydrase from Aspergillus niger was fed to three coeliac patients in remission.

2. Xylose absorption, mucosal morphology and brush-border enzymes were used to assess the toxicity of the carbohydrase-treated gliadin.

3. Gliadin treated with carbohydrases did not damage the intestinal mucosa of the coeliac patients.

4. The primary structure of the gliadin proteins was not altered by the enzyme treatment.
Effect of Anticonvulsants on the Uptake of 5-Methyltetrahydrofolic Acid by the Choroid Plexus in Rabbits
Authors: Taguchi H. , Abdul-Cader Z. , Perry J. , Reynolds E. H. , Chanarin I.
Published: August 2015

1. The isolated choroid plexus of the rabbit takes up 5-methyltetrahydrofolate from the incubation medium.

2. Other folate analogues (pteroylglutamic acid, methotrexate, 5-formyltetrahydrofolate = folinic acid) inhibited the uptake of 5-methyltetrahydrofolate.

3. The uptake of 5-methyltetrahydrofolate was inhibited by low temperature, anaerobic conditions and dinitrophenol.

4. The anticonvulsant drugs, diphenylhydantoin and phenobarbital, had no effect on 5-methyltetrahydrofolate uptake.

5. The inhibitory effect of pteroylglutamic acid on the uptake of 5-methyltetrahydrofolate by the choroid plexus may explain the effect of long-term folic acid therapy in aggravating vitamin B12 neuropathy in pernicious anaemia.