bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.