bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Radioimmunoassay and Immunocytochemical Localization of Renin in Human Kidneys
Authors: Ménard J. , N'goc P. W. , Bariety J. , Guyenne P. T. , Corvol P. 
Published: August 2015

1. Highly specific antibodies to human renin were prepared in rabbits and used for the preparation of a renin-free substrate, the direct radioimmunoassay of renin in plasma and kidneys, and the localization of renin with fluoresceinated antibodies.
2. In a patient with a partially infarcted kidney, plasma renin activity was increased, and could be activated by acid. The direct measurement of plasma renin by radioimmunoassay gave identical values before and after acidification.
3. In the ischaemic part of the kidney, renin content was high, both by the enzymatic and the direct method of measurement. It was low in the non-ischaemic part of the kidney.
4. All afferent and some interlobular arteries of the obsolescent glomeruli were stained with fluoresceinated anti-renin antibodies. In the non-ischaemic area, the juxtaglomerular apparatus did not stain.
5. Renin can now be measured in human plasma and kidney as an entity, by a specific radioimmunoassay. A direct investigation of this intrarenal hormone is now possible at the renal tissue level.
Acute and Chronic Effects of Nifedipine on Plasma Renin Activity and Plasma Adrenaline and Noradrenaline in Controls and Hypertensive Patients
Authors: Corea L. , Miele N. , Bentivoglio M. , Boschetti E. , Agabiti-Rosei E. , Muiesan G. 
Published: August 2015

1. Nifedipine, a calcium antagonist drug, was given sublingually (10 mg) to seven normal subjects and 19 patients with essential hypertension. In addition, 12 of the hypertensive subjects then received nifedipine (10 mg thrice daily) for 3 weeks.
2. Sublingual administration of nifedipine in hypertensive patients induced a prompt and sustained reduction of blood pressure, without a significant increase of heart rate; in normotensive subjects blood pressure did not change, and heart rate was significantly increased. After chronic treatment, blood pressure remained reduced and heart rate did not rise.
3. Plasma catecholamines and plasma renin activity increased significantly in normotensive subjects after acute administration.
4. After both acute and chronic administration, only plasma noradrenaline was significantly increased in hypertensive patients; in long-term treatment, it was increased in both the lying and standing positions.
5. Nifedipine is an active antihypertensive drug, which may induce some degree of sympathetic activation.
Contribution of the Kidneys but not Adrenal Glands to the Acute Antihypertensive Effects of Captopril in Spontaneously Hypertensive Rats
Authors: Antonaccio M. J. , High J. P. , Rubin B. , Schaeffer T. 
Published: August 2015

1. Captopril (100 mg/kg, orally) decreased blood pressure in spontaneously hypertensive (SH) rats.
2. Bilateral adrenalectomy either before or after captopril administration did not alter the antihypertensive effect of captopril.
3. Bilateral nephrectomy reversed the established antihypertensive effect of captopril and prevented any change in blood pressure to a subsequent dose of captopril.
4. It is concluded that kidneys but not adrenal glands are essential to the antihypertensive actions of captopril in SH rats.
Does the Renin—Angiotensin System Maintain Blood Pressure in Both Hypertensive and Normotensive Subjects? a Comparison of Propranolol, Saralasin and Captopril
Authors: MacGregor G. A. , Markandu N. D. , Roulston J. E. 
Published: August 2015

1. Propranolol, saralasin and captopril changed blood pressure in normotensive as well as hypertensive subjects.
2. The percentage change in blood pressure with these three drugs for a given plasma renin activity was similar in normotensive and hypertensive subjects.
3. This suggests that when the renin-angiotensin system is maintaining blood pressure, it maintains the blood pressure to the same extent in percentage terms in normotensive and hypertensive subjects for a given plasma renin activity.
4. Saralasin has marked agonist activity, and probably underestimates the participation of the renin—angiotensin—aldosterone system in the maintenance of blood pressure. The fall in blood pressure that occurred with captopril in normal subjects on their normal sodium intake suggests that the renin—angiotensin—aldosterone system may have an important role in the control of blood pressure in normal subjects on their normal sodium intake. If it does, our results suggest that the renin—angiotensin—aldosterone system plays no greater role in maintaining blood pressure in patients with essential hypertension than normotensive subjects for a given plasma renin activity.
Effects of an Angiotensin Converting Enzyme Inhibitor on Psychosocial Hypertension in Mice
Authors: Henry J. P. , Vander A. J. , Stephens P. M. 
Published: August 2015

1. Renin-associated, chronic psychosocial hypertension of 150–160 mmHg develops in groups of mice interacting socially in complex population cages.
2. The blood pressures of 16 males in a cage were measured and an intraperitoneal injection of the angiotensin coverting enzyme inhibitor captopril (SQ 14 225) was given. Three hours later blood pressures were measured again.
3. During the first 3 weeks of psychosocial hypertension SQ 14 225 was without effect. But at 1 month and subsequently up to 7 months, SQ 14 225 reduced blood pressure to the normal range of 120–130 mmHg.
4. Plasma renin activities were not related to the extent of blood pressure reduction by SQ 14 225. Hence other factors in addition to the renin—angiotensin mechanism play a part in maintaining chronic psychosocial hypertension.
A Sympathetic Pressor Reflex in the Conscious Dog
Authors: Pagani M. , Bergamaschi M. , Malliani A. 
Published: August 2015

1. The effects of mechanical activation of aortic sympathetic sensory fibres have been studied in conscious dogs.
2. A cannula covered by an inflatable rubber balloon, previously implanted in the descending thoracic aorta, was used to stretch the aortic walls without obstructing blood flow.
3. Aortic stretch significantly increased mean arterial blood pressure and heart rate from control values in the absence of pseudo-affective reactions.
4. This response indicates that positive feedback sympathetic reflexes are operative in the conscious, fully innervated animal.
Noradrenaline Clearance in Hypertensive Patients with Various Degrees of Renal Function
Authors: Masuyama Yoshiaki , Nishimura Takuzo , Nishio Ichiro , Kuchii Masato 
Published: August 2015

1. Hypertensive patients with normal renal function showed significantly higher plasma urinary noradrenaline than the normotensive controls, and the hypertensive patients with mild to moderate disturbance of renal function showed the same noradrenaline concentration as the controls.
2. Hypertensive patients with severe renal function disturbance showed significantly higher plasma noradrenaline concentrations and lower urinary noradrenaline excretion than the controls.
3. Noradrenaline clearance calculated by free plasma noradrenaline and total urinary noradrenaline was significantly decreased in those subjects with severe renal dysfunction.
4. Conjugated plasma noradrenaline was increased in the hypertensive patients with the severe disturbance of renal function, and conjugated urinary noradrenaline increased in those without severe renal dysfunction.
Is Blood Pressure Variability Related to Activity of the Sympathetic System?
Authors: Clement D. L. , Mussche M. M. , Vanhoutte G. , Pannier R. 
Published: August 2015

1. In 70 patients with untreated essential hypertension, blood pressure variability was correlated to plasma catecholamines and to the response of blood pressure and peripheral flow to cold pressure and handgrip tests.
2. Supine blood pressure was recorded every 5 min, during 3 h. Variability was defined as the standard deviation of the mean of the readings in that period.
3. Blood pressure variability is positively and significantly correlated to the level of pressure and to age.
4. No significant correlation could be found with plasma catecholamines and sympathetic function tests.
5. It is concluded that blood pressure variability is related to the level of pressure but not to activity of the sympathetic nerves.
The Effect of Mental Stress on Prostaglandin F2α in Patients with Essential Hypertension and in Healthy Subjects
Authors: Ignatowska-S̀witalska H. , Klonowicz T. , Feltynowski T. 
Published: August 2015

1. The influence of mental stress, 30 min Kraepelin's arithmetic test under noise on the plasma concentration and urinary excretion of prostaglandin (PG) F2α was studied in patients with essential hypertension and in healthy subjects.
2. Before the arithmetic test the plasma PGF2α in hypertensive patients was significantly higher than in healthy subjects. The mental stress produced a significant increase in plasma PGF2α in healthy subjects but not in patients with essential hypertension.
3. Three hour urine excretion of PGF2a before stress was about two times lower in hypertensive patients than in healthy subjects. After exposure to stress a significant decrease in urinary excretion of PGF2α was found in healthy subjects, but not in hypertensive patients.
4. The stress-induced increase in plasma PGF2α of healthy subjects may reflect elevated brain PGF2α synthesis. The individual differences in response to stress in hypertensive patients may result from specific impairments in synthesis and/or prostaglandin turnover.
Adrenocorticotropin Inhibition of Mineralocorticoid Hormone Production
Authors: Biglieri E. G. , Chang B. , Hirai J. , Brust N. , Rost C. R. , Schambelan M. 
Published: August 2015

1. Adrenocorticotropin (ACTH)-induced steroidogenesis, obtained by continuous administration of ACTH for 3 days, produces in man (a) sustained elevations of plasma deoxycorticosterone and cortisol concentrations, (b) transient elevations of plasma aldosterone and 18-hydroxycorticosterone concentrations that return to near-control values, and (c) brisk initial increases in plasma 18-hydroxydeoxycorticosterone and corticosterone concentrations that fall to 20–68% of peak values 30 h thereafter.
2. Dexamethasone (8 mg/day, orally) treatment for 2 days in man permits a greater postural increase in plasma aldosterone and 18-hydroxycorticosterone concentrations. A dampening effect of ACTH is suggested.
3. An ACTH-initiated inhibition of 11β- and 18-hydroxylation is proposed to be operative in regulation of mineralocorticoid hormones.
Reactive Hyper-Reninaemia to Angiotensin Blockade Identifies Renovascular Hypertension
Authors: Case D. B. , Atlas S. A. , Laragh J. H. 
Published: August 2015

1. Saralasin and converting enzyme inhibitors SQ 20881 and captopril induced increases in plasma renin activity to greater than 14 ng h−1 ml−1 in 43 out of 44 patients with untreated renovascular hypertension when studied in the seated position and on normal sodium intake. This degree of response was absent in patients with normal-renin essential hypertension and present in only three out of 26 with high-renin essential hypertension.
2. Reductions of greater than approximately 9% in diastolic pressure in response to these three drugs occurred regularly in renovascular hypertension (95%) but also frequently in high-renin (65%) and normal-renin (26%) essential hypertension.
3. Prior sodium depletion abolished the specificity of the renin and depressor responses to angiotensin blockage for renovascular hypertension.
4. Some patients with bilateral renovascular and all with malignant hypertension also exhibited these responses to angiotensin blockade that are characteristic of unilateral renovascular hypertension.
Response of Arterial Blood Pressure, Plasma Renin Activity and Plasma Aldosterone Concentration to Long-Term Administration of Captopril in Patients with Severe, Treatment-Resistant Malignant Hypertension
Authors: McCaa Connie S. , Langford H.G. , Cushman W. C. , McCaa R. E. 
Published: August 2015

1. The response of arterial blood pressure, plasma renin activity and plasma aldosterone concentration to inhibition of angiotensin I converting enzyme (kininase II) with captopril has been studied in patients with severe, treatment-resistant, malignant hypertension.
2. Nine patients with a past history of severe hypertension, supine diastolic blood pressure &gt; 120 mmHg before conventional antihypertensive therapy and resistant to conventional antihypertensive therapy were studied.
3. Captopril administration resulted in a marked decrease in arterial blood pressure and plasma aldosterone concentration and an increase in plasma renin activity.
4. Although arterial blood pressure remained significantly below the values observed during the control period, pressure did tend to increase again after 3 days. Addition of hydrochlorothiazide kept arterial pressure significantly below pretreatment control values.
The Effects of Metoprolol on Ambulatory Blood Pressure
Authors: Mann S. , Craig M. W. Millar , Altman D. G. , Melville D. I. , Raftery E. B. 
Published: August 2015

1. Continuous monitoring of arterial pressure was performed via an indwelling cannula over 24 h in 12 hypertensive patients before treatment and again 2–4 months after starting metoprolol (100 mg twice daily).
2. During treatment, heart rate and systolic and diastolic pressures were significantly reduced.
3. The circadian patterns of heart rate and blood pressure changes were similar before and during therapy.
Comparative β-Adrenoreceptor-Blocking Effects and Pharmacokinetics of Propranolol and Pindolol in Hypertensive Africans
Authors: Salako L. A. , Falase A. O. , Aderounmu A. Fadeke 
Published: August 2015

1. The β-adrenoreceptor-blocking effects of pindolol were compared with those of propranolol and a placebo in a double-blind cross-over trial involving nine hypertensive African patients.
2. Heart rate, systolic blood pressure and diastolic blood pressure were measured at rest and immediately after exercise before and at intervals up to 6 h after oral administration of the drugs. In addition, plasma pindolol and propranolol concentrations were determined at the same intervals.
3. Pindolol diminished systolic blood pressure at rest and after exercise and antagonized exercise-induced tachycardia, but had no effect on resting heart rate. Propranolol diminished systolic blood pressure predominantly after exercise and reduced both resting and exercise heart rate. Both drugs had no effect on diastolic pressure.
4. The mean plasma concentration reached a peak at 2 h for each drug and this coincided with the interval at which maximal β-adrenoreceptor-blocking effect was observed.
Effect of Increasing Doses of Labetalol on Blood Pressure, Plasma Renin Activity and Aldosterone in Hypertensive Patients
Authors: Salvetti A. , Pedrinelli R. , Sassano P. , Arzilli F. 
Published: August 2015

1. Four different doses of labetalol (150, 300, 600 and 900 mg/day) were given for 1 week to each of four groups of patients with essential hypertension (six patients for each group).
2. Labetalol decreased mean blood pressure and heart rate to the same extent on the first and the seventh days of treatment. Only standing blood pressure showed a dose-dependent decrement, and heart rate showed a dose-dependent inhibition both in the supine and upright position.
3. Labetalol exerted a net inhibitory effect on plasma renin activity, which was related to basal renin values and was already maximal at the lowest doses. This effect was well maintained in the supine position, although during standing it tended to be less evident with increasing doses.
4. Urinary aldosterone was decreased in a dose-dependent fashion and its changes were largely independent of plasma renin activity.
5. Neither basal values nor changes of renin and aldosterone were related to the hypotensive effect of labetalol.
6. During labetalol treatment urinary sodium excretion fell for 2–3 days and then returned to basal values. The retentive effect of labetalol on sodium was directly related to the decrease of blood pressure, and the successive sodium escape might be explained either by the observed increase of plasma volume (indirectly measured by packed cell volume) or by aldosterone inhibition.
Effect of Captopril on Renal Vascular Tone in Patients with Essential Hypertension
Authors: Mimran A. , Brunner H. R. , Turini G. A. , Waeber B. , Brunner D. 
Published: August 2015

1. The effect of acute inhibition of angiotensin-converting enzyme by captopril (50 mg) on renal haemodynamics and function was assessed in nine patients with essential hypertension on unrestricted sodium intake (n = 8) or low sodium diet (n = 1).
2. Captopril induced a rapid and significant decrease in arterial pressure, which was maximal within 60 min.
3. Effective renal plasma flow (ERPF) increased, glomerular filtration rate (GFR) did not change and filtration fraction (FF) decreased after captopril. No change in sodium excretion and a decrease in urinary potassium occurred.
4. In the patient on low sodium diet, captopril induced striking increases in GFR and ERPF (64 and 106% respectively).
5. The logarithm of baseline plasma renin activity was positively correlated with the change in ERPF and negatively correlated with changes in FF and renal resistance.
6. The results indicate that in patients with essential hypertension angiotensin participates actvely in the maintenance of renal vascular tone at the efferent arteriolar level. A possible influence of kinins remains to be defined.
Modulation of the Baroreceptor Reflex by Angiotensin II and other Vasoactive Drugs in Anaesthetized Greyhounds
Authors: Marker J. D. , Miles T. S. , Scroop G. C. 
Published: August 2015

1. The effects of vascular infusions of acetylcholine, angiotensin II, noradrenaline and prostaglandin F2α on the baroreceptor reflex were studied in the anaesthetized greyhound.
2. Vertebral artery infusions of low doses of angiotensin II, but not of acetylcholine or prostaglandin F2α, resulted in a significant reduction in the depressor response to carotid sinus nerve stimulation.
3. The increases in blood pressure and heart rate in response to bilateral carotid artery occlusion were not significantly changed during vertebral artery infusions of acetylcholine, angiotensin II or prostaglandin F2α.
4. The increases in blood pressure in response to intravenous infusions of noradrenaline were significantly enhanced during vertebral artery infusions of acetylcholine and angiotensin II, but not of prostaglandin F2α. The bradycardia during noradrenaline infusions was significantly enhanced by angiotensin II alone.
5. The depressor response to carotid sinus nerve stimulation was significantly reduced during intravenous infusions of both noradrenaline and angiotensin II.
6. It is considered that although angiotensin II can be shown to have a specific central action to attenuate the response to carotid sinus nerve stimulation, the role of this action in the complete baroreceptor reflex is unproven.
Response of Chronic Renovascular Hypertension to Surgical Correction or Prolonged Blockade of the Renin–Angiotensin System by Two Inhibitors in the Rat
Authors: Thurston H. , Bing R. F. , Marks E. S. , Swales J. D. 
Published: August 2015

1. Removal of the renal artery constriction but not of the clipped kidney restored the blood pressure to normal levels in Goldblatt two-kidney rats with hypertension of more than 4 months' duration.
2. Despite the differences in blood pressure response, both surgical procedures lowered plasma renin concentration to normal or below normal values.
3. Administration of the oral converting enzyme inhibitor SQ 14 225 produced a marked fall in blood pressure in Goldblatt kidney rats with chronic hypertension. However, a prolonged infusion of the angiotensin II antagonist saralasin was quite ineffective. The difference in response to the two inhibitors may have been due to bradykinin potentiation by the converting enzyme inhibitor.
4. Although plasma renin is often elevated in Goldblatt two-kidney rats with hypertension of more than 4 months' duration, the renin-angiotensin system plays no role in the maintenance of blood pressure at this stage.
The Effect of Mineralocorticoid Administration on Urine Free Dopamine in Man
Authors: Oates N. S. , Perkins C. M. , Lee M. R. 
Published: August 2015

1. Five normal subjects were studied under metabolic conditions on a controlled sodium and potassium intake.
2. Plasma and urine free dopamine concentrations were measured in these subjects before, during and after 5 days administration of fludrocortisone (0·2 mg twice daily).
3. Urine free dopamine showed a tendency to fall during the early phase of fludrocortisone administration and then rose towards normal.
4. In a patient with primary hyperaldosteronism there was no evidence of increased renal production of dopamine. Urine dopamine fell when plasma renin activity rose as a result of spironolactone administration (200 mg three times a day for 5 days).
5. If renal dopamine has a role in mineralocorticoid ‘escape’ then it may be permissive only. The mechanisms of control of dopamine production could include tubular sodium concentration, tubular chloride concentration and intrarenal renin activity.
An Evaluation of the Clinical Potential of a Comprehensive Model of Human Respiration in Artificially Ventilated Patients
Authors: Hinds C. J. , Ingram D. , Adams L. , Cole P. V. , Dickinson C. J. , Kay J. , Krapez J. R. , Williams J. 
Published: August 2015

1. We have investigated the feasibility of accurately simulating the respiratory function of artificially ventilated patients, using a computer model of the respiratory system. Twelve patients artificially ventilated after uncomplicated cardiac bypass surgery were studied.
2. The basic information required to simulate individual ventilated subjects was measured or derived. A program was written to enable key model parameters to be adjusted automatically to match model predictions to these clinical measurements. On completion of this matching procedure all the variables computed by the model were compared with patient values (measured or derived) and their accuracy was assessed.
3. The matching algorithm successfully optimized parameters of the model representing metabolic activity, tissue respiratory quotient, venous admixture, physiological dead space and total body bicarbonate to match measured values for oxygen consumption, carbon dioxide production, Pa,o2, Pa, co2 and arterial HCO−3 respectively. Other variables compared arise from the solution of equations within the model and correlation between model and patient values is generally good (r &gt; 0·9). However, values of PV̇,o2 correlate less well (r = 0·85). Factors affecting the accuracy of patient simulation are discussed and some deficiencies analysed.
4. The creation of an accurate, steady-state representation of a patient by the model opens up the possibility of using it interactively as an aid to clinical management. Some possible future developments of the technique are discussed.
Equilibration of Tracer Radioiron with Body Iron
Authors: Charlton R. W. , Fatti L. P. , Lynch S. R. , Torrance J. D. , Bothwell T. H. 
Published: August 2015

1. The degree to which a tracer quantity of 55Fe bound to transferrin and introduced into the plasma 36 months previously had equilibrated with the body iron was studied in a subject who was phlebotomized repeatedly until iron-deficiency anaemia developed.
2. Analysis of the results with two mathematical models showed that equilibration with haemoglobin iron and storage iron was complete.
3. Estimates of the quantity of iron initially stored in the body by three different methods yielded values of 37·3, 33·1 and 34·8 mmol.
4. Since the previously determined mean initial plasma ferritin concentration was 185 μg/l (462 pmol/l), there was 0·179–0·197 mmol of stored iron per 1 μg of plasma ferritin/l.
5. The study suggests that the assumption on which currently accepted values for daily body iron loss were calculated is valid.