bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma Catecholamines and Blood Pressure Responses to the Carotid Baroreceptor Reflex in Essential Hypertension
Authors: Mancia G. , Leonetti G. , Picotti G. B. , Ferrari A. , Galva M. D. , Gregorini L. , Parati G. , Pomidossi G. , Ravazzani C. , Sala C. , Zanchetti A. 
Published: August 2015

1. Slight decreases and increases in carotid baroreceptor activity were induced in subjects with essential hypertension by slight alterations in carotid transmural pressure (variable pressure neck-chamber technique) in order to obtain limited increases and reductions in sympathetic adrenergic activity.
2. When sympathetic activity was reflexly increased there was a rise in arterial pressure but no significant increase in plasma catecholamines. Likewise when sympathetic activity was reflexly reduced there was a fall in arterial pressure but no significant reduction in plasma catecholamines.
3. Plasma noradrenaline and adrenaline significantly and markedly increased in the same subjects when sympathetic activity was increased by activation of both arterial and low pressure baroreceptor reflexes with tilting.
4. It is suggested that measurements of catecholamines in systemic plasma may reveal marked degrees of sympathetic activation but may not be a sensitive index of more moderate changes in sympathetic tone.
Increased Plasma and Urinary Normetanephrine in Young Patients with Primary Hypertension
Authors: Kobayashi K. , Kolloch R. , DeQuattro V. , Miano L. 
Published: August 2015

1. Normetanephrine was measured in small samples of plasma and urine of hypertensive patients and normal volunteers (age 20–60 years) by a specific radioenzymatic assay with bovine adrenal phenylethanolamine N-methyltransferase and tritiated S-adenosylmethionine.
2. Noradrenaline was measured simultaneously in plasma and urine.
3. Plasma normetanephrine and noradrenaline concentrations varied in direct proportion to activation or suppression of sympathetic nerve function.
4. Both plasma and urinary normetanephrine concentrations were elevated in patients with phaeochromocytoma.
5. Plasma normetanephrine concentrations were related to plasma noradrenaline concentrations of hypertensive subjects.
6. Plasma normetanephrine and noradrenaline concentrations and urinary normetanephrine excretion rates were increased in some young patients with primary hypertension, suggesting that sympathetic nerve hyperactivity is a pathogenic factor in these patients.
Plasma Noradrenaline Concentration in Hypertensive and Normotensive 40-Year-Old Individuals: Relationship to Plasma Renin Concentration
Authors: Ibsen H. , Christensen N. J. , Hollnagel H. , Leth A. , Kappelgaard A. M. , Giese J. 
Published: August 2015

1. Forty-year-old individuals with mild essential hypertension, identified during a survey of a population born in 1936, were investigated. Forty-year-old normotensive subjects, drawn from the same population, served as a control group.
2. Plasma noradrenaline concentration and plasma renin concentration at rest supine and after acute stimulation, as induced by frusemide intravenously and ambulation, did not differ from reference values in the 40-year-old normotensive controls. In the hypertensive group a close correlation (r = 0·77, P &lt; 0·001) was found between plasma noradrenaline and plasma renin concentration after acute stimulation.
3. Sympathetic nerve activity, as defined by measurements of plasma noradrenaline, is normal in mild essential hypertension. Discrepancies described in the literature are probably related to a lack of comparability between hypertensive and normotensive study populations.
Effect of the α-Adrenoreceptor Agonist Ld 3098 (Cirazoline) on the Magnitude of End-Organ Responses Induced by Nerve Stimulation and Exogenous Noradrenaline in a Variety of Sympathetically Innervated Animal Tissues
Authors: Massingham R. , Dubocovich Margarita L. , Langer S. Z. 
Published: August 2015

1. Previous studies have shown that LD 3098 (cirazoline), a potent directly acting α-adrenoreceptor agonist, failed to antagonize heart rate increases induced by ansa subclavia stimulation in anaesthetized dogs. However, in the isolated perfused cat spleen LD 3098 inhibited transmitter release elicited by nerve stimulation and behaved as a preferential presynaptic α-adrenoreceptor agonist.
2. LD 3098 (0·01–10 μmol/l) increased the twitch response of the isolated rat vas deferens to field stimulation. However, preincubation of the tissue with prazosin (0·1 μmol/l) unmasked a presynaptic inhibitory effect of LD 3098, which was antagonized by yohimbine.
3. LD 3098 was a full agonist in isolated dog saphenous veins and in low concentrations (0·01 μmol/l) shifted the concentration—response curves to noradrenaline, potasium (K+) and prostaglandin F2α (PGF2α) to the left without changing the maximum response. Furthermore the potentiating effect of LD 3098 on PGF2α responses was antagonized by prazosin (0·1 μmol/l).
4. It is concluded that LD 3098 produces a non-specific sensitization of vascular smooth muscle by acting on postsynaptic α-adrenoreceptors.
5. This increase in end-organ sensitivity might explain why LD 3098 appears as an α-adrenoreceptor agonist with preferential affinity for postsynaptic receptors when end-organ responses to nerve stimulation are measured and yet it is a preferential presynaptic agonist in 3H-labelled transmitter-release studies. Such findings further emphasize the need for caution when assessing presynaptic activity indirectly via end-organ response to nerve stimulation.
Effect of Neonatal Sympathectomy by 6-Hydroxydopamine on Volume and Resistance Regulation in Stroke-Prone Spontaneously Hypertensive Rats
Authors: Schömig A. , Dietz R. , Rascher W. , Ebser H. , Voss U. , Gross F. 
Published: August 2015

1. Neonatal sympathectomy with 6 hydroxydopamine (6-OHDA) was used as a tool to assess the significance of an increased sympathetic vascular tone for the development of high blood pressure in stroke-prone spontaneously hypertensive rats. After administration of 6-OHDA the rise in blood pressure was blunted for the following 9 weeks until innervation was re-established. 6-OHDA-treated rats retained more sodium and had larger plasma and blood volumes than sham-treated rats.
2. Catecholamines in plasma were increased 2–10-fold immediately after sympathectomy, but their concentrations were subnormal on day 7. Eight weeks after sympathectomy plasma noradrenaline and dopamine were not elevated, but plasma adrenaline has increased twofold.
3. The reactivity of resistance vessels to noradrenaline was markedly enhanced and the neuronal uptake and metabolism of noradrenaline were still reduced 8 weeks after neonatal sympathectomy.
4. These results confirm the significance of an intact sympathetic nervous system for the development in these rats. Sodium retention and increased plasma and blood volume may be considered as a compensatory mechanism for the vasodilatation resulting from decreased vasomotor tone.
The Effect of Mental Stress on Catecholamines, their Metabolites and Plasma Renin Activity in Patients with Essential Hypertension and in Healthy Subjects
Authors: Januszewicz W. , Sznajderman M. , Wocial B. , Feltynowski T. , Klonowicz T. 
Published: August 2015

1. Ten patients with essential hypertension and ten healthy men were submitted to mental stress consisting of Kraepelin's arithmetic test combined with noise. Concentrations of plasma and urine catecholamines and of their metabolites as well as plasma renin activity before and after the test were studied.
2. In both groups a significant increase of noradrenaline and adrenaline in blood and noradrenaline in urine was observed. The urinary excretion of dopamine fell significantly in both groups after stress.
3. After mental stress a significant increase in urinary excretion of 3-methoxy-4-hydroxyphenylglycol was observed in both groups. The excretion of vanillylmandelic acid decreased significantly only in healthy subjects.
4. The plasma renin activity rose significantly in both groups but the increase was more pronounced in healthy subjects.
Enhanced Release of Noradrenaline in the Kidney of the Young Spontaneously Hypertensive Rat
Authors: Collis M. G. , de Mey C. , Vanhoutte P. M. 
Published: August 2015

1. Vascular reactivity and noradrenaline overflow were studied in Tyrode solution-perfused kidneys from young (6 weeks) normotensive and spontaneously hypertensive (SH) rats.
2. The vasoconstrictor response to nerve stimulation was greater in the kidneys from young SH rats than in those from young control rats.
3. Nerve stimulation evoked a greater release of noradrenaline in the kidneys from young SH rats than in those from normotensive animals.
4. The results demonstrate that the renal sympathetic nerves release more noradrenaline than normal in the young SH rats, which could be an important factor in causing hypertension.
Modulation of Sympathetic Vascular Tone by Prostaglandins in Corticosterone-Induced Hypertension in Rats
Authors: Rascher W. , Dietz R. , Schömig A. , Burkart G. , Lüth J. B. , Mann J. F. E. , Weber J. 
Published: August 2015

1. In corticosterone-induced hypertension in rats the activity of the peripheral sympathetic nervous system and its modulation by prostaglandins was studied.
2. Plasma concentrations of noradrenaline were reduced if compared with those in normotensive control rats.
3. The sensitivity of the isolated perfused hindlimb preparation to noradrenaline was enhanced before blood pressure rose and increased further with the development of hypertension.
4. Arachidonic acid, prostacyclin (prostaglandin I2), but not 6-keto-prostaglandin F1α, reversed the supersensitivity to noradrenaline.
5. These results suggest that corticosterone induces a supersensitivity to noradrenaline by inhibiting the biosynthesis of prostaglandins. Changes in the sensitivity of the vascular smooth muscle may play a role in the development of glucocorticoid hypertension.
Urinary Kallikrein in Normotensive Subjects and in Patients with Essential Hypertension
Authors: Zschiedrich H. , Fleckenstein P. , Geiger R. , Fink E. , Sinterhauf K. , Philipp TH. , Distler A. , Wolff H. P. 
Published: August 2015

1. Excretion of urinary kallikrein was normal in 13 out of 15 patients with uncomplicated essential hypertension.
2. Frusemide increased urinary kallikrein excretion in normotensive subjects and in patients with essential hypertension. The stimulating effect of frusemide on urinary kallikrein was significantly diminished in patients with essential hypertension.
3. No correlations of urinary kallikrein with sodium, potassium, and aldosterone excretion were found.
4. The results do not support the idea that urinary kallikrein plays a primary role in the pathogenesis of essential hypertension.
Urinary Prostaglandins and Kallikrein in Essential Hypertension
Authors: Weber P. C. , Scherer B. , Held E. , Siess W. , Stoffel H. 
Published: August 2015

1. Urinary prostaglandins (PG), kallikrein and plasma renin activity (PRA) were measured in 35 patients with essential hypertension and 22 normotensive controls before and 15 min after frusemide (40 mg intravenously).
2. PGE2 and kallikrein excretion rates were lower in hypertensive subjects, and failed to rise to the same extent after frusemide. PGF2α excretion was not significantly different in the two groups of patients either before or after frusemide. PRA rose less in the hypertensive subjects after frusemide.
3. These findings support the view that there is an abnormality of renal vasodilator systems (PGE2 and kallikrein) in essential hypertension.
Sodium Balance, Urinary Prostaglandin E2 and Renin in Normal Man
Authors: Nielsen I. , Elmgreen J. , Christensen P. , Hesse B. 
Published: August 2015

1. Urinary prostaglandin (PG) E2 excretion and plasma renin were measured in five healthy volunteer subjects for 2 h after intravenous injection of frusemide (protocol A) and during salt restriction for 7 days with frusemide added on the 2 last days (protocol B).
2. In protocol A, peak values in PGE2 and urine flow were reached in 10–20 min, after which the values rapidly subsided. Plasma renin increased twofold in 60 min.
3. In protocol B, even during severe anti-natriuresis (day 5) and during maximal negative sodium balance (day 7), no change in urinary PGE2 excretion was observed. Plasma renin increased twofold on day 5 and increased tenfold on day 7.
4. The result of protocol B does not suggest any essential role of renal PGE2 for sodium excretion or sodium homeostasis in man. The result of protocol A may point to a role of renal prostaglandins for the diuretic action of frusemide.
Factors Influencing Blood Pressure in Chronic Alcoholics
Authors: Saunders J. B. , Beevers D. G. , Paton A. 
Published: August 2015

1. Of 96 alcoholics admitted for detoxification, 48% were hypertensive (systolic blood pressure &gt; 140 mmHg and/or diastolic pressure &gt; 90 mmHg).
2. Elevation of both systolic and diastolic blood pressures was related to the severity of alcohol-withdrawal symptoms.
3. After these symptoms had abated only 9% of patients remained hypertensive.
4. Blood pressure remained normal if patients abstained from alcohol after discharge but rose in those who started drinking again.
5. Hypertension was not consistently related to the presence or severity of alcoholic liver disease.
6. Alcohol-related hypertension may be the result of the alcohol-withdrawal syndrome; increased noradrenergic activity is suggested as the likely mechanism.
Responsiveness to Prazosin in Renal Failure
Authors: Stokes G. S. , Monaghan J. C. , Frost G. W. , MacCarthy E. P. 
Published: August 2015

1. The fall in blood pressure produced by a test dose of prazosin was greater in a group of patients with chronic renal failure than in a group with normal renal function.
2. This difference could not be attributed to increased reactivity, measured as the slope of the regression line relating mean blood pressure and plasma prazosin concentration, nor to retarded elimination of the drug.
3. The enhanced antihypertensive effect of prazosin in renal failure appears to reflect changes in the bioavailability or distribution of the drug, which result in higher drug concentrations for a given dose.
Influence of Selective and Non-Selective β-Adrenoreceptor Blockade on the Haemodynamic Effect of Adrenaline during Combined Antihypertensive Drug Therapy
Authors: Houben H. , Thien TH. , De Boo TH. , Lemmens W. , Van Herwaarden C. L. A. , Fennis J. F. M. , Van 'T Laar A. 
Published: August 2015

1. Haemodynamic effects of adrenaline were studied in 27 hypertensive patients, successively during treatment with propranolol and metoprolol. In 12 patients β-adrenoreceptor blockade was combined with diuretics and in 15 patients the blockade was combined with vasodilators.
2. During propranolol adrenaline caused a marked pressor effect: there was a considerable rise in systolic as well as in diastolic blood pressure and a marked fall in heart rate. During metoprolol there was only a slight rise in blood pressure and an increase in heart rate.
3. Forearm blood flow was decreased by adrenaline during propranolol and was increased during metoprolol. Calculated vascular resistance showed opposite changes.
4. Results were essentially the same when β-adrenoreceptor blockade was combined with diuretics or with vasodilators and did not differ from previous results obtained in patients treated by blockade alone.
5. If adrenaline infusion can be considered as a model for acute stress, our results seem to favour a selective β-adrenoreceptor blocking agent over a non-selective one, even when the blocker is combined with a diuretic or a vasodilator.
Long-term Effect of Sotalol on Plasma Lipids
Authors: Lehtonen A. , Viikari J. 
Published: August 2015

1. We studied the effect on plasma lipids of sotalol given orally over a 12 month period to patients with essential hypertension.
2. Plasma free fatty acid concentration was lower than initially at 1, 3, 6 and 12 months. The difference was significant (P &lt; 0·01) at 1 and 3 months.
3. Plasma cholesterol (VLDL + LDL-cholesterol) increased during treatment. Plasma total cholesterol increased from 5·49 ± sd 0·94 mmol/l at the beginning to 6·37 ± 1·10 mmol/l at 12 months (P &lt; 0·01).
4. HDL-cholesterol concentration and the ratio of HDL-cholesterol to total cholesterol decreased significantly. The ratios were 0·28 and 0·18 at the beginning and at 12 months respectively (P &lt; 0·001).
5. Plasma triglycerides increased simultaneously from 1·14 ± 0·31 to 1·89 ± 0·99 mmol/l (P &lt; 0·01).
Observations on Some Properties of a Long-Acting Preparation of Propranolol
Authors: Shanks R. G. , Neill J. D. , Leahey W. J. , Varma M. P. S. 
Published: August 2015

1. The effects of 160 mg of propranolol and 160 mg of a long-acting (LA) formulation of propranolol were studied in healthy subjects.
2. Both drugs reduced an exercise tachycardia but the peak was less and the 24 h effect greater after long-acting propranolol than after propranolol.
3. These differences were maintained on repeated dosing for 8 days.
4. In contrast to single doses of 400 mg of sotalol, 160 mg of oxprenolol and 160 mg of slow-release oxprenolol, the peak effect of long-acting propranolol was less and that at 24 h was greater.
Intraluminal Dilatation of Renal Artery Stenosis
Authors: Geyskes G. G. , Puylaert C. B. A. J. , Oei H. Y. , Boomsma J. H. B. 
Published: August 2015

1. In 13 patients with hypertension and renal artery stenosis the stenosis was dilated by an intra-arterial balloon catheter under local anaesthesia.
2. In all but one instance arteriography after the dilatation showed considerable widening of the stenosed area.
3. Six patients had a temporary increase of serum creatinine that lasted only a few days.
4. In seven patients, who had a prolonged transit time at renography, this marker of renal blood flow improved after the dilatation.
5. The effect of the dilatation on the blood pressure in this group of patients, selected on arteriographic criteria only, was variable, but comparable with results of renovascular surgery.
6. Dilatation of renal artery stenosis by an intra-arterial balloon catheter is a promising treatment for patients with hypertension and renal artery stenosis. It is a rapid procedure needing only local anaesthesia. Complications in our experience so far are minor.
Renovascular Hypertension: Comparison of Medical and Surgical Therapy
Authors: Whelton P. K. , Harris A. P. , Russell R. P. , Walsh P. C. , Williams G. M. , Harrington D. P. , Walker W. G. 
Published: August 2015

1. Results of medical and surgical therapy were compared in 28 patients with hypertension and unilateral renovascular ischaemia.
2. Renal function remained normal in both groups throughout the study period. After 6 months of follow-up systolic and diastolic blood pressures were significantly lower in the surgically treated patients. After 12 months of follow-up there was no significant difference between the two groups in diastolic blood pressure and after 24 months of follow-up there was no significant difference between the two groups in either systolic or diastolic blood pressure.
3. Sixty per cent of surgically treated patients were cured 6 months after operation, but only 40% remained cured after 24 months of follow-up.
4. All patients cured at 6 months who subsequently required antihypertensive medication had arteriosclerotic renovascular disease.
Transport of Lignocaine by Rabbit Choroid Plexus In Vitro
Authors: Spector R. 
Published: August 2015

1. Lignocaine readily passes from blood into cerebrospinal fluid. The isolated rabbit choroid plexus, a locus of the blood—cerebrospinal fluid barrier, accumulated [14C]lignocaine by two processes: an active, saturable transport process and a non-saturable process.
2. The accumulation of [14C]lignocaine by choroid plexus was not due to non-specific binding or metabolism of lignocaine within or on the choroid plexus.
3. These results suggest that the choroid plexus may transport lignocaine between blood and cerebrospinal fluid in vivo by a specific carrier-mediated process.
The Influence of Physical Activity on Arterial Pressure during Ambulatory Recordings in Man
Authors: Rowlands D. B. , Stallard T. J. , Watson R. D. S. , Littler W. A. 
Published: August 2015

1. Ambulatory blood pressure recordings were made over a 48 h period on six hypertensive patients. The conditions of study were standardized, particularly with regard to physical activity, and during one period of each day the patients were randomly allocated to be active or inactive.
2. Results show that blood pressure was highest during physical activity and lowest during sleep. There was no significant difference between the arterial pressures measured during the same physical activities carried out at the same time each day. However, during the same time on consecutive days when activity was randomized, there was a significant difference between the pressure recordings during physical activity compared with those during inactivity. Heart rate changes showed a similar trend during the randomized period.
3. Physical activity and sleep have a profound effect on continuous arterial blood pressure recordings and these are independent of time alone. These observations should be taken into account when using this ambulatory system to assess hypotensive therapy.
Serum Inorganic Fluoride: Changes Related to Previous Fluoride Intake, Renal Function and Bone Resorption
Authors: Waterhouse Christine , Taves D. , Munzer A. 
Published: August 2015

1. Inorganic fluoride concentrations were determined in serum and urine specimens of 24 subjects receiving a standardized low fluoride intake. Serum fluoride was directly correlated with previous intake and appeared to reflect bone fluoride stores.
2. A positive correlation between creatinine and fluoride clearance was found. However, striking reductions in fluoride clearance, which resulted in increases in serum fluoride, were not usually seen until the creatinine clearance was below 25 ml/min.
3. Parathormone produced an increase in serum fluoride and thyrocalcitonin a decrease, probably by their action on bone.
4. Six patients with chronic increased bone resorption had elevated fluoride concentrations. In five, when treatment was successful, serum fluoride fell. Interpretation of the data from this group of patients is complicated by initially low filtration rates associated with hypercalcaemia and hypercalciuria.
5. The sensitivity of the serum fluoride concentration to previous intake, glomerular filtration and the intensity of bone resorption suggests that the human organism exerts no direct homeostatic control over this ion.
Cardiogenic Hypertension: Experimental Evidence from a Comparison between Intravenous and Intracoronary Administration of Dobutamine in Conscious Dogs
Authors: Liard J.-F. 
Published: August 2015

1. We have studied whether the progressive rise in peripheral resistance observed in response to chronic intracoronary administration of dobutamine in conscious dogs could have resulted from extracardiac or non-β-adrenergic cardiac effects of the drug.
2. Six conscious dogs received dobutamine, 1.56 × 10−8 mol min−1 kg−1, intravenously for a 7 day period and seven conscious dogs were given dobutamine, 1.51 × 10−8 mol min−1 kg−1, into the left coronary artery under oral propranolol treatment for the same period while arterial pressure, cardiac output (electromagnetic flowmeter) and heart rate were measured.
3. Intravenous dobutamine produced no increase in arterial pressure, but a decrease in peripheral resistance and an increase in cardiac output which persisted until the end of the infusion.
4. With propranolol treatment intracoronary dobutamine induced no significant haemodynamic changes but a short-lasting increase in mean arterial pressure and peripheral resistance.
5. It is concluded that β-adrenergic cardiac effects of dobutamine are essential to the development of hypertension and increased peripheral resistance after prolonged intracoronary infusion of this drug.