Plasma Noradrenaline and Adrenaline in Patients with Thyrotoxicosis and Myxoedema

1973 ◽  
Vol 45 (2) ◽  
pp. 163-171 ◽  
Author(s):  
N. J. Christensen
Keyword(s):  
Venous Blood ◽  
Nervous Activity ◽  
Age Groups ◽  
Normal Subjects ◽  
Plasma Noradrenaline ◽  
Sympathetic Nervous Activity ◽  
Plasma Adrenaline ◽  
The Difference ◽  
Noradrenaline And Adrenaline ◽  
Hypothyroid Patients

1. Employing a precise and sensitive double-isotope derivative technique plasma noradrenaline and plasma adrenaline were measured in sixteen normal subjects, in eight patients with myxoedema and in ten patients with thyrotoxicosis. Venous blood was obtained while the subjects rested in the supine position. 2. In the normal subjects plasma noradrenaline averaged 0·22±SD 0·09 ng/ml and plasma adrenaline 0·05±SD 0·05 ng/ml. Plasma noradrenaline rose with increasing age. 3. In patients with myxoedema, plasma noradrenaline was increased approximately threefold. The difference between the normal subjects and the hypothyroid patients was more pronounced in the older age-groups. 4. Despite their elevated pulse rate patients with thyrotoxicosis showed significantly decreased plasma noradrenaline concentrations compared to the normal subjects. 5. In the hypothyroid and hyperthyroid subjects plasma adrenaline concentrations were not different from the values obtained in the normal subjects. 6. It is suggested that sympathetic nervous activity is decreased in thyrotoxicosis as a compensatory phenomenon to the direct effect of thyroid hormones on the cardiovascular system.

Variations in Individual Organ Release of Noradrenaline Measured by An Improved Radioenzymatic Technique; Limitations of Peripheral Venous Measurements in the Assessment of Sympathetic Nervous Activity

1981 ◽  
Vol 61 (5) ◽  
pp. 585-590 ◽  
Author(s):  
M. J. Brown ◽  
D. A. Jenner ◽  
D. J. Allison ◽  
C. T. Dollery
Keyword(s):  
Renal Artery ◽  
Renal Artery Stenosis ◽  
Nervous Activity ◽  
Artery Stenosis ◽  
Plasma Noradrenaline ◽  
Sympathetic Nervous Activity ◽  
Release Of Noradrenaline ◽  
Noradrenaline Concentration ◽  
Sympathetic Nervous ◽  
Noradrenaline And Adrenaline

1. The validity of plasma noradrenaline as an index of sympathetic nervous activity was assessed by estimating variation in individual organ contribution to circulating concentrations. 2. Arteriovenous (A—V) differences in noradrenaline and adrenaline concentration were measured across several organs in nine patients with mild essential hypertension, in five with renal artery stenosis and 15 phaeochromocytoma patients. 3. In patients with phaeochromocytomas the percentage extraction of noradrenaline and adrenaline (estimated from the A—V differences) was similar across all organs, suggesting that adrenaline extraction could be used as a marker for noradrenaline extraction. 4. In the non-tumour patients the A—V difference for noradrenaline was less than that for adrenaline across most organs studied, reflecting the net result of noradrenaline release and extraction. The estimated contribution of various organs to the noradrenaline concentrations in their venous effluent was: heart. 21%; kidney 47%; legs 68%. 5. This pattern of A—V difference proved a positive diagnostic feature for non-tumour patients since it was not found even in the patients with small phaeochromocytomas, whose peripheral venous noradrenaline concentration alone did not distinguish them. 6. The venous-arterial difference across the adrenal glands of non-tumour patients was more than 10-fold greater for adrenaline than that for noradrenaline. Since the mean arterial concentration of noradrenaline was more than fivefold higher than that of adrenaline, the normal adrenal contribution to circulating noradrenaline is likely to be less than 2%. 7. In the patients with renal artery stenosis renal venous concentrations of noradrenaline (from the ischaemic kidney) were higher than arterial values, but mean arterial values were no higher than in the essential hypertensive patients. 8. Local variations in sympathetic activity may occur without altering the plasma noradrenaline concentration measured in peripheral plasma.

Renin Release during Head-up Tilt Occurs Independently of Sympathetic Nervous Activity in Tetraplegic Man

1980 ◽  
Vol 59 (4) ◽  
pp. 251-256 ◽  
Author(s):  
C. J. Mathias ◽  
N. J. Christensen ◽  
H. L. Frankel ◽  
W. S. Peart
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Nervous Activity ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Renin Activity ◽  
Plasma Noradrenaline ◽  
Sympathetic Nervous Activity ◽  
Head Up Tilt ◽  
Sympathetic Nervous

1. The role of the sympathetic nervous system in the release of renin during head-up tilt has been studied in five normal subjects and in four tetraplegic patients with cervical spinal-cord transection above the sympathetic outflow. Blood pressure, heart rate and concentrations of plasma noradrenaline, plasma adrenaline and plasma renin activity were measured during head-up tilt to 45° before and after acute β-adrenoreceptor blockade with intravenous propranolol. 2. In the normal subjects there were minimal changes in blood pressure during head-up tilt and there was a rise in both plasma noradrenaline concentration and plasma renin activity. After propranolol values of plasma renin activity at rest fell with little change occurring during head-up tilt. 3. In the tetraplegic patients there was a substantial fall in blood pressure during head-up tilt. Concentrations of plasma noradrenaline and adrenaline did not change but there was a marked increase in plasma renin activity. Values of plasma renin activity both at rest and during head-up tilt were unaffected by propranolol. 4. We conclude that in tetraplegic patients renin release during head-up tilt may occur independently of sympathetic nervous activity and is probably largely dependent on activation of renal vascular receptors.

Plasma Catecholamines and Plasma Renin Activity at Birth and during the First Days of Life

1980 ◽  
Vol 59 (s6) ◽  
pp. 319s-321s ◽  
Author(s):  
G. Leonetti ◽  
C. Bianchini ◽  
G. B. Picotti ◽  
A. Cesura ◽  
Letizia Caccamo ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Umbilical Cord Blood ◽  
Plasma Catecholamines ◽  
Plasma Renin ◽  
Renin Activity ◽  
Plasma Noradrenaline ◽  
Plasma Adrenaline ◽  
Noradrenaline And Adrenaline ◽  
Noradrenaline Levels

1. Plasma noradrenaline and adrenaline concentrations and plasma renin activity were measured in 21 mothers at delivery and in their babies at birth (umbilical cord blood) and on days 1 and 5 of extrauterine life. 2. At birth plasma renin activity was significantly higher in the newborn than in mothers. Plasma renin activity increased further, but not significantly, on day 1 of life and significantly decreased on day 5. On day 5, 10 min head-up tilting caused no change in plasma renin activity. 3. Plasma noradrenaline in the newborn was higher than in mothers at birth and significantly decreased thereafter. Plasma adrenaline levels at birth were similar in the newborn and their mothers and significantly lower in the newborn in subsequent days. Tilting caused no increase in either plasma adrenaline or noradrenaline levels. 4. No correlation was found between plasma noradrenaline and adrenaline levels and plasma renin activity, or between noradrenaline, adrenaline or plasma renin activity and blood pressure.

Choice of Control Groups in the Appraisal of Sympathetic Nervous Activity in Essential Hypertension

1979 ◽  
Vol 57 (4) ◽  
pp. 339-344 ◽  
Author(s):  
D. H. Jones ◽  
Carlene A. Hamilton ◽  
J. L. Reid
Keyword(s):  
Essential Hypertension ◽  
Nervous Activity ◽  
Plasma Noradrenaline ◽  
Sympathetic Nervous Activity ◽  
Urinary Catecholamine ◽  
Control Groups ◽  
Laboratory Staff ◽  
Metabolite Concentrations ◽  
Vanillyl Mandelic Acid ◽  
Sympathetic Nervous

1. Plasma noradrenaline concentrations were similar in normotensive and hypertensive outpatients, but were significantly lower in laboratory control subjects. 2. Standing plasma noradrenaline concentrations were similar in all three groups. 3. Urinary vanillyl mandelic acid, catecholamines and metanephrines were also similar in the normotensive and hypertensive groups. 4. Laboratory controls, possibly because of familiarity with the techniques of sphygmomanometry and blood sampling, may attain a ‘basal’ resting level of sympathetic nervous discharge more readily and rapidly than subjects who are unfamiliar with such procedures. 5. After orthostatic stimulation by standing for 2 min, the activity of the sympathetic nervous system, as determined by pulse rate and plasma noradrenaline concentrations, was similar in the three groups, despite the lower starting values in the laboratory staff. 6. The absence of differences in plasma noradrenaline or urinary catecholamine and metabolite concentrations does not support the hypothesis of excessive sympathetic nervous activity in essential hypertension.

Ischemic muscle chemoreflex response elevates blood flow in nonischemic exercising human forearm muscle

1999 ◽  
Vol 277 (2) ◽  
pp. H635-H642 ◽  
Author(s):  
M. E. Tschakovsky ◽  
R. L. Hughson
Keyword(s):  
Blood Flow ◽  
Nervous Activity ◽  
Sympathetic Nervous Activity ◽  
Exercise Condition ◽  
Vasoconstrictor Response ◽  
Forearm Vascular Conductance ◽  
The Difference ◽  
Forearm Exercise ◽  
Small Muscle ◽  
Condition C

We tested the hypothesis that forearm blood flow (FBF) might be reduced during forearm exercise when a vasoconstrictor response was evoked by calf exercise during calf ischemia (CE + I). In nine healthy subjects, brachial artery FBF and finger-cuff mean arterial pressure (MAP) were measured beat by beat during rest and forearm exercise. CE + I initiated before 5 min of forearm exercise ( condition A) increased MAP by 24% and reduced resting forearm vascular conductance (FVC) by 24% such that FBF remained at the same level as without CE + I (control, condition C). With the onset of forearm exercise, the difference in FVC between condition A and condition C was abolished; consequently, the FBF adaptation to exercise was greater after 3 min of exercise in condition A (247.0 ± 14.8 ml/min) than in condition C(197.1 ± 9.4 ml/min, P< 0.05) because of the elevated MAP. Gradual stimulation of the chemoreflex by the addition of CE + I at 3 min of a 9-min bout of forearm exercise ( condition B) did not affect FVC such that progressive elevations in MAP resulted in proportional increases in FBF. We concluded that chemoreflex-mediated increases in systemic sympathetic nervous activity appear to affect resting FVC. Evidence from this study suggests that local factors responsible for initiating and maintaining vasodilation during moderate, small-muscle mass exercise can quickly override this vasoconstrictor influence such that FBF is elevated during exercise in direct proportion to the elevation in MAP.

Oxygen deficit is a sensitive measure of mild gas exchange impairment at inspired O2 between 12.5% and 21%

2020 ◽  
Vol 319 (1) ◽  
pp. L91-L94 ◽  
Author(s):  
Matthew A. Liu ◽  
Phoebe C. Stark ◽  
G. Kim Prisk ◽  
John B. West
Keyword(s):  
Gas Exchange ◽  
Repeated Measures ◽  
Age Groups ◽  
Normal Subjects ◽  
Oxygen Deficit ◽  
Arterial Blood ◽  
History Of ◽  
Older Subjects ◽  
The Difference ◽  
End Tidal

The oxygen deficit (OD) is the difference between the end-tidal alveolar Po2 and the calculated Po2 of arterial blood based on measured oxygen saturation that acts as a proxy for the alveolar-arterial Po2 difference. Previous work has shown that the alveolar gas meter (AGM100) can measure pulmonary gas exchange, via the OD, in patients with a history of lung disease and in normal subjects breathing 12.5% O2. The present study measured how the OD varied at different values of inspired O2. Healthy subjects were split by age (young 22–31; n = 23; older 42–90; n = 13). Across all inspired O2 levels (12.5, 15, 17.5, and 21%), the OD was higher in the older cohort 10.6 ± 1.0 mmHg compared with the young −0.4 ± 0.6 mmHg ( P < 0.0001, using repeated measures ANOVA), the difference being significant at all O2 levels (all P < 0.0001). The OD difference between age groups and its variance was greater at higher O2 values (age × O2 interaction; P = 0.002). The decrease in OD with lower values of inspired O2 in both cohorts is consistent with the increased accuracy of the calculated arterial Po2 based on the O2-Hb dissociation curve and with the expected decrease in the alveolar-arterial Po2 difference due to a lower arterial saturation. The persisting higher OD seen in older subjects, irrespective of the inspired O2, shows that the measurement of OD remains sensitive to mild gas exchange impairment, even when breathing 21% O2.

scholarly journals Pattern reversal visual evoked potentials in adults: variability with age

2017 ◽  
Vol 40 (6) ◽  
pp. 252 ◽  
Author(s):  
Raja Sawaya ◽  
Helen Sawaya ◽  
Gilbert Youssef
Keyword(s):  
Linear Trend ◽  
Age Groups ◽  
Normal Subjects ◽  
Pattern Reversal ◽  
Checkerboard Pattern ◽  
Check Size ◽  
Band Pass ◽  
The Difference ◽  
And Gender ◽  
Visual Evoked

Purpose: Pattern reversal visual evoked potential (PRVEP) is an electrophysiological test for evaluating the visual pathway. This study measured the changes in the latencies and amplitudes of the PRVEP with age and gender in normal subjects. Methods: Healthy participants (n=81; 162 total eyes), between the ages of 20 and 92 years were recruited for the study. Stimulation was performed monocularly with a high-contrast (>50%) black-white checkerboard pattern with a check size of 30° at a reversal rate of 2 Hz, a band-pass of 1-100 Hz, a sweep of 250 msec and an average of 150 stimulations in a dark room. Mean and standard deviations for three latencies (N75, P100 and N145) and the amplitude (N75-P100) for each decade were measured. Results: There was a linear trend by age for all three latencies, indicating that the higher age groups had longer latencies. The latencies decreased in the 5th decade before increasing in the higher age groups. The amplitude of N75-P100 decreased with age. The P100 latencies were longer in males than females in all age groups and the difference increased with increasing age.

Reduced plasma noradrenaline during angiotensin II-induced acute hypertension in man

1985 ◽  
Vol 68 (6) ◽  
pp. 621-624 ◽  
Author(s):  
Jens H. Henriksen ◽  
Jens Kastrup ◽  
Niels Juel Christensen
Keyword(s):  
Angiotensin Ii ◽  
Intravenous Infusion ◽  
Plasma Noradrenaline ◽  
Ang Ii ◽  
Acute Hypertension ◽  
Plasma Adrenaline ◽  
Ganglionic Blockade ◽  
Arterial Blood ◽  
Sympathoadrenal Activity ◽  
Noradrenaline And Adrenaline

1. Plasma noradrenaline and adrenaline concentrations were measured in ten subjects before, during and after intravenous infusion of angiotensin II (ANG II) in order to determine the sympathoadrenal response of ANG II challenge in man. In five subjects ganglionic blockade was additionally performed by intravenous infusion of trimethaphan. 2. During ANG II infusion mean arterial blood pressure increased by 30% (P<0.001), and plasma noradrenaline decreased by 25% (P<0.001). Plasma adrenaline decreased less. 3. During ganglionic blockade plasma noradrenaline decreased significantly (P<0.005) and similarly to the decrease obtained with ANG II infusion. 4. The results indicate that a decrease in sympathoadrenal activity occurs during ANG II-induced acute hypertension in man. This may be elicited by the arterial baroreflex, which seems to dominate any direct sympathoadrenergic facilitating effect of ANG II.

β-Thromboglobulin in Antecubital Vein Blood - The Influence of Age, Sex and Blood Group

1979 ◽  
Vol 42 (04) ◽  
pp. 1159-1163 ◽  
Author(s):  
H A Dewar ◽  
T Marshall ◽  
D Weightman ◽  
V Prakash ◽  
P J Boon
Keyword(s):  
Blood Group ◽  
Blood Donors ◽  
Age Groups ◽  
Normal Subjects ◽  
Abo Blood Groups ◽  
Mean Values ◽  
Significant Difference ◽  
Satisfactory Method ◽  
The Mean ◽  
The Difference

SummarySamples of blood for estimation of beta-thromboglobulin (B. T. G.) in normal subjects have been obtained both from blood donors at the end of their donation and from other volunteers by standard venepuncture. The former was a satisfactory method in males only.By standard venepuncture females have on average lower values than males and in the pre-menopausal age groups the difference is statistically significant.Mean values vary little up to 59 years after which they rise slowly but steadily. There is no significant difference in the mean B. T. G. values between the ABO blood groups.

scholarly journals The Effects of Gallamine and a Mixture of Pancuronium and Alcuronium on the Pressor and Plasma Catecholamine Responses to Tracheal Intubation

1984 ◽  
Vol 12 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Mary F. Cummings ◽  
W. J. Russell ◽  
D. B. Frewin ◽  
Wendy A. Miller
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Tracheal Intubation ◽  
Arterial Pressure ◽  
Plasma Noradrenaline ◽  
Plasma Catecholamine ◽  
Plasma Adrenaline ◽  
Noradrenaline Concentration ◽  
Noradrenaline And Adrenaline

Tracheal intubation can be accompanied by significant increases in arterial pressure, heart rate and the plasma levels of noradrenaline and adrenaline. The drugs used at induction can enhance or attenuate these responses. In nine patients who had received gallamine, intubation was associated with a 45% rise in mean arterial pressure, a twofold rise in plasma adrenaline and a 49% rise in plasma noradrenaline concentration. When a mixture of pancuronium and alcuronium (in a ratio of 4:10 by weight) was used in ten patients, blood pressure fell 24% after induction and rose 49% after intubation. A 24% rise in plasma noradrenaline in response to intubation was also observed. Compared with pancuronium alone, the use of the mixture attentuates the rise in blood pressure and noradrenaline concentration associated with intubation but does not abolish them. In addition, the mixture was associated with a significant fall in blood pressure between induction and intubation, whereas this was not found with gallamine.

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