Influence of the Sympathetic Nervous System on Aortic Compliance

1980 ◽  
Vol 59 (s6) ◽  
pp. 279s-282s ◽  
Author(s):  
C. L. Alicandri ◽  
R. Fariello ◽  
E. Agabiti-Rosei ◽  
G. Romanelli ◽  
G. Muiesan
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Stroke Volume ◽  
Pulse Pressure ◽  
Plasma Noradrenaline ◽  
Aortic Compliance ◽  
Sympathetic Nervous ◽  
Group 2 ◽  
Group 1 ◽  
Noradrenaline Levels

1. Aortic compliance and plasma catecholamine levels were determined in 26 essential hypertensive patients: 14<45 years (group 1) and 12>45 years (group 2). 2. Aortic rigidity, the reciprocal of aortic compliance, was calculated by the ratio of pulse pressure to stroke volume. Pulse pressure was derived by arterial pressure measured in the ascending aorta. Stroke volume was obtained by dye dilution. 3. A significant correlation (r = 0.60) was found between aortic rigidity and plasma noradrenaline in group 2. In this group both aortic rigidity and plasma noradrenaline levels were consistently higher than in group 1. 4. In 15 patients (seven of group 1 and eight of group 2) aortic rigidity was again measured after acute phentolamine (five patients) and labetalol (ten patients) administration. 5. Aortic rigidity was reduced significantly after both α-adrenoreceptor blockade alone and combined α- and β-adrenoreceptor blockade. A highly significant correlation was found between aortic rigidity reduction and pretreatment noradrenaline levels (r = 0.77). 6. Aortic compliance is influenced, at least in part, by sympathetic nervous system activity. Drugs which block the peripheral effects of catecholamines may improve aortic compliance and consequently the control of systolic hypertension in selected cases.

Effects of Oxygen Withdrawal on Catecholamine Release in Patients on Home Oxygen Therapy

1990 ◽  
Vol 79 (2) ◽  
pp. 155-159 ◽  
Author(s):  
M. S. Balter ◽  
K. R. Chapman ◽  
M. R. Maleki-Yazdi ◽  
F. H. H. Leenen ◽  
A. S. Rebuck
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Oxygen Therapy ◽  
Plasma Noradrenaline ◽  
Mental Function ◽  
Plasma Adrenaline ◽  
Sympathetic Nervous ◽  
Long Term Oxygen Therapy ◽  
Noradrenaline Levels

1. Long-term oxygen therapy in appropriate patients prolongs survival and corrects neuropsychological function. Some tests of mental function paradoxically improve during short periods of oxygen withdrawal in patients on long-term oxygen therapy, although the mechanism of this response is unknown. 2. To evaluate the effects of transient hypoxaemia on plasma adrenaline and noradrenaline levels, we studied eight oxygen-dependent patients who underwent either a 4 h period of oxygen withdrawal or their routine therapy, in a randomized, blinded fashion, on 2 separate days. 3. Plasma noradrenaline did not differ at baseline between study days. During normoxic conditions, plasma noradrenaline levels did not increase significantly with time. By contrast, under hypoxic conditions, plasma levels of noradrenaline rose significantly from 0 to 4 h (P < 0.05). The magnitude of the noradrenaline response was correlated with baseline noradrenaline such that subjects with the highest resting levels had the largest increase during hypoxia (r = 0.95, P < 0.001). 4. Plasma adrenaline did not differ at baseline between study days and there were no significant effects of hypoxia on plasma adrenaline levels. 5. We conclude that the sympathetic nervous system, but not the adrenal medulla, is stimulated in chronically oxygen-dependent subjects made acutely hypoxaemic. The magnitude of this stimulation appears to be related to the state of sympathetic nervous system activity at baseline. Improvement in some tests of mental function during transient periods of oxygen withdrawal may be due to non-specific arousal caused by a catecholamine surge.

Plasma Dopamine β-Hydroxylase and Noradrenaline Amounts in Essential Hypertension

1973 ◽  
Vol 44 (6) ◽  
pp. 617-620 ◽  
Author(s):  
L. B. Geffen ◽  
R. A. Rush ◽  
W. J. Louis ◽  
A. E. Doyle
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Essential Hypertension ◽  
Sympathetic Nervous System ◽  
Diastolic Blood Pressure ◽  
Plasma Catecholamines ◽  
Plasma Noradrenaline ◽  
Elevated Blood Pressure ◽  
Elevated Blood ◽  
Sympathetic Nervous

1. Plasma dopamine β-hydroxylase (DβH) amounts were measured by radioimmunoassay in twenty-eight patients, twenty of whom had essential hypertension. There was a positive correlation between resting diastolic blood pressure and plasma DβH concentration. 2. Plasma DβH amounts also correlated significantly with those of plasma noradrenaline (NA) in individual patients. 3. These findings provide further support for the conclusions drawn from studies of plasma catecholamines that the sympathetic nervous system contributes toward the maintenance of the elevated blood pressure in essential hypertension.

scholarly journals Positive End-Expiratory Pressure Increases Plasma Catecholamine Levels in Non-Volume Loaded Dogs

1986 ◽  
Vol 14 (4) ◽  
pp. 421-425 ◽  
Author(s):  
B. Chernow ◽  
S. Soldano ◽  
D. Cook ◽  
P. Lyons ◽  
M. Barton ◽  
...  
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Water Pressure ◽  
Plasma Noradrenaline ◽  
Plasma Catecholamine ◽  
Sympathetic Nervous System Activity ◽  
Plasma Adrenaline ◽  
System Activity ◽  
Nervous System Activity ◽  
Sympathetic Nervous

Positive end-expiratory pressure (PEEP) is commonly used in the treatment of critically ill patients whose sympathetic nervous system is stressed; however, PEEP's actions on sympathetic nervous system activity are unknown. We therefore measured the plasma noradrenaline response (an index of sympathetic nervous system activity) to graded doses of PEEP in nine mongrel dogs. After 30 minutes at each level of PEEP, plasma noradrenaline concentrations increased from baseline mean values of 300 (SD 108) pg/ml to 388 (SD 225) pg/ml (P< 0.05) at 5 cm, 433 (SD 255) pg/ml (P <0.01) at 10 cm and 1194 (SD 882) pg/ml (P<0.01) at 20 cm water pressure of PEEP. The increases in plasma noradrenaline concentrations correlated inversely (r= - 0.43, P< 0.01) with PEEP-induced changes in cardiac output. Plasma adrenaline levels did not change significantly in response to 5 or 10 cm of PEEP; however, plasma adrenaline increased, while heart rate and mean arterial blood pressure fell, at 20 cm water pressure of PEEP (P < 0.05). Within 15 minutes after discontinuation of PEEP, the plasma catecholamine concentrations returned to baseline levels. Conclusions: 1. PEEP significantly increases sympathetic nervous system activity in a rapid, dose- dependent, reversible manner; 2. the PEEP-induced increases in sympathetic activity may explain the reductions in organ blood flow which others have observed following the initiation of PEEP; 3. PEEP-related changes in sympathetic nervous system activity are a consequence of PEEP- induced reductions in cardiac output.

Impaired Response of Plasma Renin Activity to Tilting after Renal Transplantation

1981 ◽  
Vol 61 (1) ◽  
pp. 69-73 ◽  
Author(s):  
J. Cunningham ◽  
M. J. Vandenburg ◽  
J. M. P. Holly ◽  
F. J. Goodwin
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Sympathetic Nervous System ◽  
Plasma Renin Activity ◽  
Pulse Rate ◽  
Dominant Role ◽  
Plasma Renin ◽  
Renin Activity ◽  
Plasma Noradrenaline ◽  
Sympathetic Nervous

1. Changes in plasma renin activity, plasma noradrenaline, pulse rate and blood pressure after tilting were measured in normal subjects and in patients with renal transplants. 2. There was a marked difference between the renin responses in the two groups, the increases in plasma renin activity in the control subjects being much greater than those in the transplanted patients. 3. Activation of the sympathetic nervous system after tilting, as indicated by changes in pulse rate, blood pressure and plasma noradrenaline, was similar in the two groups. 4. We conclude that the ability of the transplanted kidney to increase plasma renin activity after tilting is impaired, probably as a result of sympathetic denervation of the kidney during transplantation. The results suggest a dominant role of the sympathetic nervous system in the mediation of renin release after tilting.

Endogenous Agonist Regulation of α-Adrenoceptors in Man

1981 ◽  
Vol 61 (s7) ◽  
pp. 207s-210s ◽  
Author(s):  
I. B. Davies ◽  
D. Sudera ◽  
P. S. Sever
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Inverse Relationship ◽  
Normal Subjects ◽  
Plasma Noradrenaline ◽  
Adrenergic Agonist ◽  
Receptor Affinity ◽  
System Degeneration ◽  
Receptor Number ◽  
Sympathetic Nervous

1. Plasma noradrenaline concentrations and platelet α-receptor properties were measured in 14 normal subjects, five phaeochromocytoma patients and nine patients with multiple system atrophy and sympathetic nervous system degeneration (MSA). 2. Plasma noradrenaline concentrations in phaeochromocytoma were 10- to 20-times greater than those of normal subjects and one-fifth to one-half of normal in MSA patients. 3. Platelet α-receptor numbers were increased in MSA and decreased in phaeochromocytoma compared with normal subjects. There was no change in platelet α-receptor affinity in either group. 4. The inverse relationship between α-receptor numbers and plasma noradrenaline concentrations may reflect regulation of α-receptor number by endogenous adrenergic agonist concentrations in man.

Plasma Noradrenaline and Renovascular Hypertension in the Rat

1976 ◽  
Vol 51 (s3) ◽  
pp. 439s-442s
Author(s):  
J. L. Reid ◽  
H. J. Dargie ◽  
S. S. Franklin ◽  
Beverly Fraser
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Renal Artery ◽  
Renovascular Hypertension ◽  
Plasma Noradrenaline ◽  
Hypertensive Rats ◽  
Contralateral Kidney ◽  
Sympathetic Nervous ◽  
Peripheral Sympathetic Nervous System

1. Plasma noradrenaline was measured in groups of rats up to 4 weeks after application of a renal artery clip. 2. When renal artery clipping was accompanied by contralateral nephrectomy (one-kidney model) plasma noradrenaline was significantly higher in hypertensive rats than in sham-operated control rats at 7, 14 and 28 days. 3. Plasma noradrenaline was not altered at any time examined in the two-kidney model (unilateral clip and contralateral kidney left in situ). 4. Neurogenic mechanisms mediated by the peripheral sympathetic nervous system appear to participate in the development of one-kidney renovascular hypertension, but do not play a significant role in the two-kidney model.

Reduced plasma noradrenaline concentrations in simple-obese and diabetic obese patients

1991 ◽  
Vol 80 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Arne V. Astrup ◽  
Niels Juel Christensen ◽  
Leif Breum
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Plasma Noradrenaline ◽  
Obese Group ◽  
Diabetic Patients ◽  
Obese Patients ◽  
Plasma Noradrenaline Concentration ◽  
Fasting Plasma ◽  
Noradrenaline Concentration ◽  
Sympathetic Nervous

1. Obesity may be associated with a decreased activity of the sympathetic nervous system and also with a deficiency of the response to stimuli activating the sympathetic nervous system. As insulin activates the sympathetic nervous system, the present study was undertaken to measure the plasma noradrenaline concentration in the fasting state and after 75 g of oral glucose in simple-obese patients (n = 13), in non-insulin-dependent (type 2) diabetic patients (n = 37) and in normal control subjects (n = 12). 2. The fasting plasma noradrenaline concentration was similarly reduced in the simple-obese group and in the diabetic obese group compared with the control group (P = 0.005). The glucose-induced increase in plasma noradrenaline concentration was normal in the simple- obese group, but was abolished in the obese diabetic patients (P = 0.008). 3. Step-wise regression analysis indicated that independent effects on the fasting plasma noradrenaline concentration were exerted by age (r = + 0.32, P = 0.002), glucose concentration (r = −0.32, P = 0.02) and the degree of obesity (r = −0.37, P = 0.007), but not by plasma insulin concentration. 4. These results show that obese patients have a reduced fasting plasma noradrenaline concentration independently of accompanying diabetes, but that the response of noradrenaline to oral glucose is only abolished in the obese diabetic patients.

Thyroid hormone-catecholamine interrelationships during exposure to cold

1981 ◽  
Vol 97 (1) ◽  
pp. 91-97 ◽  
Author(s):  
H. Storm ◽  
C. van Hardeveld ◽  
A. A. H. Kassenaar
Keyword(s):  
Nervous System ◽  
Plasma Concentration ◽  
Thyroid Hormone ◽  
Sympathetic Nervous System ◽  
Plasma Levels ◽  
Surgical Procedure ◽  
Exposure To Cold ◽  
Basal Plasma ◽  
Sympathetic Nervous

Abstract. Basal plasma levels for adrenalin (A), noradrenalin (NA), l-triiodothyronine (T3), and l-thyroxine (T4) were determined in rats with a chronically inserted catheter. The experiments described in this report were started 3 days after the surgical procedure when T3 and T4 levels had returned to normal. Basal levels for the catecholamines were reached already 4 h after the operation. The T3/T4 ratio in plasma was significantly increased after 3, 7, and 14 days in rats kept at 4°C and the same holds for the iodide in the 24-h urine after 7 and 14 days at 4°C. The venous NA plasma concentration was increased 6- to 12-fold during the same period of exposure to cold, whereas the A concentration remained at the basal level. During infusion of NA at 23°C the T3/T4 ratio in plasma was significantly increased after 7 days compared to pair-fed controls, and the same holds for the iodide excretion in the 24-h urine. This paper presents further evidence for a role of the sympathetic nervous system on T4 metabolism in rats at resting conditions.

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