Changes in Plasma Renin Activity after Hypoglycaemia in Sympathectomized Man

1981 ◽  
Vol 61 (2) ◽  
pp. 245-247 ◽  
Author(s):  
B. M. Frier ◽  
R. J. M. Corrall ◽  
J. L. Pritchard ◽  
P. S. Sever
Keyword(s):  
Spinal Cord ◽  
Plasma Renin Activity ◽  
Cervical Spinal Cord ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Renin Activity ◽  
Plasma Noradrenaline ◽  
Adrenal System ◽  
Glucose Plasma ◽  
Stimulation Of

1. The changes in blood glucose, plasma noradrenaline and plasma renin activity were measured in 11 normal subjects and in six tetraplegic subjects with a transection of the cervical spinal cord (preganglionic sympathectomy), in response to acute insulin-induced hypoglycaemia (0.15 unit/kg). 2. After hypoglycaemia, a pronounced rise in plasma noradrenaline was observed in the normal subjects but was absent in the tetraplegic group; plasma renin activity increased markedly in both groups. 3. It is concluded that the stimulation of renin release in response to hypoglycaemia can occur independently of any activation of the sympatho-adrenal system.

Plasma Catecholamines, Plasma Renin Activity and Plasma Aldosterone in Tetraplegic Man, Horizontal and Tilted

1975 ◽  
Vol 49 (4) ◽  
pp. 291-299 ◽  
Author(s):  
C. J. Mathias ◽  
N. J. Christensen ◽  
J. L. Corbett ◽  
H. L. Frankel ◽  
T. J. Goodwins ◽  
...  
Keyword(s):  
Plasma Renin Activity ◽  
Cervical Spinal Cord ◽  
Plasma Catecholamines ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Plasma Aldosterone ◽  
Renin Activity ◽  
Normal Male ◽  
Head Up Tilt ◽  
The Brain

1. Plasma catecholamines, plasma renin activity, plasma aldosterone and haematocrit were measured in four subjects with physiologically complete cervical spinal cord transections, before, during and after head-up tilt to 45° for 30 min. Plasma catecholamines were measured in five normal male volunteers in the supine position and after head-up tilt to 45° for 10 min. 2. After 10 min of head-up tilt, the plasma noradrenaline rose 14% in the tetraplegic patients and 115% in the control subjects. These findings indicate a failure of sympathetic activity in response to head-up tilt in the tetraplegic patients, probably caused by interruption of pathways by which the brain normally controls sympathetic outflow. 3. In the tetraplegic patients the resting plasma renin activities were above normal, and rose more quickly and greater on head-up tilt than in published studies of normal subjects. It is likely that the renal baroreceptors are important in the control of renin release. 4. In the tetraplegic patients, there was a late rise in plasma aldosterone which was probably due to the elevation in plasma renin activity.

Catecholamines in Peripheral Venous Plasma in Patients on Chronic Haemodialysis

1978 ◽  
Vol 55 (1) ◽  
pp. 89-96 ◽  
Author(s):  
B. P. McGrath ◽  
J. G. G. Ledingham ◽  
C. R. Benedict
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Renin Activity ◽  
Plasma Noradrenaline ◽  
Chronic Haemodialysis ◽  
Plasma Adrenaline ◽  
Anephric Patients ◽  
Venous Plasma

1. Concentrations of noradrenaline and adrenaline from peripheral venous plasma were measured after 60 min of supine rest in 55 patients on chronic haemodialysis (including six anephric patients) and in 18 normal subjects. In the patients, plasma catecholamine measurements were related to concurrent measurements of blood pressure, pulse rate, plasma renin activity, plasma angiotension II, blood volume and sulphate space. 2. Mean resting peripheral venous plasma noradrenaline concentration was higher by almost twofold, but mean resting plasma adrenaline concentration was lower, in the 49 non-nephrectomized patients than in the normal subjects. In the six anephric patients, resting peripheral venous plasma noradrenaline concentrations were similar to those of normal subjects. 3. Mean resting plasma noradrenaline concentrations in peripheral venous blood were similar in normotensive and hypertensive non-nephrectomized patients; mean plasma adrenaline concentration was higher in the hypertensive patients. A positive correlation was found between plasma adrenaline and plasma renin activity but not between plasma noradrenaline and plasma renin activity. 4. Resting concentrations of both catecholamines were positively correlated with resting pulse rate and inversely related to blood volume. 5. After renal transplantation resting peripheral venous plasma noradrenaline concentrations were normal in eight patients in whom high values had been recorded whilst on chronic haemodialysis. 6. In response to 40° of head-up tilt, plasma noradrenaline increased significantly in six non-nephrectomized patients, whether sodium replete or depleted, and the changes observed in both these states were similar to those of 14 normal subjects studied on a normal diet. 7. Diastolic blood pressure increased on standing in the majority (41/55) of patients: in only four patients was there a fall in diastolic pressure of more than 5 mmHg in the erect position and in two of these blood volumes were low. 8. The cause of increased peripheral plasma noradrenaline concentrations in haemodialysis patients is uncertain.

The Immediate Pressor Response to Saralasin in Man: Evidence against Sympathetic Activation and for Intrinsic Angiotensin II-Like Myotropism

1984 ◽  
Vol 66 (5) ◽  
pp. 517-524 ◽  
Author(s):  
C. J. Mathias ◽  
R. J. Unwin ◽  
F. A. Pike ◽  
H. L. Frankel ◽  
P. S. Sever ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Plasma Renin Activity ◽  
Cervical Spinal Cord ◽  
Pressor Response ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Renin Activity ◽  
Sympathetic Activation ◽  
Basal Plasma ◽  
Dose Dependent

1. The cardiovascular and hormonal effects of intravenous saralasin (0.5, 1 and 5 μg min−1 kg−1) were assessed in nine tetraplegic patients (with complete cervical spinal cord transaction above the sympathetic outflow) and in six normal subjects. 2. In the tetraplegic patients, saralasin caused an immediate transient pressor response which was not dose-dependent and substantially greater than the pressor response in normal subjects. The pressor response in the tetraplegic patients was not accompanied by a rise in levels of plasma noradrenaline. 3. In the tetraplegic patients, after α-adrenoceptor blockade with thymoxamine (1 mg kg−1 h−1), twice the dose of intravenous noradrenaline was needed to induce the same pressor response. The pressor response to saralasin (5 μg kg−1 min−1), however, was unaffected by thymoxamine. 4. Saralasin caused minimal changes in levels of plasma renin activity and plasma aldosterone in both groups. There was no relationship between basal plasma renin activity and the pressor response in either group. 5. We therefore conclude that the immediate transient pressor response to saralasin in man is not due to central sympathetic stimulation, is unlikely to be due to peripheral sympathetic activation and is probably the result of intrinsic angiotensin II-like myotropism.

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.

VARIATIONS IN PLASMA RENIN ACTIVITY AND URINARY ALDOSTERONE EXCRETION IN NORMAL SUBJECTS AFTER SALT RESTRICTION AND ACUTE PITUITARY INHIBITION WITH 6-DEHYDRO-16-METHYLENE HYDROCORTISONE

1971 ◽  
Vol 67 (1) ◽  
pp. 159-173
Author(s):  
A. Peytremann ◽  
R. Veyrat ◽  
A. F. Muller
Keyword(s):  
Plasma Renin Activity ◽  
Salt Intake ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Inhibitory Effect ◽  
Renin Activity ◽  
Sodium Balance ◽  
Experimental Conditions ◽  
Salt Restriction ◽  
Aldosterone Production

ABSTRACT Variations in plasma renin activity and urinary aldosterone excretion were studied in normal subjects submitted to salt restriction and simultaneous inhibition of ACTH production with a new synthetic steroid, 6-dehydro-16-methylene hydrocortisone (STC 407). At a dose of 10 mg t. i. d. this preparation exerts an inhibitory effect on the pituitary comparable to that of 2 mg of dexamethasone. In subjects maintained on a restricted salt intake, STC 407 does not delay the establishment of an equilibrium in sodium balance. The increases in endogenous aldosterone production and in plasma renin activity are also similar to those seen in the control subjects. A possible mineralocorticoid effect of STC 407 can be excluded. Under identical experimental conditions, the administration of dexamethasone yielded results comparable to those obtained with STC 407.

Are Racial Differences in Essential Hypertension Due to Different Pathogenetic Mechanisms?

1978 ◽  
Vol 55 (s4) ◽  
pp. 383s-386s ◽  
Author(s):  
P. S. Sever ◽  
W. S. Peart ◽  
T. W. Meade ◽  
I. B. Davies ◽  
D. Gordon ◽  
...  
Keyword(s):  
Essential Hypertension ◽  
Plasma Renin Activity ◽  
Racial Differences ◽  
Plasma Renin ◽  
Urinary Sodium Excretion ◽  
Renin Activity ◽  
Plasma Noradrenaline ◽  
Noradrenaline Concentration ◽  
Blacks And Whites ◽  
Made In

1. Plasma noradrenaline concentration and plasma renin activity were measured in a control, British, urban population (n = 115) in which blacks were matched for age and sex with whites. 2. Similar measurements were made in subjects with essential hypertension (77 white and 23 black), and 48 healthy normotensive white civil servants. 3. In controls blood pressure was significantly higher in blacks; it correlated with age in both races and with pulse rate in blacks. There were no significant racial differences in plasma noradrenaline which was positively correlated with age in both blacks and whites. Mean plasma renin activity was 55% lower in blacks, and this difference was not related to urinary sodium excretion. 4. In hypertensive subjects plasma noradrenaline positively correlated with age in blacks. This relationship was not found in whites in whom 20% of young hypertensive subjects (<45 years) had significantly raised plasma noradrenaline. Plasma renin activity was again significantly lower in blacks. In white hypertensives plasma noradrenaline and renin activity were significantly correlated. 5. There may be racial differences in the pathogenesis of essential hypertension.

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.

PLASMA RENIN ACTIVITY IN PANHYPOPITUITARISM

1972 ◽  
Vol 69 (3) ◽  
pp. 531-541 ◽  
Author(s):  
M. Murakami ◽  
R. Takeda ◽  
S. Morimoto ◽  
K. Hirasawa ◽  
K. Uchida ◽  
...  
Keyword(s):  
Serum Level ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Normal Subjects ◽  
The Other ◽  
Renin Activity ◽  
Sodium Restriction ◽  
Normal Limits ◽  
Furosemide Administration ◽  
Very High

ABSTRACT The response of plasma renin activity (PRA) to sodium restriction, furosemide and ACTH administration were studied in six patients with panhypopituitarism of various causes and in a patient with Addison's disease. In all the patients with panhypopituitarism, the basal levels of PRA were within normal limits and the responses of PRA and sodium homoeostasis to sodium restriction and furosemide administration were not significantly different from those of normal subjects. On the other hand, in an Addisonian patient the basal level of PRA was very high and this was further increased with a decrease in the serum level of sodium and an increase in the serum level of potassium after one day of sodium restriction. The administration of 1 mg of synthetic β1–24 ACTH every 12 hours for 2 days caused an increased plasma 11-OHCS and urinary 17-OHCS. with a decrease of sodium and an increase of potassium loss in the urine but failed to change PRA in patients with panhypopituitarism. In the Addisonian patient, ACTH did not influence the levels of plasma 11-OHCS, urinary 17-OHCS, PRA as well as serum and urinary electrolytes. From these results it is suggested that ACTH does not directly act on renin secretion and that PRA can adequately respond to various stimuli such as sodium restriction and furosemide administration in a condition of ACTH deficiency.

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