Comparison of the Renin Response to Dopamine and Noradrenaline in Normal Subjects and Patients with Autonomic Insufficiency

1974 ◽  
Vol 46 (4) ◽  
pp. 481-488 ◽  
Author(s):  
C. S. Wilcox ◽  
M. J. Aminoff ◽  
A. B. Kurtz ◽  
J. D. H. Slater
Keyword(s):  
Autonomic Failure ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Control Groups ◽  
Autonomic Reflexes ◽  
Fractional Increase ◽  
The Mean ◽  
Autonomic Insufficiency ◽  
Stimulation Of

1. The effect on plasma renin activity (PRA) of dopamine and noradrenaline infusions was studied in three patients with Shy—Drager syndrome, three patients with Parkinson's disease and normal autonomic reflexes, and three healthy volunteers. The patients with the Shy—Drager syndrome had functional evidence of a peripheral lesion of the sympathetic nervous system and subnormal PRA on a controlled sodium intake. 2. In all subjects catecholamines were infused step-wise for 4 min until a 30% rise in systolic blood pressure occurred. 3. In each subject, PRA fell after noradrenaline but rose after dopamine. The mean fractional increase in PRA after dopamine was no less in the Shy—Drager patients than in the control groups. 4. The results suggest, first, that stimulation of dopamine receptors can release renin, and secondly, that inadequate renin stores cannot explain the low PRA found in our patients with autonomic failure.

Dietary chloride modifies renin release in normal humans

1981 ◽  
Vol 241 (4) ◽  
pp. F361-F363 ◽  
Author(s):  
R. J. Koletsky ◽  
R. G. Dluhy ◽  
R. G. Cheron ◽  
G. H. Williams
Keyword(s):  
Sodium Intake ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Renin Release ◽  
Upright Posture ◽  
Ang Ii ◽  
Low Salt ◽  
Normal Humans ◽  
The Mean ◽  
Induced Changes

The effect of high and low chloride diets on the responses of plasma renin activity (PRA), angiotensin II (ANG II), and aldosterone (Aldo) to upright posture was studied in the same normal subjects in balance on constant sodium intake. Diet 1 consisted of 10 meq Na/day (low Na) and either 50 or 150 meq Cl/day. Diet 2 consisted of 200 meq Na/day (high Na) and either 20 or 200 meq Cl/day. The mean recumbent PRA level on the high Na-high Cl diet tended to be lower than on the high Na-low Cl diet but was not significantly different. However, the absolute peak upright PRA levels, 8.8 +/- 1.0 vs. 4.4 +/- 0.8 ng . ml-1 . h-1, and the incremental difference (delta PRA) between recumbent and peak upright PRA levels, 5.5 +/- 0.8 vs. 2.2 +/- 0.5 ng . ml-1 . h-1, were significantly less on the high Na-high Cl diet compared with the high Na-low Cl diet. Similar significant changes were seen in ANG II and Aldo levels. However, there were no significant changes in PRA, ANG II, and Aldo responses to upright posture on the low Na diet when the dietary Cl was varied. It is concluded that dietary Cl is another factor modifying renin release. However, Cl is probably less important than Na because Cl-induced changes in PRA were not seen in the low salt state.

AT1 and TxA2/PGH2 receptors maintain hypertension throughout 2K,1C Goldblatt hypertension in the rat

1996 ◽  
Vol 271 (4) ◽  
pp. R891-R896 ◽  
Author(s):  
C. S. Wilcox ◽  
J. Cardozo ◽  
W. J. Welch
Keyword(s):  
Blood Pressure ◽  
Receptor Antagonist ◽  
Sodium Intake ◽  
Late Phase ◽  
Plasma Renin ◽  
Type I ◽  
Ang Ii ◽  
Control Groups ◽  
The Mean ◽  
Antihypertensive Response

Angiotension II (ANG II) increases the generation of vasoconstrictor prostaglandin endoperoxides (PGH2) and thromboxane A2 (TxA2). Two-kidney, one-clip (2K,1C) Goldblatt hypertensive rats have an increased plasma renin activity (PRA) and ANG II level during the early, but not the late, phases of hypertension. Therefore, the aim of these studies was to compare the antihypertensive efficacy of an ANG II type I (AT1) and a TxA2/PGH2 receptor antagonist during different phases of 2K,1C hypertension. Rats were maintained on a fixed sodium intake for 3 days before and throughout the period of drug administration. These studies assessed the antihypertensive response to administration of the AT1 receptor antagonist losartan (20 mg.kg-1.day-1), the TxA2/PGH2 receptor antagonist ifetroban (20 mg.kg-1.day-1) or vehicle given for 3 days to rats with early (2-4 wk postclip), intermediate (10-12 wk postclip), and late (36-42 wk post-clip) 2K,1C hypertension and to two control groups of rats corresponding in age to the early or intermediate and the late 2K,1C groups. The mean arterial pressure (MAP) was measured directly with indwelling arterial cannulas. The MAP of sham-operated rats was 109 +/- 5 mmHg. In the early phase of 2K,1C hypertension, the MAP was increased to 143 +/- 6 mmHg, and it was increased further to 162 +/- 5 mmHg during the intermediate and to 179 +/- 4 mmHg during the late phase. The PRA, compared with age-matched controls, was increased during early and intermediate, but not late phase 2K,1C hypertension. Neither drug lowered blood pressure in control rats. However, both drugs significantly reduced the blood pressure in the early, intermediate, and late phases of 2K, 1C hypertension. At the end of 3 days of administration, blood pressure in early 2K, 1C rats given losartan was reduced to levels of control rats, but remained slightly elevated in other groups and in those receiving ifetroban. In conclusion, AT1 and TxA2/PGH2 receptors maintain hypertension throughout the evolution of 2K, 1C hypertension in the rat, despite changes in PRA.

Sodium Homeostasis in Patients with Autonomic Failure

1977 ◽  
Vol 53 (4) ◽  
pp. 321-328 ◽  
Author(s):  
C. S. Wilcox ◽  
M. J. Aminoff ◽  
J. D. H. Slater
Keyword(s):  
Blood Pressure ◽  
Sodium Excretion ◽  
Autonomic Failure ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Sodium Balance ◽  
Control Group ◽  
Salt Restriction ◽  
Control Subjects ◽  
Autonomic Reflexes

1. The renal excretion of sodium by five patients with autonomic failure (Shy—Drager syndrome) was compared with a matched control group who had normal autonomic reflexes (Parkinson's disease). For 8 or 9 days the daily sodium intake was reduced to 17 mmol, and for 5 subsequent days it was increased to 189 mmol. 2. The sodium excretion of the patients with autonomic failure was not significantly reduced during 7 days of restricted intake whereas that of the control group fell rapidly to values comparable with their sodium intake. Patients with autonomic failure had a larger fall in body body weight than the control subjects. 3. Both lying and standing values of mean blood pressure fell during salt restriction in the patients with autonomic failure, but not in the control subjects. 4. Values of plasma renin activity (PRA) were significantly depressed in patients with autonomic failure. However, PRA rose to values similar to those of control subjects while standing during the period of restricted sodium intake. At this time the patients with autonomic failure had a large orthostatic fall in blood pressure and creatinine clearance. 5. Aldosterone secretion rates were measured in three patients with autonomic failure at both levels of sodium intake and were considerably lower than the rates found in the control group. 6. A mineralocorticoid drug (9α-fludrocortisone; 2 mg/day), given on the last 2 days of restricted sodium intake, failed to correct fully the negative sodium balance of the patients with autonomic failure, since an excessive sodium excretion persisted during the period of recumbency at night. 7. These results demonstrate a severe defect in renal salt conservation in certain patients with autonomic failure. They suggest that the defect may not be entirely due to deficient secretion of mineralocorticoid hormones.

Plasma Renin in Idiopathic Orthostatic Hypotension: Differential Response in Subjects with Probable Afferent and Efferent Autonomic Failure

1971 ◽  
Vol 41 (4) ◽  
pp. 289-299 ◽  
Author(s):  
D. R. Love ◽  
J. J. Brown ◽  
R. H. Chinn ◽  
R. H. Johnson ◽  
A. F. Lever ◽  
...  
Keyword(s):  
Orthostatic Hypotension ◽  
Autonomic Function ◽  
Autonomic Failure ◽  
Plasma Renin ◽  
Sympathetic Block ◽  
Baroreceptor Reflexes ◽  
Idiopathic Orthostatic Hypotension ◽  
Autonomic Reflexes ◽  
Efferent Pathways ◽  
Venous Plasma

1. The changes of peripheral venous plasma renin concentration (PRC) induced by head-up tilting were studied in four patients with orthostatic hypotension. 2. Two of the patients had the Holmes—Adie syndrome and tests of autonomic function suggested that they had an afferent block from baroreceptors with intact efferent pathways; the others had no evidence of the Holmes—Adie syndrome and investigations suggested that they had interruption of efferent sympathetic pathways. 3. In the two patients in whom lesions of the afferent side of baroreceptor reflexes were suspected, a marked increase in PRC occurred with upright tilting, whereas no change in PRC occurred in the two patients thought to have an efferent sympathetic block. 4. During repeated tilting, supine blood pressure and PRC increased progressively in the two patients with suspected afferent block, but not in the two patients with suspected efferent block. 5. It is suggested that an increase in plasma renin may contribute to the supine hypertension sometimes observed in patients with orthostatic hypotension. 6. It is also suggested that renin release does not require intact autonomic reflexes although certain components of efferent sympathetic pathways, not dependent on baroreceptor reflexes, may be important.

Hormonal responses to gradual changes in dietary sodium intake in humans

1989 ◽  
Vol 256 (6) ◽  
pp. R1171-R1175 ◽  
Author(s):  
G. A. Sagnella ◽  
N. D. Markandu ◽  
M. G. Buckley ◽  
M. A. Miller ◽  
D. R. Singer ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Progressive Increase ◽  
Plasma Aldosterone ◽  
Dietary Sodium ◽  
Sodium Balance ◽  
Initial Increase ◽  
Hormonal Responses

The effects of gradual (50 mmol/day) increases in dietary sodium intake from 10 to 350 mmol/day on plasma atrial natriuretic peptide (ANP), aldosterone, and plasma renin activity (PRA) were studied in six normal subjects. With the increases in sodium intake there was a progressive increase in urinary sodium from 12.2 +/- 4.4 to 314.8 +/- 31.4 mmol/24 h; plasma ANP increased gradually from 9.9 +/- 1.1 to 23.3 +/- 2.2 pg/ml, with the increases being closely associated with the changes in cumulative sodium balance. Plasma aldosterone decreased significantly from 2,519.7 +/- 147.4 pmol/l on the 10 mmol/day to 1,393.3 +/- 125.4 pmol/l when the sodium intake was increased to 50 mmol/day and decreased further to 251.6 +/- 78.7 pmol/l by the end of the study. The changes in PRA paralleled those in plasma aldosterone with the exception of no significant change in plasma PRA within 24 h of the initial increase in sodium intake. This marked sensitivity in the responses of both the ANP and the renin-aldosterone system to small increases in sodium intake clearly points to their importance in the renal adaptations to alterations in dietary sodium intake.

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.

Influence of Age and Sodium Intake on Plasma Renin Activity of Normal Subjects

Nephron ◽  
1980 ◽  
Vol 26 (4) ◽  
pp. 189-194 ◽  
Author(s):  
S. Salvetti ◽  
R. Pedrinelli ◽  
A. Magagna ◽  
L. Poli ◽  
P. Sassano ◽  
...  
Keyword(s):  
Plasma Renin Activity ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Renin Activity

Plasma vasopressin responses in postpartum hypopituitarism: impaired response to osmotic stimuli

1992 ◽  
Vol 127 (6) ◽  
pp. 494-498 ◽  
Author(s):  
MA Arnaout ◽  
K Ajlouni
Keyword(s):  
Diabetes Insipidus ◽  
Hypertonic Saline ◽  
Arginine Vasopressin ◽  
Plasma Osmolality ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Plasma Vasopressin ◽  
Basal Plasma ◽  
The Mean ◽  
Thyroxine Replacement Therapy

The neurohypophyseal function was assessed in a group of 15 patients with postpartum hypopituitarism by measuring plasma arginine-vasopressin concentrations during 5% hypertonic saline infusion. None of the patients had symptoms of diabetes insipidus and all patients were on adequate cortisone and thyroxine replacement therapy before testing. The mean basal plasma vasopressin value in the patients (0.6±0.1 pmol/1) was significantly lower than that in the normal subjects (2.9±0.3 pmol/l; p<0.01), whereas the mean serum sodium, plasma osmolality, plasma renin activity and serum aldosterone values were similar in the two groups. During the osmolar load (5% hypertonic saline), the patients revealed varying degrees of arginine-vasopressin responses to the increase in plasma osmolality. Three patients showed normal arginine-vasopressin responses, 10 had subnormal responses, and 2 had no response. During the dehydration test, the patients revealed significantly lower maximum urine osmolalities (p<0.0025) with significantly higher concurrent mean plasma osmolality (p<0.0025) than the controls. None of the patients showed overt polyuria at the time of the study. The results indicate the impaired osmoregulation of arginine-vasopressin secretion to an osmolar stimuli in patients with postpartum hypopituitarism, suggesting neurohypophyseal damage. In patients with Sheehan's syndrome, partial diabetes insipidus seems to be much more frequent than previously believed.

Age-Dependent Changes of Plasma Renin Concentration in Humans

1973 ◽  
Vol 45 (s1) ◽  
pp. 273s-278s ◽  
Author(s):  
K. Hayduk ◽  
D. K. Krause ◽  
W. Kaufmann ◽  
R. Huenges ◽  
U. Schillmöller ◽  
...  
Keyword(s):  
Sodium Intake ◽  
Post Partum ◽  
Age Groups ◽  
Plasma Renin ◽  
Relative Increase ◽  
Upright Posture ◽  
Healthy Children ◽  
Absolute Increase ◽  
Plasma Renin Concentration ◽  
The Mean

1. Plasma renin concentration (PRC) in newborns greatly exceeded PRC in children and adults. PRC in cord plasma of newborns was higher than peripheral venous PRC in their mothers. PRC in the newborns increased further in the first 48 h post partum and then gradually decreased. 2. The mean PRC of healthy children and adults on free sodium intake decreased with age by an exponential function. 3. The absolute increase of PRC in response to upright posture (PRCupright — PRCrecumbent) decreased with age. The relative increase of PRC in response to upright posture (PRCuprjght:PRCrecumbent) remained unchanged with age, the PRC in upright posture being about twice the basal PRC in all age groups.

scholarly journals Amplitude of Somatosensory Evoked Potentials (SEPs) in Short-Latency SEPs Condition is 80% of that in Giant SEPs

2021 ◽  
Author(s):  
Ai Demura ◽  
Yutaka Demura ◽  
Kazuaki Sato ◽  
Masako Kinoshita
Keyword(s):  
Evoked Potentials ◽  
Somatosensory Evoked Potentials ◽  
Neurological Disorders ◽  
Bandpass Filter ◽  
Normal Subjects ◽  
Short Latency ◽  
Cortical Hyperexcitability ◽  
Recording Conditions ◽  
The Mean ◽  
Stimulation Of

Abstract The recording conditions of somatosensory evoked potentials (giant SEPs) are different from those of short-latency SEPs (SSEPs). We investigated the waveform characteristics obtained for each condition. Forty-eight upper limbs of 24 adult normal subjects (12 males, age 35.5 ± 9.7 years (mean ± SD)) were investigated. The main differences in recording conditions were reference electrodes (giant SEPs: the earlobe electrode ipsilateral to the stimulated limb, SSEPs: Fz), stimulus rate (1 Hz, 5 Hz), and bandpass filter (1 Hz–1 kHz, 20 Hz–3 kHz). SEPs were elicited by unilateral percutaneous electrical stimulation of the median nerve at the wrist. The amplitudes of N20o–N20 and N20–P25 were significantly larger in the giant SEP condition than in the SSEP condition (p<0.001). The mean + 3SD of N20–P25 amplitude was 10.0 µV in the giant SEP condition and 7.8 µV in the SSEP condition. The N20–P25 amplitude was significantly correlated between the giant SEP and SSEP conditions (R=0.64, p<0.001). Thus, the amplitude of SEPs in the SSEPs condition is equivalent to 80% of that in the giant SEPs condition. The information is useful for detecting cortical hyperexcitability in various neurological disorders including myoclonic epilepsy.

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