Plasma noradrenaline in Goldblatt models of renovascular hypertension in the rat, before and after surgical reversal

1986 ◽  
Vol 71 (2) ◽  
pp. 199-204 ◽  
Author(s):  
S. M. Walker ◽  
R. F. Bing ◽  
J. D. Swales ◽  
H. Thurston

1. Plasma noradrenaline (NA), blood pressure (BP) and heart rate (HR) were measured simultaneously in conscious rats under basal conditions in the early phase (4–6 weeks) of one-kidney, one-clip hypertension (1K1C), in the early (4–6 weeks) and chronic (> 16 weeks) phases of the two-kidney, one-clip model (2K1C) and in age-matched loose clip control animals before and 2 days after unclipping. 2. The elevated BP in all three hypertensive groups fell to normal after unclipping, whereas removal of the constricting clip in loose clip controls had no effect on BP. 3. Plasma NA was elevated in 1K1C hypertension (P < 0.05) and fell slightly but non-significantly on unclipping. However, in the early phase of 2K1C hypertension plasma NA was unaltered before and rose significantly (P < 0.05) after unclipping. Plasma NA did not change with unclipping in the chronic phase of 2K1C hypertension and was not different from controls. Unclipping loose clip control animals produced no change in plasma NA. 4. Changes in HR on unclipping followed a similar pattern to changes in plasma NA: changes in the two variables were significantly correlated in all three models (1K1C: r = 0.61, P < 0.005; early 2K1C: r = 0.45, P < 0.05; chronic 2K1C: r = 0.62, P < 0.01). However, BP was only correlated with plasma NA in 1K1C hypertension (r = 0.49, P < 0.02) and not in either phase of the 2K1C model. There was also a highly significant correlation between HR and plasma NA in 1K1C hypertension (r = 0.71, P < 0.001). The pattern of the changes in plasma NA and HR that occurred with reversal of 1K1C hypertension was significantly different from those in the early phase 2K1C model (P < 0.05). 5. These data suggest that there is sympathetic nervous system (SNS) activation in the early phase of 1K1C hypertension, but provide no evidence for increased sympathetic activity in either the early or chronic phases of the 2K1C model. Neither do they support the hypothesis that the fall in BP with unclipping in this model is mediated by reduced SNS activity.

1980 ◽  
Vol 238 (4) ◽  
pp. H521-H526 ◽  
Author(s):  
N. Alexander ◽  
M. T. Velasquez ◽  
M. Decuir ◽  
R. F. Maronde

Blood pressure and circulating levels of norepinephrine (NE), epinephrine (Epi), and dopamine-beta-hydroxylase (DBH) were measured sequentially in sinoaortic-denervated (SAD) Wistar rats and in sham-operated (SO) rats. Systolic tail pressure, plasma NE and E, and plasma DBH all increased significantly within 2 days in SAD rats. In separate studies of rats with indwelling arterial catheters, arterial pressure and plasma NE and DBH were increased in SAD rats in home cages; restraint caused similar increases of pressure and catecholamines in both groups. Systolic pressure remained increased up to 4 mo and plasma DBH for 10 wk in SAD rats; plasma NE and E, however, declined by 3 wk and thereafter remained close to values of SO rats. Additionally, DBH was increased in heart, mesenteric blood vessels and adrenal glands of SAD rats up to 6 wk; tissue monoamine oxidase activity was also increased up to 4 mo. These findings suggest that activation of the sympathetic nervous system initiates and probably sustains hypertension in SAD rats up to 6 wk after operation; thereafter some other mechanism(s) sustains the hypertension.


1995 ◽  
Vol 79 (6) ◽  
pp. 1991-1997 ◽  
Author(s):  
S. Fagette ◽  
L. Somody ◽  
F. Bouzeghrane ◽  
J. M. Cottet-Emard ◽  
C. Gharib ◽  
...  

Rats were tail suspended, keeping their forelimbs weight bearing for 14 days, and then allowed to recover for a short (6-h) or a long (24-h) period to assess the behavior of the sympathetic nervous system after weightless simulation. Sympathetic activity was determined by measuring norepinephrine (NE) turnover in the brain stem cell groups involved in central blood pressure control and in organs playing a key role in the cardiovascular regulation (heart and kidneys). The NE turnover was greatly reduced in the rostral (-56%; P < 0.001) and caudal (-73%; P < 0.001) A2 nucleus of suspended rats but was unchanged in the A1, A5, and A6 cell groups compared with attached rats. The NE turnover in the cardiac atria (-34%; P < 0.001) and ventricles (-35%; P < 0.001) and kidneys (-31%; P < 0.001) was decreased after suspension. The central and peripheral sympathetic activities returned to normal within 24 h of release from suspension, but there was hyperactivity after 6 h of recovery. This raises the problem of interpreting the results obtained in animals killed a few hours after return from spaceflight.


1985 ◽  
Vol 248 (1) ◽  
pp. E95-E100 ◽  
Author(s):  
D. Baum ◽  
J. B. Halter ◽  
G. J. Taborsky ◽  
D. Porte

The effects of intravenous pentobarbital were studied in dogs. Plasma pentobarbital concentrations were inversely related to epinephrine and norepinephrine concentrations. Plasma catecholamines appeared fully suppressed at pentobarbital levels greater than 25-30 micrograms/ml. Furthermore, pentobarbital levels were negatively related to rectal temperature, heart rate, and mean blood pressure. The methods of pentobarbital administration influenced plasma pentobarbital as well as epinephrine and norepinephrine levels, temperature, heart rate, and blood pressure. These observations suggest the possibility that pentobarbital inhibits the sympathetic nervous system, which in turn may affect temperature, heart rate, and blood pressure. Because pentobarbital anesthesia affects plasma catecholamine concentrations, the regimen used in animal models requires consideration when interpreting data potentially influenced by the sympathetic nervous system.


1980 ◽  
Vol 59 (s6) ◽  
pp. 323s-325s ◽  
Author(s):  
G. Recordati ◽  
S. Genovesi ◽  
D. Cerati ◽  
R. Di Cintio

1. Experiments were carried out to investigate whether the activation of renal chemoceptive receptors by natural stimuli might induce reflex alterations of efferent postganglionic activity to the ipsilateral kidney and preganglionic activity to the ipsilateral adrenal. 2. In anaesthetized rats with intact nervous system back-flow of urine and occlusion of the renal artery were accompanied by increments in efferent sympathetic activity both to the kidney and adrenal without concomitant changes in heart rate and blood pressure. 3. Greater excitatory responses in nerve activity to the same test stimuli were observed in rats with the spinal cord cut at C1. 4. These results indicate that the natural activation of renal chemoceptive receptors might induce reno-renal and reno-adrenal excitatory reflexes which are likely to be integrated at spinal and supraspinal levels.


2019 ◽  
Vol 133 (9) ◽  
pp. 1097-1113 ◽  
Author(s):  
Ken Chen ◽  
Dongdong Sun ◽  
Shuang Qu ◽  
Yue Chen ◽  
Jialiang Wang ◽  
...  

Abstract Environmental temperature plays a role in the variation of blood pressure. Maternal cold stress could affect the physiological phenotype of the offspring, including blood pressure elevation. In the present study, we found that adult offspring of dams exposed to cold have increased systolic and diastolic blood pressure, and decreased urine volume and sodium excretion, accompanied by increased heart rate and heart rate variability, secondary to increased activity of the sympathetic nervous system. Renal denervation or adrenergic receptor blockade decreased blood pressure and increased sodium excretion. The increase in peripheral sympathetic nerve activity can be ascribed to the central nervous system because administration of clonidine, a centrally acting α2 adrenergic receptor agonist, lowered blood pressure to a greater degree in the prenatal cold-exposed than control offspring. Moreover, these prenatal cold-exposed offspring had hypothalamic paraventricular nucleus (PVN) disorder because magnetic resonance spectroscopy showed decreased N-acetylaspartate and increased choline and creatine ratios in the PVN. Additional studies found that prenatal cold exposure impaired the balance between inhibitory and excitatory neurons. This led to PVN overactivation that was related to enhanced PVN-angiotensin II type 1 (AT1) receptor expression and function. Microinjection of the AT1 receptor antagonist losartan in the PVN lowered blood pressure to a greater extent in prenatal cold-exposed that control offspring. The present study provides evidence for overactive peripheral and central sympathetic nervous systems in the pathogenesis of prenatal cold-induced hypertension. Central AT1 receptor blockade in the PVN may be a key step for treatment of this type hypertension.


2015 ◽  
Vol 10 (7) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Chi-Jung Chen ◽  
K. J. Senthil Kumar ◽  
Yu-Ting Chen ◽  
Nai-Wen Tsao ◽  
Shih-Chang Chien ◽  
...  

Meniki ( Chamecyparis formosensis) and Hinoki ( C. obtusa) are precious conifers with excellent wood properties and distinctive fragrances that make these species popular in Taiwan for construction, interiors and furniture. In the present study, the compositions of essential oils prepared from Meniki and Hinoki were analyzed by gas chromatography-mass spectrometry (GC/MS). Thirty-six compounds were identified from the wood essential oil of Meniki, including 5-cadinene, y-cadinene, 5-cadinol, α-muurolene, calamenene, linalyl acetate and myrtenol; 29 compounds were identified from Hinoki, including α-terpineol, α-pinene, 8-cadinene, borneol, terpinolene, and limonene. Next, we examined the effect of Meniki and Hinoki essential oils on human autonomic nervous system activity. Sixteen healthy adults received Meniki or Hinoki by inhalation for 5 min, and the physiological and psychological effects were examined. After inhaling Meniki essential oil, participant's systolic blood pressure and heart rate (HR) were decreased, and diastolic blood pressure increased. In addition, sympathetic nervous activity (SNS) was significantly decreased, and parasympathetic activity (PSNS) was significantly increased. On the other hand, after inhaling Hinoki essential oil, systolic blood pressure, heart rate and PSNS were decreased, whereas SNA was increased. Indeed, both Meniki and Hinoki essential oils increased heart rate variability (HRV) in tested adults. Furthermore, in the Profile of Mood States (POMS) test, both Meniki and Hinoki wood essential oils stimulated a pleasant mood status. Our results strongly suggest that Meniki and Hinoki essential oils could be suitable agents for the development of regulators of sympathetic nervous system dysfunctions.


1973 ◽  
Vol 44 (6) ◽  
pp. 617-620 ◽  
Author(s):  
L. B. Geffen ◽  
R. A. Rush ◽  
W. J. Louis ◽  
A. E. Doyle

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.


2021 ◽  
pp. 026988112199710
Author(s):  
Sophie Metz ◽  
Woo R Chae ◽  
Christian E Deuter ◽  
Christian Otte ◽  
Katja Wingenfeld

Introduction: Facial expressions contain important affective information, and selective attention to facial expression provides an advantage in the face of loss, stress and danger. In addition, the sympathetic nervous system and hypothalamus-pituitary-adrenal axis mediate the organism’s response to loss and danger. Here, we aimed at investigating the influence of sympathetic nervous system and hypothalamus-pituitary-adrenal axis activation on selective attention to affective facial stimuli. Methods and materials: One hundred-and-four healthy men between 18–35 years old (mean (standard deviation) age: 24.1 (3.5) years) participated in the study. We used a randomised, double-blind, placebo-controlled design. Participants received either: (a) yohimbine, (b) hydrocortisone, (c) yohimbine and hydrocortisone or (d) placebo only and participated in a dot-probe task with sad, happy and neutral faces. We collected salivary samples to measure cortisol and alpha amylase activity in addition to measurements of blood pressure and heart rate. Salivary cortisol served as correlate of hypothalamus-pituitary-adrenal axis activation and salivary alpha amylase activity, blood pressure and heart rate as correlates of sympathetic nervous system activation. Measurements were carried out before and after drug administration. Results: We did not find a main effect or interaction effect of hydrocortisone or yohimbine administration on selective attention to happy faces. However, we found an interaction of yohimbine and hydrocortisone on selective attention to sad faces. Post-hoc t-test revealed an attentional bias away from sad stimuli and towards neutral faces in the hydrocortisone-only group. Discussion: Only hydrocortisone administration led to an attentional bias away from sad faces. Future studies should investigate these effects in major depression disorder, as this disorder is characterised by glucocorticoid resistance and increased processing of sad stimuli.


1980 ◽  
Vol 58 (1) ◽  
pp. 37-43 ◽  
Author(s):  
R. D. S. Watson ◽  
C. A. Hamilton ◽  
D. H. Jones ◽  
J. L. Reid ◽  
T. J. Stallard ◽  
...  

1. Forearm venous plasma noradrenaline, heart rate and intra-arterial blood pressure were measured sequentially during and after upright bicycle exercise in five normotensive and six hypertensive patients. 2. Plasma noradrenaline increased significantly between 4 and 8 min during exercise. 3. On stopping exercise blood pressure and heart rate decreased rapidly whilst plasma noradrenaline increased in each subject to reach a maximum at a median time of 108 s after exercise. 4. Plasma noradrenaline decreased in five of six normotensive patients between the end of exercise and 2 min after exercise performed in the supine position. 5. Evidence in favour of a reflex increase in sympathetic activity after upright exercise is discussed.


Sign in / Sign up

Export Citation Format

Share Document