Haemodynamic Responses to Exercise and Acute β-Receptor Blockade in Renin Sub-Types of Essential Hypertension

1976 ◽  
Vol 51 (s3) ◽  
pp. 493s-496s ◽  
Author(s):  
F. Burkart ◽  
F. R. Bühler ◽  
M. Pfisterer ◽  
B. E. Lütold ◽  
M. Küng
Keyword(s):  
Essential Hypertension ◽  
Plasma Renin ◽  
Receptor Blockade ◽  
Control Mechanisms ◽  
Exercise Tachycardia ◽  
Adrenergic Control ◽  
Before And After ◽  
Pre Treatment ◽  
Β Receptor

1. Haemodynamic and renin responses to dynamic exercise before and after intravenous β-adrenoreceptor blockade with propranolol were compared in twenty-one patients with essential hypertension and either high (n = 7), normal (n = 7) or low plasma renin activity (n = 7). 2. Renin and heart-rate responses to exercise and β-receptor blockade diminished from high-renin to normal and to low-renin patients, effects which were blunted with increasing age. 3. Among the renin groups cardiac output, stroke volume, diastolic pulmonary artery pressure, systemic pressure and peripheral vascular resistance as well as their changes produced by exercise and acute β-receptor blockade were not significantly different. 4. Long-term anti-hypertensive propranolol effects correlated with the pre-treatment renin status, renin stimulation and its suppression by acute β-receptor blockade as well as with the exercise tachycardia and the patient's age. 5. The results suggest different adrenergic control mechanisms in renin sub-types of essential hypertension, age being a modulating factor.

Differential Effects of Acute and Chronic β-Adrenoreceptor Blockade on Blood Pressure and the Renin—Angiotensin—Aldosterone System in Essential Hypertension

1976 ◽  
Vol 51 (s3) ◽  
pp. 537s-540s
Author(s):  
R. Kolloch ◽  
K. O. Stumpe ◽  
H. Vetter ◽  
W. Gramann ◽  
F. Krück
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Chronic Administration ◽  
Plasma Renin ◽  
Plasma Aldosterone ◽  
Receptor Blockade ◽  
Plasma Aldosterone Concentration ◽  
Group 2 ◽  
Β Receptor ◽  
Group 1

1. Serial measurements of plasma renin activity (PRA), plasma aldosterone concentration (PA) and blood pressure were performed overnight in patients with borderline (group 1) and sustained essential hypertension (group 2) before and after acute and chronic administration of either propranolol or pindolol. 2. Group 1 patients exhibited a typical rhythm of recumbent PRA with low values before midnight and large increases early in the morning. 3. In contrast, no rhythm and very low PRA values were observed in patients of group 2. Blood pressure was higher in group 2 than in group 1. There was a significant correlation between the hyporeninaemic and hypotensive effect of either acute (r = 0·79) or chronic (r = 0·4) β-receptor blockade. 4. In group 1, after β-receptor blockade the day—night profile of renin was similar to that observed in group 2 before treatment. Thus, in this latter subgroup, low-renin profiles might reflect reduced β-adrenoreceptor activity. 5. Plasma aldosterone was lower in group 2 but appeared to be inappropriately high relative to renin. 6. The data suggest that in hypertensive patients classified according to their blood pressure and recumbent PRA profiles a significant relationship exists between changes in PRA and arterial pressure. Thus patients with high PRA respond better to treatment than patients with low renin. We conclude that in the patients studied sympathetic nervous system activity mainly determined renin values as well as anti-hypertensive effectiveness of the β-blocking drugs.

Decrease in α-Adrenoceptor-Mediated Vasoconstriction Parallels the Antihypertensive Response to Propranolol in Patients with Normal Renin Essential Hypertension

1981 ◽  
Vol 61 (s7) ◽  
pp. 445s-448s ◽  
Author(s):  
F. W. Amann ◽  
P. Bolli ◽  
L. Hulthén ◽  
W. Kiowski ◽  
F. R. Bühler
Keyword(s):  
Essential Hypertension ◽  
Plasma Renin Activity ◽  
Forearm Blood Flow ◽  
Plasma Renin ◽  
Renin Activity ◽  
Plasma Adrenaline ◽  
Before And After ◽  
Β Receptor ◽  
Antihypertensive Response ◽  
Propranolol Therapy

1. α1-Adrenoceptor-mediated vasoconstriction was studied before and during propranolol therapy in eight normal renin essential hypertensive patients; four were known ‘responders’ and four, age-matched ‘non-responders’ to previous β-receptor blocker monotherapy. Plasma renin activity, plasma adrenaline and noradrenaline concentrations as well as forearm blood flow were measured before and during regional postjunctional α1-adrenoceptor blockade with prazosin. All measurements were done on placebo and again after 6 weeks’ propranolol monotherapy (320 mg/day). 2. Propranolol reduced heart rate and plasma renin activity to the same extent in ‘responders’ and ‘non-responders’. Resting plasma adrenaline concentrations tended to be higher in ‘responders’ before propranolol; they remained unchanged in both groups on propranolol. Plasma noradrenaline concentrations were similar in both groups before and on propranolol. 3. Before propranolol forearm flow was not different in ‘responders’ and ‘non-responders’. Non-specific vasodilatation with sodium nitroprusside produced a similar increase in forearm flow before and after propranolol in both groups. 4. Prazosin-induced increments in forearm flow tended to be higher in ‘responders’ before propranolol. After propranolol the vasodilator effect of prazosin was attenuated in ‘responders’ but it remained unchanged in ‘non-responders’ (P < 0.01). 5. In patients with normal renin essential hypertension the antihypertensive response to propranolol monotherapy is paralleled by a decrease in postjunctional α1-adrenoceptor-mediated vasoconstriction.

Maintenance of renal autoregulation during infusion of aminophylline or adenosine

1985 ◽  
Vol 248 (3) ◽  
pp. F366-F373 ◽  
Author(s):  
A. J. Premen ◽  
J. E. Hall ◽  
H. L. Mizelle ◽  
J. E. Cornell
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Filtration Rate ◽  
Plasma Renin ◽  
Receptor Blockade ◽  
Renal Metabolism ◽  
Renal Autoregulation ◽  
Before And After ◽  
Anesthetized Dogs

Adenosine has been postulated to link control of glomerular filtration rate (GFR) and renal blood flow (RBF) with changes in renal metabolism. In the present study, we examined the role of adenosine in renal autoregulation by comparing the responses of normal anesthetized dogs to step decreases in renal artery pressure (RAP) to the response obtained after receptor blockade of adenosine with aminophylline or by flooding the kidney with exogenous adenosine. In six dogs at normal RAP, intrarenal infusion of aminophylline (10 mumol/min) did not alter renal hemodynamics. GFR and RBF were well autoregulated (greater than 90% of control) at RAP values equal to or greater than 85 mmHg before and after aminophylline. At RAP equal to 75 mmHg, GFR and RBF decreased by 27 +/- 10 and 20 +/- 8%, respectively, before aminophylline and by 25 +/- 7 and 13 +/- 6% after aminophylline. In a different group of six dogs, intrarenal infusion of adenosine (6 mumol/min) significantly increased RBF (32 +/- 9%) and decreased GFR (38 +/- 10%) at normal RAP. However, GFR and RBF were both well autoregulated (greater than 90% of control) at RAP values equal to or greater than 85 mmHg before and after adenosine. At RAP equal to 75 mmHg, GFR and RBF decreased by 10 +/- 5 and 7 +/- 3%, respectively, before adenosine and by 12 +/- 6 and 17 +/- 5% after adenosine. Neither aminophylline nor adenosine attenuated the elevations in plasma renin activity associated with reductions in RAP. These data fail to provide evidence that adenosine is an important factor in autoregulation of GFR and RBF during acute reductions in RAP within the autoregulatory range.

The Effect of Mental Stress on Catecholamines, their Metabolites and Plasma Renin Activity in Patients with Essential Hypertension and in Healthy Subjects

1979 ◽  
Vol 57 (s5) ◽  
pp. 229s-231s ◽  
Author(s):  
W. Januszewicz ◽  
M. Sznajderman ◽  
B. Wocial ◽  
T. Feltynowski ◽  
T. Klonowicz
Keyword(s):  
Essential Hypertension ◽  
Plasma Renin Activity ◽  
Urinary Excretion ◽  
Mental Stress ◽  
Healthy Subjects ◽  
Plasma Renin ◽  
Renin Activity ◽  
Vanillylmandelic Acid ◽  
Before And After ◽  
Noradrenaline And Adrenaline

1. Ten patients with essential hypertension and ten healthy men were submitted to mental stress consisting of Kraepelin's arithmetic test combined with noise. Concentrations of plasma and urine catecholamines and of their metabolites as well as plasma renin activity before and after the test were studied. 2. In both groups a significant increase of noradrenaline and adrenaline in blood and noradrenaline in urine was observed. The urinary excretion of dopamine fell significantly in both groups after stress. 3. After mental stress a significant increase in urinary excretion of 3-methoxy-4-hydroxyphenylglycol was observed in both groups. The excretion of vanillylmandelic acid decreased significantly only in healthy subjects. 4. The plasma renin activity rose significantly in both groups but the increase was more pronounced in healthy subjects.

Increase of Total Body Potassium and Decrease of Exchangeable Sodium after Long-Term Treatment with a β-Receptor-Blocking Agent (Prindolol) in Essential Hypertension

1976 ◽  
Vol 51 (s3) ◽  
pp. 551s-554s
Author(s):  
H. M. Brecht ◽  
E. Werner ◽  
W. Schoeppe
Keyword(s):  
Essential Hypertension ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Term Treatment ◽  
Renin Activity ◽  
Exchangeable Sodium ◽  
Total Body Potassium ◽  
Long Term Treatment ◽  
Total Body

1. The effect of long-term treatment with prindolol on blood pressure, total body potassium (Kt), exchangeable sodium (Nae) and plasma renin activity was investigated in twelve patients with essential hypertension. 2. Systolic and diastolic pressures were significantly reduced from 164/112 to 127/90 mmHg under basal conditions. 3. Before treatment Na. in patients with essential hypertension was significantly higher than in normotensive individuals. After an average of 16 weeks on prindolol Nae in patients with essential hypertension was significantly decreased, despite an average increase in body weight of 2 kg in the patients. 4. In contrast to the decrease in Nae, Kt was found to be significantly increased after long-term treatment with prindolol. Kt values of patients before and after prindolol, however, did not differ significantly from the corresponding sex- and age-dependent normal values. 5. Plasma renin activity was slightly diminished under basal and orthostatic conditions; the stimulatory effect of orthostasis was not abolished but reduced by prindolol. 6. It is suggested that the changes in sodium balance contribute to the anti-hypertensive effect of prindolol in patients with essential hypertension.

Effects of open field testing and associated handling v. handling alone on the adrenocortical reactivity of piglets around weaning

2002 ◽  
Vol 74 (3) ◽  
pp. 485-491 ◽  
Author(s):  
M. S. Herskin ◽  
K. H. Jensen
Keyword(s):  
Blood Sample ◽  
Open Field ◽  
Field Testing ◽  
Blood Sampling ◽  
Cortisol Response ◽  
Temporal Development ◽  
Novel Object ◽  
Before And After ◽  
Pre Treatment

AbstractEffects of open field testing and associated handling (including blood sampling) v. handling (with blood sampling) alone on adrenocortical reactivity were investigated in piglets around weaning. After weaning at day 28, piglets were mixed to form eight replicates with three litter each and kept on slatted floors. Treatments were open field/novel object testing and associated handling (OFT + H) v. handling alone (H) (no. = 40). Testing took place on the following days (weaning day 0): -4, 0, 1, 4 and 8 (no. = 16). The open field/novel object test lasted 10 min and blood was sampled by venipuncture before and after the test and/or handling procedures. In the first blood sample, plasma concentration of cortisol did not differ between OFT + H and H piglets. In the second blood sample, however, OFT + H piglets had a higher concentration of cortisol and a larger increase in cortisol than H piglets (P < 0·01). In the first blood sample the concentration of cortisol was affected by day (P < 0·05), with concentration on day -4 being lower than those on day 0, 1, and 4 and the concentration on day 8 was lower than the concentration on day 0 as well. However, no differences were found between days for the second blood sample nor the adrenocortical reactivity. In conclusion, the increase in pre-treatment cortisol in the first 4 days after weaning as well as the lack of changes in the adrenocortical reactivity after weaning suggest that the temporal development of HPA activity and reactivity in piglets after weaning are comparable with other, more standardized long-term stressors. Exposure to an open field/novel object test and associated handling results in higher adrenocortical reactivity than handling alone but the latter (including blood sampling) in itself accounts for proportionately 0·74 of the cortisol response.

Effect of Intravenous Frusemide on Plasma Renin Concentration: Suppression of Response in Hypertension

1975 ◽  
Vol 49 (4) ◽  
pp. 353-358 ◽  
Author(s):  
P. L. Padfield ◽  
M. E. M. Allison ◽  
J. J. Brown ◽  
A. F. Lever ◽  
R. G. Luke ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
High Blood Pressure ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Primary Hyperaldosteronism ◽  
Plasma Renin Concentration ◽  
Low Renin Hypertension ◽  
Renal Adaptation

1. Intravenous frusemide produced in normal subjects a prompt rise of plasma renin concentration which correlated with urinary sodium. 2. The renin response to frusemide was suppressed in patients with primary hyperaldosteronism. 3. In patients with low-renin hypertension and normal renin essential hypertension, the renin response to frusemide was similarly suppressed. 4. Suppression of the renin response to frusemide is therefore a feature of hypertension not confined to patients with primary hyperaldosteronism and low-renin hypertension. 5. Thus low-renin hypertension does not appear to constitute a distinct diagnostic entity. 6. It is suggested that suppression of the renin response is part of a long-term renal adaptation to high blood pressure.

scholarly journals The Efficacy of a Virtual Reality Exposure Therapy Treatment for Fear of Flying: A Retrospective Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Amihai Gottlieb ◽  
Glen M. Doniger ◽  
Yara Hussein ◽  
Shlomo Noy ◽  
Meir Plotnik
Keyword(s):  
Virtual Reality ◽  
Treatment Period ◽  
Outcome Measures ◽  
Large Scale ◽  
Exposure Therapy ◽  
Fear Of Flying ◽  
Efficacy Outcome ◽  
Before And After ◽  
Pre Treatment

Background: Fear of flying (FoF) is a phobia with 10–40% prevalence in the industrialized world. FoF is accompanied by severe economic, social, vocational, and emotional consequences. In recent years, virtual reality (VR)-based exposure therapy (VRET) for FoF has been introduced. Positive long-term efficacy of FoF-VRET has been reported by several studies, which, however, were limited by relatively small, non-representative samples and a lack of comparative pre/post functional efficacy outcome measures. Our objective was to evaluate the efficacy of a VRET treatment utilizing a large-scale VR system, experienced by a representative sample of self-referred individuals.Methods: We conducted a retrospective survey. Of 274 individuals who received the treatment (over a period of 3 years), 209 met inclusion/criteria, and 98 agreed to participate. We mainly collected information regarding flight activity before and after treatment relying on evidence such as boarding passes and flight tickets. The primary outcome measures were (1) number of flights per month (FpM) and (2) number of flight hours per month (FHpM). For each participant, these outcomes were computed for the post-treatment period (≥6 months after FoF-VRET) and the corresponding pre-treatment period.Results: FpM (mean ± SD) increased from 0.04 ± 0.06 to 0.16 ± 14 flights (p &lt; 0.0001). FHpM rose from 0.19 ± 0.35 to 0.79 ± 0.87 h per month (p &lt; 0.0001).Conclusion: These results are indicative of FoF-VRET treatment efficacy. Future studies should evaluate long-term maintenance of the treatment effect and thus identify the optimal frequency for delivery of periodic booster treatments.

Compared Incidence of First Myocardial Infarction in Hypertensive Patients under Treatment Containing Propranolol or excluding β-Receptor Blockade

1976 ◽  
Vol 51 (s3) ◽  
pp. 509s-511s ◽  
Author(s):  
I. McD. G. Stewart
Keyword(s):  
Myocardial Infarction ◽  
Term Treatment ◽  
Receptor Blocker ◽  
Receptor Blockade ◽  
Hypertensive Patients ◽  
Long Term Treatment ◽  
Significant Difference ◽  
Group A ◽  
Β Receptor

1. After some exclusions, 169 severe uncomplicated essential hypertensive patients presenting consecutively were divided into two groups according to their treatment. Of these, 121 had been given long-term treatment containing propranolol (PC group) and forty-eight had been treated with hypotensive agents excluding any β-receptor-blocker group, the non-β-receptor-blocker (NBB) group. 2. There were no significant differences in myocardial infarction risk factors between the two groups. 3. After a mean follow-up of 5·25 years, nine of the 121 subjects (7·5%) in the PC group had suffered first infarctions and fifteen of the forty-eight subjects (31%) in the NBB group, a significant difference (P < 0·01). 4. It was concluded that the presence of propranolol had prevented more or caused fewer infarctions, perhaps a combination of both, than had the older hypotensive agents unsupported by β-receptor blockade.

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