Comparison of Metoprolol and Propranolol in Modification of Haemodynamic and Renin-Aldosterone Responses to Tilting in Humans

1976 ◽  
Vol 51 (s3) ◽  
pp. 533s-535s
Author(s):  
G. W. Viol ◽  
E. K. M. Smith ◽  
J. D. Fitzgerald

1. Acute oral administration of metoprolol and propranolol to ten normal males resulted in equal reduction in heart rate both supine and after passive tilting to 60°. 2. Tilted systolic blood pressure was reduced by both agents but metoprolol alone reduced supine systolic blood pressure. 3. Tilted but not supine diastolic blood pressure was reduced by both agents. 4. Metoprolol and propranolol both reduced the rise in plasma renin activity induced by tilting. 5. No effect of tilting was observed on plasma aldosterone.

1981 ◽  
Vol 60 (4) ◽  
pp. 399-404 ◽  
Author(s):  
C. J. Mathias ◽  
H. L. Frankel ◽  
I. B. Davies ◽  
V. H. T. James ◽  
W. S. Peart

1. The effect of endogenous sympathetic stimulation (induced by urinary bladder stimulation) and intravenous infusion of noradrenaline and isoprenaline on blood pressure, heart rate and levels of plasma renin activity and plasma aldosterone were studied in six tetraplegic patients. Data from infusion studies were compared with data from six normal subjects studied in an identical manner. 2. Bladder stimulation in the tetraplegic patients caused a marked rise in blood pressure and fall in heart rate, but no change in plasma renin activity or plasma aldosterone. 3. Noradrenaline infusion resulted in an enhanced pressor response in the tetraplegic patients when compared with the normal subjects. Heart rate fell in both groups. Plasma renin activity and plasma aldosterone did not change in either group. 4. Isoprenaline infusion caused a fall in both systolic and diastolic blood pressure in the tetraplegic patients, unlike the normal subjects in whom there was a rise in systolic and a fall in diastolic blood pressure. Heart rate and plasma renin activity rose in both groups. Plasma aldosterone did not change in either group. 5. We conclude that in tetraplegic patients neither endogenous sympathetic stimulation by bladder stimulation nor infusion of noradrenaline raises plasma renin activity. Isoprenaline increases plasma renin activity to the same extent as in normal subjects. Renin release mechanisms in tetraplegic patients therefore do not appear to be hypersensitive to catecholamines. Plasma aldosterone is not influenced by any of the stimuli.


1978 ◽  
Vol 45 (6) ◽  
pp. 870-874 ◽  
Author(s):  
F. H. Leenen ◽  
P. Boer ◽  
G. G. Geyskes

Changes in heart rate, blood pressure, and plasma renin activity (PRA) were assessed during infusion of increasing doses of isoproterenol and during increasing work loads of dynamic exercise in five normal young men. Studies were performed at three levels of dietary sodium restriction: normal, moderately, and more severely restricted. Isoproterenol induced the expected dose-related increases in heart rate, systolic blood pressure, and PRA and decreases in diastolic blood pressure. Changes in dietary sodium intake affected these changes only to a minor degree. Dynamic exercise also induced the expected work-load-related increases in heart rate, systolic blood pressure, and PRA and decreases in diastolic blood pressure. Also these changes were not significantly affected by changes in dietary sodium intake. Apparently dietary sodium restriction does not sensitize the renin-releasing mechanisms to sympathetic stimulation.


1985 ◽  
Vol 68 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Margareta Bramnert ◽  
Hökfelt Bernt

1. There is evidence that opioid peptides influence blood pressure and heart rate in animals and man. In the present investigation the effect of naloxone on the exercise-induced increase in blood pressure, heart rate, plasma catecholamines, plasma renin activity (PRA) and plasma aldosterone was investigated in nine healthy men. A submaximal work test was performed on two occasions. The test consisted of ergometer bicycling for 10 min on 50% of maximal working capacity immediately followed by 10 min on 80% of maximal working capacity. Ten minutes before exercise the subjects received in a randomized manner a bolus dose of naloxone (10 μg/kg) or a corresponding volume of saline followed by a slow infusion (15 ml/h) of naloxone (5 μ h−1 kg−1) or saline, respectively. 2. After exercise systolic blood pressure, heart rate, plasma catecholamines, PRA and plasma aldosterone increased during both saline and naloxone infusion. The changes were similar in both studies. 3. Accordingly, opiate receptors sensitive to naloxone in a moderate dosage seem not to be involved in the cardiovascular response and the increase in plasma catecholamines, PRA and plasma aldosterone induced by exercise.


1976 ◽  
Vol 51 (s3) ◽  
pp. 113s-115s
Author(s):  
B. F. Johnson ◽  
I. K. Smith ◽  
J. Labrooy ◽  
Carole Bye

1. Seven healthy sodium-replete male volunteer subjects remained supine during and for at least 1 h before the study. Heart rate and blood pressure were recorded continuously, and peripheral venous blood samples were taken every 15 min for determinations of plasma renin activity. 2. All subjects were studied twice: after 3 days of oral practolol (100 mg, three times daily) and after a similar period on placebo. Each study consisted of an intravenous infusion of isoprenaline in graded doses (0–2·0 μg/min in the placebo phase; 0–16 μg/min in the practolol phase), followed after rest for 2 h by an intravenous infusion of salbutamol (0–20 μg/min after placebo; 0–80 μg/min after practolol). 3. Both salbutamol and isoprenaline produced dose-related increases in systolic blood pressure, heart rate and plasma renin activity and decreases in diastolic pressure. 4. The increases in heart rate and plasma renin activity induced by either agonist were competitively blocked by practolol, as was the fall in diastolic blood pressure induced by isoprenaline; the salbutamol-induced fall of diastolic blood pressure was unaffected by practolol. 5. Comparison of dose ratio — 1 estimates confirmed that practolol selectively blocked increases in heart rate and plasma renin activity due to salbutamol; no selective blockade against isoprenaline-induced changes was shown. 6. Selective blockade of salbutamol-induced changes indicate that a β1-adrenoreceptor mediates changes in plasma renin activity.


1982 ◽  
Vol 50 (1) ◽  
pp. 219-230 ◽  
Author(s):  
Richard J. Roberts ◽  
Theodore C. Weerts

This study was designed to determine if visualization of anger- and fear-provoking scenes produced differential physiological patterns similar to those produced by in vivo manipulations. Normotensive college students were selected on the basis of their responses to newly developed Anger and Fear/Anxiety questionnaires and for their ability to construct arousing scenes during a screening interview. In a 2 × 2 design (intensity × emotion), four scenes (high and low anger, high and low fear) were constructed individually for each of 16 subjects to imagine. Diastolic blood pressure, systolic blood pressure, and heart rate were monitored during visualization of each scene. Change in diastolic blood pressure was significantly greater for high anger than for high fear as predicted. Analysis of change in heart rate and systolic blood pressure showed significant effects for intensity only. These results provide further support for the concept of physiological differentiation in human emotion and suggest the utility of imagery for systematic study of human emotional responding.


Author(s):  
Rishman Tandi ◽  
Tanvi Kumar ◽  
Amritpal Singh Kahlon ◽  
Aaftab Sethi

Introduction: Acute coronary syndrome remains as one of the most important causes for morbidity and mortality in developed countries. Therefore, evidence-based management strategy is required to offset the loss of health during an acute coronary syndrome. An effective approach includes both medical and surgical methods. This study was conducted to evaluate the medical method of management. Objective: To study blood pressure and heart rate variability after administration of Ivabradine or metoprolol in cases with acute coronary syndrome. Materials and methods: The study was a Prospective single center observational study conducted in patients attending Cardiology Intensive Care Unit in Nayyar Heart and Superspecialty Hospital, a tertiary care centre located in an urban area. All patients with Acute coronary syndrome admitted to the emergency or cardiac care unit were analysed with ECG as a preliminary diagnostic test and confirmed with troponin markers. They were either given Ivabradine or Metoprolol. Baseline evaluation and follow up was done and necessary data was collected and analysed.   Results: 100 patients were included in the study out of which 50 were given Metoprolol (Group A) and 50 were given Ivabradine (Group B). Themean age of studied cases was found to be 66.54 years in group A and 68.69 years in group B. It was observed that there was a fall in heart rate by 26.8 beats per minute with beta blocker and 24.4 beats per minute with Ivabradine. In case of blood pressure measurement, in patients with beta blocker administration, there was a fall of 25 mm Hg in systolic blood pressure and 17 mm Hg in diastolic blood pressure However, with Ivabradine there was only a fall of 8mm Hg in systolic Blood pressure and 6 mm Hg in diastolic blood pressure. Conclusion: Although Metoprolol is the drug of choice to decrease heart rate and blood pressure in acute coronary syndrome, Ivabradine is being increasingly used in cases where beta blockers are contraindicated as it has similar efficacy in lowering heart rate without compromising contractility of cardiac muscle, thereby maintaining LVEF and blood pressure. Keywords: Acute coronary syndrome, Beta Blockers, Metoprolol, Ivabradine.


1985 ◽  
Vol 69 (2) ◽  
pp. 207-214 ◽  
Author(s):  
D. P. Worth ◽  
J. N. Harvey ◽  
J. Brown ◽  
M. R. Lee

1. γ-l-Glutamyl-l-dopa was given by intravenous infusion to eight normal subjects at doses of 12.5 and 100 μg min−1 kg−1. 2. Both doses of the dipeptide resulted in an increase in mean urinary sodium excretion. 3. Mean effective renal plasma flow rose at both doses, but mean glomerular filtration rate increased only at the lower dose. 4. There was a fall in mean plasma renin activity after the infusion of both 12.5 and 100 μg min−1kg−1. 5. Mean urine free dopamine excretion increased by 280- and 2500-fold at infusion rates of 12.5 and 100 μg min−1 kg−1 respectively. 6. Mean plasma free dopamine rose at both doses but the increase at 12.5 μg min−1 kg−1 was not to a level previously associated with systemic effects of the catecholamine. 7. On administration of the dipeptide at 12.5 μg min−1 kg−1 there were no changes in blood pressure or heart rate, but at the higher dose there was a fall in diastolic blood pressure. 8. At a dose of 12.5 μg min−1 kg−1 in man, there is kidney specific conversion of gludopa to dopamine.


1988 ◽  
Vol 119 (2) ◽  
pp. 257-262 ◽  
Author(s):  
Sadao Nakajima ◽  
Hiromichi Suzuki ◽  
Yo Kageyama ◽  
Takashi Takita ◽  
Takao Saruta

Abstract. The effects of atrial natriuretic peptide (ANP) on mean arterial blood pressure, heart rate, plasma renin activity, aldosterone, cortisol, norepinephrine, epinephrine and arginine vasopressin were studied in 6 anuric subjects receiving regular hemodialysis. An iv bolus injection of 8 nmol of ANP followed by infusion at 32 pmol·kg−1·min−1 for 1 h in the pre- and posthemodialysis period was performed. Basal plasma ANP was higher before than after hemodialysis. ANP administration produced a reduction in mean arterial blood pressure accompanied by an elevation of norepinephrine and of plasma renin activity (from 2.49 ± 0.52 to 3.39 ± 0.85 nmol·l−1·h−1 predialysis and from 2.78 ± 0.71 to 3.15 ± 0.86 nmol·l−1·h−1 postdialysis, respectively, mean ± sem; P < 0.05). Plasma aldosterone and cortisol were significantly decreased. Plasma epinephrine and AVP remained unchanged. These hemodynamic and hormonal changes were similar in the pre- and the postdialysis period. These results suggest that 1) ANP causes a fall in mean arterial blood pressure, which in turn induces reflex tachycardia and activation of the sympathetic nervous system without diuresis; 2) the activated sympathetic nervous system as reflected in elevation of plasma norepinephrine may increase plasma renin activity; 3) reduced plasma aldosterone is not influenced by enhancement of the reninangiotensin system; therefore, 4) reduction of plasma aldosterone as well as cortisol is probably due to direct action of ANP, and finally 5) AVP had no direct relation with ANP administration.


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