A comparison of the actions of ICI66082 and propranolol on cardiac and peripheral β-adrenoceptors

Singh, Bramah N.; Nisbet, Heather D.; Harris, E. A.; Whitlock, Robert M. L.

doi:10.1016/0014-2999(75)90227-7

Cited by 39 publications

(9 citation statements)

References 24 publications

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“…However, Henningsen (1977) reported that of 17 hypertensive asthmatic patients taking atenolol, 16 were well on the drug after 3 years. Secondly, cardioselectivity is a dose-related quality (Lertora et al, 1975;Singh et al, 1975). This point has been well shown in man (Formgren, 1976) where bronchospasm was induced by metoprolol at doses above 100 mg/day.…”

Section: Discussionmentioning

confidence: 88%

Beta-blockers and asthma.

Decalmer¹,

Chatterjee²,

Cruickshank³

et al. 1978

Heart

127

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In a single-blind, randomised, crossover study in 10 asthmatic patients, the effects of approximately equipotent oral doses of 3 cardioselective beta-blockers-atenolol (100 mg), metoprolol (100 mg), and acebutolol (300 mg)-and 4 non-cardioselective beta-blockers-proranolol (100 mg), oxprenolol (100 mg), pindolol (5 mg), and timolol (10 mg) upon FEV1 were compared. All drugs, except pindolol, produced a significant reduction in standing pulse rate and prevented an increase in heart rate after inhaled isoprenaline (1500 microgram). All drugs caused a fall in FEV1 but only atenolol did not differ significantly from placebo in this respect. The bronchodilator response to inhaled isoprenaline was blocked by the 4 non-cardioselective drugs; the 3 cardioselective agents permitted some bronchodilatation, but only atenolol did not differ from placebo.

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Section: Discussionmentioning

confidence: 88%

Beta-blockers and asthma.

Decalmer¹,

Chatterjee²,

Cruickshank³

et al. 1978

Heart

127

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“…The clinical utility of these agents was further enhanced by their associated antiarrhythmic properties. However, P-adrenoceptor antagonists can produce cardiac decompensation (Epstein & Braunwald, 1966;Singh, Till & Kelly, 1971) and they may aggravate bronchospasm in susceptible patients (Singh & Jewitt, 1974). Attention has therefore focused on the development of less depressant P-adrenoreceptor antagonists with greater cardioselectivity (Vaughan Williams, Bagwell & Singh, 1973;Ablad, Carlsson & Ek, 1973;Singh et al, 1975).…”

Section: Introductionmentioning

confidence: 99%

Effects of Amiodarone and L8040, Novel Antianginal and Antiarrhythic Drugs, on Cardiac and Coronary Haemodynamics and on Cardiac Intracellular Potentials

Singh

Jewitt

Downey

et al. 1976

Clin Exp Pharmacol Physiol

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1. The effects on the coronary and systemic haemodynamics of intravenous and intracoronary injections of two benzfuran derivatives, amiodarone and its brominated analogue (L8040), were studied in open-chest anaesthetized dogs. The effects of L8040 on cardiac intracellular potentials after 6 weeks of 20 mg/kg intraperitoneal injections in rabbits were also investigated. 2. Both compounds produced dose-related and quantitatively similar decreases in coronary vascular resistance following their intracoronary administration; threshold effects occurred with about 0-25 mg of each drug and maximal effects with 4 mg. Larger intracoronary doses produced measurable systemic effects. 3. Intravenous injections of amiodarone and L8040 (2-5-10 mg/kg) produced dose-related decreases in heart rate and aortic pressure with a fall in total peripheral resistance. The left ventricular output was either unaffected or increased with a consistent augmentation in stroke volume. 4. The bradycardia produced by both drugs was associated with prolongation of the P-R interval of the electrocardiogram with no significant effect on the QRS duration or the Q-T interval. 5. Each drug produced a decrease in the total peripheral vascular resistance with no change in left ventricular end diastolic pressure except after 10 mg/kg doses which led to an increase in this parameter. 6. Cardiac contractile force and peak LV dp/dt were reduced by both drugs in a dose-related manner. 7. Chronic intraperitoneal administration of L8040 in rabbits caused a prolongation of the duration of the atrial and ventricular intracellular potential without an effect on the maximal rate of depolarization. 8. The effect of amiodarone or L8040 on the coronary circulation and arterial pressure may be attributed to their vasodilator properties but their depressant actions on cardiac contractile force and peak LV dp/dt with an increase in left ventricular end diastolic pressure at high doses, also suggest intrinsic negative inotropic propensity for both compounds. 9. It is concluded that the overall effects on coronary and systemic haemodynamics of amiodarone and its brominated analogue are likely to permit a favourable influence on the balance of oxygen supply and demand in myocardial ischaemia; in addition, their actions on sino-atrial and atrio-ventricular conduction as well as those on cardiac repolarization suggest potential antiarrhythmic properties which merit investigation.

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“…These findings suggest that atenolol may be less effective in relieving essential tremor than propranolol or sotalol in doses which have an equipotent cardiac chronotropic (,j3-adrenoreceptor) effect. Several studies have shown that atenolol produces greater blockade of f3,-(cardioreceptors) than 182-adrenoreceptors in vitro (Barrett et al, 1973;Conway et al, 1976;Coleman and Somerville, 1977) and in vivo in animals and man (Singh et al, 1975;Vilsvik and Schaanning, 1976;Decalmer et al, 1978). The present findings, therefore, suggest that 12adrenoreceptor antagonism may be the mechanism of the therapeutic action of 1adrenoreceptor antagonists in essential tremor.…”

Section: Discussionmentioning

confidence: 99%

beta-Adrenoreceptor antagonists in essential tremor.

Jefferson¹,

Jenner²,

Marsden³

1979

Journal of Neurology, Neurosurgery & Psychiatry

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Three different 8-adrenoreceptor antagonists-propranolol, sotalol, and atenololwere compared in a double-blind study with placebo in nine patients with essential tremor. All three drugs produced an equal reduction in standing pulse rate but atenolol was less effective in reducing tremor than propranolol and sotalol. These results suggest that the reduction in tremor produced by fi-adrenoreceptor antagonists is mediated by an effect on peripheral 9,-adrenoreceptors.

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A comparison of the actions of ICI66082 and propranolol on cardiac and peripheral β-adrenoceptors

Cited by 39 publications

References 24 publications

Beta-blockers and asthma.

Beta-blockers and asthma.

Effects of Amiodarone and L8040, Novel Antianginal and Antiarrhythic Drugs, on Cardiac and Coronary Haemodynamics and on Cardiac Intracellular Potentials

beta-Adrenoreceptor antagonists in essential tremor.

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