Isolated muscle cells from adult rat heart were used to study the involvement of G-proteins in the regulation of the glucose transporter by insulin and isoprenaline. Efficient modification of G-protein functions was established by measuring isoprenaline-stimulated cyclic AMP production, viability and ATP content after treating the cells with cholera toxin and pertussis toxin for 2 h. Under thes...

1. Rat hearts were perfused with 32Pi, and contractile force was increased by positive inotropic agents (agents that increase contractility). The inhibitory subunit of troponin (troponin I) was then isolated by affinity chromatography in 8M-urea, and its 32P content measured. Incorporation of phosphate into the subunit was calculated on the basis of the [gamma-32P]ATP specific radioactivity in ...

Eightyears ofpersonal experience of long-acting isoprenaline in the treatment of chronic complete heart block is described. In selected patients the long-term results can be very satisfactory and examples are given. The isoprenaline infusion test is invaluable in selecting most patients who will not do well on long-acting isoprenaline. Of those who begin on treatment about half have done well. ...

N1-Acetylspermidine is not detectable in rat heart, but its content greatly increases after a single injection of isoprenaline (10 mg/kg), reaching a concentration of about 10 nmol/g of tissue 4 h after the treatment. Part of the accumulated N1-acetylspermidine was split to putrescine. Isoprenaline also caused an increase of N1-acetylspermidine in the spleen, where its concentration increased 3...

Basal intracellular cAMP levels of lymphocytes from patients with systemic sclerosis, all suffering from Raynaud's phenomenon, were significantly lower than those obtained from normal controls. Moreover, the cAMP response to isoprenaline of these patients' lymphocytes was inhibited. Intravenous infusion of prostaglandins (E1 and I2) restored the basal levels and greatly improved the responsiven...

We investigated the vasodilatory effect of isoprenaline at large vessels (aorta, renal and saphenous arteries, vena cava, renal and saphenous veins) in doxorubicin-induced model of heart failure. Thirty salinetreated (normal group) and thirty doxorubicin treated rabbits (1 mg/kg administered intravenously twice weekly for 8 weeks) were studied after 16 weeks of treatment. Chronic heart failure ...

We have used the whole-cell patch clamp recording technique to characterize a swelling-activated chloride current in guinea pig atrial and ventricular myocytes and to compare the electrophysiological and pharmacological properties of this current with the isoprenaline-activated chloride current in the same cell types. Osmotic swelling of guinea pig cardiac myocytes caused activation of an outwa...

When propranolol is given to prevent hypoxaemic episodes in children with tetralogy of Fallot who are awaiting operation it is advisable to continue the treatment until shortly before the induction of anaesthesia. Because catecholamines are often required to maintain adequate cardiac output after surgical correction the effect of preoperative treatment with beta blockers on the response to isop...

The acute effects of beta-adrenergic stimulation on myocardial stiffness were evaluated. New-Zealand white rabbits were treated with saline (control group) or doxorubicin to induce heart failure (HF) (DOXO-HF group). Effects of isoprenaline (10(-10)-10(-5) M), a non-selective beta-adrenergic agonist, were tested in papillary muscles from both groups. In the control group, the effects of isopren...

OBJECTIVES To assess the impact of β1 -adrenoceptor blockers (β1 -blocker) and isoprenaline on the incidence of idiopathic repetitive ventricular arrhythmia that apparently decreases with preprocedural anxiety. METHODS From January 2010 to July 2012, six patients were identified who had idiopathic ventricular arrhythmias that apparently decreased (by greater than 90%) with preprocedural anxie...