It is not known whether surgical denervation leads to increased beta-receptor sensitivity after human cardiac transplantation. We assessed cardiac beta-receptor sensitivity by studying the heart rate response to isoprenaline of the denervated donor heart as compared with the innervated recipient heart in eight patients who underwent heterotopic cardiac transplantation and in six patients with o...

The present investigation was undertaken to study the effects of K+ channel openers in the relaxant responses to various agonists in estrogen primed rat uterus. Adrenaline and isoprenaline produced a dose-dependent relaxation in the estrogen primed rat uterus. The relaxant responses were found to be significantly potentiated when the preparations were exposed to PSS devoid of calcium. The respo...

AIMS To investigate the effects of beta-adrenoceptor stimulation, using the agonist isoprenaline and the antagonist propranolol, on migrating motor complexes in the upper intestine of 16 healthy human volunteers. METHODS Fasting motility was monitored using a tube with water perfused side holes connected to a pneumohydraulic system. Continuous eight hour recordings were obtained from each vol...

OBJECTIVE TGF-beta stimulation of cardiac myocytes induces a hypertrophic responsiveness to beta-adrenoceptor stimulation. This study investigates whether this beta-adrenoceptor mediated effect depends on induction of ornithine decarboxylase (ODC). METHODS Isolated adult ventricular cardiomyocytes from rats were used as an experimental model. Cells were either cultured in 20% (v/v) FCS to act...

The effects of several beta-adrenoceptor agonists on the relaxation of precontracted human bronchial rings and the inhibition of IgE-mediated histamine release from human lung mast cells (HLMC) were studied. For the relaxation of bronchial rings, isoprenaline, fenoterol and terbutaline were full agonists whereas salbutamol was a full agonist in some (two out of six) experiments and a partial ag...

same extent as M-( -)-propranolol (by 80%). Treatment of membranes with isoprenaline + GMP converts N from the closed GDP-bound state to an open Gpp(NH)presponsive form (Braun et af . , 1982). This form of N was found to be relatively insensitive to propranolol and also attenuated the filipin inhibition of Gpp(NH)p stimulation, but to a lesser extent. The reason for this is unclear, but may be ...

Phosphorylation of myofibrillar and sacroplasmic-reticulum (SR) proteins was studied in Langendorff-perfused rabbit hearts subjected to various inotropic interventions. Stimulation of hearts with isoprenaline resulted in the phosphorylation of both troponin I (TnI) and C-protein in myofibrils and phospholamban in SR. Phosphorylation of phospholamban could be reversed by a 15 min perfusion with ...

Background. The regulation of contractility of the transplanted heart depends on circulating catecholamines resulting from cardiac denervation. Supersensitivity to circulating catecholamines may result from loss of presynaptic neuronal uptake or upregulation of postsynaptic (adrenergic receptors. Methods and Results. Dose-response curves using the j3-adrenergic receptor agonists isoprenaline (n...

the β2-adrenergic effects of macerated extract, aqueous extract, ethanol extract, and essential oil of carum copticum, 5 nm propranolol, and saline were tested by performing cumulative log concentration-response curves of isoprenaline-induced relaxation of precontracted isolated guinea pig tracheal chains in three different conditions including: non-incubated (group 1, n=9) incubated with 1 µm ...

The action of beta- and alpha-adrenoceptor agonists (isoprenaline, orciprenaline, noradrenaline, phenylephrine and ephedrine) and antagonists (propranolol, metipranolol, exaprolol, BL 445 and phentolamine) on the resting tension and cAMP level of the guinea pig and the mechanical and electrical activities of the dog trachea were studied. By activating beta 2-adrenoceptors, isoprenaline and orci...