We investigated whether deficiency of inducible nitric oxide synthase (iNOS) could prevent isoproterenol-induced cardiac hypertrophy in iNOS knockout (KO) mice. Isoproterenol was continuously infused subcutaneously (15 mg/kg/day) using an osmotic minipump. Isoproterenol reduced body weight and fat mass in both iNOS KO and wild-type mice compared with saline-infused wild-type mice. Isoproterenol...

An isoproterenol infusion (1.0-4.0 microgram/min) was administered to 15 patients with intermittent bundle branch block (BBB) and two patients with apparently fixed BBB. Three main effects were documented: (1) In all patients with phase 3, or tachycardia-dependent, BBB, isoproterenol caused a pronounced shortening of refractoriness in the affected fascicle. (2) In patients showing phase 4, or b...

Impaired left ventricular relaxation and filling is an important pathophysiologic mechanism in hypertrophic cardiomyopathy. To determine whether isoproterenol, known to improve relaxation in isolated cardiac muscle, could favorably modify this efFect, we assessed simultaneous left ventricular volume and regional systolic asynchrony (by radionuclide angiography), left ventricular pressure (by mi...

The chronotropic response of right atria isolated from 5-day-cold-exposed rats to isoproterenol and norepinephrine was studied. A large increase in the sensitivity of the pacemaker to isoproterenol and a decrease in the sensitivity to norepinephrine occurred. Determination of pA2 values of propranolol and metoprolol using isoproterenol and norepinephrine as agonists and analysis of the slopes o...

BACKGROUND Head-upright tilt (HUT) testing is valuable in evaluating syncope. Isoproterenol is used to increase sensitivity. However, isoproterenol is contraindicated or dangerous in undiagnosed heart disease and produces false-positives. We introduced esmolol withdrawal during esmolol HUT, hypothesizing that (1) acute withdrawal of the ultrashort-acting beta-blocker induces beta-adrenergic eff...

Heme oxygenase (HO)-1 is a well-known cytoprotectant against oxidative stress and exhibits an antiproliferative effect in vascular smooth muscle cells (VSMCs). The purpose of the present study was to test whether isoproterenol, one of the synthetic catecholamines having beta-adrenergic activity, affected angiotensin II (Ang II)-induced cell proliferation and reactive oxygen species (ROS) produc...

Withania somnifera (WS) (Dunal) or Ashwagandha is a well-known hypolipidemic herb and antioxidant. In this study, 75% ethanolic extract of WS attempted to evaluate the cardioprotective activity isoproterenol-induced cardiotoxicity in Triton WR 1339-induced hyperlipidemia. addition, phytochemical evaluation same extracts analyzed by gas chromatography–mass spectrometer (GC–MS). This study found ...

OBJECTIVE Overweight and heightened sympathetic activity are more common in hypertensive than normotensive subjects. beta-adrenoceptor down-regulation has been described in hypertension. We tested the hypothesis that chronic sympathetic overactivity impairs beta-adrenergic-mediated thermogenesis and thereby favours gain of weight in hypertension. PARTICIPANTS The study included 13 hypertensiv...

BACKGROUND Although the Task Force Criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC) have recently been updated, the diagnosis remains challenging in the early stages. The aim of this study was to evaluate the diagnostic value of β-adrenergic stimulation in ARVC. METHODS AND RESULTS We evaluated 412 consecutive patients (213 men, age 41.5±16 years) referred for premature ven...

Although sarcolemmal (SL) Na+/Ca2+ exchanger is known to regulate the intracellular Ca2+ concentration ([Ca2+]i), its involvement in catecholamine-induced increase in [Ca2+]i is not fully understood. To gain some information in this regard, isolated rat cardiomyocytes were treated with different agents, which are known to modify Ca2+ movements, in the absence or presence of a beta-adrenoceptor ...