1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU), a soluble epoxide hydrolase inhibitor, lowers L-NAME-induced hypertension through suppression of angiotensin-converting enzyme in rats.

Objective: This study evaluated the efficacy of the soluble epoxide hydrolase (sEH) inhibitor, TPPU on chronic NG-Nitro L-arginine methyl ester (L-NAME)-induced hypertension in rats and its effects on plasma Angiotensin II (Ang II), cardiac Angiotensin-converting enzyme (ACE) and Angiotensin II receptor type 1 (AT1R) expressions.

Materials And Methods: Forty Sprague Dawley rats were divided into 5 groups. Two groups served as control and received orally either vehicle or TPPU (3 mg/kg) for five weeks.

Cardioprotective Effect of Olive Oil Against Ischemia Reperfusion-induced Cardiac Arrhythmia in Isolated Diabetic Rat Heart.

Background Olive oil is rich in monounsaturated fatty acids and has been reported for a variety of beneficial cardiovascular effects, including blood pressure lowering, anti-platelet, anti-diabetic, and anti-inflammatory effects. Diabetes is a major risk factor for cardiac dysfunctions, and olive oil prevents diabetes-induced adverse myocardial remodeling. Objective The study aimed to evaluate the effects of olive oil against streptozotocin-induced cardiac dysfunction in animal models of diabetes and ischemia and reperfusion (I/R)-induced cardiac arrhythmias.

Protective effect of fenofibrate against ischemia-/reperfusion-induced cardiac arrhythmias in isolated rat hearts.

Fenofibrate is a peroxisome proliferator-activated receptor (PPAR)-α activator that lowers triglycerides and influences cytochrome P-450 (CYP-450) epoxygenase-dependent arachidonic acid (AA) metabolism. CYP-450 epoxygenase metabolizes AA to epoxyeicosatrienoic acids (EETs). EETs have coronary dilating and cardiac and renal protective properties.

Investigation of the antifibrillatory drug interactions between Amiodarone and Ibutilide in isolated, perfused Rabbit hearts.

In view of the reliability of the serial-shock method of measuring ventricular fibrillation threshold (VFT) in quantitatively assessing the antifibrillatory potency of many anti-arrhythmic drugs and the alarming reports of the proarrhythmic effects of several anti-arrhythmic agents, it was decided to use the above technique to study the possible interactions that may occur when anti-arrhythmic drugs from different classes are combined. Hearts isolated from New Zealand white rabbits of either sex weighing 1.5-2 kg were perfused by the Langendorff method with McEwen's solution.

Effect of piperine, a major component of black pepper, on the pharmacokinetics of domperidone in rats.

The present study was aimed to investigate the effect of piperine, a major active ingredient of black pepper, on the pharmacokinetics of domperidone in rats. Animals were given oral (p.o.

Evidence for the binding of beta-adrenoceptor blockers to microsomal Na+/K+-ATPase in guinea pig heart preparations.

We reported in a previous study that beta-adrenoceptor blockers inhibit the Mg2+-dependent ATP-hydrolytic function of Na+/K+-ATPase. To determine if this action is a result of binding of beta-blockers to the receptor sites that bind the digitalis glycosides, we performed displacement binding assays of eight beta-blockers with [3H]-ouabain (OUA) in guinea pig myocardial microsomal preparations. In the first series of experiments, 10-200 microM of the beta-blockers were displaced with 250 nM OUA.

Class I antiarrhythmic drug effects on ouabain binding to guinea pig cardiac Na+ -K+ ATPase.

The notion that the inhibition of the Mg2+ -dependent ATP-hydrolytic function of the myocardial Na+ -K+ ATPase by class I antiarrhythmic agents occurs as a result of their binding to the same receptor sites as the digitalis glycosides was tested by performing competitive binding assays of [3H]ouabain (OUA) with eight drugs: disopyramide, encainide, lidocaine, lorcainide, phenytoin, procainamide, quinidine, and tocainide in guinea pig heart microsomal preparations. In the first set of experiments, 10-200 microM concentrations of the drugs were preincubated with the enzyme and displacement assays performed with 250 nM OUA. The drugs showed receptor occupancy of 19-32% at 50 microM, 25-44% at 100 microM, and 37-56% at 200 microM.

Effects of amiodarone on ouabain binding to microsomal Na+, K(+)-ATPase in guinea-pig heart preparations.

1. The influence of amiodarone on [3H]ouabain (OUA) binding to myocardial Na+, K(+)-ATPase was studied at various KCl concentrations in guinea pig heart microsomal preparations to test the hypothesis that the drug acts on the same receptor sites as cardiac glycosides. 2.

Sympathetic activity in children undergoing balloon valvuloplasty of pulmonary stenosis.

We studied the influence of balloon valvuloplasty on alpha- and beta-adrenoceptor densities, plasma catecholamine, and cAMP levels in children and infants with pulmonary stenosis before and 10 min after balloon dilatation, employing as controls children undergoing transcatheter occlusion of patent ductus arteriosus (PDA) with Qp/Qs ratio < 1.5. In the PDA group, the alpha-adrenoceptor density (Bmax) was 3.

Effect of left ventricular pressure and volume overload on alpha-adrenoceptor activity in patients with rheumatic heart valvular disease.

We have investigated the possibility that the various left ventricular load conditions may exert different effects on the sympathetic function by comparing the influence of volume (VOL) and pressure (POL) overload on platelet alpha-adrenoceptor activity, plasma catecholamines and cAMP in 44 patients with rheumatic heart valvular disease. Receptor activity was determined by radioligand binding methods, catecholamines by HPLC using an electrochemical detector, and cAMP by radioimmunoassay. The mean alpha-adrenoceptor density (Bmax) of the control group (n = 29) was 4.

Regulation of sympathetic activity in children with various congenital heart diseases.

We studied the alpha- and beta-adrenoceptor activity and catecholamine and cAMP levels in 112 children and infants admitted to the hospital for diagnostic or interventional catheterization of tetralogy of Fallot, ventricular septal defects with or without hypertension, pulmonary stenosis, coarctation of the aorta, and various complex cyanotic congenital cardiac diseases and compared them with 14 children undergoing transcatheter occlusion of patent ductus arteriosus with insignificant left-to-right-shunts. The mean total platelet alpha-adrenoceptor density of the study population was elevated by 73%. Both the increases in acyanotic (p < 0.

Characterization of lymphocyte beta-adrenoceptor activity and Gs-protein in patients with rheumatic heart valvular disease.

In order to test whether the beta-adrenoceptor activity in rheumatic heart valvular disease depends on the ventricular load conditions, we determined their density and binding affinity to [125I]-iodocyanopindolol in lymphocytes, as well as plasma catecholamine and cAMP levels in 69 patients with regurgitant and stenotic lesions of the aortic and mitral valves. The patients were classified as having left ventricular pressure overload (LVP), left ventricular volume overload (LVV), mixed lesions (MOL) or right ventricular pressure overload (RVP). The beta-adrenoceptor activity was determined by radioligand binding methods, catecholamines by high performance liquid chromatography using an electrochemical detector and cAMP by radioimmunoassay.

Actions of amiodarone on mitochondrial ATPase and lactate dehydrogenase activities in guinea pig heart preparations.

The effects of amiodarone on mitochondrial ATPase (EC 3.6.1.

Synthesis and pharmacological evaluation of the antifibrillatory effect of fluorinated derivatives of carazolol and celiprolol: comparison with propranolol.

1. The effects of carazolol, celiprolol and their respective fluorinated derivatives (FD) on electrical stimulation threshold (EST) and ventricular fibrillation threshold (VFT) were compared with those of propranolol and propranolol-FD in Langendorff-perfused rabbit hearts. 2.

Investigation of class I anti-arrhythmic drug actions on guinea-pig cardiac mitochondrial lactate dehydrogenase activity.

1. The effects of the Class I anti-arrhythmic drugs quinidine, procainamide, lidocaine, phenytoin and tocainide on mitochondrial lactate dehydrogenase activity were compared in guinea-pig heart preparations. 2.

Effects of class I antiarrhythmic drugs on mitochondrial ATPase activity in guinea pig heart preparations.

1. The effects of three class I antiarrhythmic drugs quinidine, lidocaine and lorcainide on undamaged myocardial mitochondrial ATPase [ATP: phosphohydrolase, EC 3.6.

Inhibition of myocardial Na(+)-K(+)-ATPase activity by bretylium: role of potassium.

The effects of bretylium on the Mg(2+)-dependent ATP-hydrolytic action of myocardial Na(+)-K(+)-ATPase (EC 3.6.1.

Effects of beta-adrenoceptor blockers on mitochondrial ATPase activity in guinea pig heart preparations.

The effects of three beta-adrenoceptor blockers atenolol, indenolol and nadolol on myocardial mitochondrial ATPase (ATP: phosphohydrolase EC 3.6.1.

Variations in potassium concentration modify the inhibitory effect of lorcainide on myocardial Na(+)-K(+)-ATPase activity.

1. The inhibitory action of lorcainide on the myocardial Na(+)-K(+)-ATPase (EC 3.6.

Interaction between potassium concentration and inhibition of myocardial Na(+)-K(+)-ATPase by two class 1A antiarrhythmic drugs: quinidine and procainamide.

The inhibitory actions of quinidine and procainamide on the Mg(2+)-dependent ATP hydrolytic action of myocardial Na(+)-K(+)-ATPase (EC 3.6.1.

The influence of potassium concentration on the inhibitory effect of amiodarone on guinea-pig microsomal Na(+)-K(+)-ATPase activity.

The effects of varying incubation K+ concentration on the inhibitory action of amiodarone on the Mg(2+)-dependent ATP hydrolysis by myocardial Na(+)-K(+)-ATPase (EC 3.6.1.

Effects of beta-adrenergic blockers on Na(+)-K(+)-ATPase activity in guinea-pig heart preparations: comparison with ouabain.

The effects of the beta-adrenergic receptor antagonists carazolol, celiprolol, indenolol and propranolol on myocardial Mg(2+)-dependent, Na(+)- and K(+)-activated adenosine triphosphatase (Na(+)-K(+)-ATPase, EC 3.6.1.

Influence of lorcainide on microsomal Na+, K(+)-ATPase in guinea-pig isolated heart preparations.

1. The effects of lorcainide on the myocardial Mg2(+)-dependent, Na+ and K(+)-activated adenosine triphosphatase (Na+, K(+)-ATPase) were compared in guinea-pig heart preparations with those of ouabain, a specific inhibitor of the enzyme activity. 2.