Dose-related shortening of ventricular tachycardia cycle length after administration of the KATP channel opener bimakalim in a 4-day-old chronic infarct anesthetized pig model.

Potassium channel openers are known to act on potassium ATP-dependent channels in cardiac tissue. Such agents may exacerbate acceleration of acute ischemia-induced ventricular repolarization and aggravate arrhythmias. To test whether activation of K( ATP) channels during the healing period of myocardial infarction (MI) can still influence the electrophysiologic properties and the type of inducible arrhythmias, we investigated the effects of bimakalim (BIM) on sustained ventricular tachycardia (VT) 4 days after ligation of the left anterior descending (LAD) coronary artery in pigs.

Assessment of local atrial repolarization in a porcine acetylcholine model of atrial flutter and fibrillation.

Objectives: Progressive electrical alternans followed by conduction block and fibrillatory conduction have been suggested to precede disorganization of atrial flutter (Afl) to atrial fibrillation (AF). The purpose of the present study was to investigate patterns of local repolarization in the high and low right atrium to determine the site with pronounced propensity to action potential disorganization during Afl and AF.

Methods: Combination pacing/recording contact monophasic action potential (MAP) catheters were utilized to evaluate repolarization from the upper and low atrial endocardium in 16 pigs.

Mechanisms of the action of zoledronic acid on human MG-63 osteosarcoma cells.

The aim of our study was to analyze the action of zoledronic acid on MG-63 human osteosarcoma cells. The proliferation of MG-63 cells was inhibited by either continuous or pulsatile exposures of zoledronic acid in a dose-dependent manner (10-250 microM). Zoledronic acid did not produce evidence of MG-63 cell death when administered at 100 mM for 48 hours, but only after exposure of 96 hours.

Calcium dobesilate and transmembrane potential in canine cardiac cells. A preliminary study.

The electropharmacological effects of calcium 2,5-dihydroxybenzene sulfonate (calcium dobesilate, Doxium) were studied by means of intracellular microelectrode technique in order to measure the changes in action potentials (A.ps.) in dog isolated cardiac Purkinje fibers and the adjacent ventricular tissue superfused with Tyrode's solution.