Vertebrate embryos define an anatomic plane of bilateral symmetry by establishing rudimentary anteroposterior and dorsoventral (DV) axes. A left-right (LR) axis also emerges, presaging eventual morphological asymmetries of the heart and other viscera. In the radially symmetric egg of Xenopus laevis, the earliest steps in DV axis determination are driven by microtubule-dependent localization of ...

8779 Observations on the antifibrillatory activity of 1,10-phen-anthroline on the rabbit heart. 8780 Ventricular arrhythmias following the administration of Na2EDTA. W.G. Nayler 5 8781 Chronotropic response following direct electrical stimulation of the isolated sinoatrial node: A pharmacologic evaluation. 14 8782 Therapeutic and toxic effects of ouabain on K-ion fluxes in rabbit atria. 8783 So...

The control of force by [Ca2+] was investigated in rat cardiac trabeculae loaded with fura-2 salt. At sarcomere lengths of 2.1-2.3 microns, the steady state force-[Ca2+]i relationship during tetanization in the presence of ryanodine was half maximally activated at a [Ca2+]i of 0.65 +/- 0.19 microM with a Hill coefficient of 5.2 +/- 1.2 (mean +/- SD, n = 9), and the maximal stress produced at sa...

A carbon fiber-based cell attachment and force measurement system was used to measure the diastolic stress-sarcomere length (SL) relation of mouse intact cardiomyocytes, before and after the addition of actomyosin inhibitors (2,3-butanedione monoxime [BDM] or blebbistatin). Stress was measured during the diastolic interval of twitching myocytes that were stretched at 100% base length/second. Di...

Four bis(thiosemicarbazonate)gold(III) complexes (1-4) with a general formula [Au(L)]Cl {L=L1, glyoxal-bis(N(4)-methylthiosemicarbazone); L2, glyoxal-bis(N(4)-ethylthiosemicarbazone); L3, diacetyl-bis(N(4)-methylthiosemicarbazone); L4, diacetyl-bis(N(4)-ethylthiosemicarbazone)} were synthesised and screened for activity against the human immunodeficiency virus (HIV). Complexes 1-4 were characte...

Investigation of the mechanisms of arrhythmia genesis and maintenance has benefited from the use of optical mapping techniques that employ excitation-contraction uncouplers. We investigated the effects of the excitation-contraction uncouplers 2,3-butanedione monoxime (BDM) and cytochalasin D (Cyto D) on the induction and maintenance of arrhythmia by electric shocks. Electrical activity was opti...

OBJECTIVE Initial warm cardioplegic reperfusion is widely used to ameliorate cardiac reperfusion damage after cardioplegic arrest. However, undesired effects of the high potassium concentration of the cardioplegic perfusate may limit the beneficial effect of this treatment. Contraction uncoupling by a negative inotropic and vasodilating agent such as 2,3-butanedione monoxime (BDM) may be superi...

Experiments in isolated ventricular cardiomyocytes have greatly facilitated the study of cellular and subcellular physiology in the heart. However, the isolation and culture of high-quality adult murine ventricular cardiomyocytes can be technically challenging. In most experimental protocols, the culture of viable adult murine cardiomyocytes for prolonged time periods is achieved with the addit...

BACKGROUND 2,3-Butanedione monoxime (BDM) has been shown to possess cardioprotective properties related to the inhibition of cross-bridge force development, the reduction of myofilament Ca2+ sensitivity, and the attenuation of intracellular Ca2+ transients. This study tested the hypothesis that cardiac arrest achieved with BDM would be as effective as that achieved with St. Thomas' solution (St...

Little is known about the mechanisms of vulnerability and defibrillation under ischemic conditions. We investigated these mechanisms in 18 Langendorff-perfused rabbit hearts during 75% reduced-flow ischemia. Electrical activity was optically mapped from the anterior epicardium during right ventricular shocks applied at various phases of the cardiac cycle while the excitation-contraction decoupl...