Alexander Omelchenko

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Cardiac muscle fails to relax upon replacement of extracellular Ca2+ with Ba2+. Among the manifold consequences of this intervention, one major possibility is that Na(+)-Ba2+ exchange is inadequate to support normal relaxation. This could occur due to reduced transport rates of Na(+)-Ba2+ exchange and/or by failure of Ba2+ to activate the exchanger molecule(More)
Ion transport and regulation of Na(+)-Ca(2+) exchange were examined for two alternatively spliced isoforms of the canine cardiac Na(+)-Ca(2+) exchanger, NCX1.1, to assess the role(s) of the mutually exclusive A and B exons. The exchangers examined, NCX1.3 and NCX1.4, are commonly referred to as the kidney and brain splice variants and differ only in the(More)
Chinese hamster ovary cells expressing the bovine cardiac Na+-Ca2+ exchanger (NCX1.1) accumulated Cd2+ after a lag period of several tens of seconds. The lag period reflects the progressive allosteric activation of exchange activity by Cd2+ as it accumulates within the cytosol. The lag period was greatly reduced in cells expressing a mutant exchanger,(More)
Ion transport and regulation were studied in two, alternatively spliced isoforms of the Na+-Ca2+ exchanger from Drosophila melanogaster. These exchangers, designated CALX1.1 and CALX1.2, differ by five amino acids in a region where alternative splicing also occurs in the mammalian Na+-Ca2+ exchanger, NCX1. The CALX isoforms were expressed in Xenopus laevis(More)
abstract Ion transport and regulation of Na ϩ –Ca 2 ϩ exchange were examined for two alternatively spliced iso-forms of the canine cardiac Na ϩ –Ca 2 ϩ exchanger, NCX1.1, to assess the role(s) of the mutually exclusive A and B exons. The exchangers examined, NCX1.3 and NCX1.4, are commonly referred to as the kidney and brain splice variants and differ only(More)
The activity of the cardiac Na(+)/Ca(2+) exchanger (NCX1.1) undergoes continuous modulation during the contraction-relaxation cycle because of the accompanying changes in the electrochemical gradients for Na(+) and Ca(2+). In addition, NCX1.1 activity is also modulated via secondary, ionic regulatory mechanisms mediated by Na(+) and Ca(2+). In an effort to(More)
For the purpose of obtaining novel fundamental knowledge, there are studied regularities of manifestation of synergism under simultaneous combined action of hyperthermia (47.5–60°C) and antitumor compounds (cyclophosphamide, cisplatin) on survival of yeast cells. To calculate the efficiency of synergic interaction, we used experimentally obtained(More)
The MIT/Draper Technology Development Partnership Project was initiated and sponsored by Charles Stark Draper Laboratory, Inc. (CSDL) to give students an opportunity to design, develop and validate a first-of-a-kind high technology system. This program addresses projects that meet one of the important national needs and the organizational requirements of(More)
The activity of the cardiac Na +-Ca 2+ exchanger (NCX1.1) undergoes continuous modulation during the contraction/relaxation cycle due to the accompanying changes in the electrochemical gradients for Na + and Ca 2+. In addition, NCX1.1 activity is also modulated via secondary, ionic regulatory mechanisms mediated by Na + and Ca 2+. In an effort to evaluate(More)