Learn More
We have produced mice in which expression of the rat cardiac Na(+)/Ca(2+) exchanger (NCX1) transgene was switched on when doxycycline was removed from the feed at 5 wk. At 8 to 10 wk, NCX1 expression in induced (Ind) mouse hearts was 2.5-fold higher but protein levels of sarco(endo)plasmic reticulum Ca(2+)-ATPase, alpha(1)- and alpha(2)-subunits of(More)
Previous studies in adult myocytes isolated from rat hearts 3-9 wk after myocardial infarction (MI) demonstrated abnormal contractility and decreased Na(+)/Ca(2+) exchanger (NCX1) activity. In addition, a program of high-intensity sprint training (HIST) instituted shortly after MI restored both contractility and NCX1 activity toward normal. The present(More)
The second member of the transient receptor potential-melastatin channel family (TRPM2) is expressed in the heart and vasculature. TRPM2 channels were expressed in the sarcolemma and transverse tubules of adult left ventricular (LV) myocytes. Cardiac TRPM2 channels were functional since activation with H2O2 resulted in Ca(2+) influx that was dependent on(More)
BAG3 is a cellular protein that is expressed predominantly in skeletal and cardiac muscle but can also be found in the brain and in the peripheral nervous system. BAG3 functions in the cell include: serving as a co-chaperone with members of the heat-shock protein family of proteins to facilitate the removal of misfolded and degraded proteins, inhibiting(More)
Phospholemman (PLM), a member of the FXYD family of small ion transport regulators, inhibits cardiac Na+/Ca2+ exchanger (NCX1). NCX1 is made up of N-terminal domain consisting of the first five transmembrane segments (residues 1-217), a large intracellular loop (residues 218-764), and a C-terminal domain comprising the last four transmembrane segments(More)
Activation of the A(2A) adenosine receptor (A(2A)R) has been shown to be cardioprotective. We hypothesized that A(2A)R overexpression could protect the heart from adriamycin-induced cardiomyopathy. Transgenic (TG) mice overexpressing the A(2A)R and wild-type mice (WT) were injected with adriamycin (5 mg.kg(-1).wk(-1) ip, 4 wk). All WT mice survived(More)
Previous studies in adult myocytes isolated from rat hearts 3 weeks after myocardial infarction (MI) demonstrated abnormal contractility and intracellular Ca 2+ concentration ([Ca 2+ ] i) homeostasis, decreased sarcoplasmic reticulum (SR) Ca 2+-ATPase (SERCA2) expression and activity, but SR Ca 2+ leak was unchanged. In the present study, we investigated(More)
Ornithine decarboxylase (ODC), the first enzyme of polyamine metabolism, is rapidly upregulated in response to agents that induce a pathological cardiac hypertrophy. Transgenic mice overexpressing ODC in the heart (MHC-ODC mice) experience a much more dramatic left ventricular hypertrophy in response to β-adrenergic stimulation with isoproterenol (ISO)(More)
Previous studies in adult myocytes isolated from rat hearts 3 wk after myocardial infarction (MI) demonstrated abnormal contractility and intracellular Ca(2+) concentration ([Ca(2+)](i)) homeostasis and decreased sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2) expression and activity, but sarcoplasmic reticulum Ca(2+) leak was unchanged. In the present study,(More)
Phospholemman (PLM), when phosphorylated at serine 68, relieves its inhibition on Na(+)-K(+)-ATPase but inhibits Na(+)/Ca(2+) exchanger 1 (NCX1) in cardiac myocytes. Under stress when catecholamine levels are high, enhanced Na(+)-K(+)-ATPase activity by phosphorylated PLM attenuates intracellular Na(+) concentration ([Na(+)](i)) overload. To evaluate the(More)