Dipika Tuteja

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The repolarization phase of cardiac action potential is prone to aberrant excitation that is common in cardiac patients. Here, we demonstrate that this phase is markedly sensitive to Ca2+ because of the surprising existence of a Ca2+-activated K+ currents in cardiac cells. The current was revealed using recording conditions that preserved endogenous Ca2+(More)
Small conductance Ca(2+)-activated K(+) channels (SK channels) have been reported in excitable cells, where they aid in integrating changes in intracellular Ca(2+) (Ca(2+)(i)) with membrane potential. We have recently reported the functional existence of SK2 channels in human and mouse cardiac myocytes. Moreover, we have found that the channel is(More)
We directly examined the role of the Ca(v)1.3 (alpha(1D)) Ca(2+) channel in the sinoatrial (SA) node by using Ca(v)1.3 Ca(2+) channel-deficient mice. A previous report has shown that the null mutant (Ca(v)1.3(-/-)) mice have sinus bradycardia with a prolonged PR interval. In the present study, we show that spontaneous action potentials recorded from the SA(More)
Address for correspondence and proofs: Nipavan Chiamvimonvat Division of Cardiovascular Medicine, Department of Medicine University of California, Davis Genome and Biomedical Sciences Facility 451 East Health Sciences Drive, Room 6315 Davis, CA 95616 voice: (530) 754-7158 fax: (530) 754-7167 email: nchiamvimonvat@ucdavis.edu Articles in PresS. Am J Physiol(More)
Sustained cardiac hypertrophy represents one of the most common causes leading to cardiac failure. There is emerging evidence to implicate the involvement of NF-kappaB in the development of cardiac hypertrophy. However, several critical questions remain unanswered. We tested the use of soluble epoxide hydrolase (sEH) inhibitors as a means to enhance the(More)
We directly examined the role of the Cav1.3 ( 1D) Ca 2 channel in the sinoatrial (SA) node by using Cav1.3 Ca 2 channel–deficient mice. A previous report has shown that the null mutant (Cav1.3 / ) mice have sinus bradycardia with a prolonged PR interval. In the present study, we show that spontaneous action potentials recorded from the SA nodes show a(More)
BACKGROUND Previous data suggest that L-type Ca2+ channels containing the Cav1.3(alpha(1D)) subunit are expressed mainly in neurons and neuroendocrine cells, whereas those containing the Cav1.2(alpha1C) subunit are found in the brain, vascular smooth muscle, and cardiac tissue. However, our previous report as well as others have shown that Cav1.3 Ca2+(More)
Small-conductance Ca2+-activated K+ channels (SK channels, KCa channels) have been reported in excitable cells, where they aid in integrating changes in intracellular Ca2+ with membrane potential. We recently reported for the first time the functional existence of SK2 (KCa2.2) channels in human and mouse cardiac myocytes. Here, we report cloning of SK1(More)
RATIONALE Ca(2+)-activated K(+) channels are present in a wide variety of cells. We have previously reported the presence of small conductance Ca(2+)-activated K(+) (SK or K(Ca)) channels in human and mouse cardiac myocytes that contribute functionally toward the shape and duration of cardiac action potentials. Three isoforms of SK channel subunits (SK1,(More)
Sphingomonas paucimobilis degrades aerobically α, β, γ and δ-hexachlorocyclohexane. With α-HCH, complete degradation occurred after 3 days but with β and γ, and with δ-HCH, 98 and 56 % degradation occurred after 12 and 8 days of incubation, respectively. Pentachlorocyclohexene was formed as the primary metabolite during the degradation of all the HCH(More)