Reduction in number of sarcolemmal KATP channels slows cardiac action potential duration shortening under hypoxia
نویسندگان
چکیده
منابع مشابه
Shortening of cardiac action potential duration near an insulating boundary.
It is known, from both experiments and simulations, that cardiac action potentials are shortened near a non-conducting boundary. In the present paper, this effect is studied in a simple, two-current ionic model, with propagation restricted to a 1D fibre. An asymptotic approximation for the dependence of action potential duration on distance to the boundary is derived. This estimate agrees well ...
متن کاملPharmacological and histochemical distinctions between molecularly defined sarcolemmal KATP channels and native cardiac mitochondrial KATP channels.
A variety of direct and indirect techniques have revealed the existence of ATP-sensitive potassium (KATP) channels in the inner membranes of mitochondria. The molecular identity of these mitochondrial KATP (mitoKATP) channels remains unclear. We used a pharmacological approach to distinguish mitoKATP channels from classical, molecularly defined cardiac sarcolemmal KATP (surfaceKATP) channels en...
متن کاملBepridil, an antiarrhythmic drug, opens mitochondrial KATP channels, blocks sarcolemmal KATP channels, and confers cardioprotection.
Bepridil, which is clinically useful in the treatment of arrhythmias, has been reported to inhibit sarcolemmal ATP-sensitive K(+) (sarcK(ATP)) channels. However, the effect of bepridil on mitochondrial ATP-sensitive K(+) (mitoK(ATP)) channels remains unclear. The objective of the present study was to determine whether bepridil activates mitoK(ATP) channels and confers cardioprotection. SarcK(AT...
متن کاملDiazoxide causes early activation of cardiac sarcolemmal KATP channels during metabolic inhibition by an indirect mechanism.
OBJECTIVE We have used isolated myocytes to investigate the effects of diazoxide on sarcolemmal KATP channel (sarcoKATP) activity and action potential failure during metabolic inhibition, and the role of these channels in protection of functional recovery on reperfusion. MATERIALS AND METHODS Isolated adult rat ventricular myocytes were exposed to metabolic inhibition (NaCN and iodoacetate) a...
متن کاملDistinct myoprotective roles of cardiac sarcolemmal and mitochondrial KATP channels during metabolic inhibition and recovery.
The protective roles of sarcolemmal (sarc) and mitochondrial (mito) KATP channels are unclear despite their apparent importance to ischemic preconditioning. We examined these roles by monitoring intracellular calcium ([Ca]int), using fura-2 and fluo-3, in enzymatically isolated rat right ventricular myocytes. Myocyte mortality, estimated using a trypan blue assay, changed approximately in paral...
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ژورنال
عنوان ژورنال: Biochemical and Biophysical Research Communications
سال: 2011
ISSN: 0006-291X
DOI: 10.1016/j.bbrc.2011.10.125