Reductions in the Cardiac Transient Outward K (cid:2) Current I to Caused by Chronic (cid:3) -Adrenergic Receptor Stimulation Are Partly Rescued by Inhibition of Nuclear Factor (cid:4) B *

The fast transient outward potassium current ( I to,f ) plays a critical role in the electrical and contractile properties of the myocardium. I to,f channels are formed by the co-assembly of the pore-forming (cid:5) -subunits, Kv4.2 and Kv4.3, together with theaccessory (cid:3) -subunitKChIP2.Reductionsof I to,f arecommon in the diseased heart, which is also associated with enhanced stimulation of (cid:3) -adrenergic receptors ( (cid:3) -ARs). We used cultured neonatal rat ventricular myocytes to examine

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