The chain shortening action of AMSH is consistent with its high selectivity for Lys63-linked chains; it can disassemble Lys63-linked chains but perhaps cannot remove ubiquitin completely from the cargo.
We found that both ICA-105574 and NS1643 concentration-dependently shortened action potential duration (APD) in ventricular myocytes, and QT/QTc intervals in isolated guinea-pig hearts.
It shortened action potential duration (APD) in isolated rat ventricular myocytes, and increased the threshold current for triggering action potential, but had no effect on the inward rectifier K+ current IK1.
In turn, this shortens action membrane potential and prevents influx of Ca2 + and Ca2 + overload, which is cardioprotective [2].
It is traditional view that the activation of KATP channels shortens action membrane potential resulting in decreased influx of Ca2+ and prevention of Ca2+ overload [30].
Persistent atrial arrhythmias are associated with ectopic beats [ 6], shortened action potentials [ 1, 7], and high rates of tissue excitation [ 8].
In fact, terfenadine, which also shortened action potential duration in the SCREENIT test system (10 µM [ 23]), has recently been suggested to cause arrhythmias not by a TdP mechanism, but by its strong INa-blocking activity [ 46].
Traditionally, it has been suggested that the opening of sarcolemmal KATP channels shortens action membrane potential, prevent influx of Ca2+ and intracellular Ca2+ overload, which is the main cause of cellular death in metabolic stress [reviewed in 2].
Hyperkalemia reduces the resting membrane potential, slows conduction velocity, increases the rate of depolarization and repolarization due to increased membrane permeability for potassium, and shortens action potential duration [ 42, 45, 46].
