Arrhythmogenic effect of a crude extract from sea anemone Condylactis gigantea: Possible involvement of rErg1 channels

► Toxins from sea anemones are used for studying ion channel structure and function. ► An extract and a low-molecular weight fraction from Condylactis gigantea venom were studied. ► The extract caused a prolongation in the QT interval in the rat ECG. ► A ∼5 kDa fraction isolated from this extract affected rErg1 channel activity.