Interactions of protons and cardiac K^+ channels

C.E.H.A., University Leuven, Belgium Protons exert a diversity of effects on different K+ currents that play a role in determining the resting and action potential in cardiac cells. Some currents are inhibited, others are enhanced or activated, and in some cases both agonist and antagonist effects, depending on the conditions, may be seen on the same current. The site of action is also variable: external or internal side of the membrane, in the pore or outside the