CARDIAC ION CHANNELS IN HEALTH DISEASE

摘要

Ion channels form the basis for excitability in cardiac tissue. These membrane bound proteins are composed of subunits arranged around a central channel pore that allows the passage of current in the form of ions when the channel assumes an open conformation. The stimulus that induces the channel to make the transition from the closed conformation found in the quiescent cell to the open conformation that passes current (i.e. that "gates" the channel) may take the form of a change in transmembrane voltage, the binding of an extracellular agonist, the activity of an intracellular second messenger, or stretch of the cell membrane. This presentation will focus primarily on the structure and function of voltage gated sodium, calcium, and potassium channels as they pertain to cardiac physiology and pathophysiology.