Pharmacological basis of Ca2+ channels and Ca2+ channel antagonists

Ca2+ plays multiple roles in muscle E-C coupling, secretion, and neural transmission, in addition to survival, proliferation, and death of cells. The voltage-dependent L-type Ca2+ channel is a transmembrane protein that selectively permeates Ca2+ on activation by membrane depolarization. Ca2+ channel blockers (or Ca2+ antagonists) selectively block this channel. The blocking action is exerted in a tissue-specific manner, which underlies the unique pharmacological properties of Ca2+ channel blockers. The later generation of slowly-acting and long-lasting Ca2+ channel blockers has been designed to overcome the side effects of classical Ca2+ channel blockers. The pharmacological and molecular basis for the unique action of Ca2+ channel blockers will be discussed.