T-type calcium channel expression and function in the diseased heart

The regulation of intracellular Ca2+ is essential for cardiomyocyte function, and alterations in proteins that regulate Ca2+ influx have dire consequences in the diseased heart. Low voltage activated, T-type Ca2+ channels are one pathway of Ca2+ entry that is regulated according to developmental stage and in pathological conditions in the adult heart. Cardiac T-type channels consist of two main types, Ca(V)3.1 (alpha 1G) and Ca(V)3.2 (alpha 1H), and both can be induced in the myocardium in disease and injury but still, relatively little is known about mechanisms for their regulation and their respective functions. This article integrates previous data establishing regulation of T-type Ca2+ channels in animal models of cardiac disease, with recent data that begin to address the functional consequences of cardiac Ca(V)3.1 and Ca(V)3.2 Ca2+ channel expression in the pathological setting. The putative association of T-type Ca2+ channels with Ca2+ dependent signaling pathways in the context of cardiac hypertrophy is also discussed.