Low-voltage-activated calcium channels, so called because they have transient and tiny currents, are rapidly inactivated and have low conductance. They respond to relatively small depolarizations and are involved in cardiac pacemaking and regulation of blood flow. Three family members have been cloned (α1G, α1H, and α1I). Mutations in α1H are associated with idiopathic generalized epilepsy. The channels are modulated by various hormones and neurotransmitters. Efonidipine blocks both L- and T-type channels.
Subjects: Medicine and Health.