In the open state, channels allow charged ions to move across the membrane into and out of cells. When specialized classes of channels are open, they transport calcium ions into cells. This results in responses as varied as muscle contraction and secretion of compounds which then act on other cells.
Calcium channels are under the control of the nervous system.
These questions are addressed by examining calcium channel modulation in intact cells isolated from cardiac muscle tissue by enzymes. In this way, the intracellular solution is dialyzed against the pipette- filling solution, thereby permitting the intracellular application of ions, channel blockers, second messengers, nucleotides, enzymes, and so on. This technique is assisted by ultrafast external application of neurotransmitters and activators of intracellular second messenger pathways and rapid intracellular concentration jumps of ions and second messengers by UV-triggered photorelease from caged molecules. By characterizing how the transmembrane calcium current is affected by substances released from nerves and related intracellular biochemical agents, I hope to further our understanding of the translation of nerve impulses into cellular responses such as contraction under normal and abnormal conditions. The work has implications for cardiovascular disorders.