Electric stimulation regulates the level of Ca-channels in chick muscle culture

To examine the role of muscle activity in the expression of 1,4-dihydropyridine (DHP)-sensitive Ca-channels, we electrically stimulated chick skeletal muscle cells growing in culture. The number of Ca-channels was determined by a radioligand binding technique using [ 3H]PN200-110. The function of these channels was measured by depolarization-induced 45Ca uptake. We found that both the amount and the function of these channels were higher as a result of the increased muscle activity caused by electrical stimulation (ES).