Differential Regulation by Mechanical Stretch of the Expressions of Large-Conductance Ca 2+ -Activated K + Channel and L-Type Voltage-Dependent Ca 2+ Channel in Rat Uterine Smooth Muscle Cells.

Large-conductance Ca 2+ -activated K + (BK Ca ) channel and L-type voltage-dependent Ca 2+ channel (L-VDCC) play important roles in regulating uterine contractility. The uterus stretch, occurring during pregnancy, is a critical factor to trigger uterine contraction. However, how mechanical stimuli impact the two channels remains unknown. Here we investigated the effects of exposure to mechanical stretches with varying magnitudes and durations on expressions of the two channels in rat uterine smooth muscle cells. Our results show that stretch down-regulates the BK Ca channel expression but upregulates the L-VDCC expression. These findings are helpful to better understand the roles of L-VDCC and BK Ca channel in stretch-triggered uterine contraction.